LT5PWR

For those of you who have put 4.56 gears in your Zs, how do you like them?

Would you put same gears back into your car?

What rpm are you at at quarter mile in 4th?

What brand of gear are you using?

What flywheel are use using with these gears?

BTW I have an extra Dana 44 for sale! Best Offer


[Modified by LT5PWR, 4:54 AM 1/23/2002]

Rkreigh

I think you might be revving too high in 4th gear unless you run really tall tires. car would need some BIG slicks to hook up with these gears and be pretty tough to hook up on street radials. sure like to hear anyone who has "been there, done that" with the LT5 being a bit weak on low end grunt, these would sure get the car "up on the secondaries" pretty quick!! :troll

USAZR1

The Vette Doctors were once well known for installing 4.56 cogs in quite a few ZR-1's. I almost went that route before ending up with 4.27's(since switched out to 4.10's because of nitrous useage).
Kurt White is running 4.56's. At least,his sig says he is.
Ask Phil DeJohn how well they work. His White 92 ran some 11.70's with them on drag radials.

wheelsup

I don't have any experience with 4.56 gears ,but I have run the 4.30's.Also,see the Forsale section (C4) for a set 4 sale.
Phil

LIMEY

Guys,

I have the 4:56 gears in my car, have had them in for 2 years now.

They are a riot to drive, 1st gear is ridicolous, no traction at all, 6th gear is a lot of fun too, the car actually pulls pretty good in 6th.
However, they are not a good gear for drag racing, i am certain my car slowed down in the 1/4 mile, although I have no times to back this up, just experience from drag racing on the street with other cars.

The thing with the 4:56 gears is you're out of the power band too quick, 1st & 2nd gear go by so fast that you are not accelerating & pulling like you should.
The MPH suffers, but your ET may improve, only if you have slicks, street tyres are a joke.
I wouldn;t recommend the gears for drag racing, unless you're serious about drag racing only & traction is not a problem, if you drive regularly on the street, stay away from them.

As you guys may know, I had a 368 motor last year, thats been upgraded to a 415" 700 + HP motor, with NO2 & the 4:56 gears :-) although I have no intentions of keeping these gears in the car for very long, I will keep them for long enough to give you guys the ultimate feedback on acceleration times & all that good stuff.

I can pretty much guess that this will be one scary ride when finished, I hope to have it ready for May's gathering in KY, that all depends on how soon Jerry Crews can finish up on my crank.

This ZR-1 will be a riot to drive & a show car too, I had every piece of aluminium suspension polished on the car, all the bolts are stainless steel, all new leather & carpets bought direct from GM over 5 years ago & stashed away for a rainy day, new weatherstripping & windshield, complete bare body repaint, all new body moldings, new wheels , rebuilt tranny and so on.
For the money i spent on this car, I could have bought the 512TR i so badly want, ah heck, I'll get that later :-)

These pictures are of the 368" motor from last year.

Tata.

Kurt
http://www.whiteracingproducts.com






[Modified by LIMEY, 12:52 AM 1/26/2002]


[Modified by LIMEY, 12:54 AM 1/26/2002]

Rkreigh

Hey Kurt!!! that 415 sounds awesome. you may want to consider the stock or even a taller gear for that much torque.

are you staying with the same NX nitrous kit and did you determine what caused the piston failures??? I am looking to go to nitrous this year and want to do it right.

hope you can bring your car to BG, it sounds awesome!!!

mcmonroe

I look forward to lots of details on the sprayed 415". I am not aware of anyone that has sprayed a 415" yet. Should be an interestng ride.

:-)

Mark Monroe
Harrisburg NC

USAZR1

Warbird is running a NX 300hp two-stage set-up on his 415" car. Ever since he purchased a real P-51 Mustang awhile back,he's been kinda scarce on the Forum,though.

