convert to automatic trans

[rbidwell]

I am considering putting a 4L80E automatic transmission in my ZR-1 and would like to hear from those who have had any experience with that conversion. When the car is done it should have around 600+ rwhp. I know that fuel mileage will suffer some, but I am hoping the drivability and less worry about maintenance on the manual transmission, might make the switch worth it. I will not be drag racing the car or driving it very hard. I may do the one mile run just to see what it will do. The Sandhills race in Nebraska is the closest. Thanks for any help.

Ron Bidwell

[Blue Flame Restorations]

You need to speak with Pete, in Chicago. Maybe he'll see this thread.

[Hog]

I wish the 4l80e has the gearing of the 200r4 from the BOP cars. A nice 2.74:1st gear and a deeper 0.67:1 OD ratio.
4l80e is 2.48:1 1st, 1.48:1 2d, 1:1 3rd all the same as thm 400, but with the 0.75:1 OD ratio.

There are some companies that can make some super stout 200r4's, and then the electronic ocntrol isnt needed, but a Throttle Valve cable is needed as the 200r4 uses the TV cable to adjust line pressure just like the 700r4/4l60 non elecronic trans does.

A nice 4000rpm torque converter would work great, or even better dyno the car to find its torque peak, and get a coresponding TC that will stall to that rpm.

peace
Hog

[Pete]

I'm not understanding what your asking.

I have done a couple of these conversions.
One was a Turbo Z went with 4L80E,but the one i can comment on is the on a local guy (Chicago area) that went with the auto conversion from 4L80E and then to 4L65E the Z has a 441ci 575RWHP runs mid 10's @ 133 MPH he has a Precision Industries TC 2800 stall w/lock up 3.91 rear gears.
He has driving the car to Bowling Green from Chicago with no issues.
The 4L80 has .75 fourth gear same as the ZF's 5th gear and since our Z's run top speed in 5th gear if you keep stock 3.45 rear gears i can't see why you could not hit 180+ MPH.
With the lock up TC it drives like a stock car,real nice street manors.

On a turbo car auto is the way to go.
If you decide to do the auto conversion it will be funny for a few days you'll be looking for the clutch pedal.:)

I don't reccommend the 4L60E/4L65E he went thru 4 or 5 of them now he might be going back to the 4L80E.
If you need more info feel free to ask.

Pete

[Pete]

I wish the 4l80e has the gearing of the 200r4 from the BOP cars. A nice 2.74:1st gear and a deeper 0.67:1 OD ratio.
4l80e is 2.48:1 1st, 1.48:1 2d, 1:1 3rd all the same as thm 400, but with the 0.75:1 OD ratio.

There are some companies that can make some super stout 200r4's, and then the electronic ocntrol isnt needed, but a Throttle Valve cable is needed as the 200r4 uses the TV cable to adjust line pressure just like the 700r4/4l60 non elecronic trans does.

A nice 4000rpm torque converter would work great, or even better dyno the car to find its torque peak, and get a coresponding TC that will stall to that rpm.

peace
Hog

You can change to 2.75 1st gear in the 4L80E we are stuck with the .75 4th just go with 3.33 rear gear.

Pete

[Gunny]

Check with John Becker (forum name - aafc). If I'm not mistaken he has a white Z that's an auto and it might be the 4L80E.

[Bob Eyres]

There was a Colorado ZR-1 with a 415 and 600+h.p. that had a 4L80e in it. I don't remember the owner's name, but he did all his own wrenching and built a lot of street rods. A good man to talk to if someone here can come up with a contact #.

I used to hammer my car quite a bit at the drag strip, but gave it up when I got sick of the trans breakage and clutch issues. I wish I had an automatic to solve that. But if you're not drag racing the car, why the automatic?

BTW, back in the last century there was an company in Indianapolis that did the conversion. The price tag at the time was $12K. :jawdrop:

[rbidwell]

to Hog: I have been thinking about putting a 200R4 in my 66 Chevelle SS and agree with you, the 200R4 does have better gearing.

to Pete: thanks Pete, this is the information I was looking for

to tuband: thank, will try to John

to Bob Eyres: that would be Ron DeWild. I think I have his number some place.

