My RB26/TH400 install write-up

Discuss the RB20, RB25 and RB26 series engines.
truckskinjoe
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Sweet. what a fine swap. And a bulletproof setup!


rb25drag
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Man I wish I had an AUTO setup. This 5speed is KILLING My et at the track! Im Loosing a FULL second in the 1/8th mile. My time slips vs a few buddies of mine, Im actaully 60ft them bad But by the 330ft Im .500 behind and By the top end Im 1.000 behind and Im actually 1-3 mph Faster.

If I had the $$$$ I would go this route No questions asked!

Good looking setup and awesome write up.


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meet07
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^^^I agree. If I keep this 240 im pretty sure in the next few years im doing this swap. There is a 280z with a rb25/auto tranny on youtube. I may ask him about his sway as well. But you cant beat it.

I want the racthet shifter. If im not mistaking it should almost be similar to the japs tranny which has the bump forward action for upshifting and bumping back for the downshift!!

rb25drag
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My question is why can't we buy the Rb Auto trans, and Put a Trans Brake setup in it? You would not even need a Stall with a TransBrake. It would be alot cheaper. Im sure its not nearly as strong internally as the th400. But Is there not an option of making the stock auto trans to work?

I know he said a while back the Auto seemed to take the balls out of it, But If mine would Pull as hard as it does all the way threw without hesitation of changing gears, It would have way more NUTS!!!

If I don't go to an auto within the next 2yrs, Mine will have a small block chevy with a 101mm turbo with an auto setup. Im ready to go fast and if thats what it takes then Thats what it will be.

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meet07
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http://www.youtube.com/watch?v=zAQGCmSEfDU

but there isnt much info...?? But im with converting over to the big boys!!

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HxC_Nismo
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haha i just had my 4th gear synchro go out on my trans just 2 weeks ago and i just got done today swapping my bellhousing to another rb25 trans w/o bellhousing i bought from a rb 300zx swap guy in illinois last year. i would just miss the manual to much but when the time comes ill deffinitly go this route. can you email me some more info on the bellhousing conversion for the th400? also whats your top speed now that you only have 3 gears?

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WhatsADSM
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FWIW, I am pretty sure the OP has actually changed back to the Nissan 5-speed since this thread was started.

Third gear on a TH400 is 1:1 so whatever your top speed is with the RB25 trans in 4th gear is what the top speed will be with the TH400 in 3rd (assuming all other variables like FD and tire size are the same).

Also I thought some TH400s had an overdrive option, but don't quote me on that.

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SuperHatch
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meet07 wrote:I know this is old.........im with matafied. More info on the auto rb26 bellhousing and conversion kit??
The auto RB26 bellhousing isn;t actually an RB26 bellhousing, it is an auto RB20 or 25 bellhousing (they are both the same).

The adaptor is from BDE-Performance (http://www.bde-performance.com). Brett is a good guy, he did the adaptor for my VH powered 240SX with a TH400.
rb25drag wrote:Man I wish I had an AUTO setup. This 5speed is KILLING My et at the track! Im Loosing a FULL second in the 1/8th mile. My time slips vs a few buddies of mine, Im actaully 60ft them bad But by the 330ft Im .500 behind and By the top end Im 1.000 behind and Im actually 1-3 mph Faster. If I had the $$$$ I would go this route No questions asked!

Good looking setup and awesome write up.
I was able to pull 1.51 60' times consistently with my TH400 setup. Stock VH, 2800lb with driver, 26x11.5" MT ET Streets, stock suspension.

Transbrakes are FUN
meet07 wrote:I want the racthet shifter. If im not mistaking it should almost be similar to the japs tranny which has the bump forward action for upshifting and bumping back for the downshift!!
I had my trans built with a reverse shift pattern and used a ratchet shifter exactly as you describe.
rb25drag wrote:My question is why can't we buy the Rb Auto trans, and Put a Trans Brake setup in it? You would not even need a Stall with a TransBrake. It would be alot cheaper. Im sure its not nearly as strong internally as the th400. But Is there not an option of making the stock auto trans to work?I know he said a while back the Auto seemed to take the balls out of it, But If mine would Pull as hard as it does all the way threw without hesitation of changing gears, It would have way more NUTS!!!

