Turbo delay.

is there a way to get turbo delay 100% gone on a mercedes 2.5 liter desil turbo?

You should try the forum for your car. If you are talking about turbo lag, then you could use a really small turbo like a T-25. I don't know what line of turbos mercedes uses, but getting a smaller turbo will virtually eliminate it. 100% gone, probably not. Noticably gone, more than likely.

ok i see thanks, if any others can give second of third opinion i would appriciate it.

Turbo lag can be the cause of alot of factors:
1. Engine size
2. Turbo size
3. Exhaust
and the list goes on...

A bigger engine will spool a turbo faster, a smaller turbo will spool faster, and the less restrictions an exhaust system has will help a turbo spool quicker.

Is your boost lag a serious problem, or do you just want the constant power of an NA... because if you do, you might have gone w/ the wrong car...

humm worng car? i dunno man all i need is some turbo lag gone, i dont think its impossible. you also say less restrictions on exaust system, im not quite sure what that means this is my first car im gonna put mods on. the only thing i really know about is how engins work, i really dont even know what a turbo does exactly. iv also heard of super chargers are they the same thing? or can your super charge a turbo? man i got no clu someone help me out. whats a turbo kit do exactly and whats a cupercharger? how do i make this desiel own in a race?

The only way I know of to completely eliminate turbo spool time, or turbo lag is through the use of nitrous. You can use a very small shot to inject into the intake charge and help spool the turbo. However, this introduces a new problem, traction issues.

This will also get better responses in the forced induction forum. I'll move it there.

"i dont think its impossible" these gotta be another way than a nitros system i dont want to buy. traction on a MB is great (not in the rain iv got too much torque) only slid once in the rain dooing something retarded. i plan on getting new weels and rims anyway, strut bar dont sound bad either, so some of my questions remain...are super chargers the same thing as turbos? or can your super charge a turbo? man i got no clu someone help me out. whats a turbo kit do exactly and whats a cupercharger? how do i make this desiel own in a race?

ok you deffinately need to read the turbo 101 and turbo vs supercharger threads at the top of this forum.

also check www.howstuffworks.com and find out how a turbo works and what it does.

a less restrictive exhaust system means you want a big exhaust pipe like 2 1/2 or 3 inch in diameter from the turbo back and if you want to be legal you should put a cat and muffler on there too but try to get those the same size as the exhaust pipe. this will allow the exhaust gas to out of the turbo faster and therefore spool faster. you also want to put a less restrictive intake, i have found that a pvc pipe and an intake from the import isle at autozone work fine.

"i dont think its impossible" these gotta be another way than a nitros system i dont want to buy. traction on a MB is great (not in the rain iv got too much torque) only slid once in the rain dooing something retarded. i plan on getting new weels and rims anyway, strut bar dont sound bad either, so some of my questions remain...are super chargers the same thing as turbos? or can your super charge a turbo? man i got no clu someone help me out. whats a turbo kit do exactly and whats a cupercharger? how do i make this desiel own in a race?

ok first things first....superchargers and turbos are completely different...turbos are basically "free horsepower" meaning it doesnt take any power to drive one.....it is driven by the exhaust to force air into the motor.superchargers are belt driven and it takes horsepower to drive one....this is a poor example but on drag cars it take i believe 600 hp to drive the supercharger on those cars(correct me if im wrong). all i can say about this is to read up a little about each of them and youll understand wut ive said a little better.

as far as freeing up some lag that youve got....you should have plenty of room to run a 3 inch exhaust system....for turbo cars you want to open the exhaust as much as you can....you lose a little bottom end but you turbo spools much faster thus making your power sooner and longer through the power band. you can also remove the cat or get a high flow cat and a straight through muffler.

if your car has a MAF sensor it might have a screen in there....if so you can remove the screen and that supposedly good for a couple more pounds of boost. also get a k&n drop in filter will let the air get to the turbo a little easier.

I don't think a diesel, will ever do that great at the strip, unless it is much larger or has lots of money in it. It probably doesn't rev very high, even if it is a mercedes td. I have gotten beat by a Powerstroke F-250, but it had tons of money into it. Diesels are not race cars normally.

ok well its rare that a desiel races that one of the reasons i wanna race this one to be diffrent u know. i actuall have seen a benz 300D with body kit rims and prolly allot under the hood. it was freakin loud as $#!+ and hauled ass. it looked like it could own pretty badly. it revs quite nice i may add, so tell me. if i get a bigger muffler system the turbo will "spool" faster? ok thanks guys your really helping :D. what else can i do to this monster? and another thing would dual exaust system bigger help even more? and someone said something to me about a blow-off air intake? what is that?

ok well its rare that a desiel races that one of the reasons i wanna race this one to be diffrent u know. i actuall have seen a benz 300D with body kit rims and prolly allot under the hood. it was freakin loud as $#!+ and hauled ass. it looked like it could own pretty badly. it revs quite nice i may add, so tell me. if i get a bigger muffler system the turbo will "spool" faster? ok thanks guys your really helping :D. what else can i do to this monster? and another thing would dual exaust system bigger help even more? and someone said something to me about a blow-off air intake? what is that?

dual exhaust most likely wouldnt help much more...not worth the extra money in my oppinion. someone said something about a blow off air intake...they were referring to a blow off valve...you could get one but it doesnt do anything performance wise...it just saves your turbo.

