DSKREET

A little backround.
06 z06 A&A kit with V2 S trim
stock bottom , ARH, Ron Davis Rad, RPS clutch
Dyno'd in 2007 by first owner at 570rhp/471tq. very Conservative tune
I have my heads off to re-work. My goal I would like to get 650WHP or more, This car is a primary hwy play car, It will do maybe 3 HPDE a year. I like to drive this car alot in the summer.

My Questions,
- Can I get 650whp or more safely with a Cam, re-worked heads and no meth?
- What cam would you recommend ?

Any additional info would be greatly appreciated
Thanks

old motorhead

Your stock cam is actually a pretty good "mild" blower cam. I'd use it before the LS9 cam that the masses are so enamored with. Only difference between the two is the slightly narrower LSA on the LS7 cam...which I think is good as long as you have good fuel.

I'd optimize the rest of the powertrain (good intake and exhaust) and add as much boost as needed to hit my numbers. If you don't have access to good/consistent 93 octane, meth would be a plus.

slow02gt

i would actually add the cam instead. Less boost to get more power is always better than more boost to get more power.. i would throw a cam am in you will lose some boost but make good power(can even pulley it up to keep the same boost).

slow02gt

i wouldnt worry about working the heads besides doing the guide and valve issue.

Chance42

I have a LS7 blower cam for sell actually. It's a ragin' racing v1 blower cam. 224/248 117+4 LSA .625 lift. It was VERY streetable, with a good tune I had no surge, gas mileage was great, and I made 760 rwhp on 93 pump at 8.5 psi on a 2.9 Whipple. My timing was slightly aggressive on that tune at 19 degrees. On the conservative tune it made 704 rwhp with I think 16 degrees of timing.

lilredvette05

Yeah 650 shouldnt be a problem with a decent cam. I actually have a cam in my car now thats a 237 252 117+4 that made 657 with no meth and drove pretty decent, I'm going to switch to a different cam to see how better it would be since I'm kinda picky. I'm gonna sell the one I have now that's only got 600 miles on it

SpinMonster

The later intake valve closing point kills mid band TQ.

SpinMonster

Bone stock LS3s make 650 on a centri.

LG made 630rwhp N/A with Lou's LS7.

I just don't get the point of such a huge cam with boost.

SpinMonster

Meth in your case would make more gains than a cam. You will be over 700. A bigger head unit will outperform worked heads. In both cases, you will be at the same cost.

DSKREET

Thank you all for this info. My way of thinking right now is, "I have the heads off, why not just put in a cam while there off. "
Just trying to do my research on blower cams. This is my first GM. I've owned A mopar for the last 7 years

DSKREET

Any input on the LS9 cam ??

Unreal

I made 705rwhp, no meth, 91 octane, with a 228/234 cam. Something in the 230/240 range would be great. My current cam is a 232/246 and it drives great.

SpinMonster

The LS9 and LS7 cams are identical except for the LSA. The LS9 has a wider LSA and its intended to lower cylinder pressure in the midband and high rpm for the use of boost early in the RPM band for the 2300 blower on the LS9's 6.2L but its exactly what you dont want for a centri blower. It closes the intake valve later so the engine can't start building pressure (or boost) as fast. Its a terrible choice for an LS7 and only lowers your mid and low TQ.

To gain power, you want bigger durations while holding overlap near zero. Big split cams have high overlap and hearing that car A made 700 on XYZ cam is a waste of research effort because an LS2 with the same blower and a 224/230 cam (ecs blower cam) will make the same 700rwhp.

427's can make over 600rwhp just from H/C alone so to make 700 on boost is pretty sad.

Porting LS7 heads for forced induction is also a waste of money. They aren't a restriction. In fact its a bad idea because you are making a bigger runner to fill which is already big for the application. For what they charge to port them, you could buy a set of Trick Flow 245's and sell the LS7 heads and make more across the board with better throttle response. Using a Trick flow 235 and a 236/242 cam I made 628/578rwtq on a 427 through an automatic just to illustrate what can be had with better parts.

A great cam that would let in a big shot of a/f to fill the huge LS7 runner would be a 224/234 on a 116+0. It peaks where it should and it isnt holding the exhaust valve open during overlap letting the boost blow into the exhaust. Its -3 overlap and will net about 70rwhp. Have it ground on XE lobes which are lazy and soft. Coupled with the 1.8 rockers, it will still be a long living lift under .600"

That same cam is about 550rwhp and 500rwtq on motor.

