fd engine with 6speed trans ?
 

I know someone has had to try it. Will it hold up to a basicly stock fd motor, making around 270~ hp ?
I know the rx8 made 232 ish stock so I don't see 40 more flywheel horsepower being a giant jump. Any experience?

I ran around 300whp on my 6 spd for years with no ill effects . Depends on how you treat it though ............... dropping the clutch and doing burnouts etc ........ doubt it would last ten mins.

My thought exactly. I kinda baby the 7. I beat on the 8

Lot's of people are running RX-8 transmissions in REW swaps. Like Bret said, it depends on how you treat it, and how much power you are making. and of course it depends on what 6 speed you are talking about because the S2 trans is better than the S1. And then there is the RX-8 5 speed trans which is basically a FD trans made to fit in an 8.

Power wise they hold up OK up to about the 400HP/350 TQ level.....after that they don't tend to last long :)

Does the rx8 6spd trans bolt right up to 13b? What bell housing is needed? Any other special considerations to mate the OEM trans to FD or FC block?

They bolt up......but you have to decide which clutch you are going to use. The FD clutch is a pull type clutch and the FC and the RX-8 use the same push type

For simplicity why don't you get an RX-8 5 speed and use that..then you can use the RX-8 type clutch flywheel and starter

Touching on what dannobre is saying, I do think the 5 speed bolt up would be more reliable and simpler in the long run. This is what I plan for my primary Rx-8 when I do the REW swap

You can get a series one 5 spend for less than $380.00 its just they are not super common. I have been actively looking for about a year and only find them several thousand km's away

Seems like the importers have figured out the 5 speeds are worth more money. They seem to have jacked up the price a lot over the last year or so

If you can get one for $380 buy it.....the shipping difference won't really matter that much

So if I have an S2 with a 6 speed and I swap for a 13b rew, would it be ok to stay with the stock 6 speed or swap to a s1 5 speed? If I swap to the 5 speed, would it fit properly without extra fabrication?

The S2 6 speed may be stronger than the S1 unit....might as well try it

RX8 5 speed is a bolt on

Awesome. Thank you. I think ill end up keeping the s2 trans and keep the power a little down until I get the money for a 5speed rx8 trans

Anyone know if you can use the 6 speed dual clutch tranny with the fd engine? Has anyone tried it?

What dual clutch? You can do it. ...but the tranny won't hold more than about 300 ft/lbs without dying a horrible death...so not much point 😎

Just FYI based on the original basis for this thread, the FD3 twin turbo setup won't fit/bolt in on the RX-8 chassis. There's a lot less room from the engine to the subframe and chassis rail on the RX8 than the FD3. So at a minimum you'd need to do a single turbo conversion using some RX8/13B conversion parts. Or you need to modify and rework the chassis with some very serious metal working skills, maybe ...

Thanks for sharing this. I've seen these 2 swap kits for the 13brew, and neither say anything about needing to switch to single setups. I do see a single setup in the second one though. I just wish they'd explain that. Maybe they mention it when you order it from them. Also, any input on either of these kits?

https://www.rx8performance.com/products/13b-engine-swap-kit-v2

rotary-works.com: 13B Engine Mount For Mazda RX8 Swap RX7 FD REW Rotary Motor

Those kits are strictly for mounting the REW motor in the RX8 chassis. You have a blank canvas to run whatever manifold/turbo combo you want.

fixed that for you ....

Yeah that's what I was guessing. I of course was assuming looking at them that the swap would include the TT setup. But then again there are many different versions of the REW so I could just as well take one out of an NA Fc and swap it in with this I'm guessing. Then Single turbo it as well.

Lol thanks for that.

I really wanted to do a BNR Stage 3 sequential setup and swap it into the 8 with one of these kits. but from what you two are saying that probably won't be possible without a lot of fabrication on top of these kits.

Stop living in the past. There are way better single turbos now that perform equal or better than that without all the complicated, messy BS ...

yeah this is true. I could always go with a twin scroll EFR and probably have just as good low end with better top end

The transmission holding up has been one of my biggest issues, but I beat the ever living shit out of my car whenever I get the chance, so i should expect it.

I've tried S1, S2 boxes and REW Boxes.
1st and 2nd gear didn't like the engine in any of the boxes.
This time round, I'm rebuilding the box and treating the gears. (The first REW box was a used one that was thrown in.)

Personally, I've found the REW gearbox to suit the powerband of the car/motor better, biggest downside is the higher RPMs when cruising.

Because the RX8 is setup for NA. You need to swap to a 3.9 rear gear. The turbo provides enough low end torque to pull it fine.



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Green Bros. in NZ offers a bolt-on adapter that allows a Tremec TKO600 5-spd trans on an FD/, so it should also fit the RX8. The Tremec trans will require a 26 spline clutch disc/hub and a 31 spline driveshaft yoke, but it's rated for 600 ft/lbs.

Products - Green Brothers Racing Ltd


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from what I have gathered you can also use the tranny from 350Z all you need is some sort of an adapter I am not sure if T56 would mate with REW motor..