I don't think a diesel, will ever do that great at the strip, unless it is much larger or has lots of money in it. It probably doesn't rev very high, even if it is a mercedes td. I have gotten beat by a Powerstroke F-250, but it had tons of money into it. Diesels are not race cars normally.

obviously youve never gone to cummings website...i belive they havea 9 second drag car thats diesel. and ive seen videos of a 12 second cummings powered dodge ram that was extended cab dually long bed....ver big truck and it even had a 6 speed tranny which suck for accelleration.

ok, thanks. in another post or maybe this one, someone said to get a smaller turbo as well. a t-25 if i remember right. a smaller turbo spools faster, thats good, but does it give the same horse power? probally not im guesing but will the car go faster is it a speed power tradeoff? a smaller turbo spools faster ok but in the long run is that better than a bigger turbo?

obviously youve never gone to cummings website...i belive they havea 9 second drag car thats diesel. and ive seen videos of a 12 second cummings powered dodge ram that was extended cab dually long bed....ver big truck and it even had a 6 speed tranny which suck for accelleration.

wow.

do you have aol im if so i might be able to help you out a little bit more?
if so mine is forcefanad

To reduce lag, get a full exhaust system, from the turbo downpipe to the muffler tip, 2.5" to 3". SINGLE piping, dual is just extra weight. Getting just a muffler wont do anything. Get a pvc pipe and a K&N filter and fab up a custom intake. DONT downgrade your turbo to a smaller one. Yes that will reduce lag but you'll make less power, whats the point? Lets say your turbo doesnt kick in till 3.5k rpm. Well if racing from a roll, dont start at 2k rpm, start at 3.5k (or whatever you think the turbo kicks in at) or a little higher. Even though you will most likely have to shift almost right away (depending on when your turbo kicks in at and when you redline) it will be faster then bogging and letting your opponent get a car on ya. Also, your car isnt a good starting platform anyway just because its turbo doesnt mean its suppose to be raced. I believe early turbo cars were just made to make it easier for low hp cars to go up big hills :) but since you want to make this car a racer to be diff, go for it! just know you might have some disadvantages. Oh and you said your upgrading your wheels, I suggest not getting huge 18inches or something. That wont help with your speed problem. At the most I would get +1 size bigger then stock. But personally I wouldnt worry about wheels till you can beat civics :P
OH and a blow off valve, will not help peformance but it saves your turbo from abuse. I would also find a site that knows about MB diesels and thier limits. Then buy a boost controller and turn up the boost a bit
have fun

Nitrous can damage the turbocharger, it also doesn't work on a diesel engine.

There is no way to really completely get rid off the lag, but it can be decreased.

Almost all modern diesels use a variable geometry turbocharger, if your engine isn't fitted with one this will probably be the best method of decreasing lag.

ok first things first....superchargers and turbos are completely different...turbos are basically "free horsepower" meaning it doesnt take any power to drive one.....it is driven by the exhaust to force air into the motor.superchargers are belt driven and it takes horsepower to drive one....this is a poor example but on drag cars it take i believe 600 hp to drive the supercharger on those cars(correct me if im wrong). all i can say about this is to read up a little about each of them and youll understand wut ive said a little better.

as far as freeing up some lag that youve got....you should have plenty of room to run a 3 inch exhaust system....for turbo cars you want to open the exhaust as much as you can....you lose a little bottom end but you turbo spools much faster thus making your power sooner and longer through the power band. you can also remove the cat or get a high flow cat and a straight through muffler.

if your car has a MAF sensor it might have a screen in there....if so you can remove the screen and that supposedly good for a couple more pounds of boost. also get a k&n drop in filter will let the air get to the turbo a little easier.


:newbie: :nutkick: ok just to let you know....a turbocharger is actually classfied as a supercharger. the actualy deffanition of a supercharger is any device that raises the intake pressure to a greater ammount than the local atmospheric pressure. what you are thinking of is the difference between a belt driven and an exaust driven (turbo) supercharger. to help keep some people from gettin confused i will just call a turbo a turbo and a supercharger a supercharger...a turbo is, in theory, entirely more effecient than a belt driven supercharger....this is because you harnass "lost energy" from the heat and movement of the exaust gasses. but a turbo is not entirely efficent or "free" power. a turbo's turbine does put restrictions on the exaust flow out of the engine and does have a noticeable delay between idle and spooling.... ways to decrease spooling time are to use a samller turbo...or to just swic out the current turbo impeller with a smaller one, less restrictive intake, downpipe, uppipe, headers with a little bit smaller diameter than stock (quicker exaust flow and greater concentration of heat), catalytic converter, muffler, and a larger pipe. 3 inch pipe on small engines sounds like ass....i havent heard it on a diesel but im sure it would sound just as bad as on a gasoline. a 2 1/2 will do fine. if it was on a gasoline engine then use of a better BOV would also help spooling and delay after changing gears...a belt driven supercharger isnt as efficent because it takes torque (not horse power, since horse power is torqe at RPM) to spin what ever compresses the air....there are two widely used types, rooter and cyntrifical. rooter is basicly two spinign rods with "blades" running in a screw type angle down the rods....as the rods spin the trap air and foce it into the engine....these types are often called blowers...they are what yo usee sticking out of the hood of clasic "muscel" cars often and on top of queen dragsters and funny cars....these to not, in anyway take 600hp to spin since they arent running but maybe 30lbs of boost (ya that is alot but not enough to steal 600hp, and since it is torque that spins it, not HP it wouldnt be using HP itsself...just affecting HP because HP depends on how much torque you have at any certian RPM...a cyntrifical supercharger is basicly an impeller in a case that spins and forces air into the engine. the compression works exactly like in a turbo only it is spun byt the engine and not exaust (like in a turbo).... forcefanajd you are officially :owned:

