RedGTS

I'd be interested to know if anyone who has 4.10's has actually done a before and after comparison with the stock gears in terms of track times or something objective. I'm assuming 0-60 would be a little higher than stock because you would have to shift, but presumably the car should be quicker through the 1/4.

8mywal8

My friend has 4:10 in his C5 Z. Gas milage is not to bad. The easyest way to tell you how the car is on the freeway is just drive in 5th. Its almost the same gearing. With a big cam it makes the car way more friendly around town. As for the aluminum flywheel you may get some idel surge.

bcmarly

Yeah me too, I'd like to know how acceleration times are effected. I would suppose that it would depend on the standard of measurement: i.e.; 0-40 would be faster, but 0-60 might be slower, 0-80 might be faster, etc..etc..Could somebody post the maximum acheivable speeds in each gear at redline? Thanks.

EFE Z06

From 0 to top speed will be faster with a lower geared rear end, every gear pulls harder and reaches it's limit quicker, that's the facts of going to lower gears!

I'm sure everybody understands this principle. When you race somebody from a roll, the advantage is to be at an rpm range where your engine is at maximum torque(approx 4k), that way you'll accelerate faster when you hit the throttle. If you are in any gear and only turning 2k when you hit the throttle, you'll accelerate slower until you hit the best torque range, but your opponent will probably be ahead by that time. Having a lower gear ratio gives you a better torque range in every gear, and even if you start at too low of an rpm, your engine will gain rpm faster because the differential is easier to turn.

To make it simple, which accelerates faster, taking off in first gear or second gear? I know that's a silly question, but that's the exact same principle! Having a lower final gear ratio is the same as normally down shifting to gain more torque, when you down shift to a lower gear to accelerate faster, you are feeling what a lower gear does for torque, and so it's the same with all six gears when the final gear ratio is changed. But don't let anybody tell you gas mileage doesn't change, it absolutely does! Thus the reason why Chevy installed an overdrive sixth gear to post 26 mpg in the Z06. Had they made it a close ratio gear (to fifth) and not overdrive, mpg would probably be 3 to 4 mpg less!



EFE Z06

02gt350

i have them and love them. and i have the same gearing as a Z06. 5th gear will still pull 180 mph for me. acceleration has changed so much. milage is MAYBE 0.5 different as im on the highway ALOT and i drive 85-90. so it revs.


use this to help

http://golenengineservice.com/calc/calcrpm.htm

bcmarly

Thanks

dgdoc

i don't have any data on the C6Z with 4.10's and would also be interested in seeing test results. But, have done some before/after testing with other cars and seen from .2 to .3 improvement in E.T. (on stock rubber). Much of this gain comes from improved acceleration in 1st gear due to the additional torque multiplication.

However, in order to really get the full benefit of 4.10's, you've got to be able to use full power all the way through 1st gear and also launch hard. On a C6Z, this will easily overwhelm the stock Goodyear EMT's. So, if you want to realize the full potential of this mod, you'll need to invest in a set up drag radials.

vtecnitian

i heard for every pound you eliminate from flywheel is like taking off 10 lb of you car is that correct?

EFE Z06

I don't know who figured that number, but I'm sure the equation changes depending on the engine size and HP. For sure, every engine benefits when accelerating from a low rpm with an aluminum flywheel.

A heavy flywheel can be an advantage for a small engines in drag racing where the weight of the flywheel is used to build up extra torque off the line, but the engine needs to keep the rpm at redline through the entire run. If the rpm drops too much, a smaller engine doesn't have a lot of torque to gain it back.

In street and road course driving where the engine is constantly slowing down and speeding up, an aluminum flywheel makes a gigantic difference! The Porsche CGT uses a small light flywheel and multi-plate clutch, listen to it in the following link, the sound is awesome!

http://www.youtube.com/watch?v=MkLjCYjqGDU



EFE Z06

vtecnitian

i have stock 4.10's on my s2000 and they are not fun all the time maybe when i go to my 4.44 they will be.

SG333

Is this gear set made for the C6 Z06 dif? or is this a modified C6 dif with 4.10 gears.

Wicked Weasel

very nice write-up on the difference of flywheels. When I got into RR I really started to research flywheels and ended up with the aluminum because of the quick reving capability which makes rev matching much easier.

Now just like flywheels gears will depend on driving styles. I started out with 4.10 gears because I was into 1/4 mile racing and street driving. Perfect combination assuming you keep the HP in check (I had 460rwhp). When I move from 1/4 mile to RR the 4.10s required way too many shifts on the track and I dropped down to 3.73s.

Now I changed to the LS7 engine with 565rwhp and I am still on the fence with the 3.73s. Last weekend at pocono I was easily in the 140 range on the North course. I wanted to go faster, but it would require another shift up and then a quick downshift. Since it was the first day on the track I elected to skip the shift and just live with it. Now this is not my main course so when I go to WGI in 3 weeks if I have the same problem I will drop to 3.42s.

So in the end it is all dependent on driving style.

bcmarly

I beleive it has to do with unsprung weight. Losing a pound in unsprung weight is the equivalence of losing 10 pounds in sprung weight.

clogan

I put 4.10 gears in a Cobra I used to have, and the mpg actually increased!

Hard to believe, but true. Only disadvantage I recall is having to shift out of first so quickly. After that, it's no big deal.

CL

novaz06

To put it into perspective, with 4.10s first gear would only be good for about 52mph and second would be good for about 77. While this is significantly lower than stock, it is still easily more than 95% of cars on the road, and you still have four gears left. What's the theoretical top speed with the stock gears? Over 300 right? So there is PLENTY of room to go to a lower rear end. The Z with stock gears is like an old time four speed with two extra gears tacked on.

02gt350

for anyone else curious about what RPM at any speed in any gear, this is a great calculator. just know your info


http://www.f-body.org/gears/

Congaman

Very interesting thread. As I'm not to happy with the stock gearing I'm thinking of going 4.10. But will will the change affect the top speed? If so; By how much?

Sorry, I'm a newbie at this and a speed addict.

NEVERL8

Someone PLEASE make a 4:10 or 3:90 ring and pinion set for the Z. There are pleny of us out there lurking, waiting, and hoping this will happen.

novaz06

There is a guy on here, bandit0220 I think, who runs 4.56s and loves them. He has gone to a solid axle, though.

EFE Z06

That means his car is good for nothing but drag racing, to each his own.



EFE Z06