I'm not sure where I should post this so the Moderators can push it where they want. Where can I get a 20B crate engine, twin turbo (if possible), form besides Acosta Racing? Would Our trans work with it our would we need a new trans?

 

I think the stock 8 tranny is really weak and won't be able to handle it. You're almost definitely going to need a new tranny. But don't quote me, what do I know :D

 

I Believe Racing Beat Has A Couple.

 

1. All 20B's are twin turbo stock.
2. I doubt the stock transmission would handle the torque of even the stock 20B, you will need a new transmission, probably rear end too while your at it.
3. Putting a 20B in is not like dropping a bigger V8 in a chevy you will have to worry about new engine mounts, a sub frame, bump steer etc as well as upgrading many components such as the radiator, oil coolers, etc to handle the increased heat.
4. All 20B's are cable throttle, the RX-8 is drive by wire, you will have to make a throttle linkage
5. You won't just find a 20B "crate" engine you will most likely have to buy a used one off eBay or through an engine importer or purchase a cosmo front clip.

Good luck, you can probably do the swap in about 8 hours in your garage at home if you have pulled a motor before (and your name is Amemiya-san).

 

Thanks for the help, I thought they came stock twin turbo, but I saw one on ebay that was NA it most not have been a real 20B

 

i know where there is one in a crate or at least it was still in its crate a few months ago- its probably in the car by now.

 

Mine might still be in a crate but I sold it to some other guy.

 

Anyone here put a 20b in there car?
I'm gonna do that to mine when I get my one.

 

acosta racing is the only company so far that has put a 20b into an rx8.

 

Is it hard to do?

 

Atkins has a cosmo front clip for sale

http://www.atkinsrotary.com/

From their site: "4500.00 for a used engine and 6500.00 for a rebuilt unit. Please note that not all engines have complete intake and exhaust components. And only complete front clips have the computers."

 

What's all this about the tranny being weak? Have there been any documented failures because of extreme load? Please site references.

 

My reference to the weak transmission is based off of experience with the Miata transmission that the RX-8 transmission is heavily based off. The rear end seems to be the first weakpoint around the 250 ft lbs mark then the transmission before too long after. Considering the 20B can easily make in excess of 400RWHP (in which the 2nd and 3rd gen turbo RX-7 transmissions start seeing failures) I would not even bother trying to use the stock RX-8 transmission with a 20B. Also consider that the production 20B's ONLY came in automatic form.

Is doing a 20B swap difficult? Considering most conversions on 2nd or 3rd gen RX-7s easily surpass the $20K mark; I don't think it is something your average shade tree mechanic can do from scratch in a few weekends.

 

The 20B has been out of production for some time. Some replacement parts are also no longer available new from Mazda.

 

The most popular swap for FD drag racers here in Australia is to replace the 13B-REW for the 20B.

It's the ultimate rotary engine IMO.

I would love to drop one into the engine bay of my 8, but something tells me it isn't just going to be "dropping" it in.

 

Owning a JC Cosmo with 20B power myself is the best way to enjoy it as everything is factory set.

Getitng a 20B engine for an RX-8 is hard enough, as production ceased in 95, they are all at least 9 years old if you find one (rare). More than likely you may find an A-series version from 1990 vintage. it more than likely will require an expensive re-build.

If you try to use the factory ECU, then invest plenty of time in getting the thing tricked into thinking its still in the Cosmo.

Dont bother using the standard RX-8 transmission. Its just an altered MX-5 box that will snap like a twig with serious power through it.

Expect to lose plenty of your cars balance & handling characteristics too. The added weight of the 20B with ancillary gear will throw the handling out the window turning your car into a straight line warrior at best. If you are unsure, just ask a 20B powered FD RX-7 owner. Some will try & BS you into thinking they are still the same, but in reality, they aren't.

I have even discussed this very issue with Mr Koby san. Or Mr Mazda FD RX-7 himself. He agrees that the balance of the car is the most important factor in the feeling of driving & that the 20B was never installed into the FD RX-7 due to the above reasons.

The FE RX-8 is no exception to this rule.

 

well can some one comprise me a list of every part I would need to do the conversion, the fifty-fifty weight ratio factory I already blow that with my current mods. I am going to talk to acosta tongiht but they probally want be very helpful.

 

I looked on the atkins site and coldn't find anything about rebuilt 20b's for 6500, I couldn't find any 20b's

 

There is a complete 20b on Ebay right now search under Mazda Cosmo.

 

thanks I'll check it out

 

Talked to a local shop yesterday to get a rough price estimate, they are doing some researching and should get back to me today. Can't wait! figured this would be an interesting story to follow if anyone cares so I'll maintain updates. So far we are planning: Stand alone engine managment, new tranny, T4 turbos, 150 shot of nitrous, and maybe a new rear-end or just stronger axels.

 

sounds interesting...but the cost seems to be skyrocketing...changing out the tranny the rear dif. and axels..not to mention fitting in the 20b plus all tunnig and extra parts (ie ecu, radiator, coils, etc etc.).....must be nice to be rich lol :p