Rebuild and Porting a 4port AT
 

Been doing some search and realised that most members started threads but never updated on how it did really end on their project, some are 3 to 4years old. im in the process of rebuilding my 4 port AT, and im thinking on doing just a minor porting, more of a cleaning of the ports, i really would have wanted to do more but racing beat said that their templates where only available for the 6 port.
i do have a 6port /6speed manual, sitting in the garage, was thinking on going in the same direction on the hybread 4port as far as using the 6 port parts on the 4 port ( middle plate) but again no pics where available , so im asking have anyone ported a 4 port AT and what where the results .

Rud, I have been working with AT 4 ports for quite some years, I don't post the results here as it becomes a real flame war. I do suggest that if you want to work on your AT 4 port, consider changing the stationary gears for the Manual model, the lubrication is a lot better and if you do decide to improve cooling in your Auto tranny for higher rpms you will be on the safe side and much more reliable than any manual transmission. All of the RX-8s that I have worked on (auto) I have yet to detect one transmission failure. But most of the manual models that we get at the shop have broken 2nd gear and have had clutch replacement already.

About the Hybrid motor I have no Idea on that, I know the rear end plate is totally different and there is no reason to go manual on your Auto tranny, get a lot more power with a turbo and if done right you will have a nice car. Most 6 speed owners talk about more power than the Auto but I will tell you that the Greddy kit effectively converts a 6 port engine into a 4 port with a blocking plate. It is the Auto tranny that sucks up the losses experienced but you can get a much more reliable car if you do it right. The manual tranny is made out of glass. The Auto Tranny even the 4 speed is good. As long as it is cooled properly.

The 4 port renesis is a very nice engine to mod if done right. Specially if you opt for a turbo after you rebuild it. Improve cooling for oil and transmission and for tuning do change dwell settings with Cobb Accessport with better coils. Change stationary gears for safer higher RPM rev limit and you will be happier.

Subbed

thanks Mperf, that's the idea, to use the stationary gears, and the greedy turbo, also i've been looking into upgrading to the level 10 torque converter, and yes the Cobb is a must, i've been reading about the war of the AT/Manual, but i think more can be done with the AT,

No need to use the blocking plate nowadays.

The full 6 port swap is real and can be done.

Adding a greddy does turn a 4 port into a respectable motor. Just be prepared to rebuild your turbo every couple years.

well if it's just couple years well that's not to bad, :fingersx:
will post pics as i go,

future plans are :
engine rebuild / cleaning ports
full exhaust system
Air intake
Cobb Ap
replace suspensions bushings/schoks/eibach springs
upgrade tranny level 10 TC
new set of wheels haven't found the set i want still looking
greedy turbo for last .
then a new paint job.

when my 4 port dies I will very likely swap in a 6 port and 6mt transmission... possibly 5mt -- haven't decided.

about 4 years boosted and on my 3rd turbo rebuild. i don't even bother checking compression at this point. I'll run the motor till it dies, currently at 64k, 40k boosted.

Werd and +1 for the truth.

Shell, I always thought you had a 6port.

What kind of whp numbers did you get?

I just barely hit 200whp at around 9psi on this bnr rebuild. I want to say I was 232ish with the stock greddy with its gimped wastegate control.

The upgraded wheel spins up super early but just doesn't deliver in the end. With that said, it helps the 4 port where it sucks the most, down low.

Shell,

Forgive my ignorance but how does the torque feel? Does it throw you back like a Mazda speed three at 4500rpm plus?

Smooth transition unless near WOT then its a little on the in your face side.

Haha nice. I wanted to turbo my 8 but the reliability and the price I just can't do it :-(

Should check out my old thread

https://www.rx8club.com/series-i-spe...-parts-224822/

the pictures of the rebuild are no longer there, but the info is still

Take close look at

Rebalancing
6port Center Plate for bigger exhaust port
6port Manual Stationary Gears
Side Seals
SOHNS.

In terms of transmission, i rebuilt mine completely.

It shifts instantly at over 8.5k rpm, the stock one will struggle at shifting past 7.5k rpm with throttle still down.

just the torque converter will not be enough to rectify this problem.

I had all new pressure solenoids in, valvebody done and all the gears redone. also much increased overall pressure in the transmission.

Regards
Jason

Thanks jason, it was base on your thread that i wanted to do this rebuild, i do have 6 port so will use the parts, would be nice to see those pics , what do you guys think of the level 10 TC upgrade ?

Those pics were hosted on my old isp account which i no longer have.

Ill see if i can dig them up.

In terms of power increase i doult you will see much in NA form, just help everything work better.

If FI the exhaust ports will help it breath, i was never able to see the direct difference engine alone, as there was a few things done on my car at the same time.

In terms of the level 10, i have no idea as i am based in Australia.

But it sounds like all the right stuff, valvebody, rebuild.

But you will not need anything more then the TC if you are NA and staying below the redline.

Once you goto the FI and want to go past 7.5k rpm consider rebuilding the transmission.

4.77 final gear was really good on the 4 speed transmission, really 'woke' the car up in 1st and 2nd. However driving around now with FI, first gear is non existent might switch back to stock ratio.

Be prepared for slightly higher fuel consumption with 4.77 as your cruise rpm should be 3k on 4th gear at 100kmph

thanks a million, will start on removing the block tomorrow and snap a few pics

Subbed for intrest........

it's always a flame war between people who will sell you anything to make a buck and people promoting a common sense approach instead

of all the RX8 vehicles to start with, the 4 port auto is the absolute worst


.

So what about not starting that Flame war, and let us all come to one common goal : enjoy our Zoom zoom regardless of what is worst MT/AT at the end its still remain a Mazda RX-8 in the eyes of any rotary fan young or old and guess what the ladies can care less about our HP talks, lol :yelrotflm

no pics for us yet?

yes will post them sometime today

Of all the rotary engines to work with, the renesis is the absolute worst to boost.

just a few pics how far im at, will remove engine this weekend .
Rudolf_Nicholson's Library | Photobucket

Good luck! 4 ports are easy to remove.

Hi guys , little update , yes i know been awhile but you know living in the caribbean we like to take it cool , plus been busy at work really did not had the time, but nevertheless i did get the motor out, and open and boy oh boy it wasn't pretty, got my rear housing in really bad shape, and rotor well will have to replace,front rotor and housing is in good shape , but it;s a good thing i have a 6 port motor that i will be able to use parts from and build this project.