LT5

Who here runs 4:30's or 4:56's? Are these ratios too high? Can anyone here offer their experiences with 4:10's and higher in a ZR1? thanks :cheers:

Rkreigh

Kurt White runs 4.56 I believe and possible Mr. Hooper has the 4.30s

I run the 4.10s but honestly believe the 4.30 would be a good choice.

I'd be very curious if the car could pull 180 in 6th with either the 4.30 or 4.56.

You will need a cyberdyne or other box to do the speedo correction. not sure if anyone makes speedo gear correction for the 4.30s I could be wrong.

best of luck!!! :jester

LT5

I was wondering what parts are needed to go 4:30's or 4:56's? thanks

Tyler Townsley

There is an alternative to going with a lower gear. I just put a 14 lb flywheel in my LPE 368. Now there is no way I would want a lower gear than stock, going lower would waste first gear. I also went with the Hurst shifter and find the combination very smooth. It seems to me that the HP is there quicker than with the stock FW, I will do a dyno in Jan to see if there is more HP under the curve than before. There is always the argument that the lighter FW does not give any more HP but it does seem to me what there is delivered earlier.

Tyler
90ZR1


[Modified by Tyler Townsley, 10:25 PM 11/26/2001]

USAZR1

I switched to 4.10's when the nitrous went on my car.
I seriously doubt my car could have ran 180mph with 4.30's or 4.56's. You can do it with 4.10's "if" you reprogram the rev limiter to 7400rpm.
Anything lower than 4.10's will require electronic speedo recalibration. I'm running a Cyberdyne unit and it works great.

USAZR1

Same parts as needed for 4.10's,,just the ring & pinion set.

LT5

Where do I find a cyberdyne unit? Can anyone here reccomend a vendor?

ZR WON

Tyler:

Before I had Aaron Scott at SGC do my plenum and injector housings, I was talking with Billy Kirchoffer about lightweight flywheels and he said the lightened reciprocating mass is equal to 16rwhp. Can you actually feel a difference? Some people say the thing tachs like crazy after the mod, others say the difference is little to none. I know in the old days you could put a 13lb flywheel on a 350 and it would almost tach like a little 283 or a 302....

What I can't recall(and maybe the persons you talked with gave you that insight) is whether a lightweight flywheel provides a measurable gain on a dyno, or the lightened reciprocating mass just makes it *feel* like there's a gain because it's easier to get the motor spinning. Thoughts?

USAZR1

Jegs or Summit sell these units. I got mine from the Vette Doctors.

Tyler Townsley

Brian

I got the FW Billy is talking about and until I do a Dyno in Jan I cannot attest to any rwhp change however I can attest to making first gear instant smoke at any rpm! I, Billy and several others have had many discussions about just what a lightened flywheel does to rwhp and Billy has had occasion to observe the results on a dyno which is where his number came from. I am in agreement with him. When we attended the Camp LT 5 in england the last time we went to a F1 team 'factory' and saw the clutches and fw they use for F1 (See below link to the Camp LT 5 web page for a picture.) which are about 6 in in dia and 4-5 lbs which is where Billy got the idea. The only cautionary note I have heard about is making sure it is not too light to pull the rods/pistons around on the non complession strokes. I heard this from two sources my home grown physicist son and a hot roder in another list. Since I had to change the clutch and had 160,000+ on the present flywheel I figured I would try it out and yes the difference is noticable under power. THe only thing is i understand there are some new clutch materials out there and wish I had gotten one.
http://www.physics.ucsb.edu/~townsle...aultEngine.jpg

Tyler
90ZR1




[Modified by Tyler Townsley, 7:19 PM 11/27/2001]

LT5

ttt