RB25DET Auto in a 98 240?

[fhblake04]

I was wondering if this would even be worth it because they made the RB25 with a manumatic transmision. I love my dads Prelude and with the automatic I would never have to release the gas. It would be pretty fun to drive because boost would never leave untill I left the gas.

[hannibal]

I dont think the RB25 came with an auto. But I'm not sure. THe RB20 was available with an auto. Check with the RB guys. I'm sure they have a solution for RB25 + auto.

[Vkoslak]

There are rb25det engines with auto transmission. However, only the NEO rb25det from the r34 had the "manumatic". The engine is usually more expensive than the r33 rb25det engines, and there may be fitment issues with the "manumatic". Im not sure, but it may have 5 gears in the r34 auto.

The r33/r32 automatics had the power/normal/hold buttons to change how the auto transmission acts. The hold option has the transmission start in 2nd so you dont spin the tires trying to accelerate from stop in the snow. Normal mode should be self explanitory. Power mode changes the shift points and I believe has firmer shifts by way of line pressure on the transmission. The sr20det automatics have the same option power/normal/hold options.

I've done some research into this as my wife wants a rb in her 98 240sx.

I think you will also need a driveshaft of a different length than the manual one found in the McKinney kit. Im not positive though. Auto trannys tend to be a tad longer so they need a shorter drive shaft. rb20det auto might bolt up to stock auto transmission driveshaft for 240sx. Again, Im not 100% sure on that.

Hopefully this will help you out some

[Vkoslak]

One more thing. I have an automatic 300zx twin turbo equiped with a HKS ALC for quicker, firmer shifts. It does not lose boost when changing gears.the trottle body never closes, so the turbos never slow down and need to respool. The auto 300zxTT is faster in the 1/4 mile than the 5 speed.

Downside is you have 4 gears instead of 5, so if you are already rolling, you could be in a dead area for acceleration, where when you peg the gas, the engine bogs, once turbos kick in its fast as hell, but it sucks when from rolling start impromptu race a lesser car looks like its pulling away from you, even if it is only for a short period of time. I could help eliminate this on the 300zx by swapping in a rear diff from a N/A. A skyline diff would be even better. But would hurt fuel economy.

2 long posts in a roll. lol. I know too much about my auto transmission!

[fhblake04]

"Also new to the R-34 is the popular 6-speed Tiptronic transmission, a manumatic transmission that provides the easy going Hashiriya with the option of slipping into automatic during those rare times when he’s not slashing madly through the streak dimension." Found this and thought it was cool...6spd manumatics sounding better and better!

http://formen.ign.com/news/16980.html

[SeVa-S13]

Good luck wiring the R34 RB25 though, I've yet to see one (not saying it hasn't been done) and in the end after trying and failing multiple times hacking up the harnesses, you'll most likely have to go stand-alone, which means $$$. Just a heads-up.

As for putting in a powerful auto engine for the wifey, that's just wrong...

[yelnatsch517]

Good luck wiring the R34 RB25 though, I've yet to see one (not saying it hasn't been done) and in the end after trying and failing multiple times hacking up the harnesses, you'll most likely have to go stand-alone, which means $$$. Just a heads-up.

As for putting in a powerful auto engine for the wifey, that's just wrong...

It may seem wrong at first, but I am happy for him his wife has that kind of personality. Whooo wheee... way to pick em cowboy.