gollum

iTrader: (1)

If this helps ASA race cars use the GM LS1 ASA cam: 226/236 @.050, 110 lsa, 525 lift.

ASA is oval class racing where everybody uses the exact same modified LS1 engine supplied by LIGENFELTER. I think they ran one road course this year.

GrannySShifting

iTrader: (10)

Dailys cam ran out of steam at 6000 rpm becasue it ran out of cam, not cylinder. Stock cylinder heads can support AT LEAST 460 rwhp with enough cam.

I tight lobe, small duration, cam with a bunch of advance is not the ticket to make power up top. I cam everything to be shifted around 6400-6800, dont see any sense in wasting 400 rpm of power with a valvetrain we have and decent bottom end.

You also have to consider tight lobe stuff needs a well thought out exhaust. His 400 cam only number was made with open headers. Are you going to be turning alot of rpm consitantly? Road course racing etc?

GrannySShifting

iTrader: (10)

Ok sustained above 4000 rpm.

Usually I run a XE-R type intake lobe and a slow exhaust, but you really need to watch your valvetrain. What springs are you going to run? If something good, personally Id still run something like an XE-R intake lobe

Hmm heres a interesting lobe with XE opening/closing ramps, and just a tiny bit less agreesive then XE-R after that. Would be a 226/230 on LS1 lobes, .593/573 run something around 110-111 LSA. If you get an adj timing chain its not hard to change the installed centerline. Trade some low speed torque for power up top or vice versa.

The more rpm your turn a motor and the more lift you use on the cam, its seems to be exponentialy harder on the valvetrain. Althoguh in my opinion high lift is only going to be hard on the valvetrain over the nose of the ramp, making sure the lifter follows the trailing edge of the lobe. Im generally more concerned with the valve closing ramps and valve bounce. Run Comp 918s or better yet Crane duals shimmed o the correct installed height. 135-145 lbs on the seat

Tommy Tucker

I have a (Porsche) G50/01 with LSD and I think they are nicely over-engineered. It's very smooth and with the stock clutch is so nice too, you don't need to be A. Schwarzenegger to change gear.

On the useage point: It will see WOT far more than a 1/4 mile strip.
High lift (0.58-0.61) is all very well for short drag races but I don't fancy sustaining that on and off for an hour or more every weekend.
that's why I would go for an aggressive lobe with lower lift or a kinder profile with slightly more lift, but not both.
Even with my Hotcam and the standard intake, the exhaust system I have pulls up the powerband to 3K-6K (I'm not talking dyno I'm talking about driving) Surprising what a free flow exhaust will do for the LS1. I guess GM already know this, that's why they added a bit more duration on the exhaust.

Interesting that the cam above has a reduced Ex lift in favour of more duration. To increase scavenging I suppose but keep the reversion effect minimised. This is where multiple options on cam specs are really 'try it and see' because each system (engine) will react slightly differently.
I would still like to know the habits of a 109-110 LSA cam having never driven one.

So as a result of this very interesting and helpful discussion I am a little further on and thanks to everyone for their input.
If anyone has experience of road racing this engine please let me know what you used.
Tom.

Tommy Tucker

I'll be running the Patriot Performance gold springs that came with the 5.3 heads.

marc_w

My original cam advise was based off of 'max midrange power, with power starting at about 2,500'. To me, midrange is 2,500-4,500.

Top end cams are definitely a whole 'nother thing.

GrannySShifting

iTrader: (10)

I hear ya, I think of midrange as 700 rpm below and above torque peak. midrange of a cam combo changes much with different cams. Is a car ever accelerating in a road course race at 2500 rpm? I try not to race from anything below 4K, but Im not a road racer

The intake lobe I was mentioning, while it has some lift, looks like on a LS1 lobe the time from .006 to .050 lift the ramps should actualy be a tiny bit GENTLER, then even the XE LS1 lobes (opening/closing the valve). The lift would be good for a efficient cylinder head too.

Itll be interesting to see how it actually turns out on a LS1 core, I think Ill be ordering up two variations of a cam runnning that intake lobe, and see how many rpm she turns

Tommy Tucker

In a light weight car you can actually save time by missing a gear change every now and then (0.5 sec) if you have the right ratios. But as a general rule it's going to be 3-6500 most of the time. Mine's only a 5 speed. In a 6 speed you might be in the 4-6K a lot of the time.
I think I've narrowed my choice to 3K and upwards with max power at 6500. If I can run a tight LSA with plenty of duration then I'll definitely consider it.
I'm just wondering how far you can go down that line. I would have thought someone might have produced a 3-axis graph for LSA, duration and lift to show what is/isn't possible before PtoV clearance on the LS1.
Are custom grinds reliable? Any recommended grinders?
Tom.

Stert

what do you mean a h/c car bogs when taking off? im putting an ls1 in my car this winter and and thinking about what i want to set it up with and i was just going to do all the bolt ons with h/c and then maybe take it further later on. but i dont want a car that is slugish from a stop cuz thats what my 350 does now with the 750cfm carb

Ryan02SS

iTrader: (3)

A HC car that bogs off idle is killing for one thing. Gears! My TR224 w stock 3.42s does not even bog, very close but does not bog. I can imagine a 231/237 or the like using the stock 3.42's it would be bog city.

GrannySShifting

iTrader: (10)

Thats why properly gearign a car for the cam helps. You can make pretty dyno numbers with big cams etc, but it wont perform up to expectation

Tommy Tucker

PREDATOR! YOU HAVE TO GIVE ME MORE INFORMATION ON THIS CAM OR THE GUY THAT HAS IT!! I NEED IT

Seriously though....that really sounds a dream, and coming out of the back of my T70 would be perfect. Any further info would be great.

GrannySShifting

iTrader: (10)

You have to take off your maf and tune in speed density. It also helps I beleive to have the individual TB setup, as it isolated each intake valve from reversion from the others.

Run slow lobes, very tight lsas