Nitrous can damage the turbocharger, it also doesn't work on a diesel engine.

There is no way to really completely get rid off the lag, but it can be decreased.

Almost all modern diesels use a variable geometry turbocharger, if your engine isn't fitted with one this will probably be the best method of decreasing lag.

:cwm27: nitros will not hurt a turbo...a turbo cant tell whether it is compressing oxygen mixed with nitrogen and other minority gasses or whether it is compressing nitrogen that has reacted with oxygen. nitros will work in any internal computsion engine because in order for an internal combustion engine to work it has to have oxygen to burn fule....when nitros is heated to a certian point it releases its oxygen which gives the engien a greater supply of oxygen....

:newbie: :nutkick: ok just to let you know....a turbocharger is actually classfied as a supercharger. the actualy deffanition of a supercharger is any device that raises the intake pressure to a greater ammount than the local atmospheric pressure. what you are thinking of is the difference between a belt driven and an exaust driven (turbo) supercharger. to help keep some people from gettin confused i will just call a turbo a turbo and a supercharger a supercharger...a turbo is, in theory, entirely more effecient than a belt driven supercharger....this is because you harnass "lost energy" from the heat and movement of the exaust gasses. but a turbo is not entirely efficent or "free" power. a turbo's turbine does put restrictions on the exaust flow out of the engine and does have a noticeable delay between idle and spooling.... ways to decrease spooling time are to use a samller turbo...or to just swic out the current turbo impeller with a smaller one, less restrictive intake, downpipe, uppipe, headers with a little bit smaller diameter than stock (quicker exaust flow and greater concentration of heat), catalytic converter, muffler, and a larger pipe. 3 inch pipe on small engines sounds like ass....i havent heard it on a diesel but im sure it would sound just as bad as on a gasoline. a 2 1/2 will do fine. if it was on a gasoline engine then use of a better BOV would also help spooling and delay after changing gears...a belt driven supercharger isnt as efficent because it takes torque (not horse power, since horse power is torqe at RPM) to spin what ever compresses the air....there are two widely used types, rooter and cyntrifical. rooter is basicly two spinign rods with "blades" running in a screw type angle down the rods....as the rods spin the trap air and foce it into the engine....these types are often called blowers...they are what yo usee sticking out of the hood of clasic "muscel" cars often and on top of queen dragsters and funny cars....these to not, in anyway take 600hp to spin since they arent running but maybe 30lbs of boost (ya that is alot but not enough to steal 600hp, and since it is torque that spins it, not HP it wouldnt be using HP itsself...just affecting HP because HP depends on how much torque you have at any certian RPM...a cyntrifical supercharger is basicly an impeller in a case that spins and forces air into the engine. the compression works exactly like in a turbo only it is spun byt the engine and not exaust (like in a turbo).... forcefanajd you are officially :owned:


UMMMM OWNED I DONT THINK SO. first off learn to spell...its centrifugal....not cyntrifical...and its a roots blower....not rooter. second, this guy is obviously new to turbos and superchargers.....so i was just seperating them all together. third his car is an automatic so in theory the bov would do jack shit for him. fourth who cares if 3" exhaust sounds like ass....less back pressure means the turbo will spool faster. and as far as your comment goes about diesels sounding bad with big exhaust....your fucking stupid...ever hear a banks turbo kit on a power stroke f-250 or f-350? they sound sick. and im getting the information about how it takes 600 horsepower to turn a roots style 18:71 blower on a top fuel dragster for you to shut you the fuck up once and for all. so the fact that you just said i got owned is therefore out the fucking window.

OH yea...would you care to argue any further?

:cwm27: nitros will not hurt a turbo...a turbo cant tell whether it is compressing oxygen mixed with nitrogen and other minority gasses or whether it is compressing nitrogen that has reacted with oxygen. nitros will work in any internal computsion engine because in order for an internal combustion engine to work it has to have oxygen to burn fule....when nitros is heated to a certian point it releases its oxygen which gives the engien a greater supply of oxygen....
Nitrous increase the exhaust gas mass since it contains more oxygen. The nirtous is usually also added after the compressor. This increase the gasmass to the turbine in such a matter that it can overrev and be damaged.

