JR RX8

I have a 2005 GT AT 4 speed and use the manual every time I drive. I'm the original owner with 35K on it. The car is like new and in excellent running condition all around.

I have noticed that when switching between 1st and 2nd gear there is often a lag time , sometimes in excess of a second to two. I always rev to at least 5K to 6K. If I rev to 6K+ to red-line and then shift (usually during a good rolling start) I can sometimes get an almost simultaneous/instantaneous gear shift after pressing the paddle or pulling the stick. Feels great when it happens. Going from 2nd to 3rd and 3rd to fourth is pretty quick as well, but it's that first gear shift from 1st to 2nd where I get the lag in gear shifting and find it annoying.

QUESTION: knowing this is a "drive by wire" car, is there a way to re-program the system to increase the speed between when i hit the paddle or pull the stick and the time the tranny actually shifts gears?
Thanks for any input.

Karack

it would require re-flashing the TCM, which i don't believe anyone has hacked the code for it to be able to reprogram it. you could always try calling the dealer or MNAO to see if there is other flashes available for your car that haven't been performed.

the laggy shift is probably just encoded into 1st gear since the car makes little torque before the SSV opens, where a power shift before peak power would make little sense.

unfortunately the days of quick shift kits are gone, with the newer transmissions being hydraulically controlled with electronic based hydraulic actuators.

coolcars44

iTrader: (6)

had the same issue with our rx8 4 speed auto at road atlanta we installed a new speed sensor on trans and it seems to do the trick.we bought a new one from mazda.according to mazda the factory ones suck just like the starters the new ones from mazda are i guess better updated sensors.we bought every sensor from mazda that bolted on the trans to be honest and seems to resolve shift delay up or down all the sensors were like 300 bucks new

X7rotor

iTrader: (2)

Hmm how about the 6 speed auto ??

jon15805

You bought a new one from Mazda? What exactly do you mean by Mazda? Dealership or something?

CRO8TIA

How much simpler can it be, He bought new sensors from Mazda Spare Parts, Not Mazda drive through burger joint.

JR RX8

KARACK/COOLSCAR:--- Thanks for the info. I appreciate it. It all makes sense. I just called my dealer and am waitng for a phone call back RE: TCM flash and/or new tranny sensors. Saw them online and if I can get them from the dealer, I'll do that and have a local guy do the install since dealer labor costs are pretty high. Then again, they are supposedly the experts. Anyways, thank again. Will keep you guys posted on how it turns out. Wish me luck!

JR RX8

PS: Any ideas regarding NYC Pot Holes? Almost ripped off one of my rear bumper aeros and front license plate 2 nights ago! Now have to figure out how to get the aero to stay back on using double sided tape. Man can't wait till spring till they hopefully start refilling. Time for wheel alignment AGAIN! LOL

09Factor

So digging deeper, how many miles were on your transmission when you replaced the Speed Sensor?

JR RX8

Have been experimenting somewhat with various driving and shifting techniques. First I noticed once the the engine is warmed up after about ten minutes it seems to help. Then I started waiting till at LEAST 6K and almost red line before shifting and that will usually get a pretty quick shift. I have also been doing something I rarely do in fully auto mode: instead of a typical gradual launch where the the car will shift from 1 to 2/3 before i even get to 30, I floor the pedal and it will stay in 1st until almost red line and then it will power shift itself into second and then I do the same in second which has the same effect. As long as i keep the pedal to the floor it will stay in the lower gear then shift up at almost red line. I know the auto tranny will do this normally if you are say driving and you want to pass, you just floor it and it automatically down shifts for you and have used this for years, but i never tried from a standing start and then continue on through the gear range.
Any thoughts on this technique?? is harmful to the transmission? doesn't seems like it would be and its fun as hell too and gets the desired effect i'm after without paddle shifting.

coolcars44

iTrader: (6)

our trans had about 82k on it before we changed sensors.and let me tell you if we can beat the crap out a automatic trans at road atlanta for 12hrs im sure it will take alot of abuse on the street.but we are running a huge cooler for the trans and full racing trans fluid from summit

JR RX8

OK so I brought the car into the dealership today for a checkup and asked the RX8 "expert" about the shifting lag between paddle shift and gear shift and if re-working the TCM and changing the old speed sensors for newer ones would solve the problem. he told me he was unfamiliar with that issue and couldn't even speak to me about the speed sensors and told me the best place to go was to a "speed shop". Any ideas where I might find some definitive information regarding upgrading the speed sensors? You think contacting MAZDA USA might be able to help me?? Good news is that after being put on the diagnostic machine, the engine and everything else is in perfect condition. Thanks for all your input.

coolcars44

iTrader: (6)

the dealer wont tell you much these days.but the speed sensor is easy to replace its right on the side of the trans with one bolt holding it in place.its no suprise they dont know about the speed sensor they usually think if the trans is shifting gears your trans is fine.

jon15805

I've searched quite a bit online for speed sensors. But nothing pops up.

Karack

most transmissions have several speed sensors so that the TCM can monitor for issues in the clutches. generally an input and an output, usually only available from the dealership. perhaps these days the wheel sensors are used for the output sensors, i haven't looked that far into it.

coolcars44

iTrader: (6)

yeah i had to go to the dealer and say look i need sensors on the trans there are 4 of them i had to get them to pull up the trans diagram and point each one out to them.when i asked for speed sensors and the neutral switch they had that clueless look on there face lol