Blown' In The Wind

My friend's r34 gtr had one of its stock turbo blown earlier this week. The car has a 70 shot NoS and is mildly tuned using F Con S. Without the laughing gas, it was posting 340hp on all 4 at 1 bar with loads of torque which peaks at about 3500rpm.
He was playing around with another car early one morning on the highway when he suddenly lost power. Had it checked yesterday. The back turbo, which serves the 4th/5th and 6th cyl. was blown to smithereens!
One early theory is that the dry NoS system, which he is using, does not evenly spread the gas to all cyl. It had apparently gone too much to the 4th/5th/6th cyl. causing the back turbo to overboost when NoS was being used. So it went KABOOM!
If that was true, then I suppose dry NoS system is no good. Meanwhile, my friend is now installing a second hand stock turbo as replacement for the time being. GT-SS remains hot favourite in the near future :evillol:
Let's say he wants to run the GT-SS at 1.2 bar. Must he change cams/fuel pump and injectors or could he just run stock innards? I think he can safely use stock innards at 1.2 bar of the GT-SS. But his mechanic disagrees. Any input wud be appreciated.

The problem is the design of the intake of the RB26, you will get more N2O in the 6th cylinder, because it funnles in because of for mentioned design problem.

Always have your injectors flow checked, and use the highest flow rate on number 6.

A dry shot on a RB26 is asking for problems. The guy is lucky it did not burn a piston.

Sean put out over 600hp out of a stock engine with 2530s, I do not see the GT-SS putting out more than that, but its only a matter of time before something lets go if he does run stock.

The Mech, has a point, but it comes down to how long your friend wants to dance with the DEVIL :evillol:

To clear something up, detonation is what did it.

but if the rb has a problem of putting more n2o into the 6th cylinder, arnt you supposed to put less gas into the 6th cylinder?

Thanks Sky. He's not planning to hv more than 400whp. I think that's achievable with a pair of GT-SS and stock innards. But I suppose, better be safe than regret it later. Especially with the way he's driving the car!
I don't understand the part you were saying detonation was the cause. (I am next to Mr Empty when it comes to all thses things!). Do you mean to say that detonation can hurt/damage a turbo?

Raysoh: I don't think you could map the fuel to put less gas in any particular cyl.

400whp should be very easy to achieve with the GT-SS. Not to mention, a better power band.

Detonation, and stock turbos do not mix. Think of it like little hammer constantly pounding the exhaust wheel, it will break. Yes, detonation can hurt the stock turbos. Steel ones can take a little more abuse.

The only way to cool the cylinder is with more gas, if you run lean under boost, your going to blow a hole in that piston. Majority of the time, the #6 will be your down fall. I have seen #5, and #4 as well, but most #6.

That is why the best flowing injector goes to #6.

I forgot to add, 400-425 should be fine with stock internals. Is he still going to use the N2O? How many times has he shot is, before the engine failure?

70, is actually a fairly big shot. Think of more like a 140 shot, while under boost. If he would have dropped to like a 40 shot, his turbo might still intact, but who knows.

That's why i love the Nur Turbos! :naughty: Their Steel, instead of ceramic!:screwy:

GT-SS remains hot favourite in the near future :evillol:
Let's say he wants to run the GT-SS at 1.2 bar. Must he change cams/fuel pump and injectors or could he just run stock innards? I think he can safely use stock innards at 1.2 bar of the GT-SS. But his mechanic disagrees. Any input wud be appreciated.

:Takes R33 over to the side and shares 4cyl tricks with him:


Aquamist water injection. That with good fuel and ignition tuning. Silly mechanic :P

With what you were mentioning that he was planning on doing, he'd have no problems at all with the innards

Sky/Gonth: thanks very much for the inputs. My friend wants to still use the NoS of and on. I agree with you Gonth. 1.2 bar seems ok with stock internals.