If I don't go to an auto within the next 2yrs, Mine will have a small block chevy with a 101mm turbo with an auto setup. Im ready to go fast and if thats what it takes then Thats what it will be.
The physical design of the Nissan valvebody prevents the implementation of a transbrake.

Also, I'm not sure what you mean by "stall" as the stall is a functional characteristic of the torque converter, not the trans.
WhatsADSM wrote:FWIW, I am pretty sure the OP has actually changed back to the Nissan 5-speed since this thread was started.Third gear on a TH400 is 1:1 so whatever your top speed is with the RB25 trans in 4th gear is what the top speed will be with the TH400 in 3rd (assuming all other variables like FD and tire size are the same).

Also I thought some TH400s had an overdrive option, but don't quote me on that.
He did switch back to a 5-speed, for the driver involvement issue and the fact that he couldn't get the car up on boost for a launch (converter issue, not a trans issue)

The TH400 can be upgraded with a gear vendors overdrive unit, or you can use a 4L80E which is essentially a TH400 with an overdrive. BDE might have a 4L80E adaptor available now...

DrifterProdigy85
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When using an Auto on a large turbo car, you need nitrous to get it into boost quickly. Basically you need to get the engine making tq for the tq convertor to tranfer the power to the wheels. Nitrous creates the exhaust to spool the turbo to make the boost to produce the tq. Stalled Auto is perfect for a drag/track car but not something for everyday street use.

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meet07
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SuperHatch wrote:The TH400 can be upgraded with a gear vendors overdrive unit, or you can use a 4L80E which is essentially a TH400 with an overdrive. BDE might have a 4L80E adaptor available now...
Im going to look into this 4L80E......what are they out of??

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meet07
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i was just thinkining............If you wanted a higher mph then the q45 rear end might finally be a great upgrade..

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SuperHatch
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meet07 wrote:
Im going to look into this 4L80E......what are they out of??
I honestly don't know. If I had to venture a guess, Late model Chevy Pickup Trucks....
meet07 wrote:i was just thinkining............If you wanted a higher mph then the q45 rear end might finally be a great upgrade..
You are correct. I have a 4.11:1 GTR Rear end in my S14, and I was turning over 6000RPM through the traps in high gear of the TH400. My car was running 11.90's at 110MPH. I also had 26" tall tires. My plan (if it ever came to fruition) was to go to 28" tires and swap the Q R&P into my GTR rear to increase the available top speed. This is, of course, if the car made the power to warrant it.


Booztd 3
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meet07 wrote:i was just thinkining............If you wanted a higher mph then the q45 rear end might finally be a great upgrade..
I have had a set of Richmond 4:10's in my R230 for about 5-6 years now....

Booztd 3
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And to clarify some more info....

i am back on the 5spd, and actually used the SAME one this year, without issue.

I was able to get the car on boost by hitting it with a 150 shot of nitrous for just a moment, the driving factors for reverting back was I didnt like the driveability, and I had a problem with the transbrake. My builder could never figure out why it wouldnt hold and I had several people look at it. I would get the car around 6k rpm and it would just roll forward. Since I couldnt keep the pressures equal in 1st and reverse, the launches were always lazy.

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ST240
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Boo! Man i was hoping to go auto, either c4 or th400! Why couldnt you just use foot brake to build boost instead? And what was so bad about the drivability? Maybe I'll just stick to 5spd then :/ .

Check this R33 with RB25 out! C4 auto.

http://www.youtube.com/watch?v=v4BfqJQcMB8 .

Edit:

Just read the post about the valve body on nissans. Does that mean that NO TRANSBRAKE will work on a nissan? Lawl. That sucks.

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USMCgetsome
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ressurection time! :bigthumb: Are you a necromancer?

RNCSJohn
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Hey anyone have access to these pictures?


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