Diesels work with an excess of air, the power is controlled by the fuel added. Id you simply add nitrous you will just have even more oxygen over.

Nitrous increase the exhaust gas mass since it contains more oxygen. The nirtous is usually also added after the compressor. This increase the gasmass to the turbine in such a matter that it can overrev and be damaged.

Diesels work with an excess of air, the power is controlled by the fuel added. Id you simply add nitrous you will just have even more oxygen over.

Heard of a wastegate? Unless you're spinning the turbo almost to the max and have a tiny tiny internal wastegate it will still control boost, I've sprayed turbo motors tons of times.

http://www.bullydog.com/sale.pl?cat=nitrous

oh shit, diesel nitrous!!

Supercharging originally refers to "precompression", that the air is compressed before it enters the cylinder. It does not state if it's done by a mechanically driven supercharger or a turbo supercharger.

To drive a Top Fuel supercharger it takes about 1000 hp, the amount needed depends on the gasmass, pressure ratio and adiabatic efficiency of the compressor (which for the roots is low).

all i got to say is propane....hehehehee

Heard of a wastegate? Unless you're spinning the turbo almost to the max and have a tiny tiny internal wastegate it will still control boost, I've sprayed turbo motors tons of times.

http://www.bullydog.com/sale.pl?cat=nitrous

oh shit, diesel nitrous!!
The wastegate only opens when there is a certain pressure in the intake or where ever you take the reference from. It doesn't take turbocharger speed into count (only a few racing turbos are fitted with turbocharger speed sensors).

The wastegate may also not handle the flow, and note that it's a diesel that we talk about and they usually don't use wastegates since they aren't unstable like gasoline engines (which is because the latter are lambda controlled).

I wonder how many people that have bought nitrous for diesels only to find out that it doesn't work?

all i got to say is propane....hehehehee
Why not simply increase the fuel flow from the injectors instead!

Boost preassure can also be increased since a diesel engine can't "knock".

LMAO...the faster a turbo spins the more boost it creates...and BOV is needed wether a car is auto or manual...it helps in acceleration with manual since the throttle body is closed when shifting but it is needed in an automatic as well because when you let off the gas the throttle body closes and if there is no BOV there will be compression surge...been called rooters as long as i can remember...and as i already explained HP doesnt spin the supercharger....torque does...the reason it effects HP is because HP depends on torque....if nitros sisnt help diesels then nitros wouldnt be used with diesel dragsters (yes there is such a thing) all you have to do is start pumping more and more fule into the cylender....all internal compustion engines are the same...oxygen+fule=power.....the more oxygen and fule yo ucan get into the engine the better off you are....i never said diesels sounded bad throught 3" pipe....i said 3" pipe sounds bad on small engines....and as for your waste gate not being on diesel turbos...go down to your chevy/GMC truck dealer and look at pre '03 diesel trucks....pre '03 because in '03 they started to use self controlling turbos, the turbo could in a sence "brake" its self if it began to make too much boost or spin too fast...but pre '03 diesels had a wastegate on their turbos....how to i know all this...my grandfather drives an '04 GMC seirra 2500, my uncle drives an '02 Chevy silverado 2500...both diesels....and as for your little nitros on diesels doesnt work...i know never to refer to TV shows...but on Trucks on Spike TV they put a nitros and propane injection on some bigassed diesel...i forget what modle and all...but anyway with just the computer reprogramer they gained fifty something HP and 100 something ft/lbs of torque, then with nitros alone they gained just over 50hp and with propane alone they gained 70hp, and with propane and nitros they gained 150 something hp....looks liek it works to me....bully dog is a semi respectable company....if it didnt work at al lthey wouldnt sell it....

ok, thanks. in another post or maybe this one, someone said to get a smaller turbo as well. a t-25 if i remember right. a smaller turbo spools faster, thats good, but does it give the same horse power? probally not im guesing but will the car go faster is it a speed power tradeoff? a smaller turbo spools faster ok but in the long run is that better than a bigger turbo?

These are the trade-offs of turbocharging. Response vs all power. Either you can have a car that spools very quick or a car that is insanely fast. Big turbos make big power. Not a good choice if response is your goal. Small turbos are very responsive but make low peak hp. Engine size is also very important but I'm not explaining all of that when you can simply read it. You decide where and how fast you want power. This is called "turbo sizing". You have to know what you want when you decide to use forced induction. So far, you have said you want faster spooling. Well, where does it spool now? Does it seem like it should spool sooner? What kind of power do you want? Where do you want to make power? One thing you could do is have a shop fabricate you an equal length manifold. This will help the response of the turbo. Also, check for exhaust leaks on your manifold right now. Get a high performance intake. Run 3" piping from the turbo back. Do some basic matinence too.

The wastegate only opens when there is a certain pressure in the intake or where ever you take the reference from. It doesn't take turbocharger speed into count (only a few racing turbos are fitted with turbocharger speed sensors).

