5R55 trans in a Mark VIII
- Thread starter chris2523
- Start date
Mad1stGen
Booster
This is very doable as the trans will be a bolt on with the exception of the driveshaft (flange style output shaft), and the trans mount (same mod as for the tr3650).
There is no aftermarket controller for the 5 or 6 speed autos on the market, and that is mainly due to lack of fast enough hardware that would be cost effective.
The way the bands are applied in that 5 speeds makes it impossible to control with the stock ECU, even if you had another manual switch for the OD.
Swapping an 05-10 GT ecu is an option, but I the 3V ECU is a bit crippled as well.
Best bet would be using an Aviator ECU and GT trans. Do it, wiring is fun
Ford nut
New member
Your a very sick man.Best bet would be using an Aviator ECU and GT trans. Do it, wiring is fun
SCTBIRD1173
Mark my Bird!
I always wondered the same thing Chris, I thank you for asking the question and I thank Jeremi for always having a solution to everything!
BadSax
enjoys 3 martini lunches
The idea has crossed my mind about a million times...
So the Aviator came with a 5 speed auto?
Does anyone know how 1st gear and 5th gear compare to the MK8('s 1st & 4th)?
Lvnmarks
quandoomniflunkusmoritati
4R70W
1st = 2.84
2nd = 1.55
3rd = 1
4th = .70
5R55S
1st = 3.22
2nd = 2.29
3rd = 1.55
4th = 1.00
5th = .71
Source: http://www.vibratesoftware.com/html_help/2011/Ford/Ford_Transmissions_Main.htm
1st = 2.84
2nd = 1.55
3rd = 1
4th = .70
5R55S
1st = 3.22
2nd = 2.29
3rd = 1.55
4th = 1.00
5th = .71
Source: http://www.vibratesoftware.com/html_help/2011/Ford/Ford_Transmissions_Main.htm
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driller
El Presidente
With 2nd/3rd/4th in the 4R70W equivalent to 3rd/4th/5th in the 5R55, what primary benefit would the 5 speed auto deliver?
1 more gear.....With 2nd/3rd/4th in the 4R70W equivalent to 3rd/4th/5th in the 5R55, what primary benefit would the 5 speed auto deliver?
Nigel...."this one goes to 11. "
Reporter...."why just get another that is louder and goes to 10"
Nigel...."but this one goes to 11"
SCTBIRD1173
Mark my Bird!
Well there is always the 5R55W which has slightly different than the 5R55SWith 2nd/3rd/4th in the 4R70W equivalent to 3rd/4th/5th in the 5R55, what primary benefit would the 5 speed auto deliver?
Although the 4R70W isn't as gappy as the AOD it's still a 4 speed, it needs more gears! :thumbsup:
driller
El Presidente
I'm more curious than anything else what the additional lower gear gives performance-wise, if any.
I have an acceleration program that will estimate acceleration through any gear/differential/tire combination and one thing I've noticed is the inevitable 'delay' when calculating shift times. In other words, for every shift point there is a loss of acceleration (to some degree).
In performance calculations with the 4R70W, you are only concerned with first through third. The two shifts make a substantial difference in performance. It seems adding a third shift point would only add more. I would need to run the calculations with the 5 speed ratios (1st through 4th) to see if there was indeed any difference.
If I am correct, I would presume from this exercise that is why many high performance (high torque) drag cars opt for the two speed powerglide transmission?
I have an acceleration program that will estimate acceleration through any gear/differential/tire combination and one thing I've noticed is the inevitable 'delay' when calculating shift times. In other words, for every shift point there is a loss of acceleration (to some degree).
In performance calculations with the 4R70W, you are only concerned with first through third. The two shifts make a substantial difference in performance. It seems adding a third shift point would only add more. I would need to run the calculations with the 5 speed ratios (1st through 4th) to see if there was indeed any difference.
