4l60e/gear question
Thread Starter
Staging Lane
Joined: Apr 2018
Posts: 86
Likes: 17
4l60e/gear question Little info on car first. '05 gto, heads/cam, built trans,fti triple disk,3800 nitrous stall, 3.70 gears. Been running average 10.80's ,best pass 10.67 with 1.4 60's. I just refreshed the trans, but decided to put in the sonnex 6-pinion planet, that changes the 1st gear from a 3.06 to a 2.84 ratio. Changes the 2nd gear from a 1.63 to a 1.55. From the reviews I had read, they slowed on the 60, but picked up a average of 0.3 on the big end, from the reducing the big rpm drop on the shifts. After a trip the the track..I had 1.5-1.6 60's, but slowed down on the big end.. 11.0's and some 10.9's.
My question is....do I pull the trans and put the normal planet in, change the stall or put some 3.90's in the rear???
My question is....do I pull the trans and put the normal planet in, change the stall or put some 3.90's in the rear???
Last edited by 13qtr; Aug 16, 2018 at 01:25 PM.
TECH Junkie
Joined: Dec 2012
Posts: 3,614
Likes: 1,326
From: Iowa
Mind sharing the reviews where people picked up time at the track? I've seen 0 confirmed reviews showing that planet ever picks up anything at the track. I've seen where people change that planet at the same time as changing 10 other things and there's an increase in time
The problem is that the rpm % is about the same drop
3.06--->1.62 is a 47% drop
2.84--->1.55 is a 45.5% drop
You really think that makes a difference? Its still a huge change from 1st to 2nd
The problem is that the rpm % is about the same drop
3.06--->1.62 is a 47% drop
2.84--->1.55 is a 45.5% drop
You really think that makes a difference? Its still a huge change from 1st to 2nd
Thread Starter
Staging Lane
Joined: Apr 2018
Posts: 86
Likes: 17
Mind sharing the reviews where people picked up time at the track? I've seen 0 confirmed reviews showing that planet ever picks up anything at the track. I've seen where people change that planet at the same time as changing 10 other things and there's an increase in time
The problem is that the rpm % is about the same drop
3.06--->1.62 is a 47% drop
2.84--->1.55 is a 45.5% drop
You really think that makes a difference? Its still a huge change from 1st to 2nd
The problem is that the rpm % is about the same drop
3.06--->1.62 is a 47% drop
2.84--->1.55 is a 45.5% drop
You really think that makes a difference? Its still a huge change from 1st to 2nd
1.63 to a 1.55 is only about 5%
Don't recall which sites I read ( searched alot), believe it was some corvette sites.
TECH Junkie
Joined: Dec 2012
Posts: 3,614
Likes: 1,326
From: Iowa
Regardless of what the starting ratios for each are
when you go to shift 1-2...you have a 45-47% gear ratio drop...THATS the big downfall in the gearing of these 4l60e's
Thats a BIG rpm change
and the sonnax planet doesn't change that huge 1-2 shift much at all
if you go from stock planet and 3.70's (3.06*3.70=11.322)
and get the sonnax unit and 3.90 gear (2.84*3.90=11.076)
you don't gain much of anything (especially on 1-2 shift rpm drop)... you throw away over $1000 in just parts alone... and you're left getting worse gas mileage because your overdrive ratio of the trans is the same, but now you have 3.90 gears and are turning higher revs when cruising
I think that planet is silly
when you go to shift 1-2...you have a 45-47% gear ratio drop...THATS the big downfall in the gearing of these 4l60e's
Thats a BIG rpm change
and the sonnax planet doesn't change that huge 1-2 shift much at all
if you go from stock planet and 3.70's (3.06*3.70=11.322)
and get the sonnax unit and 3.90 gear (2.84*3.90=11.076)
you don't gain much of anything (especially on 1-2 shift rpm drop)... you throw away over $1000 in just parts alone... and you're left getting worse gas mileage because your overdrive ratio of the trans is the same, but now you have 3.90 gears and are turning higher revs when cruising
I think that planet is silly
TECH Resident
Joined: May 2006
Posts: 969
Likes: 119
I am still waiting for an improvement from somebody since I posted a challenge 3-4 years ago, if anybody could show an improvement when using this gear set. Even a .005 second improvement would be enough for people in Super Stock to possibly make this change here. Unless you have horsepower to give away, I say that it will be a very odd combination that "might" benefit from this gear set. Put the money into a good torque converter, and you will "see" an improvement in ET & MPH for the same money that was spent on this. Still waiting....
