Howdy. Brief introduction.... I have an 07 Mazdaspeed6 that I'm swapping in a 2.3L Duratec (screw direct injection) and building it to be a drag monster. Gonna destroke it so I can run about 9k rpm and install a huge turbo. I've got the car gutted to all hell. I'm wanting to build the car to hold 1000hp, and run fairly close to that. As far as I can find, the rear diff in the MS6 is the same one used in the RX-8.

I've been around other Mazda forums for a few years now...so I searched thru your forum a bit before creating a new thread. Didn't really find any thread to answer my questions tho.

I'm doing my homework and trying to plan to beef up the drivetrain for the hp levels I plan to run. I've talked to The Driveshaft Shop about beefing up my front and rear axels. They're gonna make me a set to handle 1000hp. I haven't been able to find much out about the rear diff itself tho. Some MS6s have destroyed diffs, but none that I recall having upgraded their mounts.

My question is what have you guys found to be the limits of the rear diff on the RX-8s? What have the huge HP guys done to protect it? Or have you guys found it to be pretty damn solid? A member on MSF looked at the transfer case and figured it'd be good to about 1200hp due to the internal shaft sizes. But no one's really looked at the rear diff. I need it to hold crazy power levels. But for all I know it may be a very stout diff right from factory. Mazda over engineered some things and short cutted others =/

 

You should be talking about tq ratings, not hp.
Say what are your goals there and we will be able to help you better.

 

Ok touche. Tq

The Ford 2.3L Duratec is damn near identical to the Mazda 2.3L MZR. The MS6 has the DISI head tho, and I don't like direct injection so I'm swapping a Dtec in there. Planning on destroking the 2.3 with a 2.0 Dtec crank to about a 2.1L and rework the valvetrain to run high RPMs. I'm shooting for about 750awhp/600lb-ft tq. Maybe a little more. I'm aiming for low 10/high 9 second 1/4 mile ETs.

To my understanding, I share the same rear differential out of the RX-8. What kind of tq levels has the RX-8 seen before running into differential issues?

 

The Rx-8 makes TQ?

 

can anybody tell me why my rx8 is harder to start now with new plugs than it was before with burnt plugs ???

 

Dude the diff on an RX-8 won't hold 1000HP I can tell you that right now. There's a guy on here with a 20b RX8 and he had to replace the rear diff. Too much power.

 

Not in this thread we won't.
Go make your own thread.

BC.

 

That's gotta be a troll.
I refuse to believe that even the noobiest of noobs would make their first post about about spark plugs in a thread about the Rear Diff.

I just can't .... mustn't eerrr does not compute does not compute

BSOD

 

The diff won't handle that. Well it may for a short while since you're awd but still I wouldn't trust it for long.
I'm also not that sure that destroking the engine is a good idea. Displacement is a good thing and the powerband can be adjusted in different ways to suit your needs (drag).
Bearing load increases exponentially every 1k rpms or so. I'm not a drag expert though, only track.

 

Team Bergenholtz ran a destroked 2.3L in their 7 second drag Mazda 6. I don't wanna try to rev the 2.3 crank that high. With a properly built valve train I can rev the crap out of a destroked crank. Big turbo will love the higher revs. High revving big turbo will love low ETs. And I've got an incredible head guy to work with. He's actually done the heads on several 1000+ hp drag Mazdas with the 2.3 Dtec/MZR.

I figured the rear diff wasn't that strong tho. I don't really personally know of any big hp/tq or drag monster 8s tho. That's why I jumped on this forum to ask. Have you guys gotten any companies to make stronger diffs/diff swaps? Or what have you done to beef it up? Or has only one or two guys really pushed the boundaries & most just accepted the limitation & settled with xxx dyno numbers?

Not trying to sound like an ***. Just trying to find some go fast parts. If there are none I'll get em made. MSF made me this way.

 

Contact BHR for drive axials.
You'll need those as well I suspect

 

Final Drive ...Crown Wheel and Pinion is not the same in the RX-8 to the MS6.

The MS6 shares the same wheel and pinion as the CX-7 and CX-9 (R=2.928) P/N MA27-27-110.

 

before you go off building a drag monster you might want to educate yourself first about basic drag car setup and design, let alone something as serious as a 1000 hp setup, because you clearly have no idea what you are doing

 

The power is the easy part. I know what I'm doing to the engine. It's the drivetrain I'm working on getting capable of handling the power. No one makes **** for big power MS6s. The further I go the more custom stuff I'm having to do. Which is fine, I love wrenching, learning and fabbing. I've helped build and driven my buddy's 10 second GTi down the strip. But that was FWD. No transfer case, diff, driveshaft, etc to build up. I can handle the power, I just need my drivetrain to handle to too.