The wastegate may also not handle the flow, and note that it's a diesel that we talk about and they usually don't use wastegates since they aren't unstable like gasoline engines (which is because the latter are lambda controlled).

I wonder how many people that have bought nitrous for diesels only to find out that it doesn't work?

What are you talking about, seriously. Turbocharger RPM is almost directly related to boost pressure. Increase shaft speed, increase boost, it's a pretty simple phenomenon. You increase the exhaust flow, it spins the turbine wheel faster, makes more boost, if the gate is big enough it bypasses more exhaust, if it isn't big enough you get boost creep, pretty simple. I don't know what the hell you're talking about, but it doesn't really make sense.

Secondly, I don't know about you but every single diesel I've seen that doesn't use a variable geometry turbo does use a wastegate, to prevent overspinning the turbo, just like you mentioned in the first part of your post :uhoh:

I wonder how many people have tried to make posts on here to sound smart-assy, only to discover they're totally wrong? Bully Dog makes diesel performance parts. They have a nitrous kit for diesels. Nitrous express has a kit specifically for diesels (http://www.nitrousexpress.com/News/NXd.htm). NOS makes a nitrous kit specifically for diesels (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=257381&prmenbr=361)

What's that again about nitrous not working on diesels?

What are you talking about, seriously. Turbocharger RPM is almost directly related to boost pressure. Increase shaft speed, increase boost, it's a pretty simple phenomenon. You increase the exhaust flow, it spins the turbine wheel faster, makes more boost, if the gate is big enough it bypasses more exhaust, if it isn't big enough you get boost creep, pretty simple. I don't know what the hell you're talking about, but it doesn't really make sense.

Secondly, I don't know about you but every single diesel I've seen that doesn't use a variable geometry turbo does use a wastegate, to prevent overspinning the turbo, just like you mentioned in the first part of your post :uhoh:

I wonder how many people have tried to make posts on here to sound smart-assy, only to discover they're totally wrong? Bully Dog makes diesel performance parts. They have a nitrous kit for diesels. Nitrous express has a kit specifically for diesels (http://www.nitrousexpress.com/News/NXd.htm). NOS makes a nitrous kit specifically for diesels (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=257381&prmenbr=361)

What's that again about nitrous not working on diesels?



yea i definately have to throw the bull shit flag on him too...definately :owned:

What are you talking about, seriously. Turbocharger RPM is almost directly related to boost pressure. Increase shaft speed, increase boost, it's a pretty simple phenomenon. You increase the exhaust flow, it spins the turbine wheel faster, makes more boost, if the gate is big enough it bypasses more exhaust, if it isn't big enough you get boost creep, pretty simple. I don't know what the hell you're talking about, but it doesn't really make sense.

Secondly, I don't know about you but every single diesel I've seen that doesn't use a variable geometry turbo does use a wastegate, to prevent overspinning the turbo, just like you mentioned in the first part of your post :uhoh:

I wonder how many people have tried to make posts on here to sound smart-assy, only to discover they're totally wrong? Bully Dog makes diesel performance parts. They have a nitrous kit for diesels. Nitrous express has a kit specifically for diesels (http://www.nitrousexpress.com/News/NXd.htm). NOS makes a nitrous kit specifically for diesels (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=257381&prmenbr=361)

What's that again about nitrous not working on diesels?

:banghead: Variable Geometry turbo :banghead: thats what its called....

What are you talking about, seriously. Turbocharger RPM is almost directly related to boost pressure. Increase shaft speed, increase boost, it's a pretty simple phenomenon. You increase the exhaust flow, it spins the turbine wheel faster, makes more boost, if the gate is big enough it bypasses more exhaust, if it isn't big enough you get boost creep, pretty simple. I don't know what the hell you're talking about, but it doesn't really make sense.

Secondly, I don't know about you but every single diesel I've seen that doesn't use a variable geometry turbo does use a wastegate, to prevent overspinning the turbo, just like you mentioned in the first part of your post :uhoh:

I wonder how many people have tried to make posts on here to sound smart-assy, only to discover they're totally wrong? Bully Dog makes diesel performance parts. They have a nitrous kit for diesels. Nitrous express has a kit specifically for diesels (http://www.nitrousexpress.com/News/NXd.htm). NOS makes a nitrous kit specifically for diesels (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=257381&prmenbr=361)

What's that again about nitrous not working on diesels?
Turbocharger speed, if we talk about the compressor relates to pressure ratio and airflow, have you ever seen a compressor map with the shaft speeds litsted? If you take a look at one you will notice that shaft speed tend to increase at high flow rates without using high boost pressures, so when not using oversized turbochargers there is a risk of overspeeding the turbocharger. The thing is that when you overspeed a turbocharger it's hardly ever noticed since most people don't have the sensors for measuring the turbo speed.

Today many diesels are equipped with variable geometry turbines. Wastegates have been used on some basicly at later years to increase low speed torque (by allowing a smaller turbine/turbocharger), diesels are stable and do not require a wastegate, which is why they were the most common application for turbochargers (the wastegate was introduced on the automobile market on the late seventies for use in gasoline engines).
The wastgates that are found on some turbochargers for diesels are usually smaller than wastegates for gasoline engines and are not designed to handle high flow rates.

