chrisbenoit

I have a 99 FRC. I am thinking very hard on going heads and cam in the near future. Like the title says i'm looking to get 400 RWHP, on an LS1. Is this possible on 243 heads, not CNC, just stock ones? If not what is the most they will produce? I have a LS6 intake, long tubes, CAI, etc. 400 HP is pretty mild compared to some on here but i'm on a budget and 400 is a number I think I will be pretty happy with.

Also, how big a cam would I have to go with?

Any insight good or bad is appreciated. Thanks.

Pete W

I've got a dyno from ECS from my car that says I have 400 rwhp. My car has their cam package with long tube headers, borla exhaust,and other typical bolt ons. With heads and Fast intake guys are making over 500! Hope this helps.

black98c5

It's possible but you'll need a decent size cam, something in the range of a 23x/23x.

chrisbenoit

How do you think this will affect my driveability? I don't race often, and I still need to be able to drive on the street. I don't mind a lopey idle, I actually would like that .

Y2Kvert4me

Some Z06 owners have hit 400rwhp with just bolt ons (stock heads and cam).

Although that's not exactly the norm, the point is you don't need a huge cam to pull it off.
If concerned about drivability, a nice little 224/228 or so should easily do it for you, and be very easily drivable with no bad manners.

printmanjackson

you can get there easly with 243 heads and a good mild cam. Look for a cam in the 225-230 duration with @ .600 lift and you will be fine.

here is an example

http://www.ls1tech.com/forums/dynamo...is-tuning.html

YeloFevr

Do '99 FRCs have 243s??

0Shawn @ Va Speed

400rwhp is fairly easy for a set of 243's.We have made 407rwhp with a bolt on 03Z06,been in the mid to high 420rwhp range with mild cam Z06's

black98c5

Drivability is all in the tune. As far as the lope goes, a cam on a 112 lsa will chop pretty good.

Y2Kvert4me

No, it would have come with 853 castings.

Quick 68

I made 443whp on bone stock heads and a healthy cam. 400whp is very possible

0331MARINE

413RWHP with 241's heads and a 237/242 cam. 243's would be easy

~Josh

400+rwhp is no problem, but getting torque #s to match isn't as easy.

Guys with mid-400hp and barely cracking 400tq is common.

printmanjackson

so you first say tq to match isn't easy but then you say its' common?

what does that mean?

the OP asked if 400 RWHP is possible with 243 heads

chev03SSR

i'm thinking ~joshua meant that making about 450 hp and BARELY ~400 tq is common...not that it's common to match hp/tq w/ 243 castings....rather it would be rare to see tq matching hp with the stock 243 castings and a cam. i have been wrong before though.

~Josh

^ correct.

AU N EGL

We are real close.

The Wrench

Chris, we just made 381 RWHP with stock lS1 heads and a baby torque cam 216/220. Just bolting on a set of 343 heads would probably net right at 400 with that combo. Want more HP and less low-end torque, use a bigger cam.

DG