Thanks for the tip tho...that's kinda what I'm doing jumping on forums researching questions & looking for answers - exactly as I said in my OP "doing my homework"

 

Btw I wouldn't ditch the DI. Just because most tuners still can't work with that system properly it doesnt' mean that it is worse.

 

That's why I recommended that you educate yourself. You will need a tube frame chassis and solid axle rear end setup to handle 1000 hp drag launch loads, assuming that you ever get there. Dicking around with the OE setup is a complete waste of time and money. Right now you look like a guy with a fantasy who doesn't comprehend what this will take to accomplish. Are you even old enough to have a drivers license?

 

I'm not sure what led to the assumption that the two diffs were the same or related. Maybe an RX-8 diff can be adapted. They are pretty strong.

Paul.

 

you must not talk to 1k+ awhp evo guys to much huh? troll.

 

in fact OP you may want to try talking to the evo8/9 guys as there are MANY 1k hp evos that dont use solid axle swaps like know it all TeamRX8 suggested. Maybe they cant point you in the right direction.

 

Thank you sir.

Thank you as well.

Never said it's worse. In fact I'm sure in the coming years it'll prove itself to be better than PI just the same as EFI was better than Carbs. It's just newer technology that the aftermarket hasn't discovered its full potential yet. Meth is gonna have to be ran tho. DI makes for disgusting engine & manifold internals. My stock intake mani was caked with sludge when I took it off to do the VCTS delete and PnP it. IIRC Porsche actually recommends owners bring their DI models in every 20k miles for cleaning.

**** you caught me. Was it that obvious? I'm in fact a 13 year old Justin Bieber fan who loves to watch the Twilight movies with my teenie bopper bffs. I can't wait for the Twilight marathon on TNT soon!!11!1 Tube frames and solid rear ends are for RWD muscle cars. That's the **** for my Dad's 8 second Fox Body with ungodly torque that goes straight thru the rear wheels. The MS6 is in fact AWD homie. My rear end gets supplemented greatly by my front wheels. Bad for roll racing, great for launching. And snow. But Florida hasn't discovered snow yet.

A few guys on MSF recalled the RX8 rear end being used as the MS6's rear end. And since that was written on the internet it's got to be true, no? Regardless it seemed plausible Mazda would source the RX8 rear end into the MS6. I still wasn't sure if they were the same differential or not when I created this thread. I was more just trying to find out where any highly modded RX8s went to upgrade their rear end to see if I could get a one off for my car.

I honestly really don't know any personally. I've been lurking in their forums. And two forum members I know switched from Mazdas to Evos. They've led me in a few good directions. Found a few companies to try to talk to. Just wanted to see what my fellow Mazda brethren were doing in case Mazda did use the same rear end on both cars and to get even more leads on companies to talk to. I know the rotary doesn't make torque, but I know there's a few rotary guys that are insane gear heads who've exploited power that shouldn't have been able to be produced by a 1.3L motor.

 

you dont always need soild rear to.take 1k hp, but its not recommened.

evo guys dont need them? wow you havent seen their horror stories yet. unlike rx8 ppl, most evo guys prefer NOT to talk about their failures. i know a lot of evo guys IN REAL LIFE so i know.probably the reason why u dont see it on forums.

B4 any of you morons even try to bash team, he race more than most of us and most evo guys ever did.

 

FWIW, I'm not trying to bash teamrx8 either. But he came off a bit shitty towards me. I see his 11k+ posts and respect it. He's been around here for a while. I actually took what he said to heart, ******* or not I'm sure he's got more knowledge than me. I'll look into whatever I need to for the best setup for my car. I know how forums work...I'm the new guy here, but not on my frequented forums. I've come a long way in 4 years. Hell no I don't know everything. As far as I'm concerned I'm still a car newb. Hell yeah I have a fantasy, and hell yeah I'm gonna work to make it happen. I'm fine with flaming tho it's part of forums...MSF has hardened me. E-thug 4 lyfe y0. I'm a pansy IRL.

MSF has a fair share of horror stories too but that's what's helping us build the platform. We don't hide our mistakes. Evo guys clamming up about horror stories is probably why it's been so hard for me to find good info.

 

Yes, my bad for not recognizing that you intend to keep the MS6 as AWD, which is even a bigger challenge that you don't come across as being even slightly prepared to handle.

An MS6 is not an Evo. It does not have any support for that kind of power level. Everything is custom. I would rough guesstimate that to be an $80k project minimum.

He probably got the idea that the RX8 diff fits from the same source where others got the idea that RX8 axles fit ....

 

I've never heard anyone asking about the axles. I'm having the driveshaft shop one off me a set.

 

I know the axles are a weak spot, BHR makes a beefy set.

Rhoad, your sig pic is oversize, we don't use the same standards as the more decorative forums.