All wastgates work by when reaching a certain pressure, often called "cracking pressure", the wastegate lifts off from its seat. The maximum boost pressure will then depend on, except on the cracking pressure, the amount the wastegate will open when the pressure increase. The cracking pressure depends on the spring load when the wastegate is closed and the amount the wastegate is opening on the spring rate, that if we exclude the wastegate deisgn and position. So maximum boost is basicly a balance between exhaust flow and wastegate lift.
A wastegate can also open because of a high exhaust pressure, this can sometimes occur when using small wastegate actuators. High performance units often use much larger actuators in comparison with valve area and harder springs and therefore rarely opens becuase of exhaust pressure alone.

The most simple way to increase power on a diesel engine is to increase the fuel flow, diesels work with an excess of air and there is oxygen enough to burn more fuel. Remember that diesels doesn't use a throttle plate and consume all the air that they can, only regulating torque by the fuel flow. The only reason that more fuel isn't added original is because of exhaust emissions and fuel economy (leaner = more efficient).
Adding nitrous will do nothing, it will only increase the excess of oxygen unless the fuel flow is increased, and you don't increase fuel flow on a diesel like with a gasoline engine where you simply can increase fuel pressure or add an extra injector in the intake. Adding the extra fuel is the complicated part when tuning a diesel engine, increasing the oxygen can simply be done by increase the boost pressure as the engine will not suffer from engine knock like a gasoline engine.
Adding nitrous is basicly to waste money when one can increase boost instead, nitrous doesn't offer the simplicity that it offers on gasoline engines.

^^nitros still works...dumbass...otherwise so many companies wouldnt sell it...granted nitros injected with propane is twice as good...but nitros still works...

OK lets make this clear, this section of the forum will be completelly kept Civilised, so no shit talk nobody gets Owned and you absolutelly Don't use Name Calling(hint CBFryman)

You want to disagree feel free, but keep it clean and technical. SaabJohan made his posts without personally attacking any one of you and I expect the same courtesy in return.




Now back to the disscussion. Normally yes it seems that nitrous does absolutelly nothing on a diesel engine unless you dump so much fuel in it that it simply cannot get enough air in to compensate and you overfuel it. In that case nitrous might compensate. Although it would take quite an insane fuel system to provide that much fuel.

http://www.bankspower.com/tech_nitrousoxide.cfm

Quite and insane fule system? every now and then my grandfathers diesel will belch black smoke...and its brand new....and so will his johndeer tractor...but the tractor isnt turbo....along with every big rig on the road has a valve and then the exaust pressure is grate enough it releases big clouds of butt smelling smoke....im sorry for calling SaabJohan a dumbass but i hate it when people are wrong and stay persistantly wrong on otherwise common knowlege...yes i know i can be wrong often but if i am proved otherwise i do not persist...it has been proven over and over that nitros oxide can help any internal comustion engine if enough fuel is previded....

it has been proven over and over that nitros oxide can help any internal comustion engine if enough fuel is previded....


I was under the impression that one of the most significant challenges of compression ignition engines was producing a homogenous air fuel mixture during the short injection period.

Quite and insane fule system? every now and then my grandfathers diesel will belch black smoke...and its brand new....and so will his johndeer tractor...but the tractor isnt turbo....along with every big rig on the road has a valve and then the exaust pressure is grate enough it releases big clouds of butt smelling smoke....im sorry for calling SaabJohan a dumbass but i hate it when people are wrong and stay persistantly wrong on otherwise common knowlege...yes i know i can be wrong often but if i am proved otherwise i do not persist...it has been proven over and over that nitros oxide can help any internal comustion engine if enough fuel is previded....


The black smoke is not cause normally by overfueling. It is caused by improper combustion and the resulting unburned hydrocarbons and is very common especially on old diesels.

Overfueling will cause even more black smoke but its not the common cause in a regular diesel.

Also overfueling a diesel happens only in very highly modded diesels. and yes it should quite an upgrade of the fuel system.


http://www.bankspower.com/tech_nitrousoxide.cfm

To begin, a turbo-diesel has no air throttle. It is free to intake as much air as it can draw, or the turbochager can supply, on every intake stroke. Therefore, hot rodding the diesel is a matter of supplying the engine with as much fuel as can burned by the air available at maximum power. In fact, you can overfuel a diesel in the quest for power.........

Let’s assume you’ve modified your turbo-diesel to the point that it is overfueled and belching black smoke under a full load. What can you do? One solution is to add nitrous oxide injection, but in this case, you would not add extra fuel because you’re already too rich.

When you think about it, adding nitrous oxide injection to a diesel is easier than adding it to a gas engine because you don’t have to mess with adding extra fuel. In fact, there’s no point in doing it unless you’re already in an overfueled condition.



Look at that quote it is clear that nitrous should be used only after you overfueled your diesel. So SaabJohan was on the right track he just did not think of the extreme case of pushing your diesel so hard that you "flood" it with fuel. And again take this advice and do not disregard what Johan is telling you, he is very very knowlegeable.