You want low overlap on boost but a decent sized intake duration to let in the mix. Overlap is even more a no-no on turbo cars. Since intake duration is really the most important aspect in that application as it determines the shot of a/f into the cylinder, big turbo cams are reverse split to maximize the shot of gas while limiting the exhaust duration to prevent bad things happening if the exhaust valve is hung at the same time as the intake valve (overlap). If the S/C is blowing in air, where does it go if it comes in the intake valve and the exhaust valve is open at the same time? Obviously it doesn't build as much boost. The idea of using 20 degree splits on FI is puzzling to me. The exact same big split cam would make better power by cutting the split down to less than 10 degrees to reduce overlap 5 degrees. The car would also retain boost pressure. Those same two cams that differ by 10 degrees reducing overlap would likely show a 2-3 lb boost increase without a pulley change. The best FI cam result I've has on the LS2 is a 230/230 115+1. It made 704rwhp on 11psi. It was zero overlap.

For the record the durations on the LS7 and LS9 cam are identical at 211/230. Changing from the LS7 to the LS9 will lose mid band power. Those cams both have really late intake valve closing points and are both worthless in a 427. They idle good though

Bonnetts02Vette

I have the BTR Stg III cam (231/248 .653.630 120+5 LSA, with 0 overlap) and I love it. The sound and drivability are amazing and you can definitely feel the power increase through the entire rpm band. But its a PD blower cam.

SpinMonster

Its -.5 degrees overlap so it has no boost blowing out the exhaust valve and it would drive fine. The issue is the really late intake valve closing point killing low end TQ. While it makes more power everywhere as you say, it doesn't tell you how you car would run with a 231/235 117+2 which would likely pick up 40rwtq at 4000rpm.

The problem with the LS7 is its rare for anyone to swap cams for a comparison so everyone simply reports how much more power they have over the stock cam. People would likely have a great review of any cam over stock.

The cam was correctly designed for cars running a pos displacement supercharger in how is lowers midband cylinder pressure. A great LS9 cam and Brian is pretty good with this stuff.

realcanuk

I like reading this cam stuff. I would love to try various specs to see the differences, but its just too much work to do the swaps.
I run a cam with -2 degrees overlap (226/246... 119+3) with the eforce. It seems to work great and I don't see any shortage of torque anywhere.
Like Spin said, I will never really know if I could do better, since I wont take the time to do swaps.

SpinMonster

Put in a 226/232 119+3 and it will make the exact same power. Adding to exhaust duration only extends the power out past where the cam peaks its HP. A 226 on a 119 will peak so far over the forced intake manifold peak that its a silly thing to bother trying to extend.

realcanuk

I don't doubt what you are saying, but I put what was spec'd for me and it seems to run well. Like I said, unless it was a total dog I just cant be bothered with all that work. It makes power all over, and drivability is perfect through an auto.

SpinMonster

This article sums it up pretty well. Skip down to the exhaust duration paragraph to see how ridiculous big splits are.

http://www.hotcamsinc.com/TunersTips...emID=48&page=1

From the article and many like it:

"Exhaust Duration has the same effect as intake duration, but the results are more dramatic. The ranges of duration numbers that provide optimal performance for the engine package are quite narrow. Short duration helps low RPM torque and allows the engine to accept full throttle at low RPM and “chug” along. The correct duration for your engine package will provide the best peak torque and a balanced torque curve. Long duration will reduce low RPM and peak torque. The only benefit to long duration is that it allows the engine to carry out further past the horsepower peak, (although not necessarily making any more power)."

These big splits with wide LSAs make no sense. Wide LSAs extend the power band higher and also reduce low end TQ because they delay the intake valve from closing. Compression can't build until the Int Valve closes so why in hell would you combine a wide LSA with a big split?

I use a 6 degree split on my LS7 cam.

Unreal

Big splits on ls7 heads are from the big difference between intake and exhaust flow. Wouldn't that have an effect on cam selection? If you have an intake port flowing 400+cfm and a blower pushing air in, and an exhaust port doing 275cfm, don't you need more duration of the exhaust open to get all the air out?