UnsafeAtAnySpd

Yes, I know, yet ANOTHER cam question. I promise I have been doing a lot of searching and reading up on the subject. My application/goals are a little different from what I've been able to find thus far though. Also, I do plan to talk to some shops/tuners before I make my final decision, but would like some suggestions for a starting point.

Anyway, I'm 'building' my '04 CTS-V to comply with NASA's Time Trials format. I would like to compete in TTB as the car starts in TTC** to begin with. Basically, the classing is a points based system whereas every mod is assessed points and every twenty points moves you up a class. That said, I think I've solidified my plan for points incurring mods which includes a cam (a costly 6 point mod btw).

There is also a minimum adjusted weight/power ratio for each class, which at my target weight allows me to make up to 440 rwhp.

Clearly, the intended application is road course duty. I will also drive the car a fair amount on the street, but am willing to sacrifice some drivability/street manors in favor of track performance. Other related mods will be intake, Kooks headers/cat delete/electric cutouts/Corsa catback, and LW clutch/flywheel on an otherwise stock LS6/T56 combo. I can't go with heads (another 6 point mod) or much else engine-wise for now. Suggestions on a cam? Thoughts on potential power? Thanks and apologies again for another cam question...

The_Rizzle

iTrader: (4)

Does tuning cost any points? What about rod bolts? If you can't go with heads, can you still work over the current ones?

When racing, whats the highest/lowest rpm you want to go?

UnsafeAtAnySpd

My understanding of the rules is that tuning is a 'free' mod, or at least would be for my application:

instead of

Modififying the stock heads is a 6 point modification. Aftermarket ones would require a dyno reclassing.

On the track I should be between 3500 (if not higher) and redline most of the time (especially once I replace my dying clutch and can actually shift as much as I want ).

The_Rizzle

iTrader: (4)

well for starters I'd say put rods bolts in it so you can raise the redline to go with the new cam/intake/headers. It should stay together with a redline around 6800. I'd say higher, but road racing is harder on engines that drag racing, so what some guys get away with there doesn't apply too well. I'm guessing a lot of the c5 z06 guys would know what rpm they hold up to for track duty.

For a cam size, look for something in the low/mid 230's range, and a tightish lobe center to get more midrange out of it without having to rev too high. I'm thinking something lie a 234/234 on a 110.

Can you deck the heads and get a nice valve job without incuring any points penalty? Bumping up the compression really helps race engines out.

Take a look at the PAC 1518 beehives, they are one of the best out there.

If theres room for a good full exhaust, I don't see the need for a cutout with a high flowing muffler. It also lets you run a X or H system, which can help pick up power in bottom and top.

MikeZ06402

I was the NASA TT Director for Texas (06-08) and I run a C5 Z06 so I might be able to give you some decent guidance.

Get yourself an Accusump system and an oil catch can, the LS6 architecture has been known to suffer from oil starvation during high g cornering. Besides it is a free mod and could save your engine. The catch can comes in handy to see if you are getting excessive oil in the top of the motor. Unless you want to do a replacement engine; something lke a 427 CID and run TTS or TTU

I ran with a stock cam in my LS6 and managed to win TTS. I was classed there because of slicks and headers with x-pipe. The Z06's aren't given much latitude as they are great performers out of the box. ANYWHO a cam may not be the answer. I opted for the stickier tires (Hoosier VRL's 305's) and suspension tweaks and found that gave me the advantage I needed.

With that being said I realize we are comparing aples and oranges as the CTS-V suffers a weight penalty compared to the Z06 but don't underestimate the ability to hold the rubber on the track.

How many years have you been roadracing? I ask because I found doing alot of engine work made my vette a hand full to get around the course until I figured out its new behaviors.

But if you are dead set on a cam, then strengthen the entire motor as a unit. (Connector and bolts are a free mod) I have all forged internals with Katech billet mains, all internal bolts have been replaced with ARP bolts and studs, the radiator was swapped out for a Ron Davis with integrated oil cooler and stainless braided lines for the connection to the oil cooler. I also run external coolers for the transmisson and differential with stainless braided lines on those as well.

PM me your number if you want to talk more. I easily have $30K invested in my roadrace toy So I might be able to help you avoid some pitfalls.

jasonk

iTrader: (29)

On a V, this is pointless, none of the aftermarket systems outflow the stock exhaust enough to justify the $1000+, just hacking the stock mufflers off will do just as well for you.

ls1 1990 VN

If your going cam for road racing, look for torque, forget Dyno HP numbers, i change at 6-6300rpm.
Once you are happy with your engine your next performance mod is 'Suspension' Suspension' 'suspension' you will gain heaps with a proper Bilstein setup that allows your car to work properly, If it's your street car as well like mine, look at only running 3deg neg camber on your front wheels, it will get you around the corners a lot better.
You should still be able to use a good DOT rated semi slick which we use down here, they are street legal, run cold at 28psi, heated they should reach 34psi odd, if you are able to do these mods your car will surprise you.
As above, an accusump is a must, mine is solenoid controlled for off on.

Do invest in a power steer cooler.

The_Rizzle

iTrader: (4)

Well, I never said go buy an aftermarket exhaust. You're right though, the factory exhaust seems quite good. Just throw a nice set of mufflers on the back and you should be good there.

As for aiming for torque, thats the point of making hp. The same tq number shifted up 500 rpm makes way more hp. The trick is matching the rpm range to the driving you're doing.