Topic: Ultimate 3RZ Drivetrain

[BigMike]

yes I think so-

[Fireimp141]

wow that was the longest damn thread i have ever read, each post was forever long, you guys are insane! but lots of good info in there!

[JESSE_at_TLT [OP]]

I'm glad you found those dyno charts and thanks for posting them. I would REALLY like to see some dyno charts from some of these turbo engines...
Have you had a chance to talk with Marlin about any of the issues that you and I have discussed on this thread?

Questions about the R-transmissions:

What about adapting the R-family transmissions to the 3RZ? How big of a project/problem would that be? Is there any way to do it without a custom bell-housing? Even if we do need a custom bellhousing, what is a better alternative? Maybe we could just machine an existing race-spec bellhousing. I've got an extra 3RZ/5spd that we could start taking measurements from if you guys could help me out with the R-tranny numbers. How about it?

Can Marlin make a hybrid R-series Tacoma/Supra tranny to improve the strength, gearing and shifting performance?

We have another V6/5spd Tacoma with about 80k miles on it that is sometimes very hard to shift into 1st and Reverse. This seems like a common problem, but we had another 3.0L V6/5spd 4Runner that never had any shifting issues. Is something wrong with our transmission or is this just a characteristic of the R-series transmissions? If a Supra hybrid transmission is possible, would it improve the notchy feel of the shifting (through all gears). I would hope so, but I know that the old Celica All-Tracs had similar shifting problems with 1st and reverse.

Thanks-

[BigMike]

Hey Jesse-

As for the bellhousing discrepancy, no, there is no way to use currently available parts to bolt the R behind the RZ block. You will have to make a new bellhousing from scratch.

If you wanted to go R, I would check the R154 2WD tranny, it may have longer gear ratios to match your power band, and the rear tail housing and shaft can still be exchanged to either the R151F 4WD and use the gear drive t/case or from the R150F 4WD and use the chain drive t/case. But this is if you are going to stay "Toyota" parts.

About Marlin doing some work to the trans to help out with shifting Im not sure if there is much he can do. I will ask him though. My friend's '95 V6 4Runner will not engage reverse unless the truck is slightly rolling. Really strange..

BigMike

[JESSE_at_TLT [OP]]

Thanks Mike-

That's a good suggestion about the 2WD. I would like to find some gear-ratio numbers for the 4wd, 2WD and Supra transmissions. We're running 5.29's with 35" tires and I would prefer to keep the spread tight and lose a deep 1st, etc.

Regarding the bellhousing:
I wonder if the pilot bearing/input shaft are at least the same dimensions between the two transmissions. I guess the next thing to look into would be the length of each bellhousing from the block mounting surface to the transmission mounting surface. I could use a bell-housing from either R151F/R150F (since it's not likely that either could be used to determine the starter mounting location anyway), right?

I would definately want to stay with the chain-driven case because of the driver's-side front differential. Do the V6 and 4cyl Tacoma trucks use different transfer-cases?

I'm very interested to hear what Marlin has to say about all of this. Especially the Tacoma/Supra hybrid trans. That would have much wider appeal than anything I'm working on with this 3RZ truck.

Hey why don't we both edit our previous posts to cut this thread down to some good technical information?

[BigMike]

I wonder if the pilot bearing/input shaft are at least the same dimensions between the two transmissions.

I'll see if I can take some measurements today for this.

Do the V6 and 4cyl Tacoma trucks use different transfer-cases?

Yes, there are two different chain drive transfercases.

• 1988-1995 Toyota V6 4WD 5spd models / passenger side front output
• 1996+ ALL Toyota 4WD models, 4cyl, V6, V8, 5spd and Automatic / driver side front output

The 2nd generation chain drive transfercases are a bit stronger featuring a wider chian with shorter links. Marlin spoke to a lead design engineer regarding the new chain style and due to the shorter links, they could fit more links which spread the torque load more evenly accross the chain increasing its holding capacity.

So the late model drivers side front output chain drive transfercase is definately stronger than the early model passengers side front output, and the late model is also used behind the V8 Tundra, which proves its reliable.

[JESSE_at_TLT [OP]]

TRANSMISSIONS
Thanks for looking into those dimensions and gear ratios Mike-

What automatic transmission does the 4WD 3RZ Tacoma use? Is it the same as the V6 Tacoma/Tundra?

Do you know anything about the new 6-speed manual transmissions that are coming in the '05 Tacoma? Might as well use the engine too though, huh?

When I talked to G-Force, they told me that they make custom bellhousings all the time for their transmissions and since they already make a bellhousing for the 3RZ, MAYBE they could adapt it to the mounting pattern of the R-series transmissions. That would be really cost-effective, because their bell-housings only run about $300. I found a link to Browell Bellhousing on the Paradise Racing website. Those certified bellhousings get a little bit more expensive...

TRANSFER-CASES
So all of the Tacomas DO use the same transfer-case? That's cool. Would running a Marlin Crawler weaken the drivetrain any/significantly? I would really like to run one of your dual-case setups for running trails, especially if we gear a tight-ratio transmission (like Supra or 2WD Tacoma gearing).

I'm also really interested in the possibility of adapting an AWD transfer-case, like the new 4Runners use. I was told that the wiring and ECU that controls the electronically-shifted T-case would be a nightmare to adapt though. Can you think of ANY other strong AWD driver's-side output AWD transfer-cases from other applications (I think the newer IFS lexus/Land Cruisers are passenger's-side output).

