which STOCK cam is best! LT1 cams
11-15-2006, 09:03 AM
#21
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Originally Posted by Formula350
Well this thread is dead imo, then if you can only pick between 2 cams.
Go through the checklist of deleted stuff:
Seats, trim, dash, dash metal frame, factory seats, carpet, sound barrier materials, factory gas tank, factory glass replace with Plexi, hard-top I hope, alu-drive shaft, A4 (swap for M6), AC+lines and condenser, AIR, charcoal canister, cut out front inner fender wells, bumper supports.
Go through the checklist of deleted stuff:
Seats, trim, dash, dash metal frame, factory seats, carpet, sound barrier materials, factory gas tank, factory glass replace with Plexi, hard-top I hope, alu-drive shaft, A4 (swap for M6), AC+lines and condenser, AIR, charcoal canister, cut out front inner fender wells, bumper supports.
my cars weight is w/ what drag racers call a 10 point w/ 1 3/4" .120" wall DOM tube (80 ft) w. NASCAR style door bars.
11-15-2006, 09:13 AM
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Originally Posted by Old SStroker
There are a few things you could do within the "factory blueprint" portion of the rules that some would consider cheating. I guess it depends on your definition of cheating. Depending on how they check the lift and or duration on a hydraulic cam, there are a few things that could be tried. Expounding on them on line wouldn't be a good idea, IMO.
Where are your intake restrictors?
Did I understand correctly that they check max rw torque even if it's at an rpm below what you use on the track? If so, you need to push the torque and power band higher, which normally means retarding the valve timing. I doubt that there is a factory spec, but you could easily assume a +/- 1° in location of the crank and crank sprocket, cam sprocket and location of the cam keyway, as well as chain stretch. That's maybe 4-8 degrees of retard "legally" possible. More if you only want to be "almost" legal.
You have to keep your 300 lb-ft max below 4025 rpm, but if you could peak your 230 hp there and then hold it near 230 up to your shift point you'd have the max area under the curve. That would be my goal.
Someone who is good on an engine simulator like EA Pro, and has a fast PC, could run the many combinations of cam timing available with the legal and quasi-legal LT1 cams and retard/advance available and find the most area under the hp and torque curves in the rpm range you want to run. Intake restriction could also be included to move/shape the curves. A chassis dyno session using the same type dyno the sanctioning body uses could then get you as near as possible to the 300/230 numbers you want by changing restrictors to hold the max power at 230.
Of course you probably want a killer valve job and all the legal static compression you can get.
These rules are not unlike the Daytona Prototype engine rules. A lot of work has been done on LS1 engines for this class, but the concepts are similar.
I guess it depends on how "edgy" you want to be.
My $.02
Where are your intake restrictors?
Did I understand correctly that they check max rw torque even if it's at an rpm below what you use on the track? If so, you need to push the torque and power band higher, which normally means retarding the valve timing. I doubt that there is a factory spec, but you could easily assume a +/- 1° in location of the crank and crank sprocket, cam sprocket and location of the cam keyway, as well as chain stretch. That's maybe 4-8 degrees of retard "legally" possible. More if you only want to be "almost" legal.
You have to keep your 300 lb-ft max below 4025 rpm, but if you could peak your 230 hp there and then hold it near 230 up to your shift point you'd have the max area under the curve. That would be my goal.
Someone who is good on an engine simulator like EA Pro, and has a fast PC, could run the many combinations of cam timing available with the legal and quasi-legal LT1 cams and retard/advance available and find the most area under the hp and torque curves in the rpm range you want to run. Intake restriction could also be included to move/shape the curves. A chassis dyno session using the same type dyno the sanctioning body uses could then get you as near as possible to the 300/230 numbers you want by changing restrictors to hold the max power at 230.
Of course you probably want a killer valve job and all the legal static compression you can get.
These rules are not unlike the Daytona Prototype engine rules. A lot of work has been done on LS1 engines for this class, but the concepts are similar.
I guess it depends on how "edgy" you want to be.
My $.02
if i could find out what the cam ICL is w/ the +/- tolarance, that would be a step in the right direction. also, offset keyways and other things would be nice. i working on getting the B/G body cam legal. that should help make more TQ w/ less HP and move things up in RPM. i wonder what the iron heads would do for power. i'm sure they are not work the weight. i'm so weight contious, i dont run cooling fans.
right now the HP hits the limit w/ the restrictor before the TQ. the HP peaks @ a good RPM, the TQ is crap @ 2K peak. its still 250ftlbs @ 4K, but its not the 300 the 3rd gens have @ that RPM.
11-15-2006, 11:54 AM
#24
cool to see a CMC racer around i was honestly thinking of doin it with my 88 formula but now the car is an ls1 6 spd car with a vette c4 IRS rearend goin in so i guess i would have to run AIX now looks like a ton of fun to do
11-15-2006, 04:42 PM
#27
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Originally Posted by SStrokerAce
Ummm more TQ higher in RPM will raise your HP to over 230rwhp... You need 300 ft lbs from 2000-4000rpm and then get and hold 230rwhp from there out.
Good Luck
Bret
Good Luck
Bret
11-16-2006, 12:43 AM
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Can you run smaller gaskets for more compression?
And I realize that you've done all of that, but if you look at it on the same note, less weight is just like adding more torque to a heavy car. Less torque with even less weight essentially is like keeping the weight and finding a way to gain more torque.
And I realize that you've done all of that, but if you look at it on the same note, less weight is just like adding more torque to a heavy car. Less torque with even less weight essentially is like keeping the weight and finding a way to gain more torque.