About the aquamist Gonth...I am interested for my car. Is it perfectly safe? Wouldn't the water rust the innards? Are we looking at more power or better response along the power range?

Aquamist, will keep your eingine nice and shiny, not rust.

Its sort of bandaid, to detonation away.

If you tune the car with it, its fine, but if you run out of water and try to boost. Bad things will happen.

Yes, its safe. Just make sure the tank is full, when you play.

The main purpose, is so you can advance your timing in the power stroke to the point where it will not detonate. Other than that, its really useless.

Just adding it, will not make more power.

Exactly Sky, running it doesn't add power by itself. But it does lower intake charge temps and ambient temps alot so you can run more boost ;)

If you've got electronic boost control it's wonderful. Just make another boost setting w/ higher boost when injection's on.

I'm digging up a link for you.

Here you go (http://www.aquamist.co.uk/cp/sys2/sys2a.html)

Very affordable for the benifits IMHO.

*Edit*
Just get a little float from a gas tank and hook it up in your tank, run a gauge off that :P If you have room for another that is.

R33

I don't think your friend will have any problems using the GT-SS at 1.2bar + NOS.

My engine in my R34 gave up about 2 months ago. I had be using the GT2530s for over 2 years before. Also from the HKS Goods Master:

GT-SS 280ps
GT-2530 320ps

For my car:

1st year - 550hp 1.4bar
2nd year - 600+hp 1.4 bar + headwork

All engine internals were stock except head gasket and different cams.
The reason my engine failed was because I never let it cool down long enough everytime I gave it a blast. So over the 2 years, it amounted to part of piston no.4 breaking off and sticking to the bore! So looks like a turbo timer is on order....!

About the aquamist Gonth...I am interested for my car. Is it perfectly safe? Wouldn't the water rust the innards? Are we looking at more power or better response along the power range?


I have used Aquamist in my Supra and Skyline. I won't say it gives more power, but rather as a safeguard if you plan to run higher boost or if the intake temps get high in the summer. In your case its all year round!! :grinno:

I use 50% water and 50% methanol mixture in the tank. The spray nozzle is the small one I use. Tip - fit the nozzle on the hard pipe (the one joining the plenum) not on the plenum as the mixture won't be mixed well enough and the rear cylinders won't get much!
The pump is set to come on at 1.0bar+

Also if you are worried about the tank being empty, you can easily fit a water sensor in it with a LED in your dash.

Just adding it, will not make more power.

i disagree. not in this case but it can add power.

What is the max % of water that can be injected.

my friend got a tuned engine and is running lambda 0.85 to keep detonation under control. his engine can take up to L=0.7 before the mixture won't burn anymore (to slow).
We came up with the idea of waterinjection. but we don't know the ratio between 15%fuel and ..%water.

In the end the engine should run on CNG (140ron :evillol: ) with water injection.

Derby

my friend got a tuned engine and is running lambda 0.85 to keep detonation under control. his engine can take up to L=0.7 before the mixture won't burn anymore (to slow).

In the end the engine should run on CNG (140ron :evillol: ) with water injection.

Derby

Can you explain how just the O2 sensor helps keep detonation under control?

140ron, were is the timing set at?

You ain't gonna tell me that you never heard of a knocksensor, do you? No offence of course.

my car build 1986 has a knock sensor stock. that is to control the knock at low revs. It is turbo'd so when asking for high torque at low engine speeds it is a good idesa to know that there is some electronics (i hate those shit) that try to keep my engine together.

And ignition, is not a problem. just increasing boost. Boost is the thing that makes the engine knock. So with increasing the ron. the boost can be set at a high level and the engine live isn't affected.

But do you know what the substitute is for 15% more fuel in water?

Derby

knocksensor, yes.

lambda is just an O2 sensor. Please correct me if I am wrong.

