Re: 6l80e or 6L90e for our ZR-1's?
 

The 6l80e/90e has huge ratio jumps compared to the 4l80e, and even a bit more than the 4l60e/65e/70e trans.


th 350-1st 2.52, 2nd 152, 3rd 1
th-400-1st 2.48, 2nd 1.48, 3 1:1
200r4 1st 2.74:1, 2nd 1.57:1 3rd 1.00:1, 4th 0.67:1

4l60e/65e/70e 3.06 1.62 1.00 0.70
4l80e/85e 1st 2.48,2n 1.48 3rd 1.00 4th 0.75

6l80e/90e 1st 4.027, 2nd 2.364,3rd 1.532, 4th 1.152, 5th 0.852, 6th 0.667

The good thing about the 6l80e/90e is the nice deep OD ratio which is the same as the 200r4 auto of 0.67:1

The 2nd gear of the 6l80e/90e trans is pretty close to the 1 st gear of the 4l80e/85e/400/350 transmissions.

In the CTS-V V2, the ones with the LSA supercharged engine, their was a top speed limit on the 6 speed automatic cars because a certain part might let go if it spun above a certain rpm.

My point is, dont be lured into installing a transmission simply because it has more gears. Sometimes more is not better.
The TCM tuning on these clutch to clutch transmissions is critical, and they wil frag if mis calibrated.

I wish the 200r4 had teh torque capacity of a 4l85e trans. Not crazy low 1st gear, not too bad rpm drop during upshiufts, plus a nice deep OD for highway cruising.

peace
Hog

Re: 6l80e or 6L90e for our ZR-1's?
 

modern builds on the 2004R are holding up well and it's making a comeback

I've got a stout art carr 2004R that holds 500 rwtrq no problem.

much less drag on the HP than the bigger trans too.

and you don't need a tranny controller which is a big plus.

Re: 6l80e or 6L90e for our ZR-1's?
 

I have not done a 6L80/90E trans swap.

At this point the 4L80E is basicly a TH400 with overdrive and a very proven trans.
TransmissionCenter has a tailhousing for the 4L80E but you need to replace the output shaft with a 27 spline 700r4/4L60.

My tailhousing needs no mods to the 31 spline output shaft on the 4L80E
you reuse your stock ZF driveshaft,stock C-beam.

Also if you choose to on the 4L80E you can go with 2.75 first gear.

Pete

Re: 6l80e or 6L90e for our ZR-1's?
 

How about a TH400 with a early Ford OD. I have seen one in a 429 ci 66 Buick 4:56 gears 1700 rpm 65 mph in od. The trans combo is probably for sale since the owner is going back to a stock 350 and original rear. No problems just wanted a stock setup.
http://thepandatrap.com/tyler/buick/FF05_Before.jpg

http://thepandatrap.com/tyler/buick/FF11_After.jpg

If someone is interested let me know. Its running behind a 500+HP Buick 401 nailhead. well it used to be a 401.LOL

I know the guy who makes the adapter only if you are interested. No worries about all the electronics with this combo just install and GO.

Tyler

Re: 6l80e or 6L90e for our ZR-1's?
 

OP; the speed shop that did [sort of] my conversion pulled the SGI-5 speedo control module (was NOT needed :rolleyes: ). It's new, and available for postage + the cost of a plate of good grub...

Spec / data sheet available here, and PDF here

PM me, or anyone else, if interested here...

Re: 6l80e or 6L90e for our ZR-1's?
 

That mightbe akin to the Gearvendors Over/Underdrive. It bolts onto the back of the trans, just like the older 4+3 transmissions except that it handles 1400hp during engagement.

I have a buddy that has one in his 1998 Chev Tahoe with a 502 getting ready ofr a 3.3 Whipple supercharger.
He runs 4.56 gears and cruises under 2000rpm with the 4l80e trans.
http://www.gearvendors.com/

It effectively doubles the gearing that your current trans has. if you have a 4 speed 200r4, 700r4, 4l60e/65e/70e, 4l80e/85e you end up with 4 gears that can be split for 8 gears total.
If you have a 6 gears before, you had 12 gears after.

They are used in Motorholmes, so they are a stout piece.

700r4/4l60e

http://i1202.photobucket.com/albums/...gearvendor.jpg

4l80e

http://i1202.photobucket.com/albums/...rn/gv4l80e.jpg

peace
Hog

Re: 6l80e or 6L90e for our ZR-1's?
 

Pete, on the 4l80e, I am assuming that the 4l80e does OK with WOT romps in OD?
Same 0.75:1 ratio with some added torque multiplication if the TCC isn't locked.

reason I ask is after my 1st WOT 3-4 **** in a 4l60e truck, it took the trans out. Now these trucks were NOT calibrated to do a WOT 3-4 shift from the factory, I had just removed the top speed limiter and allowed the WOT 3-4 shift via the PCM tune I did.

thanks
peace
Hog

Re: 6l80e or 6L90e for our ZR-1's?
 

Yes,your right the 4L60's can not handle big power at WOT 3-4 shifts
The 4l80's we can not hurt them no matter what shift.
I don't know of any LT5 making that kind of power to be capable of braking the 4l80 at WOT 3-4 shift, of course trans would need to be done/build right.
I remember back in the day the old 700r4 would not upshift into overdrive (4th) at WOT unless it was a police impala or a corvette the rest were either speed limited or would not shift into 4th at WOT.

HD trucks used 4L80 transmissions and i know those big trucks can haul some weight besides there own weight of 6-7000lbs and pull 20,000 lbs so our little 3400 lb ZR-1's could not hurt this trans.
Heck some guys go to the boneyard take these transmissions off those old trucks put fresh fluid in them and go racing they still hold up for a while,it's crazy.

Pete

Re: 6l80e or 6L90e for our ZR-1's?
 

Thanks Pete.

I also remember those 700r4 not shifting at WOT into 4th. Dads truck was an 89 with those 1/2 moon speedommeters that after burying at 140kph, would wrap around and start reading on the other side of the speedo. I would have to lift off the throttle to get a 3-4 shift, but of course the engine wouldn't pull in 4th gear at 3/4 throttle.