n00b question about turbos

[inarifennec]

Well everyone I just started learning about modifying cars with aftermarket parts a few months ago and I'm still learning.... so this is gonna sound like a really n00b question but I need to ask. my mind can't be at rest for some reason....

I'd really like to understand how someone can regulate boost pressure. I know that my cavalier can't go beyond 10PSI with stock components... so how do I keep the turbo from going over 10 PSI?

And also... If I do decide a higher output how do I go about getting beyond 10 PSI from my turbo?

Sorry again to all you car buffs who read this and scoff at me... I'm trying my best here.

[pimpendacavi06]

U have a turbo on a cavi and u just started learning about turbos?? thats pretty good i wish i had a turbo cavi
(sorry that dint really help u i just thought it was cool)

[jayson716]

sounds like he has money to do whatever. and someone just got him into tuning a sport compact. but i am not 100% sure about it but i think Blow off valves take part in that. so when it hits a certain Psi the blow off valve opens and releifs pressure. and like i said i am not 100% sure but i would imagine thats how.

[public]

Yes you are correct. The blow off valve sets maximum pressure. It consist of a spring that holds the valve closed, when you have enough pressure the spring can no longer hold it shut. It opens and releases air until the pressure drops below the spring strength. Have fun.

[jayson716]

And well i will add to that they are adjustable lol

[93_R/T_TT_Stealth]

ya - ya really couldnt get a better answer than how public described it - nj - if your gonna go with a turbo i can asure you that it is alot more practical than a supercharger, you will get better boost more power gain an have more doors open with a turbo than of a supercharger, superchargers acually use some of the engines power just to run them cause they are belt drivin. if you have the money an the know how - i would recomend gettin a turbo timer an boost controller- very good to have with using a turbo on a car that doesnt have one normaly, the turbo timer is great because u can set the turbo to still spin even when engine is shut down so it makes the bearings an such last longer - cause ur suposed to let the turbo idle for atleast 30 seconds if u just pulled off a highway or driving a good rate of speed - cause figure it this way if u pull off a highway u were doin like 60 mph ur turbo is still spinning 80k rpm after ur in the parkin space an to shut it right down wears them down faster than normal. a boost control does such - controls boost pressure - allowing u to set a certain psi & ect... an also will allow you to control an air an fuel mixture.... both are great to have - have them installed properly though- i have both my turbo charged cars equiped with both- good luck....

[-Jayson-]

personally i think superchargers are better just for their ease of use. And most turbo guys dont know what they are talking about when it comes to superchargers. If your going to go with a supercharger get an eaton. They dont draw more than 5-10HP from the engine at most and they are so much easier to maintane. You dont need more frequent oil changes, boost controllers, boost timers, intercoolers, any of that junk. A eaton M62 blower will make 12 PSI at around 6000 RPMS. IT also has a built in wastegate that lets you electronically control the amount of boost. Also they are designed so that at low rpms they dont use any engine HP.

[inarifennec]

hmm thanks guys. If anything I'll have my friend Elias help me out on this. he's a GM guy and well if anyone would know how to modify the correct pressure and help install the thing... I'm hoping he would know what he was doing. I really appreciate the help too... meh money is kinda looking short for this month. Gotta pay the bills and eat... so the car's on the back burner for a little but hey... she's fine where she is..... for now at least. Thanks a lot guys. I really appreciate it. Hopefully I'll get some time to modify her a bit later in January. Thanks

Wish me luck.

[93_R/T_TT_Stealth]

Originally Posted by -Jayson-

personally i think superchargers are better just for their ease of use. And most turbo guys dont know what they are talking about when it comes to superchargers. They dont draw more than 5-10HP from the engine at most and they are so much easier to maintane. You dont need more frequent oil changes, boost controllers, boost timers, intercoolers, any of that junk. A eaton M62 blower will make 12 PSI at around 6000 RPMS. IT also has a built in wastegate that lets you electronically control the amount of boost. Also they are designed so that at low rpms they dont use any engine HP.

(Ok not to start a fight just to point out some facts) - an dont talk down on others when your not even correct yourself.
1. they may be easier to put on i will agree with that but they are still not worth it.
2.most turbo guys? are u stating that i am a turbo guy an dont know anything about superchargers? we turbo charged a maro with a 305 TPI - ya we gained some power but wasnt worth the money... we only pulled 10psi outa it to be safe- then a year later he got a t-kit for it which is now in some cases a lower cost but more to bolt on - we turbo'd the 305 tpi an got phenomial hp an torque curve gains - when we dyno tested it the camaro practicaly came off the dyno -even though it was properly strapped down.. when he layed into third gear it jerked sideways from all the torque an we had to shut it down for everyone's safety.
3.u stated :hey dont draw more than 5-10HP from the engine at most and they are so much easier to maintane. yet you then say : Also they are designed so that at low rpms they dont use any engine HP . LOL HOW? how does it not draw any of the cars power that is total BS - nothing u can to will completely allow a supercharger to run with out drawing any power from the engine when it is belt driving silly..
4. you dont need to have more frequent oil changes just cause you have a turbo... most of the aftermarket turbo kits are hybrid tuff guy...
5.12psi @ 6000 rpm lol you dont get hardly any boost until your car is nearly if not is redlined. where as if your turbo charged turbo lag is such ancient history u can get full boost as soon as u lay into the throttle,with or with nearly 0 turbo lag.



cant wait to see what kind of cry baby feedback this dude gives this thread

[93_R/T_TT_Stealth]

i am not bashing superchargers - my friend has a supercharged 302 mustang that puts out a nasty 500hp but it was so much work just to get it to that point, he wants to twin turbo the one he is in the process of building now - can't wait to start installing on it

[noshun]

I got to the bit about the BOV's and didn't even read-on I had to reply a.s.a.p. Teh BOV (blow off vavle) has nothing to do with regulating boost this merely releases excess bosst when the revs drop. They do open at certain pressures though. The ideas is that when you press the throttle again the pressure didn't build right up while the you were shifting for example and then whren the throttle butterfly opens it forces much more air into the motor and can cause some serious damage. Stock cars have BOV but they are usualyy called recirculating valaves and just put the air they release back into the intake. That's why when you shift in a turbo it give off the wonderful hiss or a whirr depending on the style of BOV. Boost is regulated by the wastegate!!!! This basically is a plate that is spring loaded and when the boost gets to a certain level it open and release exhaust pressure to prevent the boost from exceeding it preset level by sending less exhaust to the turbine {hence 'turbo}(wastegates are a little more complicated than that but it's easier to explain it that way) The best way to reguate boost is with an electrical 'boost controller' this basically goes in the line that goes from the manifold to the wastegate and prevents the wastegate from opening until the boost controller lets it. You can also uprate the wastegate or the wastegate actuator. 10 psi would warrant about a -34 actuator. So for 10 psi you would want a small turbine and thenuse a boost controller. Boost controllers are about $300 but you can get a bleed valve or ball valve which is a boost controller but it is basically a chaber that the gasses pass through that has a ball sitting in the end of a spring. and it's is tightened by screwing the spring seat in or out in for more boost out for less. The only problem with a ball valve, is they are pretty crude and can stop the wastegate getting anything at all! You can also make these yourself. I'm glad to be of service and also, the whole supercharger vs turbo thing. for a small amount of boost that you are lloking for supercharging will be best as it is less work to install and although you have to change a pulley to change the boost. You can still have the BOV and possibly a chargecooler/air to water intercooler whatever you prefer to call it. Also supercharger whine sounds awesome and superchargers don't have lag like a turbo and anti-lag systems demolish turbo's if anyone wants to know how anti-lag systems work let me know.If you are set on a turbo about a garret T2 size will be best although they don't look much.

[noshun]

Also The whole thing about superchargers draing engine power. Turbo do exectly the same only by way of tons of back pressure. Consider this. You spend $800 on a perfomance exhaust because it 'flows' better and an engine is essentially a pump so if you smooth out it's intake and exhaust it will be more effiecient and powerful but a trubo manifold alone has a nice tight bend in it and then the exhaust gasses have to spin a turbine and as boost increases the air is harder to compress putting resistance on the turbine wheel causeing more back pressure!!!!!! Doesn't that make sense. Oh and a supercharger does always draw power from the engine and the guy desribed a roots style blower that has a vacuum valve so that it doesn't boost when throttle is only a little open. That's purely for economy.

[noshun]

Also I have a new type of blower under development that can be extremely tuneable and completely switched off and draws, very very little from the engine to work. I've not even made a prototype yet but working on it. Money need to go elsewhere first unfortunately.

[sierrap615]

Originally Posted by inarifennec

hmm thanks guys. If anything I'll have my friend Elias help me out on this. he's a GM guy and well if anyone would know how to modify the correct pressure and help install the thing... I'm hoping he would know what he was doing. I really appreciate the help too... meh money is kinda looking short for this month. Gotta pay the bills and eat... so the car's on the back burner for a little but hey... she's fine where she is..... for now at least. Thanks a lot guys. I really appreciate it. Hopefully I'll get some time to modify her a bit later in January. Thanks

Wish me luck.

remember a turbo requires more then just bolting it on, plan to upgrade the computer and fuel system too(or at absloute minimum larger injectiors or the engine won't last)

[noshun]

Originally Posted by sierrap615

remember a turbo requires more then just bolting it on, plan to upgrade the computer and fuel system too(or at absloute minimum larger injectiors or the engine won't last)

So true. Not to mention the fact that you have to drill and tap a hole for your oil feed!!!