Gear swap:how much change in 60'? - LS1TECH - Camaro and Firebird Forum Discussion



Gears & Axles Driveshafts | Rearends | Differentials | Gears | 12 Bolt | 9 Inch | Dana

Gear swap:how much change in 60'?

Reply
 
Thread Tools Search this Thread
Old 01-12-2017, 08:23 PM   #1
8 Second Club
Thread Starter
 
turbotrks's Avatar
 
Join Date: May 2013
Location: ATL
Posts: 96
Default Gear swap:how much change in 60'?

As I twiddle my thumbs this winter waiting for the good tracks to open, I am thinking about swapping the ring and pinion in my Mustang (see sig) to improve my 60' times. I don't want to go through the trouble if it's not going reach my goal though.

Here's the details: Currently have 8.8 with 3.27 gears and the best 60' I've done is 1.36. That's leaving on 8psi with 2 step. Without loosening the converter I can't seem to make over 8 psi on the line. With a 3.73 the car was good for 1.2x 60' times, but that was in 1/8th mile. I am running 1/4mi and based on my calculations, I would need to go with a 3.55 to theoretically cross the finish line at the ideal RPM (around 6700-6800)

Sooooo, do you think going from 3.27 to 3.55 would get me back under 1.30?

Or, let me know if you see another way to reduce my 60 foot without swapping gears or tranny. Btw, I'm already running a sae 10wt transmission fluid, so I don't know of anything thinner to increase my stall.

Thanks for any advice!
turbotrks is offline   Reply With Quote
Old 01-12-2017, 08:45 PM   #2
TECH Addict
iTrader: (25)
 
madmike9396's Avatar
 
Join Date: Jan 2009
Location: North Carolina
Posts: 2,985
Default

In for proven track results
madmike9396 is offline   Reply With Quote
Old 01-13-2017, 07:40 PM   #3
8 Second Club
Thread Starter
 
turbotrks's Avatar
 
Join Date: May 2013
Location: ATL
Posts: 96
Default

Anyone out there changed the gear ratio and compared the before and after 60'? Doesn't even have to be a remotely similar set up. Just looking for any information to work with. Really don't want to go through the trouble if the general consensus says I'm only going to drop a few .01
turbotrks is offline   Reply With Quote
Old 01-14-2017, 10:16 AM   #4
TECH Senior Member
iTrader: (90)
 
01ssreda4's Avatar
 
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 22,296
Default

I increased mine and saw no difference.
01ssreda4 is offline   Reply With Quote
Old 01-14-2017, 11:22 AM   #5
8 Second Club
Thread Starter
 
turbotrks's Avatar
 
Join Date: May 2013
Location: ATL
Posts: 96
Red face

Quote:
Originally Posted by 01ssreda4 View Post
I increased mine and saw no difference.
OK, thanks for the input. What ratio did you change to and from?
turbotrks is offline   Reply With Quote
Old 01-15-2017, 03:15 AM   #6
10 Second Club
iTrader: (30)
 
zzracer's Avatar
 
Join Date: Oct 2009
Location: Denton, NC
Posts: 154
Default

I had 3.08 gears and have just put in 3.73s. I have not tried the new gears out yet put plan on going to the track soon . I will post my results.
zzracer is offline   Reply With Quote
Old 01-15-2017, 06:42 AM   #7
8 Second Club
Thread Starter
 
turbotrks's Avatar
 
Join Date: May 2013
Location: ATL
Posts: 96
Default

Quote:
Originally Posted by zzracer View Post
I had 3.08 gears and have just put in 3.73s. I have not tried the new gears out yet put plan on going to the track soon . I will post my results.
Ok, good deal.
turbotrks is offline   Reply With Quote
Old 01-15-2017, 09:47 AM   #8
TECH Senior Member
iTrader: (90)
 
01ssreda4's Avatar
 
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 22,296
Default

Quote:
Originally Posted by turbotrks View Post
OK, thanks for the input. What ratio did you change to and from?
3.73 to 4.10
01ssreda4 is offline   Reply With Quote
Old 01-24-2017, 07:31 PM   #9
8 Second Club
Thread Starter
 
turbotrks's Avatar
 
Join Date: May 2013
Location: ATL
Posts: 96
Default

New question. I am currently seeing approx 8% converter slip at 6400 rpm as I cross the line.

