There are plenty of stock block cars pushing way over 500 horsepower, its all in the tune as Steve said, keep a safe A/F ratio and keep it dialed in, get a a standalone to further watch whats going on with everything. And dont O ring your heads, go with some cometics for your bore, and some ARP headstuds, you can easily push 600 on a stock block, I can think of at least 8 guys I knwo who are doing this.

 

I have a 6 psi kit w/42# injectors.....definiety ditch the FMU.

John

 

Out of curiosity, why do away with the FMU?

 

That's pretty close to the setup my last car had. It made 444.4 hp on my highest "safe" tune but I dialed it back to 417 hp. At that tune, it ran 11.07 at 126 and change in the 1/4. My best advice would be to dump the FMU and the 38's and get some 42# injectors, 50# if you would like a little headroom. Get a good dyno tune and a chip and you should be golden.

 

Did you have any problem with the 42's dumping too much fuel when you were starting the car? The last setup I had the injectors were a little too big and to start the car sometimes you had to hold the pedal to the floor until it cranked, it was dumping too much fuel at times.

 

nah, 42#s with the proper MAF and tune it will purr like a kitten at idle...
for the record, I'm on the ditch the FMU bandwagon

 

go 10 psi....a guy i knew ran 14 (525rwhp) (he had a 93 cobra, with AFR 165's custom grind cam, 14 psi procharger, ect) and one tank of bad gas killed psiton #8 but of course those cobras did have hyperuetectic pistons.....still, i would rather be on the safe side....my dad has an 03 cobra with about 475rwhp and its way to much for the street to handle....you dont need the extra power, stay safe. 400rwhp will be plenty of fun, and you wont end up in a ditch if you let it all out at one time (almost got put in one this weekend.....when that boost comes on, its game on...about 100HP hits the ground at one time and if you got the pedal burried your tires will definatley break traction) first gear in the cobra is sweet but second is insane....as soon as that boost kicks in it becomes a different car....usually end up taking up 2 lanes .

good luck with your build, keep us updated

 

There is a lag when using a FMU between vac and boost. If you are cruising in first and romp the throttle, there is a delay, then you get boost. I didn't care too much for it, so I went with 42#'s and ditched the FMU. I sometimes have hard starting problems like you described, but it is only when the car is runing, then I shut it off and try to start it again. But, while the car is running the power is smooth, not spikey.

John

John

 

I'd do the run 42# inj and a decent sized maf, and get a great tune, its all in the tune