The car is at Henderson Performance waiting for the turbos. Corey can do the conversion.

Thanks for all the comments.

[jimmac28]

Hey Pete whats the chance of installing a 6L80e or a 6L90 in a Z?

[Pete]

Hey Pete whats the chance of installing a 6L80e or a 6L90 in a Z?

Jim,info i got on the 6L80/90 if you keep it under 500hp no problem if your putting down some big HP #'s they will not hold up.

This is what i was told from the trans guys.

The local Chicago 441ci/auto Z was thinking to go with 6L80 but after talking to the trans guy it's a no go.

Pete

[Pete]

to Hog: I have been thinking about putting a 200R4 in my 66 Chevelle SS and agree with you, the 200R4 does have better gearing.

to Pete: thanks Pete, this is the information I was looking for

to tuband: thank, will try to John

to Bob Eyres: that would be Ron DeWild. I think I have his number some place.

The car is at Henderson Performance waiting for the turbos. Corey can do the conversion.

Thanks for all the comments.


Ron,your Z is in very good hands Corey is more then capable to do the job.

Everybody has ideas on TC stall, you have to ask yourself what will you mostly use the car for, if you won't be doing too much drag racing then i would go with a tight TC 2800-3200 very good street manors still give you a kick in the bott.
I would prefer a tighter TC for street use 26-2800

Real high 36-4500 stall and street driving will suffer,feul economy and heat/cooling issues in traffic and so on, to me a stall like this is for drag racing only i can't understand why anyone would want this high stall for street use.

Trust Corey he's a smart guy.
Pete

[jimmac28]

Jim,info i got on the 6L80/90 if you keep it under 500hp no problem if your putting down some big HP #'s they will not hold up.

This is what i was told from the trans guys.

The local Chicago 441ci/auto Z was thinking to go with 6L80 but after talking to the trans guy it's a no go.

Pete

From what I hear that some trans guy have them good to 1200 hp, but its the control problems on our older cars that might hold them back. I was thinking that someone might have worked that out.

[Pete]

From what I hear that some trans guy have them good to 1200 hp, but its the control problems on our older cars that might hold them back. I was thinking that someone might have worked that out.


Yes,also the control issue,but i'm sure somebody will come up with something,soon.
I hope the 1200hp is true cause a 6 speed auto is the best of both worlds.
I remember back in the day if you wanted to use the 4L80E you had to use the controler from a diesel truck and reprogram it or use a 4L80 there were no controllers from the aftermarket.

Pete

[rbidwell]

Thanks for all the comments on helping me think through the conversion to an automatic. At this point I have decided to stay with the 6 speed.

Ron

[mgg]

Smart move !

[Pete]

Thanks for all the comments on helping me think through the conversion to an automatic. At this point I have decided to stay with the 6 speed.

Ron

That's cool.
Now lets hope clutch holds up,it is Christmas time so anything is possible :)

Pete

[matszr1]

I'm not understanding what your asking.

I have done a couple of these conversions.
One was a Turbo Z went with 4L80E,but the one i can comment on is the on a local guy (Chicago area) that went with the auto conversion from 4L80E and then to 4L65E the Z has a 441ci 575RWHP runs mid 10's @ 133 MPH he has a Precision Industries TC 2800 stall w/lock up 3.91 rear gears.
He has driving the car to Bowling Green from Chicago with no issues.
The 4L80 has .75 fourth gear same as the ZF's 5th gear and since our Z's run top speed in 5th gear if you keep stock 3.45 rear gears i can't see why you could not hit 180+ MPH.
With the lock up TC it drives like a stock car,real nice street manors.

On a turbo car auto is the way to go.
If you decide to do the auto conversion it will be funny for a few days you'll be looking for the clutch pedal.:)

I don't reccommend the 4L60E/4L65E he went thru 4 or 5 of them now he might be going back to the 4L80E.
If you need more info feel free to ask.

