Is anyone out there running the Hahn Race Craft Stage 2 Turbo Kit who destroked their Ecotec motor? De-stroked to 86mm, to square off the Stroke and Bore. Basically turn the L61 into the LSJ.

I am asking because i want to know if the fuel control unit provided by HRC would still be ok, or would things have to be recalibrated to compensate.

Would there be any other problems anyone can see in doing this?

I have already sent an email to the people at HRC asking these same question, but just want to see if anyone out there has done this.

If your compression is the same it should be fine, but its all together I don't really see any advantage to destroking your eco.


-Chris

the advantage is to rev the the @!#$ out of it


and theres alot more to an LSJ than just a destroked L61

understood on the "there's more to an LSJ than a destroked L61". What i ment was getting the bore and stroke the same as an LSJ. I need to proofread my posts better.

The reason i am wanting to destroke is not only so i can rev it like mad, but i want to have the lower compression to help avoid detonation.

So really my question is, if i drop my compression by going with the shorter rods and leaving the upgraded pistons the same size as stock, would my engine still run well, or better, than if i had the stock stroke and compression with upgraded rods and pistons. Would the fuel delivery adjustment from the fuel management unit provided in the kit still be adequate? Or would it need further adjustment?

I plan on using HP tuners in the future, but i just want to know this stuff to see if i can drive around for a while before i get HP tuners.

its cheaper to drop your compression simply by installing forged pistons with more dish. And with no way to alter ignition timing, destroking probably isn't the greatest idea. You're changing the piston speed and also the amount of time the piston "dwells" at top dead center and as such, should be adjusting the ignition timing to compensate. It may run, and seem to run well without doing this, but undoubtedly, the higher the power you made the more driveability issues you'd begin to encounter under WOT conditions, and possible even part throttle. Not to mention that without timing mapped properly to your setup, you will never achieve the best performance from any motor. So in short, no, the FMU would probably not be enough.




Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said

Thanks a lot Scarab. After talking with Adam Hahn, i think i'm just going to upgrade the engine internals with "stock size" performance stuff for now. However, i now have another question. What advantages would i get from using lower compression pistons with the turbo kit?

lower combustion chamber temps?

Lower static compression allows you to run more boost on the same octane without encountering detonation. It really depends on what power level you want to go to, as the gm racecars use 9.5:1 compression with some godawful boost pressures but they also run very high octane racing fuel. I'm a little fuzzy on the exact conversions, but since boost pressure makes the true compression ratio of the engine higher, when you start with lower static compression you can run more boost which typically its more efficient to make power with boost than static compression. If Sweetness is still around I know he has a better understanding of that than I do, he can probably explain it better too.




Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said

Scarab (Jersey Jay 1.8T) wrote:Lower static compression allows you to run more boost on the same octane without encountering detonation. It really depends on what power level you want to go to, as the gm racecars use 9.5:1 compression with some godawful boost pressures but they also run very high octane racing fuel. I'm a little fuzzy on the exact conversions, but since boost pressure makes the true compression ratio of the engine higher, when you start with lower static compression you can run more boost which typically its more efficient to make power with boost than static compression. If Sweetness is still around I know he has a better understanding of that than I do, he can probably explain it better too.

actually the GM drag cars were using 14-1 compression or around there , and 40-50psi

granted that is the 1300hp+ motors , race fuel and iced liquid to air intercoolers



stick with the 2.2 , unless your going to go full stand alone computer system , the 2.0 is better spinning to 10,000 , and the stock pcm is some what limited to fuel and spark maping , even the the 2.2 will go beyond the stock pcm with a custom tune , if built properly





Edited 1 time(s). Last edited Monday, April 09, 2007 10:36 AM