[JESSE_at_TLT [OP]]

So, I ended up working with Advance Adapters and installed a 5:1 Atlas in our Tacoma using one of their transmission adapter-plates and output shaft adapter. I helped them to develop a Tacoma-specific Atlas kit and we were planning to work on an adapter to mate the 3RZ to an R-series transmission next. But while I was building a rollcage, this guy from Australia posted on CustomTacos.Com about how he had just installed an R150 transmission behind his turbo 3RZ-powered Tacoma using an adapter from Marks 4WD (also in Australia). Marks 4WD happens to be a distributor for Advance Adapters products, so it looks like AA is going to be able to import these to the United States. I should know tomorrow when I will able to get one to install in our Tacoma.





I called earlier this afternoon to talk to Marlin about building an R-series transmission for us, but didn't get ahold of him (I think he'd left for the day). I'd like to know what the best transmission to start with is and what we can do to make it better. It sounds like we can assemble a transmission with close-ratio gearing by using a 2WD transmission and swapping the tailhousing. I'd like to know what the gear ratios are for the 4WD, 2WD and Supra transmissions. I don't need a super-low (or even stock truck low) 1st gear. The 5:1 transfer-case will give us all the reduction we need to run trails. After all, this is more of a desert race truck than a hardcore rock crawler. I'm VERY interested to hear what Marlin has to say about all this. There's nobody else I'd consider having build a Toyota transmission for us.

Oh and I've asked before, but does anyone know what pattern the new six speed manual transmissions in the '05 Tacomas use?

[JESSE_at_TLT [OP]]

After I get all this sorted out, I'll try to address the stock 7.5" front differential and CV's. Then it's Turbo Time...

[BigMike]

Hey Jess, glad you posted an update! I have been wondering how this project has been coming along!

So have you gotten the engine running yet? It looks way more bad ass than I had expected! How much boost are you planning on pushing?

It looks tits dude, very nice job

That is a nice trans adapter! We have been thinking about making a hybrid belhousing, but an adapter seems just as good aslong as the trans input can still reach the pilot bearing

As for 2WD R-trans, yes, they can be converted to 4WD.

The older Supras used a R154 2WD Transmission that had the following stock ratios:
1st 3.30
2nd 1.95
3rd 1.34
4th 1.00
5th 0.75

Compared to the R151F (and R150F) 4WD Trans,
1st 4.313
2nd 2.330
3rd 1.436
4th 1.000
5th 0.838

So not only are 1st, 2nd, and 3rd much closer together, but 5th is also a better cruising gear. Note that these gear ratios are not interchangeable. You can only run one complete set or the other.
So do you have some pics of the engine

this guy from Australia posted on CustomTacos.Com about how he had just installed an R150 transmission behind his turbo 3RZ-powered Tacoma

Are you talking about this guy?
http://board.marlincrawler.com/index.php?topic=14784.0

[reklund5]

Whatever you do, get a sprung hub clutch if you use an Rseries tranny.  A solid hub disc clutch will destroy the 1st gear thust washer in a R series trans...

I've had to go thru my trans in the Supra 3 times due to this.  The last time, I installed a new bearing retainer plate, all new bearings, all new brass, and new 1st gear, hub, and slider.  I'm only pushing 400 HP to the ground, but with a new sprung hub clutch, all seems well.

Just my .02

Ryan

[JESSE_at_TLT [OP]]

Thanks for looking into those gear ratios Mike. The Supra gearing is EXACTLY what I was hoping for (close-ratio 4spd and a better OD). That's AWESOME. I'll still have an 87:1 crawl ratio, which should be OK since I'm only running 35" tires. I talked to Marlin about all this stuff yesterday morning. He was excited about using an R-series transmission behind a 3RZ too. So I guess we can start assembling a transmission as soon as we figure out exactly what parts to use and confirm that the adapter kit doesn't require any special parts, etc.

I haven't even started building the turbo engine yet. The plan has always been to is to build a drivetrain that will be able to take the punishment so we don't spend to much time in the desert or on the trails fixing broken parts. After I do something about the front differential and CV's, I'll start the turbo buildup using a spare engine and then swap into the truck to minimize down-time. I haven't even put together a parts list yet, but I'm probably going to run a stock bottom end to start with (just to see what it can take). Thanks for all the compliments. I'm pretty happy with the way it's turning out.

Mike-
Just out of curiosity, do you know how the Supra gearing compares to a 2WD truck  (r-series) transmission?
Oh, and I don't think it's the same guy (from Australia). Follow the links I posted to see some pictures of his truck (I think it's white with blue racing stripes).

[BigMike]

Ryan,

After the R154, what is the next option for someone who keeps blowing them? What aftermarket transmissions are available and at what cost?

Jesse, I am nearly positive that 2WD Truck R-transmissions have the same exact ratios as the 4WD 2nd, 3rd, 4th, 5th, rev, but the 1st gear might be a bit higher for the 2WD.

[JESSE_at_TLT [OP]]

Right on. I think the Supra gearing will be just about purr-fect. The only other transmission that I'd like to look into is the new 6 speed manual. Marlin wasn't sure if it used the same bolt patterns as the older 5 speeds, but I've talked to a few people that have suggested that at least the transfer-case pattern is the same. Would be cool to figure that out one way or the other. Marlin and I are both going to look into it.