Pete


Pete,

Your post sounds like your trying to talk me into puting an automatic in my car. Gee with that and a set of slicks, watch out Kevin:wink:

[Pete]

Pete,

Your post sounds like your trying to talk me into puting an automatic in my car. Gee with that and a set of slicks, watch out Kevin:wink:


Almost forgot, the reason the Twin Turbo ZR-1 went with auto (4L80E) he could not get a clutch to hold it.
He used to run the Texas Mile.

Matt,hopefully we'll see you at next years Corvette challange with an auto and slicks.:)

Pete

[efnfast]

Can somebody please explain stall speed of a torque converter to me? -Steve

[Bob Eyres]

Can somebody please explain stall speed of a torque converter to me? -Steve

This is a good explanation:

http://auto.howstuffworks.com/auto-parts/towing/towing-capacity/information/torque-converter.htm

The higher the stall speed, the more rpms you can build at the line without stalling. That means you can leave harder, better 60ft. time.
But on the street that makes for a loose, sloppy feel when in traffic. Too many revs at low speed means crappy mileage, more heat, etc.

[Hog]

The higher the stall speed on a TC allows allows for less rpm drop during upshifts.

I was running a stock TC that during a WOT 5500rpm upshift would result in 3800rpm in 2nd gear. After swapping to a 1996 L36 V6 S-10 DCLF code torque converter, the same WOT 5500rpm shift woudl result in 4300rpm. Acceleration was much improved through the shifts instead of acceleration seeming to hesitate slightly, this was in a 4000 lb reg cab shortbox Vortec 350 truck with 4.10 gears.
With the stock 350 TC I could brake stall to 2000 rpm, with the V6 TC I could brake stall to 2800-2900 rpm.

Another negative with the 4l60e/65e/70e is the huge rpm drop between gears. This is only worse in the 6l80e/6l90e transmissions with their deep 4.02:1 1st gear.

You can swap gears of a 4l80e, but they are big bucks and there are fitment issues. FLT had to ship the gears back and forth to finally get them to fit correctly in a 4l80e.

peace
Hog

[aafc]

back in Aug. 2004 i removed my six-speed trans and installed a 4l60E. Pete
(FBI gang) sold me a flex plate that would bolt up to the ZR-1 motor. (SBC has 6 bolt holes and the LT5 has 8 bolt holes).
Well after braking 2 4l60E and 1 700R4 manual in 6 years (car was making
444 rwhp and 418 rwtq ). now this motor is a 368 with stage one cams. So
i installed a 4l80E with a 3200 stall convertor from FTI in Deland,fl. PETE
sold me a tail housing that would bolt up to the 4l80E trans. This allowed
me to use my six-speed drive shift and yoke assy.
On Dec. 2 ,2012 the last fun day sunday at speed world orlando i made
two passes.
1st pass I went 11.734@118.50 with 60' time of 1.771
2nd pass I went 11.592@119.58 with 60' time of 1.731
I don't road race or run the standing mile (I drove a B/ed dragster for ten
years NHRA) best run back in 1988 was 7.48@175.50. So i like going to the
track and show the z06's my wide rear end.
Now I get about 19 to 20 miles avg @ 70 mph on the highway and 15 to 17
avg around town.
The 4l80E is a tight fit and requires some thinking to make it work.
my 4l80E has 2.75 1st gear 1.57 2nd gear and 1.1 third gear 4th is .75 rear end is 3.73
the transmission shifting is handled by compushift controller.
If you are not going to drag race and you want to run an auto use a lower
stall speed convertor .

good luck with what ever you do
John Becker
member #0115
white/black #2546 one of a few auto (4l80E) eq ZR-1's

[Tyler Townsley]

What about a TH400 with a overdrive from an early ford std transmission? Friend has this combination in a 470 ci Buick (401 b and stroke) Running 4.56 rear gears he can cruze with OD in at 1800 rpm at 65. The TH400 is virtually bulletproof. He considered going the 200r4 route but his trans guy talked him into the 400 because of problems with internal case support of the tailshaft in the 200r4. The adapter to bolt the od to the trans is about 1k.

