derwankel

The new 6-speed auto in the MX-5 will be finding it's way to the RX-8 probably next year.

Lock & Load

WONDER IF IT WILL BE POSSIBLE TO TRANSPLANT THE 6SPEED AUTO BOX FOUND IN THE UPCOMING MX5 TO THE 4 SPEED RX8 AUTOS Dindnt mean to yell oops :p

Thinking of maybe buying a cheap used 4 speed Auto for the wife and putting in the new 6 speed Auto if possible , as i believe the 4 speed Autos will losse value as soon as the 6 speed Auto is released .

cheers
michael

rotarygod

Oh yeah? Actually your signature only appears in the first post when you start a new thread. You have to insert it for any other posts. Kind of like this...

rotarygod

I would love to see that done. If it had paddle shifters that are more like the Ferrari's it would be very fun.

The '89-'91 nonturbo RX-7's and the 1st generation Miata's shared the same transmission with only very minor differences. Even the manual RX-8 transmission is nothing more than the Mazdaspeed Miata transmission with minor changes. I don't see why it would be too hard to install the 6 speed auto into an RX-8. They are good at using the same parts over and over again.

EyeBall Fixer...(o)(x)

Oh Yeah! Mine is 6.5...
(Not really... )
I'd like to see 6.6 with an AT!

Lock & Load

Rotarygod

The replacement / alteration of the paddle shifters might constitute a bigger problem than the actuall 6 speed gearbox replacement , i will follow this idea closely and see were it leads .

Could 2 extra gears be added to the existing 4 speed gearbox ???

The Ford 6 speed Automatic gearbox coming out i think is the same as the New MX5'S , MAYBE SLIGHTLY reinforced to handle extra torque.

cheers
michael

truemagellen

I am aware :p

rotarygod

I didn't say it would be easy or would ever happen. It doesn't mean I can't dream though!

derwankel

The gearbox is easy ... it's the supporting logic that needs to be developed. The ECU is programmed with shift points and torque management and numerous other parameters that would need to be updated to support that engine/transmission combo. The paddles just send a signal ... i.e we are in 3rd, just got an upshift signal from the left paddle, shift to 4th. Of course, it needs to know what to do when there are 2 more gears to play with.

The engine also briefly drops torque before an upshift to smooth out the shift, that would all need to be programed. I'm thinking that a retrofit will not be so easy.

DjRx8

Let us pray to the rotarygods at Mazda bless us with that - Amen!

But then... we're gonna have to sell our 8s to get the new one!

Well, unless mods can be done to add 2 more gears like you guys said. :p

I KNOW! I'll buy the new Miata and then switch the gearbox with my 8! :D

Clavius

Expo dredged this up and its a definate good read. Way to much info for my brain to compute right now but does explain alot of what I already thought. Though the last few post's about a tranny swap does interest me slightly.

SlayerRX8

Wow, talk about digging up an old thread.

Raptor2k

wtf necromancy

JeRKy 8 Owner

This thread gives me flashbacks. I was still smoking back then.

sosonic

Now here is the funny thing about the 4 port and 6 port RX-8 Auto sold in Japan.

The 4 port RX-8 Auto was rated at 210 ps (about 205 HP). And how much more powerful was the 6 port RX-8 Auto?????????????????????????????? OK, I will stop it.

The 6 port RX-8 Auto was rated at 215 ps.... that is just around 5 HP more.

So when it comes to NA, there does not seem to be a big advantage.

The limiting factor appears more to do with the auto transmission not being able to handle the rpms.

Now, I'm no rotarygod. I'm nowhere near his level. But...

I question the advantage of the VFAD and somewhat the auxillary ports.

The VFAD is often replaced by Cold Air Intakes and ram air intakes. With the ram air intake, it appears you are getting slightly higher HP. The standard engine would appear able to compensate, by having a ram air intake. The faster you are going than the more air in. They both have a VDI, so I don't see much difference there.

I think the bottom line is that for major HP gains, you need to go turbo or supercharger with the RX-8 Auto. But, you can still make improvements with ATF cooler, 2nd oil cooler, air intake, etc.... I've had my rev limit cut and go up to 8,000 rpm and nothing has broken so far (have ATF cooler though).

Lastly, I think many people would be fine with 300 HP to 350 HP on the Auto. I don't think there are that many trying to get to above 400 HP or are trying to drag race at a pro level.

rotarygod

The 6 port engine has the advantage of having a higher rpm range than the 4 port. This is true when installed in the manufal transmission cars. The 6 port autos have the same redline. It is this higher redline on the manual cars that gives the engine the need for the more complex porting and intake manifold than the 4 port. VFAD is for noise control and nothing else.

sosonic

rotarygod, excuse me, but I read that the VFAD was suppose to allow for more air at higher RPM. I think it was at above 5500 RPM. The VFAD has 2 sections. The 1 section is open at lower speeds and the 2nd section is opened at higher speeds. It appears this is suppose to help when the auxillary ports ports open up (on the 6 port) at 6250 rpm. The VFAD is helping let more air in.

The reason that only 1 section is open at lower speeds is also to limit noise, but I believe the VFAD does have a purpose besides noise reduction. Mazda's info. is showing that it is used for increased air flow at higher RPMs and speed.

