sosonic

The RX-8 Auto engine should be able to handle 9k to 10k revs like the manual/T. The limiting factor would be the transmission. Also, when going from 0-60 or the quarter mile, the RX-8 auto hits the rev limit way too fast and this prevents it from getting its full performance.

With an Automatic Transmission Cooler and different transmission fluid, do you guys think it would be safe to remove the rev limiter/inhibitor on the RX-8 Auto?



I'm interested in your opinion.

staticlag

Thats odd, I remember a thread about this before. It must have been cleaned up or something.

Anyways:

The 4 port auto is a different engine than the 6 port manual, I'd say the limiting factor would be the port configuration in addition to the transmission.

If you wanted a safe 9-10K you would need an entirely different transmission.

Depends what model year you have, I think the new rx8s have 6 port autos

RoXanneBlack8

the 4 port autos might run outta breath that high, and if the torque converter saw 10k itd be wicked dead.

the new 6 port autos would have the ability, they make 212hp at 7500 and the manuals make 212hp at 7500 rpm.....its the same engine now cept that the revs are kept low. if they revved it to 9k like the manual, itd make the same power.

theres a reason mazda doesnt want it revving that high, i believe its mainly to save the torque converter. other guesses from other ppl aim for mazda wanting the manual to be the peak in performance and excitement or whatev......

personally, no company should sell any auto sports car. that defeats the purpose. its like gettin an suv in rwd only or a truck with no towing capacity.

suvs are to get u thru anything
trucks are for towing crap
sports cars are for fun......autos are not

canaryrx8

iTrader: (3)

I'll be sure to share you auto sentiment with my friends who drive beemer smgs, funny how I watch them destroy other "manuals" on our drives through the twisties, sure looks like they're having fun too.

JTtheDude

I would be more happy with the auto if you could just rev it up more that 2200 rpm or so on take off. If I could powerbrake and rev up even to just 3-3.5K that would be nice. I think that alone would give it a lot more pull at least in the 0-60 range.

sosonic

Well I'm going to try it. I think the RX-8 auto should be able to handle 9k, plus the ATF cooler and performance transmission fluid should help. At the very least, the attempt to increase the rev limit should help.

The question then becomes how to go about increasing the rev limit. I wonder what some Mazda mechs would think about this and if they would help.

As for the wise crack against autos. Dude, RX-8 autos can be run in "manual mode" too (not excactly the same as M/T, but still fun). I've also done 0-60s in auto and in "manual mode". The manual mode does make a big difference, because I can control when it shifts after hitting the red line and rev limit.

Its just a whole lot more fun to be able to switch from Auto to Manual mode (and back the other way) when driving in the city, getting kissed by your girlfriend (i mean upstairs and downstairs), or when watching videos on the DVD player and navi system. Lastly, if it was not for the RX-8 Auto, there might not be any more new RX-8s being produced. Not everybody is a "stick jockey". Also, the weird "auto hate" and "auto de-tune via Mazda", really makes little sense. Giving people choices, makes way more sense and increases sales. As for the Mazda "de-tune" on Autos, that is really madness because there are a number of solutions that could be thought of and I'm no Mazda tech.

I think the RX-8 autos can be modified to bring them much, much closer to M/T level performance and beyond ( if you add supercharger or turbo ).

JTtheDude, totally agree with you. If you "semi-race" the autos, you can easily see that the rev limit is one of the major issues with slowing it down. The RX-8's "power" comes from the high revs and the ability to easily and quickly rev that high. If you could launch at 3K to 4K and had a higher overall rev limit, you might be able to see a 6 second auto (with mods) and low 7s should be a very safe bet.

Right now RX-8 autos that I have been in, with the passport G-Timer and no mods, see 8 to 9 second 0-60s (high, but low enough that you can improve and get into 7s or perhaps 6s). Adding CAI, ATF cooler, new transmission fluid, 2nd oil cooler, tuning, flashing ECU, and perhaps getting that rev limiter higher should get the RX-8 autos into the sweet spot. Those combination of mods are also, NOT as expense as a supercharger or turbo (though I will eventually go supercharger anyway).

R888

Hey man, I rev up to 8100 rpm for 2 secs delay shift from 2nd gear to 3rd.

The car was choking.

sosonic

Funny thing about the Auto, is that I saw better times launching between 1500 rpm to 1750 rpm than at near its limit of 2200 rpm. Just coming near that rev limit seems to bog down starts.

I'm not clear what the 2200 rpm or so launch rev limit is all about. Obviously, 1st gear can handle more. I heard some weird sounding stuff as to the reason. But none of these reasons seem to apply to the M/T guys for some reason.

I'm not sure what the 2200 rpm rev limit is all about, so if anybody wants to provide a reason, feel free.