The thing is that with a diesel you can when you overfuel it increase the boost instead as it isn't knock limited.

There are diesels running extreme boost pressures, the highest that I've heard of is around 17 bar (246 psi) using three stage turbocharging. That case is a little extreme but since most diesels for cars aren't using that high pressures it isn't that difficult to solve.

"But if the turbo isn't large enough" you might think, well in that case you're in trouble even if you choose use higher boost or nitrous as both will overspeed the turbocharger.

^^ we already established that 99% of diesels today use either veriable geometry or wastegates....and in order to increase boost you would have to make the turbo spin faster so you are contradicting yourself...

I've read this entire thread from start to here, and CBF, I don't understand how you think SaabJohan is contradicting or wrong?! What he is saying makes perfect sense to me, not to metion, I've also learned a little more of what makes a diesel tick...

^^ we already established that 99% of diesels today use either veriable geometry or wastegates....and in order to increase boost you would have to make the turbo spin faster so you are contradicting yourself...
I've never contradicting myself. Today most diesels for passenger cars are using variable geometry, a few are probably using wastegates. But if we goes back a few years in time that wasn't the case. And if we look at larger diesels many of them, and still today are using fixed geometry turbines without wastegates.

Turbocharger speed isn't as easy as increased speed gives increased boost, not that I have the slightest clue what you are talking about. Have you heard about turbocharger matching?

yes i have head or turbo maching...but it is a known fact that the faster you spin a turbo the more boost it creates...and since all newer non big rig diesels are using variable geometry turbos or wastegates why did yo ueven begin to state that there was no boost controll on diesels....

saabjohan was talking about making massive amounts of boost. Try boosting 30 psi on a T25, you can't.

Cbfryman its cool that your posting and learning but stop acting like you know everything when here and in the honda forum you've been proved wrong repeatdly.

try running 30lbs of boost on anything but a T3 or T4...very hard...

hhhmmm, heres an idea. mate the compressor u got now to a smaller turbine, should reduce some lag. don't know why people haven't thought of that yet??? and/or spend some more money for some ball bearings.

cbrfryman: I assume you were referign to a t3/t4 since T3's aren't all that big. However that was my point its hard to boost 30 lbs on a regular size turbo, I thought you were claiming that you could always increase the boost by increasing the turbine speed, and obviously you can't do that indifnately since it would destroy the turbo. saabjohan was refering to turbo compounding for disel trucks which alows massive amounts of boost.


Tran_nsx: It sounds like your talking about a T3/ T4 setup to me. The turbine is from a T3 turbo ( used in passenger cars) and the T4 part is a large compressor.

Tran_nsx: It sounds like your talking about a T3/ T4 setup to me. The turbine is from a T3 turbo ( used in passenger cars) and the T4 part is a large compressor.

theres different variations, but the most popular t3/t4 hybrid is an example of what im talking about. im not trying to influence him into getting this exact turbo since this is for a mercedes and not for a sport compact. he says all he wants is to reduce lag, nothing about making power, so a smaller turbine is what he really needs mated to his factory compressor.

Oh sorry man I never read the orginal topic, so I assumed you were curious why no one ever thought of that idea at all. Lol my bad

All diesel engines are not state of the art with electronic control variable geometry turbines. Also, if you're building a high performance diesel there is usually no need for variable geometry, and in racing it's sometimes forbidden. Take a look at the Ricardo-Judd V10 turbodiesel for example, 600 hp at 6000 rpm, two fixed geometry turbochargers feed the engine with pressurized air, the turbochargers are equipped with inlet restrictors according to regulations and they doesn't use wastegates.

Variable geometry turbochargers are usually also sensitive to high exhaust temperatures.

Garrett Variable Nozzle Turbine
http://www.technologie-entwicklung.de/vtg-sequenz.gif

The reason that you don't mix a large compressor with a small turbine is that they simply don't match. The small turbine use high speeds, work with low massflow rates and makes a low power. The large compressor work at lower speeds, work with high massflow rates and consumes more power.

Garrett T3 and T04 are really old stuff, altough they have been further developed they are originally back from the 60-70:ties. There are much better turbochargers availible today.
Using high boost pressures isn't that strange, it's just a different compressor design that must be used, one that work only under more narrower conditions. The turbine output must also be optimized. This is usually done by using a larger turbine, often matched with a smaller turbine housing.
Most smaller turbochargers are matched for small gasoline engines and aren't built fo higher boost pressures, that isn't the case with for example the larger of the GT turbochargers from Garrett or the HX series from Holset. Typically special "high pressure ratio" compressors are also availible, for example Holset offer HPRC in cast titanium.
Many small turbochargers also doesn't have bearings with are designed for higher loads caused by high pressure ratios, many small Garrett turbochargers do for for example use 270 degree thrust bearings while other turbochargers are equipped with 360 degree thrust bearings or even ceramic ball bearings.

http://www.3k-warner.de/en/products/images/img_21_principle_g.gif

A compressor map showing the principle, it's on german since I took it from BorgWarner Turbosystems homepage (the brands KKK and Schwitzer).

