Jenson

iTrader: (32)

Ive been researching a lot on the subject lately and I have yet to see someone put a large cam in an LS3. Im about to order this comp LSR grind:

dur - 243/259 lift - .624/.624 on 114 or maybe their 239/255 version.

The car is an 01 camaro, 4L80 (manualy shifted), 4.30's, 26" tire, ~3200 race weight. Im going to run a Victor Jr with 4bbl throttle body, ported/milled LS3 heads(11.5:1), 1-7/8 headers, and duals. My original goal was for the car to reach 10's (stock intake, stock heads, TSP 231 LS3 cam) but now I seem to be going crazy trying to reach mid 10's N/A. A comp rep actually suggested for me to run a 251/263 .624/.624 on 112?!? Yes this will be an all out drag car but would something smaller actually be better? I know I cant be the first to try and stuff a huge cam in an LS3?!? Thanks in advance for any insight

raymond mckinney

iTrader: (4)

Unless you have flycut your pistons theirs not enough ptc with a big cam on Ls3's.

Patrick G

iTrader: (14)

There are two reason why you don't see cams this big in LS3s.

1. They absolutely will not fit without big valve reliefs in your pistons (most people don't want the hassle of fly-cutting stock pistons).

2. The LS3 heads do not respond to excessive overlap. Running a cam this big with stock compression (even with valve reliefs) will be a turd.

bozzhawg

Look at maybe a 23X/23X and try to cut more weight off the car and you should be there are hella close..... make that 3200lb car 2800lbz..... But if your comp is 11.5, sounds like your heads are milled pretty aggressive so it will be hard for you not to have to flycut, period....

They have 4000lbz cars running 11's with 22X/22X cams....... If I were you and it is a drag car, I would concentrate more on taking weight off the car vs adding duration to the cam.... Its physics.... A 4000lb car thats running 11's should run faster ET's as you decrease the weight....Now lighten up the car 400-600lbs and you will see quicker ET's. in that 4000lb car....... 3400lb car now..... So you can use that info how you want when selecting your cam.....

Just use this as an example or theory(not written in stone): Take your car as it stands now: We'll use 500 rear wheel horsepower as the standard

3200LB will need around 490-500rwhp and a trap speed around 120-125mph to hit 10.5-11 range.....

now knock some weight off

2800LB will need around 490-500rwhp and trap speed around 128-135mph to hit 10-10.5 range.......
This is just a ballpark and range to give you something or a different angle to think about.

I find that alot of guys concentrate on cams or other stuff beside the complete package... When I look at ET's especially when a guy has a budget build, the car that has the best, not the most expensive combination will have the faster ET..... Combination, combination,combination..........

thedak

iTrader: (1)

Looks like a great selection...

Aussie 6L

In a 6L but 239/247 lsr 11.7 comp milled/ported heads fast lsxr 102 t/b 1 7/8 headers etc etc Flycut pistons 100thou(must do)

358rwkw's or 485hp on a conservitive dyno, and the thing drives nice but revs like a monster. Don't go such a large duration on the exhaust and a bigger lsa 114>115. Get a awesome tuner and you'll get a good result..

Go for it...........

Jenson

iTrader: (32)

Yes I know I have to flycut the pistons, thats a given. The motor is sitting on a stand right now and I do it for a living, so no worries. My focus will be getting weight out of the car as well, once its all put together though. Im on a budget. Tubular K member, lexan, yada yada yada, which is all more expensive than the cam. It will be gutted for now with a seat, steering wheel, and a dash pad. Im just guessing it will come in at 3000ish + gas + me = 3200.

Anyway back to the cam....so none of those. You say 230\230, but I was under the impression that the LS3 doesn't like a cam like that. I thought they like a big split from intake to exaust duration. The next one down on comp's list is a 235/251 .621/.624 on 113, also LSR lobes. Then a drastic jump down to 227/243 .614/.624 on 113. Then there is TSP's 231/236 .641/.615 on 112 and my top choice at the start of this build the Vengeance 239/251 .624/.624 on 113+3.

Aussie, how much did you have to mill off to get 11.7? Im thinking it will only take .015-.02" but maybe Im wrong. Great info on the flycut, saves me from doing all that math.

Patrick G

iTrader: (14)

With all due respect to Comp Cams, TSP has done more R&D on camshaft selection for GenIV engines. I would trust their recommendations more. The huge splits (12-16 degrees) are not necessary. The fastest L92 racers in OZ run splits in the 4-8 degree range.

