Differences between a 34 GTT and HR34 GT

[Nippon_nick]

Hi Guys,

Im trying to get my head around whats involved to do a manual gtt conversion to an auto hr34 coupe. I'm just wondering if anybody here has done this before, what all the differences between them are(stuff im going to need)?

So far on my list ive got : Engine, box, diff, driveshaft and brakes.... basically the whole f*cking car ?‍♂️ I've also read here that it uses different shocks.... don't tell me it uses different sub frames too? If i was to go down the road of a doner car, would a mt/turbo stagea be a straight bolt on, bolt off situation?

 Any help, idea's, feedback, criticism all welcome. Just trying to get my head around it. If the answer is buy a smashed gtt sedan or stagea, and transfer everything over, easy. If the subframes are different, but i can get away with running different coil overs? Thats great too, i'l just buy a 33 box, neo and all the other stuff separately.   

(Before you tell me to buy a GTT, im located in Japan... and the average price for them is now 2 million yen. I was a able to snag a mint, own owner gt coupe for 600k & parts/doner cars here are cheap)

 

Edited September 9, 2020 by Nippon_nick

[GTSBoy]

You don't need to worry about the suspension. GTT have fork type rear dampers. Your car has eyelet type. But that's the same as R33 GTST, so not problem, there is suspension available.

Your rear subframe won't have HICAS. Win. That's one less thing to worry about.

Your car won't have traction control. So if/when you put a factory Neo RB25DET ECU into the car, it will chuck the shits at you because not TCS computer and probably no ABS computer eithers. You will need Nistune to dial that out, or an aftermarket ECU.

You will need the engine bay loom, and the driver's side engine bay/gearbox loom, and you will probably still have to do wiring mods.

You will need a clutch pedal bracket and pedal, master, wiring for the clutch switch, etc.

Buy a VQ37 and CD009 instead.

[Nippon_nick]

15 minutes ago, GTSBoy said:

You don't need to worry about the suspension. GTT have fork type rear dampers. Your car has eyelet type. But that's the same as R33 GTST, so not problem, there is suspension available.

Your rear subframe won't have HICAS. Win. That's one less thing to worry about.

Your car won't have traction control. So if/when you put a factory Neo RB25DET ECU into the car, it will chuck the shits at you because not TCS computer and probably no ABS computer eithers. You will need Nistune to dial that out, or an aftermarket ECU.

You will need the engine bay loom, and the driver's side engine bay/gearbox loom, and you will probably still have to do wiring mods.

You will need a clutch pedal bracket and pedal, master, wiring for the clutch switch, etc.

Buy a VQ37 and CD009 instead.

 

Ok, cheers mate. This is exactly the info i needed. The suspension is a relief, sounds like it should all be straight forward except for the wiring. I take it GTT sway bars just bolt in too? Id love to go something like a VQ but that's starting to sound a bit too ambitious for me. That said I'm still dreaming at the moment and gathering info. Still months away from starting this so maybe i grow a pair of balls in that time. Thanks again.

[GTSBoy]

NAs have no rear ARB mounts on the body, so you will need to get those.

[Nippon_nick]

4 hours ago, GTSBoy said:

You don't need to worry about the suspension. GTT have fork type rear dampers. Your car has eyelet type. But that's the same as R33 GTST, so not problem, there is suspension available.

Your rear subframe won't have HICAS. Win. That's one less thing to worry about.

Your car won't have traction control. So if/when you put a factory Neo RB25DET ECU into the car, it will chuck the shits at you because not TCS computer and probably no ABS computer eithers. You will need Nistune to dial that out, or an aftermarket ECU.

You will need the engine bay loom, and the driver's side engine bay/gearbox loom, and you will probably still have to do wiring mods.

You will need a clutch pedal bracket and pedal, master, wiring for the clutch switch, etc.

Buy a VQ37 and CD009 instead.

 

Ok. I was really hoping i could get away with just swaping ecu's and using the original wiring. If i really need all the wiring too i should really just buy a doner car, will be far cheaper and easier i think. Manual turbo stags here are dirt cheap.. will that work? How about a 4wd one or is that too much work?

 

Edited September 9, 2020 by Nippon_nick

[Kinkstaah]

The only thing that will directly bolt on is the car you are trying to turn this in to. Also it won't directly bolt on.

Your ABS will be different to a GTT, so your rear diff is a S15 style too. Which you will need, cause you will have an open diff. The closest you will get is the looms etc from a GTT, but be aware, this will not plug and play and "just work" you will have cluster issues (speedo etc) to deal with.

This car will teach you many things, in $ or in learning. There is no completely non-thinking way to achieve this goal.

2 million yen is what they sell for here too. You will only save money in sweat equity.

Source, had R34 Non turbo, then put a turbo motor in it, then obtained a GTT, then manual converted it, then put a LS V8 and T56 into that GTT. I've seen things.

You will too.

[Nippon_nick]

18 hours ago, Kinkstaah said:

The only thing that will directly bolt on is the car you are trying to turn this in to. Also it won't directly bolt on.

Your ABS will be different to a GTT, so your rear diff is a S15 style too. Which you will need, cause you will have an open diff. The closest you will get is the looms etc from a GTT, but be aware, this will not plug and play and "just work" you will have cluster issues (speedo etc) to deal with.

This car will teach you many things, in $ or in learning. There is no completely non-thinking way to achieve this goal.

2 million yen is what they sell for here too. You will only save money in sweat equity.

Source, had R34 Non turbo, then put a turbo motor in it, then obtained a GTT, then manual converted it, then put a LS V8 and T56 into that GTT. I've seen things.

You will too.

 

Thanks mate. So it sounds like again, the biggest problem is going to be wiring. Il give your build thread a good read.

[Kinkstaah]

It's not actually so bad - If you have a manual gearbox from a R33 GTST this is something that has been done many, many times. See also: a R34 GTT gearbox. Just make sure it's a turbo gearbox.

The workshop manuals will get you home with a gearbox conversion and/or its been covered here many times.

This fixes 90% of the problems, because the only 'hard' stuff is making the auto work. If you have no auto to talk to anymore, then eh, any of the WIDELY available ECU's can run the motor, and the your brain can be the ECU for the manual

[Nippon_nick]

46 minutes ago, Kinkstaah said:

It's not actually so bad - If you have a manual gearbox from a R33 GTST this is something that has been done many, many times. See also: a R34 GTT gearbox. Just make sure it's a turbo gearbox.

The workshop manuals will get you home with a gearbox conversion and/or its been covered here many times.

This fixes 90% of the problems, because the only 'hard' stuff is making the auto work. If you have no auto to talk to anymore, then eh, any of the WIDELY available ECU's can run the motor, and the your brain can be the ECU for the manual

 

I can go with anything really, whatever is easiest /cheapest.  The cost of these cars is currently out of control here BUT parts are still somewhat cheap thank god. I will keep my eye out for a binned manual gtt sedan / stagea over the coming months. That way i can get EVERYTHING. If i cant do that i will just get a 33 box and neo from the wreckers and go that route.