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Discussion Starter #1
Hey guys so im planning on building a 1,5jz engine and i need transmission. The problem is that i dont know really much about those. I looked up online and found some good transmissions for example v160 getrag but the problem is that most of them are really expensive and i dont have that much money so please help
 

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What rear end gear ratio you plan on running? And how much horsepower?
 

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Discussion Starter #3
For rear gear ratio im planning on running 3.08:1 and something about 600-700 horses
 

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Wow, thats very low.

What is the car built for? Street car, or some form of track/drag use?

You could get away with an R154 with some upgrades, but those ratios wont work very well with your final drive.
 

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Yes i know but the car will be built for long drag strips. Im planning on increasing the power later but first i need to finish building this
 

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Do you have a top speed target to consider? Knowing that would help you select the gearbox with the best suited ratio spread
 

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No, i dont have top speed target, i just wanna go as fast as possible, at least thats the main goal. As i was searching i found cd009 and from what i heard its really good but its gear ratios are just a little bit high for me, maybe you know any similar transmissions?
 

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No, i dont have top speed target, i just wanna go as fast as possible, at least thats the main goal. As i was searching i found cd009 and from what i heard its really good but its gear ratios are just a little bit high for me, maybe you know any similar transmissions?
By "as fast as possible" you should consider if you want to gear your MKIV for the best acceleration off the line, the highest possible top speed or something in between.

Unless you're going to get yourself a 220mm 6-speed diff and rear subframe the lowest you can get for the rear end is a 3.26:1. You can find those from the Lexus GS400 and some years of the SC430 and I believe LS430's also.

However it's not ideal for all transmissions and setups.

An R154 is an excellent gearbox and they can be built to handle up to 750whp. With 3.0L JZ the best final drive gear for them is a 3.76:1 from an MKIV TT Auto or Aristo 3.0V (GTE). You can also use a 3.92 from a 1992-1997 SC400 or Soarer automatic but the gearing is a little more aggressive. With a full rebuild of the diff (which you should be doing anyway to install an LSD no matter what you get) you can also use just the internal 3.615:1 ring and pinion from a 1989-1995 LS400 rear diff.

Currently you can still buy R154 "tripod" gearboxes brand new from Driftmotion. Or you can seek out a used one and have it fully built with some stronger internal parts from Driftmotion and Marlin Crawler (which is what I did personally).

Also, if you check on CL there is now a proven DIY to convert an R150 5-speed for use with a JZ engine and an SC or MKIV chassis using Toyota parts. However its 1st and 2nd especially are not as ideal as an R154 so this is really a good durable budget alternative to an R154 if the use case fits someone's build.

The Nissan CD009 with a Collins adapter is another good bet. You get six forward gears but the final drive ratio requirement is not the same as with the R154. But it is known to be a strong transmission and there are several good clutch options for it when used with a JZ engine.

The final option is the most expensive but the best of them all. The Tremec Magnum 6-speed using the Grannas conversion kit parts for MKIVs. This one gives you two ratio combinations to choose from, is rated for a constant 700ft-lbs of torque and can be upgraded/built to handle more torque, has several excellent clutch kit options available and is a brand new transmission. The ideal final drive ratio for this one to emulate V160 gearing is actually 4.27:1 (MKIV NA Auto and SC300 Auto) but you can step it down to 3.92:1 or 3.76:1 for longer gearing and higher ultimate top speed.

Other than some minor quirks to how each of these transmissions is installed and fully set up, how their shift feel and refinement is and how their VSS signal is calibrated the usual deciding factors are:

How much power (really how much torque) will your car be making? What will your total budget be for the transmission, ALL parts needed to install it and the appropriate clutch kit?

And what will the main use and/or overall use of the car be? IE: Mostly street? Built for highway pulls? Built for very high speed pulls? 1/4 mile drag racing (This use case is the hardest on any drivetrain)? Road racing? Specific competition racing class with particular build rules that have to be followed for that class so that your car can qualify?

And also: What size and type of turbo will your setup have? A very responsive 58mm or 62mm? A much bigger and laggier turbo? Will you be using a Quick Spool Valve? A VVT-i cylinder head? Nitrous system?

All of those things may ultimately affect the most ideal transmission and gearing choice apart from the most common go-to manual transmission choices that cover most bases for most people and most of the use-case scenarios they will put their cars through.

If you want to get even crazier and are willing to spend quite a bit of cash you can get the Garage Whifbitz (UK) 7-speed DCT setup using a BMW transmission and a Syvecs controller. I'm not a fan of DCT's personally but it's an option if an unpopular one for MKIV Supras.

After that you can go really crazy into the world of expensive race-grade sequential transmissions that fit the MKIV like the OS Giken OS-88 HGT Precision 6-speed sequential :)

Many transmission and final drive gearing options are available. It just depends on what you want your MKIV to be set up to do and how much power (torque) the transmission, clutch, driveshaft, rear differential and LSD need to handle.
 

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The HGT is actually pretty cheap for a sequential. If it's a track car and they're allowed in your class, I'd seriously consider it.
 

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The HGT is actually pretty cheap for a sequential. If it's a track car and they're allowed in your class, I'd seriously consider it.
I was looking for a totally bespoke sequential transmission that JZ race cars often use to just mention to the OP if he plans to take his MKIV racing and wants to go that route but most seem to be specially adapted for the application.

There is also the T56-based PPG sequential. And I'm not 100% certain but I think Quaife does or did make a sequential that has been used with JZ engines.

I also forgot to mention PPG dog box gearsets... if the power requirement for the gearbox he wishes to use requires that much strength over helical gearing.

But I'm thinking the OP won't need to go either of those routes... unless he's building a dedicated track car.
 

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Typical SF post

OP - " I looked up online and found some good transmissions for example v160 getrag but the problem is that most of them are really expensive and i dont have that much money so please help"

Ten posts later - Have you looked into a $20,000 sequential setup? :)

All jokes aside, if you already had the rear end done with a 3.08 gear, the V160 is about the best match for that final drive ratio and power you want....Most of the other transmissions mentioned will make your gearing extremely tall. I see them on ebay and SF from time to time for 5-7k. I'd rather go that route than having to pay money to change your rear end and pay 3-4k for a cheaper transmission. The v160 trans may also appreciate in value.
 

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LOL, well the sequential is cheaper and stronger than the V160, and the gearing works a lot better with his rear end.
 

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I so wanted to pull the trigger on an HGT for my Mk3, but I have so many little things to button up before I'm comfortable putting a transmission of that caliber in the car. No sense in doing that while my steering is still leaking at the rack...

That, and with a 4.10 diff, I'd be buzzing over 4k on the highway, so that wasn't a great option, unfortunately. CinePhile, when I was doing my homework on the sequential idea, I did come across a setup that Quaife offers for JZ engines. Actually had more agreeable ratios for me than the HGT, but I wasn't exactly sold on the information presented. HGT is absolutely fantastic to work with.

Plus the weight savings isn't bad, something like 88 lbs for a 6 speed? Do want...

OP, you might look into the short ratio gear set for the T56 Magnum if you're already invested in that 3.08 diff.
 
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