Alright so ive got a 2001 c5 corvette coupe, ls1 6 speed manual. Currently the car is mostly stock with cold air intake and bullet muffler axle back exhaust. Im looking for the most cost effective and reliable route to 400whp. I have lots of experience with cars and their mechanics in general but little experience with performance mods. Ive been looking into possibly camming it and im open to possible intake or exhaust mods as well as a professional tuning, id like to keep my stock heads. I race autocross on weekends so Im hoping to maintain good street driveability while meeting CA smog, and bumping up to the neighborhood of 400whp with a good torque curve for the track. thanks for any input!

 

Why are you stuck on the stock heads? Ported with matching cam and exhaust will get you near your goal. Stock heads can do it but are pushed. If you want to stay with stock STYLE heads, the Z06/243 heads are an improvement in stock form. Still doable though.

 

The cheapest way to do this is porting the heads you have and working on the exhaust and intake setup with a mild cam. 241 heads ported won't even break a sweat if they are ported properly. They have enough CFM to support over 550hp. You can get into a budget set of headers for around $250. Keep the cam on the small side and let the cylinder heads do the work and you will have a very reliable combo that will make torque everywhere and your 400 to the tire goal.

 

You can make 400rwhp with the stock heads but the cam will likely be too big to be worthwhile autocrossing or smog wise.

 

https://ls1tech.com/forums/generatio...s-results.html

Smog legal thread. Change gears, lighter parts in engine tranny, you can be very much quicker.

 

 

I doubt you'll want to be swapping your exhaust every 2yrs so here's what I'd recommend:. For your heads send them off to AI and have them fully cnc ported and milled down to a 61- 62cc chamber size. Having you stock heads cnc port and milled for a higher SCR will allow you run a little less I/E split with the improved flow, and make noticeably more power, all while passing the visual aspect of a smog check.
FYI, I would factor in, (regardless of the actual cam spec you go with) keeping the overlap in the -6* to -8* range so you can pass smog, and sticking with a 8* to 12* I/E duration split to help offset the more restrictive exhaust. I'd also try to run minimal(+2) to no advance(+0, preferred) and keep the IVC in the 41* to 42* range.

Here's what I d try to run or very close to it: 217/225 114lsa+0, IVC is 42.5*, overlap is -7* . I can't guarantee you hit 400rwhp, but you shouldn't be far off if you don't.

 

FYI, the GM Hot Cam has to much overlap to pass smog in CA.; it's not a option.

 

This guy installed stock c6zr1 headers and h-pipe that should help
http://forums.corvetteforum.com/c5-g...sion-pics.html

 

Just port the heads and get a decent cam with headers. Paid $600 to get my 241s ported and with my 228r I ended up making 445whp

 

Procharger. Dont have to worry about smog cams and will drive like stock until you get into boost.

 

Who did the porting? Local to your or? I have the same goals

 

That would be a great choice, but he needs it to pass smog. He needs a cam with at least -4* or greater overlap, and it needs to be a traditional split pattern cam to offset the more restrictive exhaust used to pass smog.

 

He's looking for a cost effective way to get there. The Procharger would be a very effective way to get there, but not COST effective unless he was shooting for +450 rwhp.