The purpose of the VFAD appears to overlap with that of a ram air intake. That is why I believe people are able to achieve some additional HP gains, beside the air being a little bit colder by being taken in from outside the engine bay. Example replacement intakes that use this concept is the racing beat ram air intake or the odula ram air intake.. The ram intake by itself is suppose to add more HP at higher RPM. Unfortunately, the effect of the ram intakes can't be measured on a dyno, because your car needs to be moving through air, and your car is staying still on a dyno when power is being measured. But many people report the effect of increased speed with the ram air intakes and have measured faster 0-60 to 1/4 mile times.

on NA cars, I question how much of an advantage that the auxillary ports are making too. If it was such a big advantage, I would expect the 6 port RX-8 Auto to have a larger HP advantage. In Japan, where the emission laws are different, the difference between the 4 port and 6 port RX-8 Auto is only 5 HP. So it looks like the limiting factor is RPMs on the tranny and having the extra ports is not doing much.

The only way to compare on the street is to take the rev limiters off on a 4 port and 6 port RX-8 Autos, slap a ATF cooler on them with upgraded AT fluid, and see what happens. I'm thinking if you put a ram air intake on the 4 port, that the difference would not be much. In a 0-60 and 1/4 mile race, so many things are happening in a short time scale. So the auxillary ports may need more time to show any effect, time which it does not have in short runs. Furthermore, in a short race, the 4 port and 4 speed would only need to shift once, to 2nd, in a 0-60 and maybe once more in a 1/4 mile. The 6 port and 6 speed Auto, would need to shift more. I think the extra shifting can have a negative time effect or at least introduce the chance of mis-shifting in manual mode. If that is the case, than its a non-issue on NA cars. You simply are not getting an big advantage.

I do think it is smarter for Mazda to go to 6 ports on the Auto though, since they are standarizing on 1 engine configuration and most of the same aftermarket parts can be used between the auto and M/T. Of course, if they worked on the tranny problem, they may have done more. I would be interested in seeing the 0-60 and 1/4 times of a 6 port auto with the rev limiter cut and ATF cooler and different AT fluid.

In any case, the 4 port and 6 port Auto, could use extra horsepower from FI and/or a better tranny to allow them to rev higher.

MazdaManiac

iTrader: (3)

The VFAD duct is simply a bypass of the primary intake sleeve.
It doesn't really flow any more air (its path leads into the existing intake port on the airbox) and it pulls air from the same place as the primary duct, so it is no colder.
It is merely an intake noise countermeasure.

Discman2

so moon_asaad's car doesn't have any power?


He is SCed. From what everyone says it is very impressive

maxxdamigz

iTrader: (1)

I think the point is not that the AT can't make power, just that, dollar for dollar the MT will make more. So, moon's car might put down great numbers. For the same amount of work, he might be putting down more on an MT though. Is it really important to have the most HP possible? Meh, I think it's more important to find the car you like the most and make it into the car of your dreams. My other car is an auto. There are many benefits.

Discman2

I figured as much.

SlayerRX8

Pettit's kit gained more on the AT than on the MT at 4 psi. We'll have to see where the AT stops making power, though.

sosonic

I think it comes down to the right mods and what you want from your car. The right combination of mods on the RX-8 Auto, will do a lot. Who knows, a tranny solution for the RX-8 Auto may be around somewhere or around the corner in the future. Furthermore, what will work on the Auto, may be something different than what works on the M/T. So it may require those people that believe they can do more with the RX-Auto and chase the right mods and solutions.

The RX-8 Auto is not as limited as some people would like to believe. I think certain people are just die-hard M/T and the word "auto" sends them into orbit. The reality is that technology is relative. There will be advantages and disadvantages to everything. Just like there are advantages and disadvantages to having a M/T or an Auto.

The RX-8 engine still has a while to go, before its full limitations are known. Nobody, has come out with a kit that they can claim has achieved the MAX performance on an RX-8. Though, somehow, Mazsportscott's turbo kit seems to be making a run for that title at least. But, personally, I prefer a Supercharger (Twinscrew or Axial Flow(if they can do 4 ports)). In the meantime, there is nothing stopping RX-8 Auto owners from improving their cars overall, including their straight line performance.

I still question how much the Auxillary port is having an effect in 0-60 and the 1/4 mile, due to the limited time frame and distance. Obviously, at sustained high speeds the Auxillary port would have its advantages. But once you are going over 110 mph, who cares, unless you are talking at the race track and a distance race? There is not many public roads that you can push an RX-8 to 120 to 150 mph for sustained period of times and there is not a lot of people that want to, outside of the race track.

It seems to me that the manual is "taking it to the auto" at short distance because of the tranny and by doing higher rev launches. Having my rev limit cut (please get a new ATF cooler and new AT Fluid before doing this) produced faster 0-60 and 1/4 mile times for me. I will often go to 8,000 rpm (for short bursts) with no issues, so there may be a little more in the RX-8 Auto's tranny if taken care of the right way.

Also, if we are talking about getting more air into the 4 port, than it would seem there would be a number of solutions (like ram air intake and maybe others) to help do that. So it would seem that a way could be found and in most cases people are just talking about the effect it would have in the 0-60 to 1/4 mile.

blueballz

I don't know i'm happy with my AT, atleast for the fact that i'm not replacing the clutch every 10k miles.......... clutches are a pain, mod it out.................and go from there.

BigAAA

I just got my RX-8 (early august) and I love it, but now I am trying to learn more about it. From what I seem to be able to find, the AT and MT now have the same 6-port engine, but have different power due to the transmission. (Which makes the first part of this thread very confusing if you don't look at the posting dates.)

Anyways, I was wondering if the 6-port engine was added for late '06 models, or do all '06 ATs have the 6-port? and, if the engine is the same, will the turbos/SC for the MT work with the AT. I figure I should start saving now if I want to be able to afford these when I'm ready to void my warranty.

Feel free to slide this into any other thread that would be better fitting if this is the wrong place.
Thanks