If I change to a 3.55 gear, and my finish line rpm is around 6900 rpm, what percentage of slip do think I'd see?
turbotrks is offline   Reply With Quote
Old 01-26-2017, 08:55 AM   #10
TECH Senior Member
iTrader: (90)
 
01ssreda4's Avatar
 
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 22,296
Default

Slip would go up that's for sure.
01ssreda4 is offline   Reply With Quote
Old 01-26-2017, 09:24 PM   #11
8 Second Club
Thread Starter
 
turbotrks's Avatar
 
Join Date: May 2013
Location: ATL
Posts: 96
Default

Quote:
Originally Posted by 01ssreda4 View Post
Slip would go up that's for sure.
Up? Wouldn't the converter slip less at a higher RPM?
turbotrks is offline   Reply With Quote
Old 01-28-2017, 09:23 AM   #12
TECH Senior Member
iTrader: (90)
 
01ssreda4's Avatar
 
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 22,296
Default

Quote:
Originally Posted by turbotrks View Post
Up? Wouldn't the converter slip less at a higher RPM?
Sorry I misread what gears you had. Going from 3.2x to 3.5x would DECREASE slip.
01ssreda4 is offline   Reply With Quote
Old 01-30-2017, 05:15 PM   #13
TECH Enthusiast
iTrader: (5)
 
jblankenship's Avatar
 
Join Date: May 2012
Location: Mechanicsville, VA
Posts: 618
Default

If you increase rear gear the converter tightens up, this is why the 60' won't change much or at all. The car needs the correct gear for the rpm you wish to finish at. Then you need the converter spec'd for the entire combo.
jblankenship is offline   Reply With Quote
Old 01-30-2017, 07:20 PM   #14
8 Second Club
Thread Starter
 
turbotrks's Avatar
 
Join Date: May 2013
Location: ATL
Posts: 96
Default

Quote:
Originally Posted by jblankenship View Post
If you increase rear gear the converter tightens up, this is why the 60' won't change much or at all. The car needs the correct gear for the rpm you wish to finish at. Then you need the converter spec'd for the entire combo.
In a typical or ideal scenario (for a non-lockup TC), what percentage of slip should I be expecting at redline?
That % of slip needs to be in my calculation to determine the best gear ratio.
turbotrks is offline   Reply With Quote
Old 02-06-2017, 01:45 AM   #15
10 Second Club
iTrader: (30)
 
zzracer's Avatar
 
Join Date: Oct 2009
Location: Denton, NC
Posts: 154
Default Gear swap 60ft update

I went to the track yesterday to try my 3.73 gears. I did notpick my 60ft up. With the 3.08 gears my 60s averaged 1.51-1.52 . My best 60 with the 3.73s is a 1.44 so far. I think I can get it a little better with some suspension tuning.
zzracer is offline   Reply With Quote
Old 02-09-2017, 11:00 AM   #16
8 Second Club
Thread Starter
 
turbotrks's Avatar
 
Join Date: May 2013
Location: ATL
Posts: 96
Default

Thanks for the info.
turbotrks is offline   Reply With Quote
Old 02-11-2017, 08:29 AM   #17
TECH Senior Member
iTrader: (90)
 
01ssreda4's Avatar
 
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 22,296
Default

Quote:
Originally Posted by turbotrks View Post
In a typical or ideal scenario (for a non-lockup TC), what percentage of slip should I be expecting at redline?
That % of slip needs to be in my calculation to determine the best gear ratio.
6-8% I would think.
01ssreda4 is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
1986 Toyota Pickup Swap Thread mdb4879 Conversions & Hybrids 4 02-12-2017 08:39 PM
Doing gears in an A8 car? Pray Gen 6 Camaro 2016+ Forum 9 08-05-2016 07:19 PM
Turbo s10 smokes tires out of ideas Dimeomboost Drag Racing Tech 32 01-12-2016 05:27 PM
What gear ratio should I do for the 8.8? B_ROCKS_IT Cadillac CTS-V 2004-2007 (Gen I) 16 04-24-2013 03:41 AM
First post - Installing a Gen III/IV in a 1991 caprice macs_forever Conversions & Hybrids 43 11-07-2007 07:46 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 03:52 PM.


 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: