jcarp

Ok guys, I've searched the archives and read opinions until my eyes hurt, but I'm still not sure what would be the proper cam for my application.

It's a stock 00 LS1 bottom end, 243 LS2 heads with 918 springs, ti retainers,7.40 hardened rods, a LS6 intake with custom long tube headers. This is a track car only, budget road racing. M6 with custom 5 & 6 gearing (.83 & .70).
3.73 rear end gears.

It's not going to see under 2500 rpm while on the track and it's a 2500 lb car so I'm not looking for huge low end torque.

It sounds like I can't really go wrong with a 224/224, but what lift? Or would something else better suit my application without porting the heads?

Too many choices...

just-a-z

iTrader: (25)

change the spring to dual 921's and look into the MS3 from Texas Speed and the T-Rex from Thunder racing. Those seem to be the best peak HP cams on stock heads.

vodas00ss

iTrader: (14)

track only car, i would change the springs and go with a bigger cam, maybe even invest in some heads.

Rebelord

iTrader: (2)

if your looking for peaky cams, look at those said above. Try to get close to a 114lsa so that most of your power band is higher in the rpm if your gonna constantly spinning that high, and upgrade your rod bolts. DEFINATLY change your springs.

Ski

SouthFL.02.SS

For roadracing, you want to stay away from aggressive ramp rate cams if you don't have the valvetrain to back it up. Aggressive ramp rates provide us with driveability and tq down low/mid. Great for street/strip, bad for roadracing (because of the added wear on the valvetrain). "Softer" lobes tend to come on hard in the mid/upper rev range. Lift is not so much of a crucial factor, as springs are designed with lift parameters in mind.
If it's a track only car, and you have 918's already :

Futral F6 226/230 .575/.595 112 (Semi aggressive lobes)
I spoke with Futral yesterday and they confirmed this would be a nice grind for RR.

Lunati has a couple RR grinds.
Lunati 230/237 .544/.543 112 (although it does have an aggresive ramp on the exhaust).

If you don't care about low end,
Lunati 237/242 .595/.595 112 (ramps not so aggressive) check piston to valve clearance on this one.

GMPP ASA 226/236 .525/.525 110 (Would work great with Vinci/Crane 1.8RR's)

SouthFL.02.SS

For street/strip, sure!

gomer

iTrader: (13)

I would use a comp xtreme RPM high lift lobe combo. 234/236 .576/.578 110lsa 108icl.

That uses a slower lobe that will live a long time with your 918's, give you great power from 2800-6300rpm, and like you said.. it's in a 2500lb car.

SouthFL.02.SS

You might have just specified my next cam Gomer.

gomer

iTrader: (13)

LOL.. you had better call it a "Gomer Grind"

SouthFL.02.SS

I'll call it the Gomer Road Racing Grind

gomer

iTrader: (13)

I just did a 382 for a road race guy here locally. I used those same Xtreme RPM lobes, but a 240/242 .588/.592 110lsa 110icl. It is in a Porsche 914 Hybrid that only weighs 2500 or so. Setup has Eagle crank, Eagle rods, Mahle pistons, PRC stage 2.5R heads, that cam, dry sump, etc.. can't wait until the chassis guy gets finished with it so we can tune/dyno it Btw, it will be running open headers and a speed density tune.

SouthFL.02.SS

That thing sounds sick.
By the way, just to be clear, you're talking about plain ol' XE lobes, right?

gomer

iTrader: (13)

Yes, comp calls them "Extreme RPM". But, most people refer to them as XE.