3S-GTE Swap Guys -- Tranny and Gearing Related, What's it turning?? Options

[Fastbird]

For those who do have the 3S-GTE swap, couple of questions:

First, for those with the stock GT tranny, how are you finding the gearing and relative ability of the tranny to handle the power.

Second, for those with the E153 tranny, how is it's gearing compared to a stock GT's??? More or less RPM's at highway speed?? Better (shorter) gearing off the line or taller gearing??

Does anyone have a breakdown of the specific gears ratio for each tranny??

Thanks!! (I did a search but came up empty on this one)

[scothaniel]

For Reference:

MR2:
Transmission: 5-speed manual
Gear Ratios:
1st: 3.23:1
2nd: 1.91:1
3rd: 1.32:1
4th: 0.92:1
5th: 0.73:1

Final Drive Ratio: 4.29:1

Speed in Gears:

5th gear (6650 RPM): 145 mph
4th gear (7000 RPM): 125
3rd gear (7000 RPM): 91
2nd gear (7000 RPM): 60
1st gear (7000 RPM): 35


Celica GT:
Transmission: 5-speed manual
Gear Ratios:
1st (3.285):
2nd (1.96):
3rd (1.322):
4th (1.028):
5th (0.82):

Final Drive Ratio: 4.176

edited - wrong MR2 tranny the first time!

This post has been edited by scothaniel: Mar 20, 2006 - 10:30 AM

[scothaniel]

So yeah, S54 is better off the line and the E153 is (far) better for cruising. I used to hate driving my GT on the highway because the higher RPMS put the stock exhaust right in the resonant freq range. I thought the torque made 1st gear pretty pointless too - I had to start off in 2nd gear in winter to get traction.

[Fastbird]

That's EXACTLY what I was looking for. Looks like the E153 tranny is the way to go.

My main concern is going to be the 4000 RPM's at 80 MPH in the GT tranny with the motor swap. That's going to be making boost no matter what the engine load (MAP) is, thus killing gas mileage. Not that it's a big concern, but obviously a .72 overdrive is going to be nicer than the .82 overdrive.

Amazingly enough my 93 Trans Am has VERY close gearing to the GT celi but an added .62 overdrive and final drive of 3.23 stock which makes all the difference.

Now the question becomes.......is there a way to change the final drive ratio or a way to have a custom gearset made for the tranny??

[scothaniel]

Now the question becomes.......is there a way to change the final drive ratio or a way to have a custom gearset made for the tranny??

Anythings possible, for the right amount of cash

The S54 tranny that came with the JDM 3SGE motors had a different final gear ratio, I can look up the part number on the EPC when I get home - maybe its something you can special order. Otherwise, you could have some custom gears made. I had TRE (teamrip.com) rework my MR2 trans and I know they can make gears when needed - but it'll run some serious cash. My MR2 tranny shifts like a dream though!

Toyota MR2 - MKII N/A (1991 - 1994)
Engine:
Model: 3S-GE

Drivetrain:
Transmission: 5-speed manual
Gear Ratios:
1st: 3.285
2nd: 1.960
3rd: 1.322
4th: 1.028
5th: 0.820

Final Drive Ratio: 3.944

Acceleration:

5th gear (6500 RPM): 142mph
4th gear (7000 RPM): 122mph
3rd gear (7000 RPM): 98mph
2nd gear (7000 RPM): 67mph
1st gear (7000 RPM): 40mph

[Fastbird]

Man, looking at the mechanical limitations of these things, a 6 speed conversion is greatly needed. Things that make you go hmmmmm.....

[scothaniel]

There is a 6-speed conversion for the C series trans ( the manual trans for the ST models) but I dont think the gears are strong enough to handle high hp/torque motors.

[lagos]

My main concern is going to be the 4000 RPM's at 80 MPH in the GT tranny with the motor swap. That's going to be making boost no matter what the engine load (MAP)

no, turbo cars dont work that way. you never make boost while you are cruising. you can cruise at any RPM and not make boost. it only happens when you accelerate. the only difference is that the higher u are in the rpm, the faster the boost will come on. so if you are in 5th gear at 4grand, there will be almost no turbo lag and the car will become very fast. the 3sgte really comes alive at 4+ grand, so the gearing is kind of a benefit on the highway.

[BBoYRuGGeD]

ah lagos beat me to it

anyway i think 1st gear (GT tranny) is way too short with a 3sgte...but all the other gears are A-Ok to me.

bboy

[burneeed]

1st gear is bad. All I ever do is burn tire in first and I have blown 2 gt trannys because I beat on the car so bad. Both were high mileage. So right now Im actually in the process of swapping over thje mr2 turbo e153 tranny. Look for a write up by this weekend if I actually get everything going.

[Dr_Tweak]

Sean, Lagos is correct, the turbo will NOT be spooled even at 6500 rpm if you are only part-throttle. It is spooled up by the exhaust gasses, which means that air MUST be flowing through the engine... if the throttle plate is closed or mostly closed, then no airflow = no boost.

That's not to say that the E153 isn't a better tranny though.

-Doc

[Fastbird]

Thanks for edjumicating me guys. I guess it's not like a blower which will produce some boost at speed as compared to a turbo. Thanks for the help!

[scothaniel]

It does depend on the turbo though. I have a 14b on the car right now, and its hard not to boost on the freeware. Just trying to maintain a constant speed though really small hills makes over 5 psi of boost - and I do mean small hills (ski slope in Michigan wouldn't compare to the bunny hills in other states).