convert to automatic trans

[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]

Originally Posted by 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

Take a look at this article.

http://www.hotrod.com/techarticles/d...ission_review/

[Pete]

Originally Posted by 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

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]

Originally Posted by aafc

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 !

[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]

Originally Posted by 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.

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]

Originally Posted by Pete

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.