5AT 3.5 final drive differential swap.
#1
5AT 3.5 final drive differential swap.
Got it done on Friday, here are my initial impressions.
Throttle seems more responsive during city driving though there is so much traffic in LA that I didn't really get a chance to work it out.
Cruising at 80 mph the RPMs were at around 3000. The higher revving took a little getting used to, but after an hour on the highway I didn't even notice anymore.
Mileage didn't seem to drop as bad as I thought it would. I averaged about 24.5 mpg on the way down to LA from Vegas (3.2 final drive) and the return trip I got 23.3 mpg with the shorter gears.
I'll report more impressions after my next run out to the drag strip, possibly this Friday.
Throttle seems more responsive during city driving though there is so much traffic in LA that I didn't really get a chance to work it out.
Cruising at 80 mph the RPMs were at around 3000. The higher revving took a little getting used to, but after an hour on the highway I didn't even notice anymore.
Mileage didn't seem to drop as bad as I thought it would. I averaged about 24.5 mpg on the way down to LA from Vegas (3.2 final drive) and the return trip I got 23.3 mpg with the shorter gears.
I'll report more impressions after my next run out to the drag strip, possibly this Friday.
#3
Originally Posted by roneski
Got it done on Friday, here are my initial impressions.
Throttle seems more responsive during city driving though there is so much traffic in LA that I didn't really get a chance to work it out.
Cruising at 80 mph the RPMs were at around 3000. The higher revving took a little getting used to, but after an hour on the highway I didn't even notice anymore.
Mileage didn't seem to drop as bad as I thought it would. I averaged about 24.5 mpg on the way down to LA from Vegas (3.2 final drive) and the return trip I got 23.3 mpg with the shorter gears.
I'll report more impressions after my next run out to the drag strip, possibly this Friday.
Throttle seems more responsive during city driving though there is so much traffic in LA that I didn't really get a chance to work it out.
Cruising at 80 mph the RPMs were at around 3000. The higher revving took a little getting used to, but after an hour on the highway I didn't even notice anymore.
Mileage didn't seem to drop as bad as I thought it would. I averaged about 24.5 mpg on the way down to LA from Vegas (3.2 final drive) and the return trip I got 23.3 mpg with the shorter gears.
I'll report more impressions after my next run out to the drag strip, possibly this Friday.
#5
Does your cruise control still work? I know this has been an issue with this swap.
Concerning the performance, a few weeks back I ran my G at the track with my 26.3" stock 17" boat anchors and then made a couple passes on my super short 23.8" tall BFG drag radials. The DRs increased my gearing by about 8% or approximately to a 3.45 gear. The increased gearing did the following:
1) Forced a 3-4 shift 150' before the finish line. No good because that shift takes time and means the car isn't accelerating in the meaty part of the powerband. With the 17s I was crossing the finish line just before tapping the rev limiter in 3rd.
2) The car was fractionaly slower in both ET and MPH with the DRs with no real change in 60'. I ran two low 14.5s@95.8mph with the DRs and I ran a a high 14.4@97.5mph with the 17s. The motor was pretty hot when I had to make the runs on the DRs so that might have effected the ET/MPH a bit, but even so, the car was trapping nearly 2mph slower with the DRs. Much of that I blame on the late 3-4 shift.
Have you gone to the track prior to the gear swap? I'm very interested in seeing your results. I thought the 3.5 swap would be a great idea because of the deeper gearing and VLSD. For my car, the gearing didn't seem to help things. I'm considering just doing a 350Z auto swap so I can get the 3.2 VLSD.
Concerning the performance, a few weeks back I ran my G at the track with my 26.3" stock 17" boat anchors and then made a couple passes on my super short 23.8" tall BFG drag radials. The DRs increased my gearing by about 8% or approximately to a 3.45 gear. The increased gearing did the following:
1) Forced a 3-4 shift 150' before the finish line. No good because that shift takes time and means the car isn't accelerating in the meaty part of the powerband. With the 17s I was crossing the finish line just before tapping the rev limiter in 3rd.
2) The car was fractionaly slower in both ET and MPH with the DRs with no real change in 60'. I ran two low 14.5s@95.8mph with the DRs and I ran a a high 14.4@97.5mph with the 17s. The motor was pretty hot when I had to make the runs on the DRs so that might have effected the ET/MPH a bit, but even so, the car was trapping nearly 2mph slower with the DRs. Much of that I blame on the late 3-4 shift.
Have you gone to the track prior to the gear swap? I'm very interested in seeing your results. I thought the 3.5 swap would be a great idea because of the deeper gearing and VLSD. For my car, the gearing didn't seem to help things. I'm considering just doing a 350Z auto swap so I can get the 3.2 VLSD.
#6
I'm not going to post how much I paid because I got a helluva lucky deal on the pumpkin swap. So in that sense everything went much better than I had originally planned. Hint: look for someone that has upgraded to a Nismo LSD.
Otherwise the new gears run about $500 and labor including rebuild is about another $500. If you manage to find a 3.5 pumpkin already assembled then the labor comes down to about $150 or 2 hours.
So I got into the shop first thing in the morning and was out by about 10:30, plenty of time to go and get my L-spec reflash from Technosquare.
There isn't any noise increase, sounds the same as stock except for the slightly higher cruising RPMs.
Otherwise the new gears run about $500 and labor including rebuild is about another $500. If you manage to find a 3.5 pumpkin already assembled then the labor comes down to about $150 or 2 hours.
So I got into the shop first thing in the morning and was out by about 10:30, plenty of time to go and get my L-spec reflash from Technosquare.
There isn't any noise increase, sounds the same as stock except for the slightly higher cruising RPMs.
#7
My cruise control did freak out on the way back from LA. It was working then all of a sudden the set light began flashing and the cruise control disabled itself. I'll have to do some experimenting to see what might cause this and if there is any way to work around it.
I think that you are right on about adding a shift to the quarter mile. It'll be interesting to see if I can trap any higher with the shorter gears or if the extra shift will neutralize the performance increase. I've got plenty of slips from previous runs and will do a comparison as soon as I get some new runs in.
I think that you are right on about adding a shift to the quarter mile. It'll be interesting to see if I can trap any higher with the shorter gears or if the extra shift will neutralize the performance increase. I've got plenty of slips from previous runs and will do a comparison as soon as I get some new runs in.
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#12
#15
Originally Posted by Mr_pharmD
hey daveB, did u ever run your car when it was stock? Also, is that 14.49 with slicks or stock rims? Powerbrake?
Also, if I have a 05 AT with the sports package (LSD), will I lose the LSD option if I swap this out?