4.10 gears...not what I expected.

[Kevin]

Did callaway charge you extra because you spell their name wrong?

[Harvie]

Originally Posted by Kevin

Did callaway charge you extra because you spell their name wrong?

Driving back and forth from New Lime CT to drop off/pick up the motor was fun but, no they gave me a discount becaue it only lasted about 400 miles before it needed rebuilding.

You buy a motor from them also or just curious?

Oh I forgot, that would be hacking up your car, sorry for asking....mate

[Kevin]

Originally Posted by Harvie

Driving back and forth from New Lime CT to drop off/pick up the motor was fun but, no they gave me a discount becaue it only lasted about 400 miles before it needed rebuilding.

You buy a motor from them also or just curious?

Oh I forgot, that would be hacking up your car, sorry for asking....mate

Didn't buy anything from them, too broke to. m8

[Bob Eyres]

Originally Posted by KILLSHOTS

Picked up the car yesterday after having the stock 3.45 changed to 4.10 Danas. It appears that I am a victim of my own inflated expectations. After hearing the accolades and reading on this forum a post from a guy who literally said he practically had to "relearn to drive the car" after getting 4.10s, I guess I expected the car to take flight or something. Hmmm, not quite. Yeah, I can tell a small difference but I'd be willing to bet the car is no quicker to a stopwatch, which is kind of a bitter pill to swallow when I just spent $1500 to get "18% more torque to the rear wheels at all engine RPM", according to Marc.

Driving the 2 ratios back to back, I don't feel any 18% torque difference. Not even close. And yes, I did confirm that the stock 3.45s came out of the car. I can say this for sure: if your car is stock or near stock and you're thinking about new gears, DO NOT do anything less than 4.10s. You'd be flushing money down the toilet. Just my 2 cents.

It's interesting to look back at the months of discussion about the minutia of gear ration selection and tire sizes, and see that Chris is right. And that his final assessment, that 4.10 gears are the minimum numerical change recommended for noticeable performance improvement in a stock, or near stock, ZR-1, hold up pretty well.

[ZR1North]

I've read this threat several times. Thanks for starting it, Chris, and for everyone for the usual informative contributions. Now, for something a little different....

I'll start with my reason for adding - I have a whole new respect for the economy-performance balance of our ZR-1s having just driven my '16 Z06 from Michigan to Florida to extend its use when I am there on-and-off over the winter (gotta get some miles on it while warranty is still in effect).

My '91 ZR-1 has 4:10s and Marc's 510 pkg (sans the SM flywheel, so it's really 490hp). My first drive with the pkg. was Mountain Run 2015, and I noticed two key things - 1) having the 4:10s made the run through the mountains a whole lot better than what I experienced road racing it previously with the 3:45s (to Paul Workman's point in an earlier post); 2) having a useful 6th gear on the freeway made cruising a great experience from a drivability and economy perspective (I made 24 MPG highway on the trip) running @ 75MPH revving at 2K RPM. I found that I was able to accelerate around traffic in 6th quite easily; previously I was constantly downshifting to 5th to do so.

Fast forward to my trip this weekend in the Z06. After I got 1,000 miles on it, I started to experiment with various modes. I noticed that when I switched it to "Eco" mode and the computer switched the engine to "V4" for fuel economy, I was getting about 34 MPG, but that was only on flat surfaces running @ 75 MPH in 7th gear on cruise (RPM were 1,500). When I encountered a grade, it switched to "V8" mode and the MPG dropped to 22-29 range (instantaneous computer calculations). Overall, I averaged 27 MPG, mostly in 7th gear @ 1,500. When I shifted to 6th for passing, RPM jumped to 2,000, but acceleration in 6th was unlike anything I've experienced in anything else I've driven. For comparison, gear ratios in the Z06's Tremec gearbox are: 1st, 2.97; 2nd, 2.07; 3rd, 1.43; 4th, 1.00; 5th .71; 6th, .57; 7th, .48; final drive is 3:42. This compares to our Zees with: 1st, 2.68; 2nd, 1.80; 3rd, 1.29; 4th, 1.0; 5th, .75; 6th, .5 - my final drive now is 4:10.

All that to say, even with 30 years of technological advancement, our Zees are still pretty respectable in terms of performance and economy when upgraded. As for the 4:10 vs "other ratios", I wouldn't change my decision to switch to the 4:10s, but I am more of a road racer than a drag racer. I ran the NCM track in May, and as with the MR in 2015, I found the combination fantastic on both the slow corners and fast straightaways. I think it's a great combination for highway and road racing and while I haven't drag raced the car, I think what I've read here would not cause me to change from the 4:10 for the odd drag run.

FANTASTIC THREAD!

Bob