i read somewhere that n/a differential in a twin turbo would be quicker of the line whats the+ and- of this swap

 

if you put a NA diff in a TT, it will be faster off the line, but your high end wont be as good, in terms of your RPMS/speed ratio..its gonna suck..plus you will have to shift one more time(into fourth) instead of just into 3rd in the 1/4 mile

1992 NA (Charcoal)
1990 TT (Charcoal)

 

The J-spec n/a diff is 4.3. So it will be alittle quicker over the quarter. Shifting into fourth will be an advantage as you will have a higher top speed.
If you have a TT & are thinking of this swap, then get rid of the troublesome HICAS and plumbing as well, then fit an n/a power steering pump.
The lower ratio diff and alittle less weight will make your ride all the more faster.

 

That's not quite true. In reality, acceleration will be better through all gears to the top speed of the car with the 4.08 rear vs. the twinturbo 3.69. The top speed will be less, but it will accelerate through the gears faster all the way to the top speed.

 

Only1Z,
you miss read what i wrote, i never said the "top speed would be effected" i said the Speed/rpms ratio would be not good.

1992 NA (Charcoal)
1990 TT (Charcoal)

 

What do you mean the speed/RPM ratio won't be as good? It only won't be for gas mileage...lol That's all I can think of!

 

i mean at higher speeds you will be at higher RPMS, compared to the RPMS you would be at with a TT diff...and those speeds



1992 NA (Charcoal)
1990 TT (Charcoal)

 

Right...that's advantageous except for the gas mileage. :-)