GT4 gearbox with useless 1st gear

I have a GT4 4wd gearbox with the rear transfer housing plated shut. That means no rear transfer housing, no tailshaft, rear diff and rear axels. I have it in my FWD starlet. There is the transfer case complete, but not the rear section.


Now when i take off in 1st gear, the engine revs high and the car goes not far. Kinda like a very slipping clutch and the car goes little distance associated with engine speed etc. Only when i put in 2nd gear it takes off like normall.


So having said this, should i change the gearbox leaver to FWD mode? I guess its kinda like a celica gt4 with the rear end raised from the ground. Is the front end 50% and the rear 50% drivetrain ratio?


What should i know?

 

http://www.youtube.com/watch?v=g5MUl2cU0mE&list=UUNhqf-0-ZFuP_n5yAg4SAww&index=1&feature=plcp


The car does drive in 1st gear, it just revs more than what i would expect, other gears are fine.

 

If your referring to the diff/crown wheel in the transfer case, yes, its all there.


I just find that it may rev high,like up to 6000rpm just to hit 30-40kms/hour etc. 1st gear is the only drawback, the other gears are fine. I guess it may be something i have to live with. The car hooks up great from 2nd onwards.


All i know is that the centre crown wheel, in the transfer case, is just free spinning, cos it doesnt have the rear housing assebly for the tailshaft/rear diff etc. I guess the car is like super vtec or nitrous. Its just responsive because it doesnt need to spin all that extra drivetrain etc.

 

I'm getting the car dynoed tomorow morning.


The car has major torque steer on boost, so i guess its actually working etc, i'll post up results 2mrow.

 

The car made only 93kws.




Here are the specs >
12psi
11 degrees base timing
Dry ice satuarated top mount intercooler
Tyre pressure: 30psi
4th gear pull


As far as i know, hopefully, the tvis is working.

The overal power figure appears somewhat low, cos i was expecting well over 120kws minimum. The power curve is very straight for such type car and its age. Video coming soon.

 

http://www.youtube.com/watch?v=xsLxJbXWfw8&list=UUNhqf-0-ZFuP_n5yAg4SAww&index=1&feature=plcp

 

Yeah i know, i have doubts.


As far as i know, there is no leaks in the intake system causing boost leaks. Engine only has 160,000kms to it and its in A+ order. I just dont know. I'm probably guessing the tvis isnt working.

Maybe i should connect direct 12volts to the tvis and see if its working, opening the secondary butterflies. Cos thats the only thing i could think of that may cause that low output.


Its either the tvis or the dyno was not the best.

 

im pretty confident, now, that the TVIS is not working. I will now remove it, and get the car dynoed again.

 

Yep, its confirmed, a solonoid directly connected to the vacume diaphram wasnt connected. So the secondary butterflies were shut always. I will now remove the TVIS completely and ad a boost controller.


PS: I have selected FWD only mode on the gearbox, and will see what happens.

 

Today, out of curiosity, i selected FWD only mode via that adjustable plate on the gearbox. My lord what a difference it makes.


The engine actually has quicker load and turbo spool up. From my understanding, as you would expect from such gearbox selection, 100% drive power is at the front wheels and not halved. I drove around the block with no issues, so far.

What a difference, from the standard 4wd selection.