ss performance

iTrader: (17)

Does anyone make a different ratio first hear for the 4L60E?

I'm not a big fan of the 3.06:1 first gear ratio and would like to get closer to a 2.8:1 or 2.7:1.

I know that different ratios have been made for other transmissions and didn't know if anyone made the for the 4L60E.

Any input would be appreciated.

Thanks
Craig

mrvedit

A different 1st and 2nd gear ratio is available; I have it in my car now.
1st is 2.84 and 2nd is 1.57.
It is implemented with a custom billet 6-pinion front planetary set.
IIRC FLT has it as an option on their Level-7 for an additional $1200.
PATC also sells it.

ss performance

iTrader: (17)

How do you like the different gear ratios?

Did you have times and MPH before and after the change?

Thanks

mrvedit

Sorry, I don't have track times before and after; for one thing I rarely can get my car to hook well and therefore my ET is very inconsistent. Also I made too many engine/tuning changes to compare trap MPH before and after.

ss performance

iTrader: (17)

I'm thinking about changing the gear ratio because I'm concerned about hooking. With my new 408 I should be making 600rwhp.

If you are still having hooking problems then do you think it was worth it changing the ratio?

mrvedit

At 600rwhp you really should be considering a 4L80E which has a 2.48 1st gear which will help you hook at the start. Of course mostly for its greater strength and durability.
I do like the closer ratios in my 4L60E in street driving; mostly it was part of my goal to experiment with all the significant aftermarket parts for this trans. Just a hobby for me.