Hey guys, I saw this video of an AT RX8 that shows his acceleration...as you can see he is able to get the needle to the max 9k....I got my AT's engine replaced this past summer and it runs like a champ now, but I noticed I can't get my RPMs past 7k without a hiccup or jolt...it basically makes me shift at 7k everytime. This happened with my old engine too. I used to get misfires, but that was the bad engine. I have no issues with this new engine...no codes at all. I'd record my acceleration, but my RX8 is away for the winter.... Why is this guys auto so much smoother in high RPMs?

http://www.youtube.com/watch?v=F81A3KaeY6Q

 

It's not misfires or hesitations...it's the factory rev limiter kicking in.

The guy in the video must have had his tuned out to allow for higher rpm. My old automatic 04 had a rev limiter just above 7000.

 

buddy i had the same problem as you.

only solution : buy a cobb accessport. i did it and the car has sooo much power past where the normal rev limiter kicks in.
hope you can afford one cause it is needed!

 

Cool, thanks for the help, I'm glad it's not an issue with the car...i'll look into the cobb. Is it hard to tune yourself?

 

buy MMs tuning service with the cobb its a measly extra 99 bucks for better MPG and more horsepower.

 

Umm, no it does not. At least, you won't notice it with the AT torque converter.

 

thats obviously not a factory limiter.
that 7000rpm is limiting the rpm really cuz it still goes up pretty quick after 7k
the 9k version doesnt climb that fast near 9k

 

have you had personal experience with this?? I have, and with the 6 port a/t it gives a significant boost until about 8700.

 

The OP seems to have a 4port AT. You can see in the first post that the redline is 7500. You aren't going to be able to go over that without the AP.

 

Umm, isn't the whole point of the 7k rpm redline for the AT because going past that is really hard on the auto transmission?

 

Yes, I have the 4 port AT...my redline starts at 7k-7.5k...The video of the AT makes it seem like he gains some decent power from 7k-9k, where as I would have to shift....I def don't want to hurt my engine by removing the RPM limiter, but I figured allowing higher RPMs would somewhat benefit the car in getting rid of carbon buildup. So for the couple posters that have the Cobb and an AT, did you see a big difference in power and MPG to make it worth the purchase, without hurting the car?

 

This is what a normal AT RX8 does....stopping at 7k

http://www.youtube.com/watch?v=TN0jR...eature=related

 

Genius! Why didn't the engineers at Mazda who designed our slow cars think of this! .....



OH WAIT.


I don't see a gain of more than 10whp if that, by doing this. Your butt dyno does not justify that feeling you had of the car feeling faster. Higher RPM + louder exhaust note ≠ faster car.

 

For what it's worth, the AT in that first video doesn't sound like, or rev like, a stock engine. It probably has a nice tune and some other mods in addition to the rev limiter removed.

 

I feel like there are still positives to having the accessibility of the higher RPM range. Would be fun for autocross and drifting, which is possible in an auto with a few mods, like an LSD. Plus, you get that extra few seconds of rush and noise when your car is about to tap 9,000 RPMs, like when an American V8 shakes violently. It's just a feeling of engine amazingness.

Also, there is some power to be had, since the manuals only make more power because of the higher redline. Power is a function of torque, and since they make the same, reasons stands to argue that the power is linear and directly related to RPM and thusly, redline. And 10 HP s enough to be felt. That's all an intake or exhaust would get you in a piston-powered car and it's noticeable.

My two cents.

 

stopwatched clocked it at 7.9-8.0 secs

isn't that actually slower than a 6spd auto?