Aussie 6L

They were milled 40 thou but came up with a 60cc chamber more like a 60>70 thou cut??? never measured the cc before milling/porting. Remeber my info is re a 6L motor not 6.2. Listen to Pat G even get him to recommed a cam, i went with a 8deg split due to intake ports flowing 375cfm got to get rid of the gases.

A popular cam in Aust is a 233/233 would you believe.

njc.corp

Who might that be pat ?

Jenson

iTrader: (32)

That sux cuz I get comp dealer prices, hence the comp selection. Guess I need to port the heads and intake first, then get with TSP/PatG for a custom grind. But from the sounds of what you are saying the TSP 231/236 is the best off the shelf grind. Im going to slap it on the engine dyno before it goes in the car so I'll easily be able to change the cam if it doesnt do what I want it to do. Im also now thinking about doing a sheet metal intake.

bozzhawg

Comp has some grinds that have been proven to work.... You can pay someone to spec one for you or you can download the comp lobes catalog, do as much research as possible, study the lobe characteristic, call comp and ask about the ramp rates, and then come up with an idea of how you want that cam behave...... look at the number at duration @0.200 as well. If you are sold on comp lobes......

Its a touchy subject, I don't think any spec'r on here is going to flat out tell you that this off the shelf grind is better than the other..... If you got more money than time, hell get a couple of custom grinds and drop the mofoz in... But even then.... I stopped doing engine dynos due to the fact, I have seen too many 600HP+ engines not produce the same results on a chasis dyno and sometimes ET's.... There are too many varibles one the motor is in the car unless you got money to blow...... And your dyno is only as scrupulous as your dyno tuner..... I use dynos for tunning purposes only, and if I get a sexy HP number cool, but make sure you don't chase dynos and horsepower, because it is an expensive habit......

just my $2.00 and inflation is killing the dollar....Ha Ha

Jenson

iTrader: (32)

Thanks for all the wonderful insight

Here is an interesting read I just found too:
http://forums.corvetteforum.com/c6-t...-sourcing.html

I guess these LS3's are such mystical creatures no one has done what Im doing yet.

Rob2

I run a mid 230s in mid 270s ex @050 and right at 600 lift in a 6.0 and have no problems

Sales2@Texas-speed

iTrader: (5)

I'd agree on both of those points. We've done the engine and chassis dyno testing on this and I firmly believe that the "cam experts" out there and on the forums, are off on their recommendations when they throw so much split and overlap at their cams!

Jenson

iTrader: (32)

This post was so long ago, it seems people like Pat, Bozz, WKMCD, and others have either proven or convinced others the little cams work on these heads. I know Im a believer now. I couldnt drive my auto V6 any longer so that project took priority over this one but now Im back on it. I got a lot of help from Pat on the cam choice, but I changed intakes on him so I'll use something a little different than he spec'd. I plan on staying in that 8 degree split range.

r572cobra

gm high tech magasine did a 408,l92 heads 11.to one,they used a 251/267 dur.624 lift comp cam motor made 630hp.

Sales2@Texas-speed

iTrader: (5)

5 months, lol!

IDRIVEAG8GT

I think I got fantastic results with my little cam. 601/588, but the air temp was only 50 degrees so about 580ish is what I'm saying I have on the street with 10Lbs of boost. My cam is a 221/226, .567, .564, on a 114LSA, and -4 overlap. This cam works great N/A or boosted, functions with a 2100 converter or higher and operates from 2000-6400. If you wanna get really rowdy Pat will spec you out a MF for the L92 heads. E.P.S will most likely grind it and Geoff is a really really nice guy that will work with you. I never liked off the shelve Comp grinds. I always ran Lunati, Cam Motion or Iskendarian before I found out about Pat. So there are some better choices in my opinion. Specially for a race car.

Jenson

iTrader: (32)

It feels like a year ago with all I've done since then.

r572, thats a huge cam to only make 630fwhp. You gotta figure behind the 6L80 that this setup is making close to 600 at the flywheel.
https://ls1tech.com/forums/gen-5-cam...n-4-000-a.html
It's also a 376, 10 times easier to tune and drive, and Im sure makes a ton more under the curve. And if you compare that graph to graph 2 on that 408, they are not very far off.

http://www.gmhightechperformance.com.../photo_11.html
It sucks that GMHTP's graphs all start at 3500, but at 3500 the two power levels are very close.


Also that 630hp is with a Vic jr vs a LS3 on the TSP LS3 setup above. This graph 2 is a better comparison and probably has about the same peak power with a 231/236. I think the car will be more fun with a little less power up top, and be able to drive it no problem at all anytime I want. Ive never owned an auto car either, so I have no real experience with cam buck and all that Ive read about with big cams+auto's. Right now Im leaning towards a 235/243 114 LSA and 110 ICL