Why are 4L60E's so weak?!?
07-17-2011, 01:21 AM
#12
That's an option. Right now I believe I have 3.73's. I don't really want to re-gear. One, I'd have to do it twice. Two, I'd have to give up off the line performance.
Are the 80E's tall geared in first because the 3/4 ton trucks typically have 4.11's in them? I don't understand why they're first gear is ~30% higher.
Are the 80E's tall geared in first because the 3/4 ton trucks typically have 4.11's in them? I don't understand why they're first gear is ~30% higher.
07-17-2011, 07:52 PM
#14
4L60E
3.06
1.62
1.00
0.70
2.29
4L80E
2.48
1.48
1.00
0.75
2.08
That seems like a pretty substantial gearing difference. Honestly, my biggest concern is the gas mileage. I know that sounds silly when building a high horsepower engine, but it is my daily driver and 70% of my driving is freeway driving.
Gadget, you're right. The gear ratios are the same as the turbo 400's, except reverse.
3.06
1.62
1.00
0.70
2.29
4L80E
2.48
1.48
1.00
0.75
2.08
That seems like a pretty substantial gearing difference. Honestly, my biggest concern is the gas mileage. I know that sounds silly when building a high horsepower engine, but it is my daily driver and 70% of my driving is freeway driving.
Gadget, you're right. The gear ratios are the same as the turbo 400's, except reverse.
The steep 1st of the 60E is nice for takeoff. 3rd is same for both 60 & 80 1:1. So, then for you it comes down to, 1st is 3.06 (60E) vs 2.48 (80E), a big drop as compared to the big brother on the 60E to 1.62 in 2nd, whereas 80E only goes to 1.48. So, then OD gear is .70 (60E) & .75 on the 80E.
Is that OD gear for MPG reasons a deal breaker on the 80E? Not really, since it's pretty close. The 1-2 drop is where they both vary considerably. Set aside the idea of the physical part of the swap & what it takes if ya want an 80E. A built 60E costs = a built 80E, or very similiar. I'm goin by the prices if say FLT built it. So that cost is even.
Where they differ
What it costs to get an 80E (core cost too), parts to adapt, wiring, tune.
+50 # in wtg. +10 for convertor. Say 60#.
The 1-2 difference betw. both trannies & potential durability / reliability if u think 60E is a concern. OD is a minisule difference w/. only .05 ratio separating then 2 of them.
Forget bout the THM350, not sure why that's even in there unless as a comparison. Do u plan on driving alot in reverse?
Like Beatdown said, 4L80E = Turbo 400, but w/ OD & electronics. The 60E is 350 THM based. As are the 700r4 / 4L60. While they may've made improvements over time, whatever weaknesses faulted then 350THM, to some extent are in a 60E. Likewise a 400THM to a 80E. But it's flat out a brute made to take a beating. Torque capacity on a 60E is ~360 ft.lbs. 80E I'm not sure, but north of that. I know I've read it. 450 ft.lbs. maybe? Maybe more or less. I'm sure someone knows or u can find it rather easily.
Last edited by fastnblu; 07-17-2011 at 08:00 PM.
The Buick GN's love em 
07-18-2011, 03:54 PM
#18
I honestly feel like alot of people on here beat the snot out of these trannies more then they will admit... I dont know if he's a member on here but last I checked, 'Dozer' on sss.com has a 408/cog drive F1R running 14psi and a level 5 4L60E to the tune of low 11's and around 120mph.
I agree with what's been said previously... It's all in who builds the trans.
I agree with what's been said previously... It's all in who builds the trans.
07-18-2011, 04:19 PM
#19
TECH Apprentice
iTrader: (11)
Join Date: Apr 2005
Location: N.E Missouri
Posts: 390
Likes: 0
Received 0 Likes
on
0 Posts
I love how these threads get started. Someone bitching about a 60E, then someone chimes in telling them to go 80E, then the guys with tech knowledge get in and start talking technical. Always the same trans thread. It is what it is, theres a lot of variables in a trans with all the moving parts, oil passeges, and now electronics, who knows when its gonna go. Just get in and drive.....if it breaks fix it
07-19-2011, 12:28 PM
#20
Launching!
Join Date: May 2004
Location: Tuscaloosa, AL
Posts: 287
Likes: 0
Received 0 Likes
on
0 Posts
The RPM difference while in OD is only 150 more rpm for the 80e. So the gas mileage really doesnt get affected. Gas mileage is a direct reflection to what your right foot does.