Hey guys,

I believe I'm lacking some compression to get the most out of my setup. Car is listed in sig. Its a stock ls1 block, stock crank, callies rods, these diamond pistons, http://www.cnc-motorsports.com/diamo...-905-bore.html , AFR 230 heads with a 72cc chamber, .40 cometic head gaskets, and a Fast 102 setup. I'm running the EPP blower cam, F1-a procharger, lonnies dual 340 pumps I.D. 1000 injectors. Its currently burning E85. The car dissapointly only made 735 rwhp and 690 rwt. I'm wondering if I should have the heads milled to get more compression to get the most of the E85 or still mill and switch to premium. Any input and help would be much appreciated.

Kyle

 

Buddy has similar compression with a D1 and made a number lower than what he wanted as well.. Bob said it was the compression. He is switching heads up/having them milled to get closer to 9.5:1 or so.

IIRC he was around 8.8.

370 AFR heads D1 EPP blower cam 1 3/4 headers 4l80 3400 converter 9" 410s 28" radial 65XRwhp

 

i know you said you had AFR heads, but wouldnt you want to keep the head thickness as thick as possible?

 

Yes.. Trading for a lower CC head would be a much better idea.

 

I would look for a set of AFR's with 64cc chambers. Milling the ones you have to gain more compression isn't a great idea. You would be losing the advantage of having the thick deck on them.....I wouldn't mill unless they warp or need a clean up. Just my opinion.

 

Ok would it be worth it to have them welded instead?

 

How much boost?

 

18-20lbs

 

do you know anyone you trust to weld up the chambers and make all 8 the exact same?

 

like we have said, it would be better if you got different heads or another option, change out pistons. dont know how serious ($$$) your wanting to go with this but that is another ($$$) option

 

Well I think the head swap is the easiest option because the heads are off the car now. I have thought about a different short block but I just got this one built with only 750 miles on it.

 

i'm sure enough vultures, i mean members, here in the FI section would jump on them if they are still in the building stage.

 

Selling the heads you have to buy smaller chambered ones will be the best option. It shouldn't cost you much if anything to do it. Any other option will cost you more to raise compression.

I agree your HP numbers look low with that amount of boost. Maybe a different cam would help you out a bit too?

 

In my old 347 I ran those pistons with a 64 cc head.


Hell when I was running the a D1 with stock 241 heads and those piston I made 676rwhp on 93+Meth through a t56 with around 13 psi

 

OK I think I'll try to trade/sell mine for some smaller chambers. Anyone else have any thoughts on the cam keeping numbers down ?

 

Or just throw more boost at it....

 

Your torque and hp numbers are too close. I think you have something else going on.

 

i was thinking they were close for a procharger setup as well

 

I see this alot and it makes no sense to me. Increasing the boost 1-2 psi will give you more power than a full point of compression. Also for each point of compression dropped, you can usually run much more than 2psi of additional boost. IMO, Unless your out of charger, Leave it alone and add more boost.

Also dyno numbers vary so much I don't see the point in comparing your setup to anyone elses unless it was dynoed on the same day on the same dyno. Have you ran it at the track?

 

18-20 psi with a well flowing stock cube LS1 should net more power than that especially on E85 regardless of a low static compression ratio. Besides just looking at your pistons, gaskets, and combustion chamber size it looks like it should be around 9:1 which isn't super low. Obviously going with higher static compression you can make a bit more power since you are running E85 but it still doesn't explain your low numbers now.

**edit**

Just thought of something else, what kind of dyno? Many user configurable dynos will read quite different compared to a dynojet.