As for going up towards 7000 rpm, its a bit tricky. If you go to manual and shift just before the beep of the rev limiter than you can get better times. I really think thats the trick, you have to get more out of 1st and 2nd gear (on a 4 speed). By doing things to protect your transmission ( ATF cooler, ATF, etc... ) and raising the rev limit here to 8000 k than you should see an improvement in times.

The trick here is that there is a point where the extra rpms give you diminishing returns. You have to find that " auto sweet spot". It appears the rev limiter is cutting in before the "sweet spot" for additional power and below what the auto transmission can handle ( to be on the too safe side).

The cool thing about the 4speed auto is that you only have to shift once in 0-60 and just about leave it at that for the 1/4 mile (it comes close to needing that 2nd shift though and you may or may not have to depending on how much "street space" you have ahead of you). With the rev limit raised to 8000 rpm, you should only have to shift once.

Of course adding a supercharger will do wonders, but its nice to get the non-turbo and non-supercharger RX-8 up to their full potential.

It appears thats the rev limiter kicking in and its limit depends on what gear you are in. Thats what I mean about raising the rev limit, but to a just tolerable point for the auto transmission. I'm thinking the auto transmission, if taken care of, could handle a bit more.

hitman408

If the RX-8 had smg it would be different. Don't try tell me the manual mode is the same thing, is no way close.

DOMINION

http://media.putfile.com/Cj-RX8-184mph

https://www.rx8club.com/rx-8-multimedia-photo-gallery-6/184mph-rx-8-a-98135/

therm8

That's the torque converter. Stall speed is too low to brake launch much higher. The torque produced by the engine (remember the converter is a torque multiplier) overpowers the brakes. With a higher stall speed converter, the launch point could be raised. The converter would have to be modified or a new one built. The bonus of this is better converter efficiency, and custom building one would allow for making it more efficient at high rpms. Less slip in the converter would put more power to the ground. Custom TCs tend to be expensive though.


Raising the rev limit really won't do much. You could probably raise it to 8k and get a little better average power, and you'd land higher in the power band in the next gear (which would probably be the biggest benefit). But the engine is not going to get much more air above 7500 without addressing the intake ports, and then you're going to lose some low end. But the intake ports should have a lot of room for work, and combined with a supercharger/turbo would make some impressive power I bet. $$$$$ though.

sosonic

Thanks...

Even rasing the rev limit a little bit and in the 8000 range would be a big benifit to the RX-8 Auto. From 0-60 to 1/4 mile, the RX-8 is still accelearating comfortably before being "stalled" by the rev-limit. Putting the range in 8000 should also allow you to hit the "auto sweet spot" for the maximum power per rev that the auto could get in 1st and 2nd gear while doing a 0-60 or 1/4 mile.

It also seems there might be a market for an RX-8 auto torque converter. Even with the upcoming new supercharger releases, a new RX-8 auto torque converter would be something many guys may want. It would of course depend on the price and benefit. Nevertheless, rasing the rev-limit will improve 0-60 and 1/4 mile times on the RX-8 Auto; this as an inhibiting factor is very obvious when you run the RX-8 Autos.

I was checking this website, http://www.specriteconverters.com/race_series.asp , and their racing torque converters don't seem all that expensive (starting at $700 dollars). They have 3,000 to 6,000 RPM stall. That would be more than enough to launch an RX-Auto at 4,000 RPM.

It would seem that somebody making a supercharger kit for the RX-8 Auto, might want to include an torque converter option. The key would be to have people building and having experience building custom torque converters for the RX-8.

If anybody has information on building torque converters for the RX-8, feel free to give info.

sosonic

I had the rev-limit/speed-limit cut on my RX-8 Auto. Its now in the 8,500 RPM range. Re-amemiya can do 8,500 RPM or raise it to 9,000 RPM for you (for the Autos). It is advised to change your transmission oil and get an Automatic Transmission Fluid Cooler.

The change does appear to give me a 1/2 second improvement from 0-60 and of course lets me have lots more fun going really fast.

Re-amemiya has a test project going to customize torque converters. They said its very hard and will take a while. They don't expect the project to be finish until sometime around March of next year.

Off topic, but Re-amemiya has this cool test NOS kit project too. I don't know when that will be finished or if they are making it available yet.

Anyway, the torque converter is a huge "bottleneck" on the RX-8 autos, so somebody making customized torque converters for the RX-8 would be great.

I want to max everything out (rev limit, air intake, 2nd oil cooler, ATF cooler, customized torque converter, etc...) and see where that will take me, before going SUPERCHARGER (though I'm 100% going to do it and just looking for the right kit).

therm8

Automatic transmission threads in Automatic transmission forums are just that. MT vs AT has no place here. Go troll somewhere else please.

mysql101

4 port will not run out of air. The updated greddy turbo kit has a plate to block off the extra ports - making the 6 port engine 4 port. People have done this on the 7's too.