Tyler

[matszr1]

What about a TH400 with a overdrive from an early ford std transmission? Friend has this combination in a 470 ci Buick (401 b and stroke) Running 4.56 rear gears he can cruze with OD in at 1800 rpm at 65. The TH400 is virtually bulletproof. He considered going the 200r4 route but his trans guy talked him into the 400 because of problems with internal case support of the tailshaft in the 200r4. The adapter to bolt the od to the trans is about 1k.

Tyler


Take a look at this article.

http://www.hotrod.com/techarticles/drivetrain/gm_4l80e_automatic_transmission_review/

[Pete]

back in Aug. 2004 i removed my six-speed trans and installed a 4l60E. Pete
(FBI gang) sold me a flex plate that would bolt up to the ZR-1 motor. (SBC has 6 bolt holes and the LT5 has 8 bolt holes).
Well after braking 2 4l60E and 1 700R4 manual in 6 years (car was making
444 rwhp and 418 rwtq ). now this motor is a 368 with stage one cams. So
i installed a 4l80E with a 3200 stall convertor from FTI in Deland,fl. PETE
sold me a tail housing that would bolt up to the 4l80E trans. This allowed
me to use my six-speed drive shift and yoke assy.
On Dec. 2 ,2012 the last fun day sunday at speed world orlando i made
two passes.
1st pass I went 11.734@118.50 with 60' time of 1.771
2nd pass I went 11.592@119.58 with 60' time of 1.731
I don't road race or run the standing mile (I drove a B/ed dragster for ten
years NHRA) best run back in 1988 was 7.48@175.50. So i like going to the
track and show the z06's my wide rear end.
Now I get about 19 to 20 miles avg @ 70 mph on the highway and 15 to 17
avg around town.
The 4l80E is a tight fit and requires some thinking to make it work.
my 4l80E has 2.75 1st gear 1.57 2nd gear and 1.1 third gear 4th is .75 rear end is 3.73
the transmission shifting is handled by compushift controller.
If you are not going to drag race and you want to run an auto use a lower
stall speed convertor .

good luck with what ever you do
John Becker
member #0115
white/black #2546 one of a few auto (4l80E) eq ZR-1's

Hi John
Nice to see your enjoying your Z.
If i may ask who/where did you get your 4L80E trans from and how much you can PM or post either way.
Also are you happy with the 4L80E?
Pete

[aafc]

Hi Pete,
After braking my 700R4 a week after coming home from BG 2011, i went looking for a used 4l80E trans. I picked up a used 4l80E in Aug. 2011 it was all
apart. Had it rebuilt but had overheating internal in the trans. The shop took
it apart again but could not find anything, put it back together no charge.
Still had overheating internal (230 deg). Now if i put the trans in park or
neutral the temp dropped 10-20 deg in about 10 min.

Late in Nov. 2011 i found a company (P.A.T.C. in Bossier,LA.) that had a transmission dyno, talked to them and sent my 4l80E for testing. It seems that when i had the trans rebuilt the first time that some of the parts were
from a early and some from a late model. this caused the high heat in the
trans.

They called me and informed me about the problem. I said rebuild it. then
asked me if i would like to change the gears in the trans from stock 1st 2.48
2nd 1.48 3rd 1.1 4th .75 to after market set of 1st 2.75 2nd 1.57 3rd 1.1 4th .75 , ok do it.
Got my trans back late Jan. 2012. the cost was $3808. A lot cheaper then
to rpl the 4l60E every 10-12 months.

I'am more than happy with my choice. Again thanks for your help in making
this come together.

John Becker
member #0115
1990 white/black #2546
one of a few auto (4l80E ) eq. Zr-1's

[FU]

after market set of 1st 2.75 2nd 1.57 3rd 1.1 4th .75

I'am more than happy with my choice.

Hard to go wrong with the 480LE and a good (READ) expensive torque converter.I'm liking those ratio's John :thumbsup: !