The so called lambda sensor is an exhaust gas oxygen sensor which is utilized in motor vehicles with three-way catalysts for the reduction of pollutants in the exhaust gas. It monitors the concentration of oxygen in the exhaust gas in order to keep the air-fuel ratio within tight limits, close to the optimum catalyst efficiency which is at the stochiometric ratio for complete combustion of about 14.7 kg air per 1 kg gasoline

I pulled this from a web site.

The knock sensor or lambda sensor? Are they the same to you?

knocksensor, yes.

lambda is just an O2 sensor. Please correct me if I am wrong.

No your completly right.

he had about the same engine as me. his is a little older. but he know how to program a ECU. so he build injection on it made his own Dumpvalve (electronic), wastegate (also elec.). and made the car ready for CNG use.

He programmed everything on a rolling road. he experimented with different lambda figures. and he came to the conclusion that the engine knocks to many on low revs.

This month he is begon to weld on his pistons. and i have seen some results and it is really beautiful...

Derby

The engine was knocking at low revs? That does not make sense to me.

Do you know why at low revs?

The so called lambda sensor is an exhaust gas oxygen sensor which is utilized in motor vehicles with three-way catalysts for the reduction of pollutants in the exhaust gas. It monitors the concentration of oxygen in the exhaust gas in order to keep the air-fuel ratio within tight limits, close to the optimum catalyst efficiency which is at the stochiometric ratio for complete combustion of about 14.7 kg air per 1 kg gasoline

I pulled this from a web site.

The knock sensor or lambda sensor? Are they the same to you?

No i don't agree on the website stuff. Maybe i'm to wizard to you but please say it when i'm going to much off topic

O2 sensor can be used to monitor combustion. (it is always to late but there is nothing better till now) it has nothing to do with the catalyst. It only moitor the exhaust emissions.

Knock sensor is to look if the combustion is proceding at a good speed. (it is looking while the combustion is on its way so better then a o2 Sensor.) if the speed is to high. (spark late). the presure in the cilinder is building up t fast. oil is pushed out of bearings... .... ... it is bad. so when that happens (Knock) the sensor measures a weird kind of vibration and sends a signal to the ignition unit. the ignition unit makes the spark come earlier next combustion stroke.

Derby

I hope this clears up some things. Sorry it tok so long before i react but hat english is goddamn hard to learn.

Derby,

I am very impressed with your english.

I understand abuot the knock sensor.

The engine was knocking at low revs? That does not make sense to me.

Do you know why at low revs?

May i ask how old you are. if you find the question rude don't answer it.

low revs yeah. at high revs. the engine knock to but the chance to happen is small. then it is most of the time bad fuel or a glowing piece of carbon.

At low revs, high boost and a lot of resistance from the engine (pistonrings but also the weightof the car that won't te be accelerated) the cilinder pressure is high. The spark comes and the piston is moving upwards. the fire front is moving acrosst he chamber. because of a bad shape of the combustion chamber the fire front can't reach all the mixture. so on on spot of the chamber the mixture is not ignited. but is pushed in a very narrow area. then it ignites it self. the pressure rising at self igniting mixture is to great to handle. bad for bearings as stated before.

Fuel quality is important at both engine speeds. also the ron number.

Derby

I don't mind, 36.

I see what you are talking about, when do you get full boost? What do consider low revs?

And yes, Detonation is very bad. Its like a hammer nailing the top of your piston.

I don't mind, 36.

I see what you are talking about, when do you get full boost? What do consider low revs?

And yes, Detonation is very bad. Its like a hammer nailing the top of your piston.

Yeah and high rev knock (for my engine at 5500 revs/min for a skyline it is probably around 7000 maybe at 6000.) is almost inaudible and is a reallt destruction to your engine. a few seconds and you piston is fried...But as i said, it only happens with special conditions.

low revs is from 2000 to 3000rpm. before max torque.

that is why boost is set low or high (is a real seller) and low CR.

what my friend wants to do is lower CR. and running higher boost.

I want higher CR ( i don't like the low torque when idle) and a same boost.

It is a very old engine. 4 cil 8 valves. but it got huge potential...
But do you got problems with knock/detonation?
Derby

No problems with knock.

I am having this same discussion with some other guys. I want to run a higher CR as well, and they are saying its not worth it.

I think it is.


What CR are you running?

What boost level are you running?

What Oct/Ron are you using?

No problems with knock.

I am having this same discussion with some other guys. I want to run a higher CR as well, and they are saying its not worth it.

I think it is.


What CR are you running?

What boost level are you running?

What Oct/Ron are you using?

The more not-very-good-known-with-turbo-technique-people always say to me that i must increase boost cause it increases torque, what i want.

I disagree cause that torque is only there when the turbo builds up pressure. when increasing the CR. (from 1:8 to 1:8.5) the torque rises from 0rpm till max rpm. and that is what I want. So the other guys take the simple way i think...it is worth it for sure increasing CR. it increases power over the whole power band.

current Cr (stock) 1:7.9 Goal 1:8.3 (with the carb) 1:8.6 (with injection)
current Boost (stock) 0.7 bar (is about 10psi)
oct using 98. i can increase it very simple. adding toulene.

What is you goal Cr?
Derby

I was thinking of going to 9.5:1

Its the same CR as my Stang, but the VE is going to be better with the RB26, than the 5.0. So, I am drop it down to 9.1:1. I am going to have to do some more math on this one.

I look at it just like you do.

Sean posted this site on www.freshalloy.com, which is pretty good.

www.turbofast.com.au/TFcompB.html

I was thinking of going to 9.5:1

Its the same CR as my Stang, but the VE is going to be better with the RB26, than the 5.0. So, I am drop it down to 9.1:1. I am going to have to do some more math on this one.

I look at it just like you do.

Correct me i'm wrong but are you gonna lower you Cr of the Stang.
9.5:1 for a turbo engine is a little high. 9.0:1 is a nice CR. so you can run a nice bost and always lots of torque

I 've seen the ray hall calculators. but it is always guessing what the VE is. With turbo engines there is a liitle confusion on which Ve to use...on boost there is almost the same mixture in then with no turbo. but it is compressed so the volume is bigger under normal atmosphere. most of the time turbo also get to 90%


Derby

Correct me i'm wrong but are you gonna lower you Cr of the Stang.
9.5:1 for a turbo engine is a little high. 9.0:1 is a nice CR. so you can run a nice bost and always lots of torque

I 've seen the ray hall calculators. but it is always guessing what the VE is. With turbo engines there is a liitle confusion on which Ve to use...on boost there is almost the same mixture in then with no turbo. but it is compressed so the volume is bigger under normal atmosphere. most of the time turbo also get to 90%


Derby

9.5 is for the Supercharger engine. For the Turboed engine I was thinking 8.7-8.8ish.

Yes, its a guessing game throughout the whole rpm range.

I should add, the Supercharged engine will never see above 1 bar, so 9.5 is farely safe with that engine.

oh a supercharger is a whole different story. 9.5 should do. 8.8 for the turbo is nice. And how do you gonna do that. other pistons or gasket?

Derby

The Turbo is for a completly different engine. Its a T76 for a 393 stroker motor.

The Supercharger is for the 302. The 302 will stay that way.

A t76? Is that a Garrett? Is it a new one?

Derby

Its from Pro Turbo in the States. Let me find you their web site.

Here you go.

www.proturbokits.com/kitresults.htm

This is the same engine as mine will be, but I will have better heads. So, it should put out close to 850/850, but we will see.

Mike Andrews - San Antonio, Texas

93 Mustang Cobra - Daily Driver

392 cid / Victor Jr. heads / T56 Trans

Pro Turbo Kits FS58 Street kit w/ T76 & Air/Water IC

798 HP / 826 TQ @ the Rear Wheels / 14 lbs Boost

I talk to the guy from Power House Performance in Oklahoma. They have used this kit for the low 9s. So, there is plenty of power.

