SouthFL.02.SS

vs.


Heads would be 59cc TEA Stage 1 5.7's that flow:

.100 73.5
.200 144.4
.300 209.7
.400 252.3
.500 283.4
.550 296.1
.600 294.2

Beast96Z

iTrader: (21)

The 230/237 would make more power in the upper rpm's, which is where you'll likley spend more time in a road race application. If I had to choose between the 2, that is the one I would use.

SouthFL.02.SS

^Thanks. I had forgotten about this Lunati grind and it just popped into my mind.

HartAttack

iTrader: (8)

why not got with ...say tsp's torquer v.2
From everything i was researching it gets great low end torque and good top end pull.
Its something i have been considering for road race myself.
The two cams you listed would work, but wont make as much power IMO.
It would go great with those heads as well.

SouthFL.02.SS

Thanks, but I don't want to use XE-r type lobes.

HartAttack

iTrader: (8)

Too aggressive for RR? Maybe you could have Comp grind you one on XE lobes with simular specs. Or any other profile your interested in so that you have your own custom cam.
just giving ideas
-Chris

Beast96Z

iTrader: (21)

The exaust lobe on the Lunati grind is just as fast a ramp as the XE-R, but without the lift. The intake on the other hand is very slow.

DavidNJ

If you were building a road race motor with a 5.7L engine, you would probably be looking at something like a 244/248 to 256/260 depending on the track. You would be looking at an LSA of 106-107 and an ICL of +2-+4 (advanced). If it was in a competitive series you would want as much ramp as possible, pounding the intake and exhaust open with a fairly rapid intake close.

For a track day car you are already compromising the ramp and lift, presumably to reduce the stress on the valve train. So your only issue is street driving vs. track driving. Those race cams have a rumpa-rumpa idle and are very flat below 3000. Idles could be above 1000.

So your trade-off is street vs. track. If you are driving it to the track, you might want to leave the engine alone (except for oiling, cooling, and maintenance) and concentrate on the chassis and driver.

For performance mods I would concentrate on a linear and response throttle. Maybe AFR 205s with a 78mm tb and long tube headers with an x-pipe.

There is an LG testing video in one of these threads. Especially in the early part, he is on the throttle early and hard. That is easier to learn with less power and an easily modulated throttle.

11 Bravo

iTrader: (3)

I have that cam NIB. Let me know if you want to take it off my hands.

SouthFL.02.SS

Yes, you've pointed out a few things that I need to clarify.
I titled the thread "roadrace," to see what the immediate responses were.

The car will be a streetable car that will be used for lapping days at Homestead, Sebring, Moroso, etc. (I've seen you post in my RR thread, so I think you're familiar with my wants).

I've had a flat below 3K rpm with 1000rpm idle in my previous car, which was geared more fore drag, and I'm looking to build a trackable (RR) car that will have a broad powerband without having to spin past 6200rpm, albeit without sacrificing too much peak hp either. Friendly on the valvetrain too without having to put on too much sring. ASA meets my criteria. Just looking for a little bit more. The Lunati 230/237 seemed to fit the bill with its decent amount of duration and low lift.

Here's my other thread, detailing the entire setup:
https://ls1tech.com/forums/generation-iii-internal-engine/426384-south-s-planned-setup-5-7-tea-1-asa-ls6-tpis-oval-qtp-hvmc-etc-object-usable-power.html

I'm afraid of going with too much duration however, as the powerband would shift higher. I'd love to do a GM Cup style cam, but it would be a dog down low.

I'd like to step up to this Lunati grind:
But the lift has me weary. I know proper valvetrain setup can take a beating with higher lift, but I'm just be cautious.


And one last thing, leaving the engine stock is not an option .. I know driver mod is much more important, but I get a kick out of planning out the internals.

SouthFL.02.SS

Thanks. I'm not ready to buy anything just yet, but thanks anyways.

STRIPSTAR

iTrader: (4)

Smaller cam like asa and get larger head cc. 215-225 cc makes great hp and get a smaller ish cam and alot of compression to make up the torque. You will want light clutch(fidanza alum) and nasty gears 411 +. Can i go to Sebring with you? I always wanted to go to Sebring. Ive been to Pocono, etc up here but those Fla tracks are next.
Ive talked to alot of RR guys and the 02+ zo6 is flat awesome with slicks so keep the zo6 specs in mind also. ( except for the cam, its too weenie for us fbod lope heads)

SouthFL.02.SS

See now, I'd think 4.11 gear would be too much. I'm thinking more on the lines of 3.42's to stretch out that wide powerband that I'm seeking.
The heads would be 59cc 241's. Decent compression.

I learned to drive (I would now say that I really didn't know how to drive from the ages of 16-31, until I went to Skip Barber) at Sebring this year. The concrete barriers keep you honest and getting on the gas when coming out of the large turn on to the front straight is the most thilling experience I've had.

Must add light clutch to my list.

STRIPSTAR

iTrader: (4)

I may treat myself to Skip Barber soon.
No, 411+ gears will get you out of the smaller turns and compensate for any tq deficiancy. The big straights rarely would you run out of gear that i can think of. Walls and barriers are scary when can't afford to laugh and walk away. A guy rolled a gt3 Porsche at pocono and didnt think much of it. Thats when you can afford to RR I guess.

SouthFL.02.SS

Any more opinions. ASA vs. 230/237?

Patrick G

iTrader: (14)

Sounds like you've been given some good advice from people with RR experience (go with more duration and faster ramps), but it seems you're more interested in having people support an idea that you already have in your head.

For my 2 cents, I'd say limit your intake valve closing point to 40 degrees ABDC at .050" if you want to keep your rpm under 6200 and finally, use the fastest ramp rates with the most lift you can afford to maximize torque production down low. Slow ramps make for lazy torque down low (compared to fast ramps with the same duration at .050").

SouthFL.02.SS

Just saw the wicked vid.

Slow in, fast out.

SouthFL.02.SS

How does that explain the ASA's stellar tq curve?

This confuses the hell out of me.
http://i2.photobucket.com/albums/y2/TommyBoy74/scan.jpg

Patrick G

iTrader: (14)

IMO, there is nothing stellar about the tq curve on that dyno sheet. It's good, but not great. If you took the same duration at .050 (226/236) and substituted XE-R or even better yet, LSK lobes, the torque curve would be 5-10 rwtq better and the idle would be smoother.

Intake valve closing point is the biggest determiner to cylinder pressure and the rpm at which a cam makes peak power. The ASA cam (assuming it's ground on a 106ICL) has an IVC of 39 degrees ABDC at .050". This is pretty much where I recommended you keep your cam for best power below 6200. Coincidence? No, just good valve events. Go with faster ramps and watch the torque area under the curve increase.

SouthFL.02.SS

If it's a matter of 5-10 ft-lbs., why not go with a .525 lift cam?
Now, 15-20 ft-lbs., I'm on board.