I just traded my 02 GT on an 03 Cobra with the following upgrades. CAI, larger throttle body, ported intake, intercooler upgrade, long tube headers, bassani off road x, and cat back, short throw shifter, Diablo ECU upgrade and Razors edge 14 psi pulley on stock eaton blower. The dyno sheets show 500 rwhp and 580 ft pds torque. What size pulley is this, and what was stock, 8 PSI? I plan to race the car on Friday nites with drag radials but understand my axles need an upgrade, what do you suggest?Will the IRS hold up with drs or MT et streets? Anyone guess 60 foots, 1/4 mile and trap speed? Right now the car blows the stock goodyear tires off in 3rd gear at 55mph.

 

I would not run slicks unless you have aftermarket half-shafts. You would be ok with DR's. Ditch those F1's if you still have them. But you'll snap those half-shafts with slicks at the track. Razors Edge pulley? Never heard of that...size is probably 2.80 or 2.76. Yes, stock psi is 8lbs. You sure the blower isn't ported also? 560 pounds of torque on only 14lbs of boost sounds fishy to me. But I guess it's possible.

 

On the dyno sheets it shows over 560 torque from like 3k to 4k, hit 502 rwhp @ 6k till 6,800k. You think bfgs will be OK? Is it tragic to snap the shafts I have seen it happen mostly at launch and car goes nowhere but if it can happen half track I dont want to do a 90 degree turn and roll. I saw drive shaft shop has level 5 axles that hold 900rwhp on the IRS but they are $1599, what do you think, I want to mash this WOT without worrying about the axles or getting killed?

 

BFG's would be perfect. (Along with Nitto 555r's)

You snap a half-shaft, and you'll be getting towed home.

 

And have no sympathy from the dealership if you do!

Anyone know how difficult it would be to change these out with the $1600 ones?

 

Its not hard at all to change them, my buddies were done in 1/2 hour but they knew what they where doing.

 

Im running about 520 hp to the wheels right now and I just gave in and put a straight axle in with 4.30s . I was running nitto 555r's and I was snapping axles left and right ,word of advice get rid of the irs as fast as u can . If u take it to the track I wouldn't dump it past 2500rpms or there is a really good chance u will break cv
have fun with the cobra

 

Turns out my car has ported blower, dual focus fuel pumps, ken Bell boost a spark, lower pully, and heat exchanger fans as well, I talked to the shop that did it, and my dyno sheet is posted under my screen name on modulardepot.com 03 Cobra tech titled what will I run. RJM03 cobra click on the little time slip to view.

 

you can run slicks on the stock irs, all you have to be careful of is wheel hop, if that doesnt happen then your fine