AREex8u

so is there a supercharger or turbo kit for auto tranny rx8's???

SlayerRX8

blitz supercharger has just come out for the auto too. look for that thread. Hymee is making one, Pettit is making one for the AT (i think), and there are a few other options coming soon. search and you shall find.

sosonic

Another "rev-related mod" seems to be the pulley. It seems from various threads on this site that the Agency pulley is worth it ( http://www.rx7store.net/product_p/ag...r%20pulley.htm ). The Unorthodox Pulley ( http://www.rx7store.net/product_p/unorthodoxrx8.htm ) has less underdrive, which may prevent problems with the battery and running a lot of electronics, but its unknown if you can get the same results as the Agency pulley.

The benefit would be revving to higher rpms faster and a 5 to 10 HP increase. The main concern with it, is whether or not there are issues with the AC at idle, running an amp with this mod, or any long term problems.

If it can be substantiated that this mod works well in the RX-8, it should help with 0-60 times and faster starts. At the cost of only $145 dollars, this mod looks like a good choice.

kowzan5

Hey I thought I would post since ive posted a couple times on ATs. Well im not saying i know everything or pretend I know everything I just post stuff that i know and ive seen other then that I really dont pull **** outta my ***. Ok back on topic I rev to 9k with my AT but the only problem with that i really shifts bad since the torque converter slows it and its really hard shift so I really dont recommend it. I fell 8k is a good limit on the AT it shifts smooth and u fell the AT really pull. Ive got the interceptor-x, AEM cold Air, Mazdaspeed exhaust which sucks in my opionion, RP supercat, and Unorthdox pulleys. Ive even switched my oil to 5w-30 royal purple which makes the engine run smoother that just what I feel IDK u might feel something diffrent. Sorry im getting off topic but on the rev I think u would need to do some major transmission upgrades to get 9k which i really dont feel are worth it since u can work on other stuff and get power that way instead of droping money on just revving but I will admit I like revving higher. This is just my 2 cents thats all.

sosonic

kowzan5, was that unorthdox pulley worth it? Did you have any cel light isses?

I'm going back and forth between getting the Agency pulley or the Unorthdox pullery.

Also, it looks like you need an ATF cooler and new AT Fluid (Red line is good). Thats recommended with the rev-limit increase

I raised my limit to 8,500k. I backed off on the 9,000k because that was pushing it. But if I get a new torque converter, than I will probably raise back. I do feel the increased performance with the 8,500k rev limit.

I would love to see what a customized torque converter can do for the RX-8 Auto, I'm so surprised that they are not more common and people don't have kits for it.

kowzan5

Well on the CEL light no issues it went on and off the first day and then stayed off. If they are worth it well I would say ya I felt a little more power nothing like the interceptor though I fell alot from that. But on pulleys ya if you really want to go up to 9k I would recommend them like I said I felt it pull a little harder. Im sure an ATF cooler would Help hell I cant hurt and cooling is the best mod for lengthing the life on any car. I was planning on changing my Transmission Fluid to Royal Purple but its looks like a pain to change the fluid so im holding out on it for now. Good luck on getting to 9k keep us posted sound intresting.

devilish8

Could somebody in the US check out the availablility of any automatic transmission or torque convertor upgrades from this company: -

www.levelten.com

Phil's 8

iTrader: (3)

[QUOTE=sosonic]I had the rev-limit/speed-limit cut on my RX-8 Auto. Its now in the 8,500 RPM range.

I have reread this thread several times and still seem to be missing something. How did you have your rev-limit/speed limit cut on your AT? By changing a pully? I am interested in how you accomplished this.

SilverArrow8

Hi, I had mine re-mapped by Re-Amemiya. The rev-limit/speed limit was cut and I can easily rev it up to 8500rpm. I was told that it could be rev pass 9000rpm but I have not tried that yet. I am also very interested in the Agency Power pulley, have anyone else done this on an AUTO 8 and have you had any issues???
Cheers!!!

sosonic

Re-Amemiya did mine also.

The pulley would be separate mod. The pulley should help you rev to high rpms faster (since it is lighter than stock), which is arguably not a true HP increase, but will make you faster in the 0-60 and 1/4 mile and show up as an HP increase when tested. People are claiming its an 10 HP to 15 HP increase. I've not done the pulley yet and I'm looking into it.

I'm also really more interested in what a customized torque converter could do for me, but we have to find a vendor who can do it for the RX-8 and re-amemiya will not finish testing their customized torque converter until next year.