USAZR1

Kurt,your 368" on the bottle was way overgeared. Just on motor,you should've have been ok. It would've been nice to see your car run with a 3.90 cog like Julio's. I bet both of your ZR-1's are within 50hp when running the amounts of nitrous you both are. Look at his mph in the 1/4 and compare it to yours. Big difference.
What I don't like about the nitrous is the gearing problems it creates for my car. Off the bottle,the power curve on my LT5 would seem to dictate a 4.30 cog. On the bottle,a 3.90 would seem to be very close. I settled on a 4.10 ratio but (I think) it's too tall for off-juice work.
I can't imagine any ZR-1 on the bottle working well with 4.56's,however. Nitrous adds huge amounts of torque so you need to go to taller gearing when running it,not shorter.
A 415" on squeeze could probably get by with 3.07 or 3.33 gearing. The biggest problem will be keeping the drivetrain together with 900+ ft/lbs of torque at the rear wheels. The TT ZR-1's are breaking at less than 800.

xsmph

Clint, in the streets any combiantion (within reason) is more less ok.
At the track an alternative is to go with taller tires like 325 60 15 drag radials on 15x10 crager wheels. THis will reduce your effective gear ratio.
As it is right now I would have to shift into fifth gear in the 1/4 to finish with the juice. So i'm clearly not optimised for 1/4 mile racing gear wise.
However I've geared my car so i can get to 180-185 (5th gear at 7000-7200 rpms) as fast as i possibly can...
I think for your current Dual personality set up the 410's are just fine!
you can always put taller tires at the track... on the streets just roll at the lowest peed in which you have traction...

Stingy74

I don't get it. Why would nitrous screw up your gear ratio? It's not going to change anything but horsepower. You'll still have the same transmission ratios, same ring and pinion (whatever it be) and the same tire height. Your top speeds in every gear at max rpm won't change unless you rev it higher (although on the bottle it will reach it's peaks faster). If anything, a 4.09 or 4.56 is going to help accelerate your cars faster. It just happens so fast that you forgot how fast you were going. One should choose a gear ratio that has the motor at peak as you cross the finish line in a 1:1 ratio.

Of course, nothing I have said here is valid without traction.


[Modified by Stingy74, 4:16 AM 1/27/2002]

RatRacer

The reason you go to a taller gear is because peak torque increases dramatically with nitrous.

scorp508

:confused: You generally gain more torque than you do horsepower with nitrous.

Stingy74

That was a general statement, i'm sure you know what I meant. Horsepower is only a calculation of torque, which most people understand anyway :)

USAZR1

You need to do just a little bit of research about nitrous. A 150hp shot will add almost 250-300 ft/lbs of torque. That will change your gearing requirements dramatically. Generally,the more torque an engine produces,the less gear you need in the back.

LIMEY

Ok,

I realize the 4:56 Gears will be pretty much useless for my new 415" motor & nitrous, can I get some opinions on what would be my ideal gear.
I am not interested in going 200+ MPH, although the car will do that no problem.
What I want is to be able to run mid 10's in the 1/4 mile & be in 4th gear if possible.
For arguments sake, we will be running 28" tall tyres, maybe 26" if they are available.
I would rather stay in 4th, I anticipate the car will red line around 7,800 RPM.

Give me ideas both with & without the NOS, & what Gears i would be in under different ratios.
The 4:56 gears are going to stay in the car for now, but as soon as this car is broken in, out they come.

Tata, time to watch the Sopranos :-)

Kurt.
http://www.whiteracingproducts.com

RatRacer

With slicks, a set of 4.10's will be the hot set-up.

USAZR1

Since Julio is almost overgeared with a 3.92 cog,my guess would be a Super 44 3.73,,maybe even a 3.45. Since a 415" on juice will have such a huge torque output,short-shifting will probably work better. Somehow,I don't think you will have to spin a 415" on the bottle to 7800rpms.

RatRacer

3.45's will hook up better on the street. For the track, 4.10's will have you coming through the traps @ about 135mph w/ 7,200rpm in 4th gear if you have a mid 10 second car


[Modified by Cam Potter, 9:10 PM 1/27/2002]

USAZR1

Just my opinion,but I really think a 700hp 415" on the bottle needs a taller gear than a 4.10. Remember,Julio's stock displacement LT5 with a 300shot went 145mph in the 1/4. That was using 3.92 cogs and as he said,the car almost needed a shift to fifth gear. If Kurt can get that monster of his to hook up at all,it should run close to 150mph trap speeds. :eek: