I’ve seen many threads talk about the gearing in the C8. Mainly the discussion is regarding gears 5 - 8. I’ve noticed this myself, once you shift to 5th gear the car doesn’t accelerate well.

I’m assuming you could switch out gearing but I have zero experience in pulling apart transmissions. It this a difficult thing to accomplish?

 

I have no comment on the ease or desirability of changing the gear ratios. However, here is some speed vs RPM for the various gear selections - and for the two different final drive ratios (Z and non-Z). You can use it to think about how a change in gear rations or final drive ratio would affect the behavior. You may find that if you don't like gears 5-8 just dont use them.

 

You'd need someone to make the updated gear set and you'd need to be able to tune the ECM to account for the different gearing. The ability to tune the ECM is the big issue right now as I believe Trifecta is the only one who's figured out how and they have not release this for general public tuning. If we ever get general availability for tuning (i.e. HPTuners or similar), then you might see someone make an updated gear set. Personally, I think this would be a great option, and I'd definitely be interested. Making even just 5th & 6th closer/shorter ratio would provide a noticeable difference while still giving 7th & 8th for highway cruising. For those that want it even more aggressive, do a shorter 5th, 6th & 7th, and only use 8th for cruising. It'd leave a fairly big rev drop between 7th & 8th, but this wouldn't be a big issue for highway cruising. Something like:
5th: .71
6th: .6
7th: .51
8th: .329 (stock)
would give a much closer spread and optimize 7th to be able to run out to 215MPH at 6600. Not sure that the car could pull all the way there, but for modified cars (i.e. blower/turbo), it would give them great gearing for the standing mile to try and do 200. Doing these ratios would give you this:

I think this would really wake the car up at higher speeds and would probably raise the effective top speed of the car. But again, until someone can tune the ECM to handle revised ratios, I doubt we'll see anyone interested in making such gear set.

 

Is that a program available online or something you created?
Very nice.

 

https://www.gtsparkplugs.com/GearCalc.html
A super useful tool, lets you play with transmission ratios, final drive ratio, tire size, and rpm.

 

Sweet. Thank you.

 

The tune is a wild card. The C6 had an RPM and MPH trigger for WOT shifting. It might shift fine at WOT just using RPM, especially if HP is stock or near stock. Part throttle shifting was simply MPH. At part throttle if the gears were a bit shorter, the car would shift a bit higher in the rpms, probably an added bonus in terms of drivability.

The cost would be significant to R&R the trans and make the changes, but there would be interest in revised gearing in the Z06 market too.

 

Or just install a shorter tire.

 

You'd have to go to an equivalent shorter tire on the front as well to prevent TC/AH issues, and you're speedo would also be off. Really though, this would be the equivalent of a shorter final drive ratio, not optimizing 5th, 6th and/or 7th for better trans ratios.

 

So install 4 shorter tires. Cause no one makes gears or a final drive for the tremec.

 

Has anyone published a table like this for the Z06 yet?
Thanks

 

I believe the Z06 has a different transfer gear ratio (5.56:1 final gear ratio) so it might be possible to install that transfer gear set.

 

gears are my complaint. The car is a 4 speed with 4 od gears. Much more useful would have been a 6 speed with 2 overdrive gears.Yes when it shifts to 5th your head slumps toward the dash,reach for a drink or a snack and relax.