I want to turbo my 97 esi, but i got to thinking and was wondering if using high compression pistons with a turbo would be a good idea. Would the pistons help out my torque any? I know that i wouldn't be able to run as much boost, but would the HC pistons make up for all that? I live in a small Missouri town and most people around here drive huge trucks or a few with old muscle cars. I want to show everybody what a little dsm power can do! Don't get me wrong, I'm a mopar man, but i'm gonna prove my little car. Well i guess my real question is what are the pro's and con's of using HC pistons with a turbocharger compared to lower comp. pistons with turbo? Either way I want to get forged internals for durability and power.


97 Eagle Talon Esi, mostly stock... For Now...

generally when turboing an engine you want lower compression, not higher.

Ok, I understand that, and from what i've picked up that's because you can cram more air into the cylinder that way, but what i'm asking is if you were to go with a higher compression would there be any advantages?

97 Eagle Talon Esi, mostly stock... For now...

yes HC will result in more hp (low comp at 8psi versus hi comp at 8 psi) but is harder to tune, especially if your a tuner w/o the budget of a racing sponsers. search this topic in the site and you'll see.
-------jezreel

You really should use the search for this question. This issue has been discussed quite a few times.

The short story is that - yes you can run high compression and a turbo, however you run into tuning issues earlier than you would with a low compression setup. For instance - on pump gas you'll only be able to hit a certain amount of boost before detonation...but thats true with low comp as well, just that this limit comes at a higher boost level. Same with using race gas - with high comp you'll only be able to take the boost so high before timing becomes an issue....same with low comp, but this limit comes at a higher boost level. Heat is the enemy and high comp makes more than low comp. Pressure makes power and high comp makes more than low comp.

The popular answer is go with low compression cause you can boost more before requiring higher octane and an ignition system. A high comp motor will make as much power at a lower boost level as a low comp motor, and at the same boost level it will be more powerfull than a low comp motor.


95 Eclipse RS : 5 speed
15.901 @ 88.34mph
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

Behold! MetalJim hath spoken and it was good.

The simple truth is you CAN run a turbo on a high compression motor, but the more compression you run, the more difficult and CRITICAL proper tuning will be.

If you want to do both, you should do the following: use the search function and read up on the higher compression issues as well as turbo issues. Then decide which way you want to go first. You will find few people on here that would suggest you jump right in and do both at once. The learning curve when you drastically change the dynamics of the engine is sharp enough just goin turbo on stock internals. You don't want to tackle the compression issue until you have lots of tuning experience under your belt, imo.

Yeah and if you happen to see how incredibly untuned and poor running some of these cars are, you won't want to take any chances :)


Jon

1997 Eclipse RS

13.887@104.648 5/30/03

Ok, thanks guys, you answered my questions, now if i do go with a lower compression what would be a good ratio to use? And also where is a good place to find forged rods and pistons for our cars? Thanks again, man i love this place...

High compression + turbo = Booooooooooooooom

lol^^^yea thanks for summing it up:thumbsup

well its more like

high comp + turbo + idiot = boom

high comp+ turbo+ exp. tunner = nice vrooom:thumbsup

send me an email i can get you a bottom end kit in any form
8.5:1 8.8:1 or custom if you like...

also have high comp piston kits...

Bill

how much are you selling a bottom end kit with 8:5:1 compression for?