Setting up for max mid range power (Tq)
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.
Last edited by gollum; Sep 13, 2004 at 04:32 PM.
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?
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
BTW, awesome car. What transaxle are you using? I know the Porsche G50 930 4-speed will handle the power, but I think some of the Ultima guys have gotten away with using the weaker G50 5-speeds.
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.
I tight lobe, small duration, cam with a bunch of advance is not the ticket to make power up top.
Top end cams are definitely a whole 'nother thing.
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
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. The Best V8 Stories One Small Block at Time

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
Here is a video of a 242/242 106LSA with a 8 individual TB setup and speed density tuning.
http://users3.ev1.net/~black_ops/video/242-106.mpg


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. Run slow lobes, very tight lsas