X-axle - volume, or massflow

Y-axle - pressure ratio

Pumpgrenze - usually refered as surge-limit limit in english. This line cannot be crossed as it leads compressor surge, that it the air stalls in the compressor and the compressor can no longer pump air.

Stopfgrenze - usually called choke. Passing this line will not increase the flow from the compressor due to that sonic speeds have been reached in the compressor. From this point on all extra volume flow measured after the compressor, or boost comes from that the air is heated, mass flow or volume flow before the compressor will not increase. Power output from the engine will also not increase.

blue-green-lines - this is the adiabatic efficiency of the compressor. This relates to how much the air will be heated and the specific work required by the compressor.

red-lines - this is turbocharger speed, the highest of the lines is the maximum speed. Note that the highest speed isn't equal to the highest pressure ratio (boost). Maximum flow is reached at 200k rpm and a pressure ratio of about 2.1 while 180k rpm is enough for the same pressure ratio with 80% of maximum flow.

The problem with using nitrous with turbocharging is usually because the turbine won't handle the higher flow. Running with the wastegate open is not only inefficient, many original wastegates can't handle much more than the original flow. I know other people which also knows quite a lot about turbocharging and they have had similar concerns. In some cases even what the "tuning companies" use can be enough to cause concern, and in some cases the airflow isn't enough to match their power claims.
When the car manufacturers do their development they usually fit them with sensors for exhaust temperature as well as turbocharger speed.

The reason that you don't mix a large compressor with a small turbine is that they simply don't match. The small turbine use high speeds, work with low massflow rates and makes a low power. The large compressor work at lower speeds, work with high massflow rates and consumes more power.

who says u can't mixed smaller turbines with bigger compressor? where have u been?

who says u can't mixed smaller turbines with bigger compressor? where have u been?


wut do u think a t3/t4 turbo is??? its a t3 flange and turbine side with a t4 compressor side.

wut do u think a t3/t4 turbo is??? its a t3 flange and turbine side with a t4 compressor side.

i already know that :rolleyes: . read the guys quote and my reply again.

oh and here is the proof for saabjohan :
http://www.turboneticsinc.com/t3-4.html

WOW WOW people back to the topic, nvm do whatever. i got it figured out, 3 inch muffler system (entire system manafold and all) td04 turbo (spools at 1500 prm i belive) wider intake, blow off vlave canvert to manual trans. well thats it thanks all.

The T04B and E compressors used are only slightly larger than the original compressor. Also, these turbos usually don't work so well in high boost applications when powerconsumption from the compressor increase. Take a look on the turbochargers used in F1 during the eighties, large turbines fitted in small turbinehouses to improve turbine efficiency and then a quite large compressor to that. Or why don't look on how a turbocharger looks on a diesel for a truck, large turbines which can power the compressor efficiently.

The basics behind matching is the same as for jet engines.
http://www.grc.nasa.gov/WWW/K-12/airplane/ctmatch.html

ok first things first....superchargers and turbos are completely different...turbos are basically "free horsepower" meaning it doesnt take any power to drive one.....it is driven by the exhaust to force air into the motor.superchargers are belt driven and it takes horsepower to drive one....this is a poor example but on drag cars it take i believe 600 hp to drive the supercharger on those cars(correct me if im wrong). all i can say about this is to read up a little about each of them and youll understand wut ive said a little better.

as far as freeing up some lag that youve got....you should have plenty of room to run a 3 inch exhaust system....for turbo cars you want to open the exhaust as much as you can....you lose a little bottom end but you turbo spools much faster thus making your power sooner and longer through the power band.
First thing - turbochargers ARE superchargers. The difference is that turbochargers are driven by a turbine which is powered by the exhaust gases, whereas superchargers (the contemporary usage of the term) are driven by a belt or chain off the crankshaft.

Second - turbochargers do not compress the intake air for free. True, they ARE powered by the exhaust flow, but some power (efficiency?) is lost since the exhaust doesn't flow as well.

Not many crank-driven superchargers take 600HP to run - the exception being the Roots blowers on Top Fuel dragsters. They can eat up to 800HP.

I'm not sure about the exhaust advice - I'll read up a bit on backpressure and such and I'll try to edit my post if necessary.

The T04B and E compressors used are only slightly larger than the original compressor. Also, these turbos usually don't work so well in high boost applications when powerconsumption from the compressor increase. Take a look on the turbochargers used in F1 during the eighties, large turbines fitted in small turbinehouses to improve turbine efficiency and then a quite large compressor to that. Or why don't look on how a turbocharger looks on a diesel for a truck, large turbines which can power the compressor efficiently.

The basics behind matching is the same as for jet engines.
http://www.grc.nasa.gov/WWW/K-12/airplane/ctmatch.html

for a sport compact, a t3/t4 hybrid turbo is the best for street purposes hands down and yes they match.

for a sport compact, a t3/t4 hybrid turbo is the best for street purposes hands down and yes they match.
T3/T04 are old designs, there are better ones today, I wouldn't spend money on these old turbos.