If I am correct, I would presume from this exercise that is why many high performance (high torque) drag cars opt for the two speed powerglide transmission?
i would presume reliability and power handling also has a lot to do with the use of a powerglide trans. as simplicity can be quite reliable.... I would presume from this exercise that is why many high performance (high torque) drag cars opt for the two speed powerglide transmission?
Ford nut
New member
Yep one shift, light car.If I am correct, I would presume from this exercise that is why many high performance (high torque) drag cars opt for the two speed powerglide transmission?
This swap I would assume would be for the street.
I would not consider it a upgrade for the track.
Ford nut
New member
Stock....they are junk.
Drag racing comes down to being consistent.
Many transmissions can be made to take abuse...a powerglide provides a one shift option that takes out one more chance of a mistake.
A great option for a light weight race car.
A steeper first gear is the reason Ford Ecoboost trucks were walking away from the Hemi Rams, now that Ram is using the 8 speeds with a steeper first they are neck and neck with the Ecoboost if not faster with no increase in horsepower. You can also run less rear gear thereby getting 4.10 like acceleration with 3.31 fuel economy.
-Alan
-Alan
driller
El Presidente
I had some flight time to kill last night on a plane and found my acceleration program and thought I'd revisit this thread.
From my research, a F1 race car transmission can shift in as little as 0.1 seconds! Most street transmissions are reported at 0.5 to 1.0 second shift times. Some very high end street cars can come close to 0.15 seconds. That seems phenomenal to me, especially considering I calculated my shift times at a paltry 0.665 seconds for the 1-2 shift and 0.475 seconds for the 2-3 shift to the nearest 5 thousandths of a second average. Mind you the shush box 4R70W I have in the Blue Flame was purpose built and already came with the J-mod.
If I extrapolate the 5R55 gearing into the acceleration spreadsheet making some minor adjustments to scientifically emulate the gear change, I believe the 5R55 could shave 0.328 seconds off my ET.
I'm not sure on the effect on the converter flash without further data but it would likely be multiplying torque in 2nd gear as in 1st gear. Even if that assumption is wrong, it would still probably be worth over 2 tenths in a like environment.
FYI... I extrapolated my shift times from several datalogs taken at the track with a known ET to be able to scale the elapsed time for the shifts. It was very repeatable giving me confidence in the numbers.
From my research, a F1 race car transmission can shift in as little as 0.1 seconds! Most street transmissions are reported at 0.5 to 1.0 second shift times. Some very high end street cars can come close to 0.15 seconds. That seems phenomenal to me, especially considering I calculated my shift times at a paltry 0.665 seconds for the 1-2 shift and 0.475 seconds for the 2-3 shift to the nearest 5 thousandths of a second average. Mind you the shush box 4R70W I have in the Blue Flame was purpose built and already came with the J-mod.
If I extrapolate the 5R55 gearing into the acceleration spreadsheet making some minor adjustments to scientifically emulate the gear change, I believe the 5R55 could shave 0.328 seconds off my ET.
I'm not sure on the effect on the converter flash without further data but it would likely be multiplying torque in 2nd gear as in 1st gear. Even if that assumption is wrong, it would still probably be worth over 2 tenths in a like environment.
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KStromberg
Vortech kicked in yo
John, just through simple observations of the driving characteristics of my buddy's 5 speed automatic 2006 3-valve Mustang, I have to agree that you are more than correct. One thing I noticed in particular is especially with his WOT runs and watching the tachometer, it shifts VERY much like a MarkVIII with a high stall converter. There is nowhere near the rpm drop between shifts that you would find on a stock converter 4R70W Mark8. I think you are onto something here. An extra gear in a Mark8 would be quite significant.
https://www.youtube.com/watch?v=9U4xFWrnDPE&feature=c4-overview&list=UUSej7dIVdVg8KuJd354Ztug
https://www.youtube.com/watch?v=9U4xFWrnDPE&feature=c4-overview&list=UUSej7dIVdVg8KuJd354Ztug
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