as the title says -

 

i know 14psi is the maximum that you should run an engine which doesnt have forged pistons.

 

I would like to hear from anyone who is consistently running more that 14psi on a relatively standard engine.

 

I was thinking about running 16psi - but i just dont know whether to risk it.

 

Regards,

 

Alex

I've run 16psi on both mine with no problems on stock internals.

With your bigger tubs though, 16psi is a lot more a flow than with stock ones, so may not be. Limiting factor is usually injectors though.

I run 15psi on stock injectors, I always fill up with Optimax and have no probs with the setup I have. I'm thinking of running 17/18psi soon.

Not much point going that high on stock turbos, they're way inefficient then, you'll probably loose power if anything as what you gain from higher pressure is offest by heating the charge more.

C.J am on 18psi max on the same tubs as you, though i do have an EGT gauge and use this to set the HKS super AFR settings for correct fueling, which according to the guy who rebuilt my engine over 2 years ago is what's most important to run higher boost levels and still going strong ;)

cheers

smithy

Hi Smithy,

 

i know the tubs do 18 psi easy but i'm worried about breaking my pistons. Don't you run with forged ones?

 

I am using a greddy e-01 to control the boost.

 

Regards,

 

alex

 

if you think i can run 18 psi with no damage to the pistons then weyhey - 18 psi here we come :dance:

LOL Thats a lotta responsibility I'm sure Smithy won't want :p

If smithy says its ok then i'll give it a go - and I wont hold him responsible at all - honest

 

:slap:

 

Is there anyone else out there runing 18 psi on stock pistons??

 

If so speak up ye brave souls

 

Regards,

 

Alex

Originally posted by _cj_

If smithy says its ok then i'll give it a go - and I wont hold him responsible at all - honest

 

:slap:

 

Is there anyone else out there runing 18 psi on stock pistons??

 

If so speak up ye brave souls

 

Regards,

 

Alex

 

Alex stock pistons under such heat WILL BREAK one day;)

I am runing 15psi no probs, if I increase it to 17 or 18 you say that the extra heat will cause problems which I can understand. So if I get so big intercoolers will this solve the problem? Its only an increase of 3psi?

That 3psi is 20% of 15psi though.

Originally posted by Homebrew

I am runing 15psi no probs, if I increase it to 17 or 18 you say that the extra heat will cause problems which I can understand. So if I get so big intercoolers will this solve the problem? Its only an increase of 3psi?

 

I have been running 15psi for 3 years,no probs at all then one day this happened.IMHO stock pistons will not take that kind of heat forever:( only 3psi? that's much more heat than you think;)

 

However mine were 12 years old so not done too bad;)

 

The stock engine and pistons are very strong.

It can take up to 575-600rwhp as long as everything is running right.

The biggest reason the pistons fail earlier is because of detonation or severe overheating.

Forged pistons can withstand detonation a lot better.

 

Personally I'd upgrade the injectors before even thinking about upgrading the turbos.

The stock 370cc injectors are already at their max with stock turbos running 16-17 psi.

The injectors just can't flow enough fuel and max out at around 370rwhp.

 

-Eric

Lymon all my pistons to say they were 12 years old are in very good condition,there is a tiny trace of detonation on the crown of no 5.

No i'm not on forged pistons, maybe one day though ;)

i know where yer coming from as regards to high boost cos it cost me a few grand. When i bought my car it had a BRAND NEW short block fitted along with new tubs and reconned box, receipt for 6.5K for the above work and that was only 18months earlier before i bought it, now then after the guy had the work done, some 6 months later he had a boost upgrade, i bought the car a year after that. 10 months later i fitted an apexi boost gauge and seen it was 19psi :eek: located the boost upgrade and ripped it out soon as i could, the very same week she was smokin for England, took it to RC Develoments for new tubs cos the last new ones came from the very same garage who done the boost upgrade, only to discover a number of oil leaks, engine stripped and mashed rings in a block only 18-20 months old from NEW :eek: all redone, fuelling/timing checked and Super AFR set to keep things sweet, some 2 years or more ago now. so far so good and she's lasting longer than the last one ;)

smithy

if it's heat that is the problem - I'm running HKS intercoolers - so that should help - maybe i'll give it a go at 16psi :D or 17 psi if i'm brave :D or.........doh someone stop me :dance:

Dont worry the engine will go or it will stop you!

