Evo 9 pistons without Tune

[gieri002]

Well I am rebuilding my car right now and I am curious whether I would be able to drive my car ~200 miles with new evo 9 pistons and rods without a tune? The reason I ask is because of the difference in compression ratios.

 

[Honto]

Yes you can drive it just don't go WOT.

 

[1457gvr4]

Ya, you need more fuel dialed in and timing adjusted at WOT.

 

[Redwidow]

Are you running stock injectors/maf? The compression ratio isn't that much difference. 8.5 on a 2g and 8.8 on evolution 9s. And that's not even completely accurate because of the difference in combustion chamber sizes between the two heads. If you are running a stock setup for stock boost on break in you will be fine. If you are running different sized injectors, etc. You need to set a base tune atleast.