couple quick questions

hey i'm new and i don't know too much about supras or cars in general. i've got a couple quick questions about supras. first, is there anything different about a supra tt and a supra n/a engine wise, besides the twin turbo? second, can i swap across generations, ie take a mk4 engine and tranny and drop it into a mk3? third, how much difference in weight is there between an mk4 vs mk3. lastly, who has the best turbo kit upgrade? if that last one is going to cause an argument, don't answer it. anything you can tell me is great and this may make my decision on whether or not to get a supra. thanks.

....wheres Tcmaboy?

Anyways, For question one: there is a difference between the MKIV NA and twin turbo models. Im not a 2JZ expert so thats about as much as I can answer. I do know the pistons are different.

You can swap engines across generations, but its not a straight bolt on process. you'd have to do some fabricating and probally have to get some parts made to swap a 2JZ into an MK3.

I was thinking there was gonna be a weight difference but I just did some quick research and both cars come out to be around 3600 lbs. I would go check my MKIII vins for ya but im not at home.

On turbo kits for the MKIII, HKS makes a rare twin turbo conversion that supposed to be very good. I am personally looking at the Stage 5 BOSS turbo offered by Suprasport.com. Its gotten good reviews and offers some nice power increase for the price. I dont know too much about MKIV turbos.

first, is there anything different about a supra tt and a supra n/a engine wise, besides the twin turbo?

The injectors on the NA motor are 315cc high impedance units.
Turbo has 550cc low impedance injectors.

The NA has high comp (9.6:1) pistons.
The turbo has low comp (8.5:1) pistons.

The turbo motor has piston oil squiters to cool the piston head.

The cams are different.

The block and head are the same. If you are doing a big build that involves replacing the internals then you can start with an NA block and go from there.

If you are doing a mild build then you should start with a trubo motor.

second, can i swap across generations, ie take a mk4 engine and tranny and drop it into a mk3?

Yes you can, but you will need to do some work to make it happen. The stock twin turbos and the down pipe hit the firewall. They need an extra inch of clearance. The motor mounts will fit the 90+ subframe. The engine brakets will need to be reworked to make the motor sit right. You might want to consider using a 1JZ engine braket for the MK III Supra. The tranny mount and drive shaft will need to be custom units. You will need to use the engine harness and ECU for the 2JZ and integrate the body harness into the MK IV fuse block. You will need to rework the harness for the gauge culster. You will aslo need a bigger fuel pump.

third, how much difference in weight is there between an mk4 vs mk3.

They weigh about the same. The MK IV handles much better than the MK III due to changes in steering and suspension. The MK III tends to be tail happy.

lastly, who has the best turbo kit upgrade? if that last one is going to cause an argument, don't answer it. anything you can tell me is great and this may make my decision on whether or not to get a supra. thanks.

There is no such thing as the "best" turbo kit. A good kit should include an exaust manifold, turbo, intercooler, intake piping, and injectors. You will need either a stand alone ECU or a piggy back fuel computer to adjust for the increased air flow. You should have your new set up dyno tuned once it is installed. The trubo you select is going to be based on your power goals and more importantly your budget.


....wheres Tcmaboy?

Tcmaboy has projects that need his constant attention.

thanks for that info and sorry about the "best turbo". i can't decide between the mk3 w/ swap or mk4. does anyone know how much the swap may cost? i've got about $15k to spend after graduation and it's either get a car or a new bike to ride.