It comes down to weight transfer, suspension and driving.

SO that is some serious shit then...i'm very interested in the result.

They use Garrett turbo's. Garrett just launched there new series The GT. with also a GT40. used by that company...

so no i'm wondering what are you gonna do about the suspension. I'm really interested in that part.

850hp you say. and running 9's with that, damn that should be a serious acceleration...i wise i could ry that too once...

Keep me informed

Derby

Those guys are running 9s. My car will not be set up for that.

They are using a Wolfe suspension, with a believe a 5 link.

My Car is set-up for road course, so it will not hook the same way.

There are a lot of issues that need to be addressed.

A car is only as good as its weakest link.

A car is only as good as its weakest link.

That's a thing most of the racers won't believe.

and it is good you do something about the suspension. it would be sad if you crash the car, cause of the bad stock-setup suspension. But is this stang for daily use. or is it more a track day car...?

Derby

Its a daily driver, very moderate cam.

Going with around 234/226 553/545 114lobe sep.

so you did your homework obviously...

Wait a minute...234/226 is that the same as open @126 btdc. (i really can't believe this.)

I really got into cams today, (Coincidence?) but all i every see is like this
http://files.automotiveforums.com/gallery/watermark.php?file=503/1109335gttcamklein-med.jpg

How should i read your figures?

Sorry for the picture on it's side. it was taken by a friend of mine and I had no time to rotate it.

Derby

That cam has 40* of over lap, Wow? To me that is a lot for a turbo cam.

260 for duration? I take it, that would be total duration, not at .050? That is kind of small.

Your valve lift, if I read it right is .498In/.495Ex, thats not bad.

That is an extremly mild cam, timing events, seem to be pretty good, except for that 40* over lap.

so you did your homework obviously...

Wait a minute...234/226 is that the same as open @126 btdc. (i really can't believe this.)

Derby


234/226 that is the duration, checked at .050 lift.

Ramp rates vary a lot on total duration, so a lot of the times they will give it at .050 to give a better indication of how mild or wild the cam is. Its still can vary, but its a little better indication of what the cam is all about.

ok. Yeah 40 overlap is a bit tricky.

I driven an turbo car with NA cam (60 degrees overlap) and that is not gonna work...somehow the spooling is just bad...Detonation all the way in low revs... So for that car a 42 degrees cam is made.
and with mild you mean the speed the valve opens...?

Derby

the text from the rest of the pic.

Timing = valve timing figures measured in crank degrees
Dur = total cam durationmeasured in crank degrees at end of ramp (which is in my opinion not the most accurate way of measuring. what is the end of the ramp...when begin the ground circle.?)
VL = valve lift measure in thousands of an inch
VC = valve clearance measure in thousands of an inch
FL = valve full lift figure measured in crank degrees, ATDC inlet, BTDC exhaust
LATDC lift at top dead centre measured in thousands of an inch.

Derby

Using Nitrous Oxide in a RB26 is like painting red bricks with red paint - pointless...

not once have anyone talked about the simple thing////////
does any of you have a 2mm steel head gasket///// no do you have JUN / COSWORTH. /////LOW COMPRETION PISTONS.///// NO . I BET YOU RUN A BLITZ DUMP VALVE .// AND YOU PUT YOUR NOS AFTER THE THROTTLE BODY/YES
NO WONDER YOU KILLED THE RB26

rb25stu,

You clearly need to learn some more.

not once have anyone talked about the simple thing////////
does any of you have a 2mm steel head gasket///// no do you have JUN / COSWORTH. /////LOW COMPRETION PISTONS.///// NO . I BET YOU RUN A BLITZ DUMP VALVE .// AND YOU PUT YOUR NOS AFTER THE THROTTLE BODY/YES
NO WONDER YOU KILLED THE RB26

So and where did you get all this info? With your kellogg's or so. What is the use of an 2mm headgasket anyway...lowcompresion kills efficiency...

Derby