Max Boost for an EVO3

[ENGINR]

I'm running CP stroker pistons in my 2.3 litre, with a compression ratio equivalent to an EVO3 (9.5:1). What's the maximum boost I could run through this engine given my compression ratio will be the limiting factor (it's a forged bottom end) with 272/272 cams and a factory, chipped EVO2 ECU? I don't want to change to an aftermarket ECU at this stage and want a car that is a torquey daily driver that will give a SS, Skyline, or WRX a scare :twisted: , not a 300kw atw monster.

Any assistance would be appreciated as I want to get the most out of my setup as it is, without risking the hardware I've spent so much on putting together. Cheers!

 

[JSTYLE]

i ran 20psi thru my stock evo 3 bottom end using a chipped factory ecu, result was 225kw.

Jon

 

[Entaran]

17-23psi is the maximum efficiency range of the e316g turbo. Check the turbine maps and you'll see. Either side of this it's a bit feral in terms of response.

More boost is more power obviously. With 272's you're not going to be torquey below 3000rpm anyway so you may as well jack up the boost to 17-23 psi or somewhere in there.

 

[whiskey]

i ran 20psi thru my stock evo 3 bottom end using a chipped factory ecu, result was 225kw.

Jon

Plus you had a different head gasket to change compression right?

 

[JSTYLE]

i ran 20psi thru my stock evo 3 bottom end using a chipped factory ecu, result was 225kw.

Jon

Plus you had a different head gasket to change compression right?

a 50thou cometic headgasket would do sfa to change compression.. its still high as... have you seen the stock e3 headgaskets? i think they would quiet easily be 50thou too.. i have one at home and its VERY similiar thickness to the cometic.

if you really want whiskey ill take a pic just for you to admire im sure most of the other evo boys who have pulled apart an e3 will know that they do come with a very thick headgasket FACTORY.

Jon

 

[whiskey]

Yeah Jon if you have a photo I would be keen to have a look, cheers.

 

[ENGINR]

Thanks for the info sofar gents. So 17-23psi should be fine, given I've got a forged bottom end, Big16g and 560cc injectors, cometic head gasket (can't remember thickness - it's a triple layer jobbie if that helps ).

I've been hearing that with the higher compression ratio of 9.5:1 I am going to be limited to about 12psi of boost (not sure about that, but want to be safe instead of sorry!).

My ideal is to run 15psi daily and 20psi for track/drags/fun....

 

[CLuTZ]

Your engine can handle as much boost as it can handle, its simple as that!


Some can handle more, some less, but what you need is someone to chuck it on the dyno, check the AFR's (air fuel ratios) and also check for knock.


Do you datalog?

 

[JSTYLE]

Yeah Jon if you have a photo I would be keen to have a look, cheers.

ill post up a pic tomorrow morning when i get home and take one.

Jon

 

[JSTYLE]

stock e3 on the left.. cometic on the right

they both look to be the same thickness..

hope this explains it all whiskey

Jon

 

[ENGINR]

Well, realised that the compression ratio stated in the CP pistons catalogue is 9:1, so with the cometic headgasket I should be just under that. The Lancer register states the compression in the E3's is 8.8:1.

 

[moi]

stroker engine, nice! you should be able to run pretty high boost with the right air/fuel ratios and keeping detonation away, I run up to 28psi at times, daily 25psi. now dont take this the wrong way but why build a good engine using good bits etc then skimp out on getting actual aftermarket management eg. autronic, haltch, motec, microtech, link etc...... ? not cheap but its the cheaper option over blowing up an engine and having to rebuild all over again. Although I see chipped ecu's do pretty well I still prefer aftermarket management with a good tuner on the dyno anyday (i run autronic PnP and couldnt be happier on my evo 1).

 

[ENGINR]

You raise a good point. The fact is that I would love to run an aftermarket system in the car, but it's a simple case of $$$$ and spending it appropriately. My project was never meant to become what it has and I've got to pull the reins in somewhere. So unfortunately that means running a chipped ECU and running the engine in a 'mild' setup until I can afford to go for a full aftermarket system and run it in a setup it has been built for (ie 'extreme' ). I don't want to destroy the engine, hence wanting to research as much as possible.