safe boost level Options

[StreetRacing10PS...]

ok, i have been working on my project 6gen for a few months now, i only drove it around a few times before i laid it up to work on it, and iam pretty much done for now that i got my turbo kit. i was wondering what is a safe boost level to run on the 7afe. its a 1995 with 86K on it. a bunch of people i no run any were from 5-13 on stock internals, but they are all honda or DSM. i was wondering if any of you 7afte guys out their know a safe amount. i herd any were from 5-9.5 but is 10 pushing it?? i just wanna find out before i set the boost controller to high and throw a piston or rod. thanks

[GT4WRC]

I personally wouldn't run anything higher than 10psi on a n/a designed engine. Even then, I'd be warey. Have you considered running water/methanol injection? Would definately help preserve the internals.
Gary

[StreetRacing10PS...]

yea, but i never done anything like that before. how hard would it be?

[97sccelica]

I personally wouldn't run anything higher than 10psi on a n/a designed engine. Even then, I'd be warey. Have you considered running water/methanol injection? Would definately help preserve the internals.
Gary
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water injection wouldnt really solve the problem of weak internals. it would allow for more boost safely, detonation wise, but the rods are still tiny in a 7afe.

[StreetRacing10PS...]

thats my worst problem. i found forged pistons for the 7afe, but cant find rods any were and i know that the 7afe rods arnt the best

[rockstarbass1]

really only 10 psi in a 7afe?? i dont know for sure but i thought in my probe it was safe to go up to about 15-17 i think???

[97sccelica]

really only 10 psi in a 7afe?? i dont know for sure but i thought in my probe it was safe to go up to about 15-17 i think???
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well, technically, it depends on the turbo, but since most 7afte setups have a t3 turbo, it would be best to keep it under 10psi

[StreetRacing10PS...]

that seems kinda high... this is what happens at 13 PSI....



This post has been edited by StreetRacing10PSI: Apr 25, 2005 - 8:51 PM

[GT4WRC]

I think the biggest problem will be heat due to the relatively high compression ratio. Too much heat and stresses on the pistons will increase resulting in catastrophic failure. Most of the time the land rings tend to break up causing the piston to fail. By using water/methanol injection, you can effectively reduce in cylinder temps which reduces the chance of piston failure.
On my rally car I'm building, I plan on upping the CR from 8.5:1 to 9.0:1 to improve off boost throttle response and will be using an Aquamist system to prevent temps from getting too high. I plan on running a max boost of around 18psi (which should easily give me over 300bhp) which is not excessive on an engine with a 'higher' CR.

Rods can be an issue with running too high a boost level. They have a tendancy to take on the shape of a banana if too much boost is thrown at them. If you want reliability, get forged internals and use water injection. Simple belt and braces.
Gary

[rockstarbass1]

my car has 160k miles on it so i dont think i need to worry about turboing it lmao

[StreetRacing10PS...]

do you know were i can get a water cooled piston kit?

[GT4WRC]

do you know were i can get a water cooled piston kit?
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It's not a 'water cooled piston kit' as such. A very fine mist of water (and methanol) is injected into the intake stystem post turbo and mixes with the intake charge. The water absorbes heat - though too much and it'll act like a fire extinguisher.

Try looking at www.aquamist.co.uk - they do one of the best kits around and also supply most of the WRC teams. Have one of their kits on my rally car and am planning on fitting one to the FOUR.

This'll give you an idea of what is involved re installation - http://www.220gti.co.nz/water%20injection.htm
Gary

[popstar]

Hmmm looks like a good place to ask ??

my boost gauge is calabrated in kg - cm2 !

can any one translate this in to real money ?

cause i've pushed up to '1.1' !!!!

any ideas, or any one got a good convertion system !!!!?????

thanks

popstar

[946thGenGT]

Hmmm looks like a good place to ask ??

  my boost gauge is calabrated in kg - cm2 !

can any one translate this in to real money ?

cause i've pushed up to '1.1' !!!!

any ideas, or any one got a good convertion system !!!!?????

thanks

popstar
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I'm pretty sure that would be about 15 or 16psi, but I could be wrong because that seems pretty high... http://www.convert-me.com/en/convert/pressure

[popstar]

hmmm that is high.....

i think i need a new boost gauge or get this one checked.......

thanks

[boosted_K2]

water injection systems are basically a cost effective way to add "octane" to fuel on demand. octane rating is just a rating that states a fuel's resistance to igniting, since water wont ignite, injecting it raises the octane in the mixture when running extremely high boost levels to prevent unwanted detonation, it doesnt exactly "cool" anything per-say.

[StreetRacing10PS...]

but it is possible to run more boost than right?? snfd if so whats safe on a 7afte, 10??11??

[playr158]

id say 8 is safe on a stock internal 7afte

10 is pushing it with stock internals

you also have to realize the rods are the weak point of the 7afe motor
not necissarily the pistons

[StreetRacing10PS...]

yes i no, but i cant find forged rods anywere!! any ideas??

[nik]

i pushed it to 14psi but ran out of injector in the top end but on stock i would keep it around 10 and i sent you a pm

[playr158]

rods......you can get them shot peen'd for added strength or go custom like NIK

but if NIK you ran out of injector where you running the FMU or electronic fuel? and stock injectors?
or did you upgrade to larger injectors?

[nik]

rods......you can get them shot peen'd for added strength or go custom like NIK

but if NIK you ran out of injector where you running the FMU or electronic fuel? and stock injectors?
or did you upgrade to larger injectors?
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i was going to buy new ones but thats when i decided to go 7agte

it was with fmu 12:1 with venom injectors 10% over stock to get in the 200+whp i would go with a set of 4agze injectors 365cc

[playr158]

4agze injectors to run on a 7afe fuel rail?

[GT4WRC]

rods......you can get them shot peen'd for added strength or go custom like NIK

Geting rods shot peened won't stop them from bending if the boost is too high. Go forged - much stronger.
Gary

[nik]

4agze injectors to run on a 7afe fuel rail?
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not sure you need about 365 cc to be safe around 200whp the 4agze are low imp
i cant remeber off hand if the 7afe is high or low

i know my new set up is running 550cc low imp for the 4agze harness

[playr158]

yea i need to figure out which injectors i can use
cause i'm defenitly shooting 200whp

[StreetRacing10PS...]

me 2. what about 500CC. . . . . to big??

[nik]

me 2. what about 500CC. . . . . to big??
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yeah to big 500-550 is more for 300whp

the venom injectors i sent you will handle 185whp at 80% duty cycle you dont want to push injectors passed 80% bad things start to happen and your injectors can get stuck open all the time.

you want to know an exact number for injectors call RC or search there are a few sites around that you just plug in your info (like horse power range etc) and it will give you a number in lbs or cc of injector you need


here http://www.rceng.com/technical.htm

This post has been edited by nik: Apr 29, 2005 - 11:24 AM