 

Just make sure you have an AA relay subscription - then you'll never need it!

 

I've never used mine and been paying for it for years. Prolly need it next week for saying that

What about water injection to keep the charge temperature down? nobody seems to mention that so isnt it a viable option?:)

Hi Alex

 

I was running 19psi on standard pistons but you know the rest bang!!

 

I think 16 will be ok as alot of people are running that kind of boost and are having no problems.

 

mmmm just ordered my greddy forged pistons:D

 

Kirbz

Originally posted by lymon

The stock engine and pistons are very strong.

It can take up to 575-600rwhp as long as everything is running right.

The biggest reason the pistons fail earlier is because of detonation or severe overheating.

Forged pistons can withstand detonation a lot better.

 

Personally I'd upgrade the injectors before even thinking about upgrading the turbos.

The stock 370cc injectors are already at their max with stock turbos running 16-17 psi.

The injectors just can't flow enough fuel and max out at around 370rwhp.

 

-Eric

That's what we like to hear :D :dance:

Tuned by B.O.B. :D

 

So Eric, would it be fair to say ?

Make sure we have big intercoolers to keep the temp of the compressed air down to a minimum,

then with the right amount of fuel and no detonation and we are good for 575-600rwhp (obviously with turbo's that can generate it).

600 bhp on stock internals :rolleyes:

 

would you spend thousands to produce that sort of bhp and not upgrade the internals....i think not ;)

 

Anyway mine was not detting but i still did my pistons and i'm not running anywhere near 600 bhp

 

Kirbz

:dance:

Originally posted by NightWolf

What about water injection to keep the charge temperature down? nobody seems to mention that so isnt it a viable option?:)

 

as far as i am lead to believe water mist injection doesnt work very well running higher boost levels because you are trying to pump water mist against higher and higher pressures - pissing into the wind as it were.

 

Regards,

 

alex

A bit of GTO knowledge to churn the brain.

 

Our stock engines are good for about 12.5 PSI.

 

To go higher requires a new fuel pump, fuel pressure regulator, injectors and a air/fuel controller as a minimum. (15 PSI)

 

To go even higher boost than this requires forged internals and bigger turbos, so big money and tuning.

 

Up until 6 months ago we believed that 1 bar (14.5 PSI) was safe on standard turbos and fuelling. Since then we found out that GTOs were knocking at 13 PSI to the extent that engines rebuilds were on the cards.

 

Do you guys have anything along the lines of TMO or PocketLogger to measure knock in your engines? This is now top of the GTO mods list to make sure that future mods don't cost a £1000 (minimum) rebuild.

 

Steve

 

Food for thought, happy to discuss

Originally posted by Homer Lawtey

Do you guys have anything along the lines of TMO or PocketLogger to measure knock in your engines? This is now top of the GTO mods list to make sure that future mods don't cost a £1000 (minimum) rebuild.

 

Interested to know more about these mods mate. Got any links for more info ?

Hi Stu

 

I was speaking to one og the gto guys last night (judas!!) there is a company in america that makes a knock sensor so it might be a good idea if someone from this club could get in contact them to see if they could knock something up (knock:D ) for us 300 boys.

 

Stu i think you should do it;)

 

http://www.pocketlogger.com/

 

Cheers

Kirbz

Originally posted by kirbz

Hi Stu

 

I was speaking to one og the gto guys last night (judas!!) there is a company in america that makes a knock sensor so it might be a good idea if someone from this club could get in contact them to see if they could knock something up (knock:D ) for us 300 boys.

 

Stu i think you should do it;)

 

http://www.pocketlogger.com/

 

Cheers

Kirbz

 

Looks cool, uses the stock det sensor from what I can tell. I'm hoping to get my Apexi AFC-2 working with the det sensor as that can measure knocking.... though haven't looked at what wiring is involved yet.