[Bob Eyres]

At the beginning of this thread Ron mentioned that he wasn't going to the automatic for Qtr. mile use, or even to drive it hard. With a 600hp+LT5 he just wanted a trans. that would hold up under the power.
It seems most owners that choose automatics for the LT5 have monster motors that can take advantage of the smoother power delivery that the automatic offers. But that leads me to ask if the auto would be an advantage at the drag strip behind a stock block, NA LT5?

Let's say you've got a stock block motor, with cams and top-end work like Pete's which puts out a max of 525(?)550hp. That's a lot of power, but is it enough to overcome the disadvantages of the automatic which are: increased weight, only three gears in the quarter instead of four, and power losses in the torque converter and elsewhere.
John B.'s 60ft. times and e.t.s indicate that the auto might not be an advantage at the drag strip, even for a cammed 368c.i. LT5.

The question: Which would be quicker, a C4 ZR-1 Qtr. Mile. setup with the stock ZF6, or an 4L80E? And, at what HP level would it become an advantage.

[Pete]

At the beginning of this thread Ron mentioned that he wasn't going to the automatic for Qtr. mile use, or even to drive it hard. With a 600hp+LT5 he just wanted a trans. that would hold up under the power.
It seems most owners that choose automatics for the LT5 have monster motors that can take advantage of the smoother power delivery that the automatic offers. But that leads me to ask if the auto would be an advantage at the drag strip behind a stock block, NA LT5?

Let's say you've got a stock block motor, with cams and top-end work like Pete's which puts out a max of 525(?)550hp. That's a lot of power, but is it enough to overcome the disadvantages of the automatic which are: increased weight, only three gears in the quarter instead of four, and power losses in the torque converter and elsewhere.
John B.'s 60ft. times and e.t.s indicate that the auto might not be an advantage at the drag strip, even for a cammed 368c.i. LT5.

The question: Which would be quicker, a C4 ZR-1 Qtr. Mile. setup with the stock ZF6, or an 4L80E? And, at what HP level would it become an advantage.

Most turbo's make a crap load of power/torque and stock clutch will not hold it for just putsing around town you'll be fine but dead hook it at WOT and watch out for the smoke from the clutch :)

What i have noticed is auto will get better ET, manual gets better MPH.
So this tells me the auto robs some power.

I would bet John's auto Z picks up 2 MPH if he puts the ZF6 manual back in it

Pete

P.S.
Let me add
From my understanding if manuals have 15% drivetrain loss autos have 18-20% drivetrain loss.
Basicly whatever percentage you use just add 3-5% more loss in an auto.

[Bob Eyres]

What i have noticed is auto will get better ET, manual gets better MPH.
So this tells me the auto robs some power.

I would bet John's auto Z picks up 2 MPH if he puts the ZF6 manual back in it

Pete


If, as you say, the auto gets the better e.t. it wins, no matter the trap speed.

But I've never actually seen an auto equipped ZR-1 beat a ZR-1 with equal power and a stick shift in the quarter mile. And the times that I've seen auto equipped ZR-1's turn do not indicate that they are quicker.

[Pete]

If, as you say, the auto gets the better e.t. it wins, no matter the trap speed.

But I've never actually seen an auto equipped ZR-1 beat a ZR-1 with equal power and a stick shift in the quarter mile. And the times that I've seen auto equipped ZR-1's turn do not indicate that they are quicker.


Yes, ET wins no matter the MPH

The reason i say this.
If i were to install an auto in my Z (no other mods) it would probably run better ET but will loose MPH.
I think the reason for this is i lift and shift my ZF the extra power (less power loss) makes up MPH in the auto no lifting to shift and if you have a good build trans that sucker will shoot you forward at shift points.

This is the way i drive my Z, Paul or Dom has a story about this with me and Jim Ingles (?sp)

A auto car can get 1.40's-1.50's 60ft they can preload rear end in our manuals if we tried to get 1.4-1.5 60ft we'd scatter parts everywhere and believe me i'm trying to get a 1.5 just ask some of the guys that seen me run and this is why i say auto will ET better it makes up the power loss in 60ft and shifts.

