sbf

Has anyone switched from a 4l60e to 4l80e.want to see how much the et changed.I no on the dyno numbers are different but that's a dyno.i want to see track difference.i no the 80e is heavier but stronger not worried about what it takes to swap it.im concerned about et.

bbond105

Take a look at this thread.
https://ls1tech.com/forums/automatic...ding-4l60.html

NorthTexasConverter

Depending on your power level, you may very well actually IMPROVE your ET with a 4L80E over the 4L60E. It's not a substantial improvement, but improvement is improvement, especially when dealing with a heavier transmission.

sbf

Thanks guys anyone else

mrvedit

Since the 4L80E has a numerically much lower 1st gear ratio, your ET improvement (if any) will depend upon your engine/cam power range, rear ratio, car weight and a few other factors. In other words, it cannot be predicted with certainty.
IIRC an active member here with a 4th gen, about 500rwhp, about 3.73 rear, got a 0.2 sec improvement in ET. Not huge, but a small improvement and he now has the drivetrain for much higher power levels.

sbf

It's going in a 71 nova.ls3 416 hoping for 500+wrhp n/a then 200 nos.im thinking 3.73-4.10 on rear gear I guess 3800+ stall. I figure around 33-3400lb.im just trying to put this car together 1 time so before I build a 60 or 80 I'm just trying to see if one was faster than other

mrvedit

With a 4L60e's 3.06 1st gear combined with 3.73 rear, significant power, high stall and relatively light car, you would have significant traction problems. This is the exact combo where a 4L80e is most likely to yield quicker ETs due to its tighter gear ratios; you have plenty of power to handle it 2.48 first gear. Indeed it would reduce your traction problems.
At 700 rwhp the 4L80e is the clear choice when you have the option.

You should use a calculator to determine the best rear ratio; I think it would be 3.73. On a 1/4 track you might run out of RPM with a 4.11 with your 200 shot. A friend of mine with a bit more power is hitting 6900 RPM with his 3.73 rear and therefore has to reduce it.

If I have time this weekend, I will try to find some threads that show ET comparisons with cars close to yours.

sbf

I would really appreciate it

floman

iTrader: (54)

Take a look at the mod list in my sig below. I made the swap last year due to some tranny issues not long after buying my car. The previous owner had issues a couple of times before I got the car, when I had an issue I decided I was not going to invest any more money into the 4L60E.

I did a lot of reading and decided to make the plunge even if it meant having the possibility of slowing down a tenth or two ( according to most peoples opinion ) I just wanted a bit more reliability.

Previous set up was a stage 2 " Century Transmission " 4L60E & a Circle D 3600 converter ( was really closer to a 4000 ) . Previous owner claimed a best 11.20 @ 122 on a 1.57 60 ft. Don't know what kind of DA he made the runs in or how much he ran the car on the track chasing #s, pretty sure he street raced quite a bit in the Houston area.

My first visit to the track ( I never got to make any track passes on the 4L60E set up ) my shift points were set lower than where they needed to be since I was still playing with the tranny tune in HP Tuners. I ran a couple of disappointing 11.70s @ 117 mph on a crappy 1.70s 60 ft passes in early May 85 deg heat. Shift points were low at 5700 1st-2nd and 6000 2nd-3rd. After getting the shift points corrected to 6500 rpms on all shifts the car picked up 11.30s-11.40s @ 119-120 mph on mid 1.65 60 ft( now in the full summer heat here in SE Texas ) but still not where I wanted to be.

In the fall and winter months when the weather finally began to cool down, the car steadily picked up into the 11.20s @ 121 1.62 60 ft or so. ( finally fairly happy as the car is as quick as the previous owner claimed, even with a heavier and supposedly power robbing tranny, AND my 275 lb *** making the race weight 125-150 lbs heavier than the previous owners ) I eventually carved the ETs down to the 11 teens on 1.59-1.60s 60 ft and 11 ohs @ 122- 122.5 mph on 1.57 60 ft.

In Feb this year I caught a good night at Royal Purple Raceway ( formerly Houston Raceway Park "HRP" ) with some great DA and a light turnout with maybe 10-15 cars present I managed a 11.003 @ 123.5 on 1.55 or so 60ft, man oh so close to that 10 sec time slip. Then I hot lapped the car 5 runs in a row never shutting off, and clicked off 5 ten sec runs in a row managing to get 10.93, 10.92, 10.93 and then the last two passes were 10.87 and finally a 10.851 @ 124.2 mph on a 1.52 60 ft all this on motor driving 180 mile roundtrip @ 3800 lb raceweight.

Made several 150 shot nitrous passes throughout the year playing with my progressive controller, but never managed a perfect full pass. My nitrous activation and tranny shift points were not set just right so I had some surging issues. I also had too much gear with the 4.11s on the nitrous, would be on the 6800 rev limiter about 75 feet before the traps.

Best pass on the 150 shot was 10.24 @ 130.5 mph on a 1.403 60 ft on a less than perfect pass. I think the car would have gone some 10.0s or so on a non -issue perfect pass. I now have 3.73s & full spool and looking forward to some full out passes without hitting the rev limiter.

sbf

floman i read your post this morning and added you as a friend.you and north texas converter help me made my decision.thanks to all that replied