Gears, Gears and More Gears!?

[Canzr1]

OK, the time for gears is getting close. I have numerous people locating a set of 4.10's for me, but I am running into dead ends with them. It seems production of the Super 44 sets is over or nearly over. I have a line on 3.90's and 4.56's, hence my problem. Has anyone EVER ran 4.56's in their ZR-1's? I personally don't know of anyone who has. Also, with the 4.56's is their a speedo correction gear for them, or would I correct it electronically only? What about the heat 4.56's would create over a long distance drive? Is this a cause for concern? What do you think?, hold out for 4.10's or take a 3.90 or maybe even a 4.56? I have questions, I hope you have answers!!

 

[USA ZR1]

Tom,if you're going to leave your engine mostly stock,I would try a set of the 4.56's. Final drive ratio in 6th gear will be 2.28 vs the 2.05 of 4.10's. Very little difference if you ask me unless you plan on running an ORR. Correcting the speedo will have to be done electronically. I doubt that high temps would be much of a problem;just change the gear lube more often.
The Vette Doctors have installed 4.56's in quite a few Long Island ZR-1's and they really haul ass. Phil Dejohn's 92 has run 11.70's with these gears,top-end package,and headers. Either 4.56's or 4.30's(also hard to find)will make an amazing difference. My ZR-1 has old-style Dana 4.27's and they work well,though noisy and too low for nitrous use.
I have a source for the Super 44 gearsets so I will see if I can acquire a gearset for you.

 

[Canzr1]

Thanks Clint for the response. I have located a set of 4.10's and am going that route. I guess I would have liked the 4.56 gear, but I don't want to cut my harness to correct the speedo. Oh well, the 4.10 should give me what I want for now, plus I am contemplating a NX system too. Would the 4.56 be a bit low for nitrous do you think? Thanks again!

 

[USA ZR1]

I'm concerned that 4.10's will be too low for nitrous use on my car. A 3.90 gear might be best for it. I have both gearsets,whatever I decide.

 

[Canzr1]

What problems would you foresee with nitrous and 4.10's Clint? Its not too late for me to change to a 3.90 as well. I am curious as to what your opinion is on this. Would I have a serious traction problem on juice with 4.10's? TIA

 

[USA ZR1]

Traction will always be a problem,Tom. But,the reason I'm looking at the 3.90's is a concern that I will run out of gear with 4.10's and nitrous. A 150hp shot will add approximately 15mph in the 1/4 which will put my car at 130mph+. 7K rpm in 4th gear is right at 130mph with a 26" tall tire,,too close for comfort. 'Course,my rev limiter has been re-programmed to 7400 so I can still run the 4.10's in a pinch. Decisions,decisions.

 

[HwyStar]

CanZR1,

If you change your mind about the 4.10's, I might be interested in it. I'm thinking about putting a set in this spring and could use it if you go with the 3.90's.

 

[Canzr1]

Have decided firmly on the 4.10's, thanks for the helpful responses guys!

 

[HwyStar]

CanZR1,

You said you were having a difficult time locating the 4.10's. Where did you wind up finding them? I haven't started looking yet but could benefit from the information. Thanks!

 

[USA ZR1]

Star,one of our Registry members in Ohio has a source for the 4.10's and 4.56's. 4.30's are really scarce right now. I sold a set at our event in Carlisle that I really wish I had kept. Oh well,hindsight is always 20/20.
Clint Hooper
LT5 Registry #001

 

[Phil DeJohn]

Clint.I changed the 456's to 430's in the 92.I was going through the traps at 7400 rpm's not really making power at that rpm. With the 430's going through @7200 just right for my car.11.71 @ 121 mph.Phil.

 

[USA ZR1]

That's interesting,Phil. Carmen always said that 4.30's were the best gear for our two cars. What are you spinning in the lights now? 6,800 or so? Seems like at BG'99, I was seeing around 6,600 or so in the traps.
Clint Hooper
LT5 Registry
http://www.lt5registry.com/

 

[rkreigh]

nitrous gears

I went with the 4.10s and now I want to try some
light nitrous.

is it worth getting the gemini twin NX kit or would
a port injection kit (sx2 nozzles would be nice).

contemplating the single stage kit as it will run over 200 HP which is all I think the stock engine will tolerate.

but then other guys run the wiz out of the stock engine and prove me wrong. have most of you guys running nitrous rebuilt the engine???

any advice appreciated.

 

[USA ZR1]

The Gemini Twin system is much easier to install than a direct port and a bunch cheaper,Ron. The former has jetting for 150-225-300hp levels and can be configured as a single or dual stage system. Believe me,a 150hp shot is a handful. Drop me a line(or ask Julio) if you need help with a nitrous system.
Clint

 

[brooks]

Go to this address http://www.chaseracing.com it computes
various speeds at a specific RPM in each gear. It will allow you to see the effects of gear and tire changes. Although the changes are liner and do not allow for such factors as tire growth, it is close.

 

[rkreigh]

Is fuel distribution still good with the gemini twin???

seems like the port setup would perform better. after looking at julio's rig get into the 10's I can't stop slobbering!!!

Julio, did you do a bunch of work to the bottom end or is it still stock. I haven't done nitrous before and not wanting to blow an LT5 learning. that's what's been holding me back (as well as the $$$) as soon as I sell my old BB 70 Mutt vette, the funds will be available.

I'll miss the old 427, but after driving the ZR1, it just doesn't seem adequate.

 

[USA ZR1]

Is fuel distribution still good with the gemini twin???
seems like the port setup would perform better. after looking at julio's rig get into the 10's I can't stop slobbering!!!

Fuel distribution is fine with either set-up,Ron. The Gemini Twin includes jetting for 150-225-300hp power levels.
I'm not trying to steer you towards any system,though. I,too,seriously considered a direct port nitrous system before Julio talked me out of it because the cost and complexity made it hard to justify. But,hey,it's only money.
If you got it,,flaunt it!
Clint