I have an 87 iroc, it's a 305 with ported aluminum L98 heads, LT4 cam, roller rockers, edelbrock base, ported intake, coated edelbrock headers, borla catback, and a lot of other mods. I just raced my brothers 2000 z28 and the race was pretty even up to 70(about six seconds). At the beginning I pull ahead by a nose at about 30, then he catches up and we are dead even at 65, but then he just starts pulling more and more. By 80 he has a whole carlength on me.

What is it going to take to increase my topend performance enough to take him? More cubes? I was already planning on putting a larger block in this summer.. I know my mods will work pretty well on a larger engine, except the headers and the tpi are probably hurting me. Any advice on how to win?

 

From what I know about the LS1.

I can tell you they pull hard 1/8th mile and up... as was shown to you.

They are ranked at 305 hp, but many times pull closes to 305-310 to the rear. (340 or so to crank)

Autos usually have 104-106 trap speeds while M6s have 106-109 trap speeds.

I'm not quite sure how your going to beat him, I'm surprised you did as well as you did. What does your car run in the 1/4?

If I had to pick something, I'd say your right... larger cubes help, and getting rid of the TPI setup and maybe miniram or superram?

Nitrous never hurts either?

 

Going to the track for the first time on the 12th, so I have no real times atm. I hope to have a new torque converter installed by then...and unless I can find a helmet I'll only get one run in. I had thought about the nos.. but I'd rather stay away from it. Would be nice to surprise some people though. Thanks for the input.

 

Your gonna need at least 350 if u want to run against them N/A. For the 305 theres always S/C's and T/C's though.

 

Ditch the 305. You'll never keep up NA. You can keep up if you use a power adder...to a stock LS1 anyway. The problem is some of them do mods too I've heard...but that might just be a vicious rumor

Plan on at least a 350 (but the more the merrier), with a minimnum 190cc head and healthy cam. And ditch the long runner setup.

 

This LS1 has a whisper lid, borla catback, and tb coolant bypass.. I put it all on myself

I will ditch the LTR setup.. how many cc's are these aluminum L98 heads stock?

 

150ish I believe..maybe 16x. I have the numbers somewhere but I don't feel like digging them up. For comparison..LS1 heads are over 200cc stock.

 

If they are 150-60ish stock, how large could you make them with a lot of porting? They had an 800 dollar port job a while ago, I picked them up afterwards. They seem to flow pretty well atop my bore-deficient block.