A £3500 alternative to the V160?

[Chris Wilson]

A gearbox is a torque multiplication device, and so of course is the back axle. A gearbox is traditionally and correctly rated by its torque handling capability in a 1 to 1 gear ratio, at its input shaft over a given RPM range. They have been rather devious and quoted it "at the rear wheels" where the axle ratio has multiplied engine flywheel / gearbox input shaft torque by the diff ratio in a direct gear.

[Luxluc]

Until the parts supply dries up, which appears to be happening now

 

Then there is only one solution : keep the car stock

[Sheefa]

The big power Supras some of us are running make life hard for the V160 / V161.

 

But that's life : nobody said it would be easy. If things break, you can always fix it.

 

True but also how often will you be running your car at max boost all the time. I know I'll be most likely running mine at 600-650fwhp the majority of time and only increasing to max boost/power when I really need to. A healthy balance is surely a good thing for the box.

[Luxluc]

True but also how often will you be running your car at max boost all the time.

 

I'm running on high boost setting all the time. Why go for a certain power goal and driving with 75% of it only ?

[Sheefa]

I'm running on high boost setting all the time. Why go for a certain power goal and driving with 75% of it only ?

 

That's because you are mental - I'm not The whole point of my power goal mate is to have a range of power I can deploy at any time via the Toucan when needed. If a Porsche Carrera comes along I'll deploy the 600rwhp. If it's a Lambo then I'll up it..... I personally don't see the need to drive it at full boost all the time, but then our UK roads are very different to yours too my friend

[Luxluc]

That's because you are mental - I'm not The whole point of my power goal mate is to have a range of power I can deploy at any time via the Toucan when needed. If a Porsche Carrera comes along I'll deploy the 600rwhp. If it's a Lambo then I'll up it..... I personally don't see the need to drive it at full boost all the time, but then our UK roads are very different to yours too my friend

 

Haha. Nice comment mate ... I like your approach.

[j_jza80]

Then there is only one solution : keep the car stock

 

You realise you're on a Supra forum, don't you?

[Chris Wilson]

There's also the issue of 4th and 5th gears being substantially overdriven. The seller makes this comment:

 

"This transmission's gearing is much different than the factory V160, therefore the rear gearing will be too high (3.13). You will need a 4.00 or taller gear to make this match the V160 gearing"

 

Err, where do I get a 4.00 to 1 or 4.11 to 1 or whatever CWP for the Supra case please mister???

 

 

He also means (I hope), shorter, not taller gear....

Edited April 11, 2016 by Chris Wilson (see edit history)

[Nodalmighty]

Isn't the N/A Manual and auto 4.083:1 ?

 

R154

 

1- 3.251

2- 1.955

3- 1.310

4- 1.000

5- 0.753

 

Diff 3.73

 

W58

 

1- 3.285

2- 1.894

3- 1.275

4- 1.000

5- 0.783

 

Diff 4.083

 

V160

 

1- 3.827

2- 2.360

3- 1.685

4- 1.312

5- 1.000

6- 0.793

 

Diff 3.266 (TT) 3.769 (NA)

 

V161

 

1- 3.724

2- 2.246

3- 1.541

4- 1.205

5- 1.000

6- 0.818

 

Diff 3.266 (TT) 3.769 (NA)

 

Auto

 

1- 2.804

2- 1.531

3- 1:1

4- 0.705

 

Diff 3.769 (TT) 4.083 (NA)

 

Auto TT

[Chris Wilson]

That's the small CWP unit though, isn't it? Not sure I'd want to spend £7K or whatever on this conversion and be stuck with the small CWP with its lesser torque handling.

[j_jza80]

Done a comparison on the calculator, first is stock UK spec 6 speed gearing, second is a Magnum with an auto diff ratio

 

 

[Nodalmighty]

There may be no choice unless £££ are prepared to be spent on diffs as well. Giken do a unit for the small case do they not?

Edited April 11, 2016 by Nodalmighty (see edit history)

[j_jza80]

The small case diff isn't weak, it just isn't as tough as the big case. Loads of people run the small case diffs for drifting etc and have no issues. For normal Road use I'd consider a small case fine for anything upto big single turbo power / torque.

[Chris Wilson]

The Giken LSD is of course just the LSD bit, and can be ordered to fit to the smaller CWP. At over £7K I would want things spot on, not limited to a small CWP diff in order to get a half sensible set of ratios.

[imi]

A gearbox is a torque multiplication device, and so of course is the back axle. A gearbox is traditionally and correctly rated by its torque handling capability in a 1 to 1 gear ratio, at its input shaft over a given RPM range. They have been rather devious and quoted it "at the rear wheels" where the axle ratio has multiplied engine flywheel / gearbox input shaft torque by the diff ratio in a direct gear.

 

thanks for the explanation - just to see if I understand this right - in reality the number would be much less than the quoted torque @ the wheels?

 

- - - Updated - - -

 

That's because you are mental - I'm not The whole point of my power goal mate is to have a range of power I can deploy at any time via the Toucan when needed. If a Porsche Carrera comes along I'll deploy the 600rwhp. If it's a Lambo then I'll up it..... I personally don't see the need to drive it at full boost all the time, but then our UK roads are very different to yours too my friend

 

The gas pedal is a good modulator

[Chris Wilson]

thanks for the explanation - just to see if I understand this right - in reality the number would be much less than the quoted torque @ the wheels?

 

Seems a bizarre thing to have put in the ad, plus his mixing up of shorter and taller ratios I have to wonder just what it all means.

 

I have never seen anyone try and cite a gearbox torque figure "at the rear wheels". The figure would vary with what diff ratio the vehicle had, for a start. Very odd. And yes the torque at the rear wheels would have to be divided by the diff ratio to get the torque at the gearbox in 4th gear ( 1 : 1 ratio).

[Nodalmighty]

I map my own turbo cars so that min and max boost are interplicants of the throttle angle anyway. I have a hyperspace button somewhere handy just in case (the auto has a mega kick down button under the throttle for this application).