Now if all is equal same 60ft etc, then yes manual will be quicker, of course it has less power loss.

I'm doing real world racing not a computer program
computer doesn't know we have spindles :-D

Pete

[Bob Eyres]

Paul or Dom has a story about this with me and Jim Ingles (?sp)

A auto car can get 1.40's-1.50's 60ft they can preload rear end in our manuals if we tried to get 1.4-1.5 60ft we'd scatter parts everywhere and believe me i'm trying to get a 1.5 just ask some of the guys that seen me run and this is why i say auto will ET better it makes up the power loss in 60ft and shifts. Pete[/QUOTE]

Yeah, Jingles ZR-1 abuse is legendary. I'd like to hear that story.

I think that the tendency to break driveline parts at launch is made worse in a stick shift car because many times the driveline is slack when the hammer is dropped at launch. This shocks the spindles, halfshafts, etc. and breaks things.
Do you use a line-loc? I never did, but it pre-loads the drivetrain by allowing you slip the clutch slightly. All that is done by the torque converter in an automatic, actually storing energy that you can use when you release the line-loc.
What were the 60ft times on those best runs that you've posted? I've only managed a 1.76 best. But without practice it's not easy to get under 2.0.

That launch is a big deal, I think the difference between a 1.50 and a 1.76 is about 6 car lengths at the other end of the track.

[Pete]

Paul or Dom has a story about this with me and Jim Ingles (?sp)

A auto car can get 1.40's-1.50's 60ft they can preload rear end in our manuals if we tried to get 1.4-1.5 60ft we'd scatter parts everywhere and believe me i'm trying to get a 1.5 just ask some of the guys that seen me run and this is why i say auto will ET better it makes up the power loss in 60ft and shifts. Pete
Yeah, Jingles ZR-1 abuse is legendary. I'd like to hear that story.

I think that the tendency to break driveline parts at launch is made worse in a stick shift car because many times the driveline is slack when the hammer is dropped at launch. This shocks the spindles, halfshafts, etc. and breaks things.
Do you use a line-loc? I never did, but it pre-loads the drivetrain by allowing you slip the clutch slightly. All that is done by the torque converter in an automatic, actually storing energy that you can use when you release the line-loc.
What were the 60ft times on those best runs that you've posted? I've only managed a 1.76 best. But without practice it's not easy to get under 2.0.

That launch is a big deal, I think the difference between a 1.50 and a 1.76 is about 6 car lengths at the other end of the track.







Oops,just saw/found this.

I don't have line lock.
My best 60ft was 1.69.

Jingles story was, someone mentioned to Jim that my Z was running 11.0's and could not hit that 10 second, he asked if i powershift i said "no" he replied that's the problem,he mentioned that he always used to powershift them and asked me why don't i powershift at which i replied GM won't rebuild my transmission for free. :)
It was all in good fun.

Pete

[Hog]

I just wanted to note that when using a transbrake, the drivehshaft/rear gear/half/shafts will be slack like a manual. The driveline would only launch in a loaded condition if foot braked.

peace
Hog

[Bob Eyres]

Oops,just saw/found this.

I don't have line lock.
My best 60ft was 1.69.

Jingles story was, someone mentioned to Jim that my Z was running 11.0's and could not hit that 10 second, he asked if i powershift i said "no" he replied that's the problem,he mentioned that he always used to powershift them and asked me why don't i powershift at which i replied GM won't rebuild my transmission for free. :)
It was all in good fun.

Pete

As far as I know, he was the quickest with a bone stock ZR-1, in the 12.8's or 9's. That's tough to do on Gatorbacks.
Yeah, it sure helps when you can walk away from a ZR-1 with trashed sychros, and say 'stick a fresh tranny in there boys".

During the early years that I had my car there were three different ZF6's in there. Very expensive practice.

[FU]

Very expensive practice.

You sure can say that again and again..............

Pete......4L80E for the 441.

[Pete]

You sure can say that again and again..............

Pete......4L80E for the 441.



Let's do it.:cheers:

But your left foot will be bored.;)

Pete