Senna

I've searched and found some older info on this issue but nothing new.

What happens is when I'm shifting from 3rd to 4th at over 8k rpm's there is a noticeable but brief slight hesitation. It also seems to happen when shifting into 5th.

The hesitation only happens at WTO. The hesitation happens every time as well. I thought at one point that I wasn't releasing the clutch completely but this isn't the case-it happens after the clutch is fully released and the throttle is on the floor.
It's not nearly as strong a hesitation as the 3k hesitation that happens to cold 3rd gens but it's still there.

If anyone else has experienced this or have any input, it would be greatly appreciated.

Miatamoto

I think I've felt the same thing in my base model 2006, but I thought it might be me not completely getting off the clutch by mistake. Hopefully someone else has some answers.

StewC625

I see you have a GT. Are you familiar with the Dynamic Stability Control - DSC? Is the traction control light in the center of the tach blinking? If so, that's the little Japanese man under the hood with his finger on the "I think not!" button. You're probably getting just enough wheelspin to invoke the traction control, which chops the power momentarily, giving that "bogging engine" feeling - but probably not enough to get a chirp from the rear wheels.

Try this - hold down the DSC button until a warning light comes on in the left cluster - that tells you the DSC is completely off - takes 5 seconds or so. Then try your WOT run - if you don't get hesitation, then you know it is the DSC working as advertised.

For the record, my car does this every time unless the DSC is off.

Miatamoto

I know you're talking to the OP, but I don't have traction control in my car. Plus this isn't as much of a power cut as when traction control kicks in (that I've experienced in other RX-8s).

StewC625

Yeah, sorry my experience base only applies to my car - an '04 GT and a number of new owners have complained about this over the years - I noticed it too but then noticed the traction control light blinking when I was doing it.

Not sure what it could be with yours ... fuel starvation? That jolt of quick g's when you shift causing a bubble in the fuel lines?

c41250n

iTrader: (5)

naw...you dont get wheelspin at 4th or 5th gear!
you need a lot of power in order to do that!

StewC625

Damn, devil is in the details, isn't it?

He's right - that high in the gears, it's not traction control See a dealer ...

VASasha

iTrader: (5)

That seems like the symptoms of weak engine mounts. Mazda has a TSB out about it. If you are still under warranty you should go get it checked out.

VASasha

iTrader: (5)

Here is the info on it: http://www.finishlineperformance.com...21-06-1559.pdf

Senna

I thought the same thing and did a bunch of runs with specific emphasis on completely releasing the clutch and it still seemed to happen. However, and this could just be me, it seemed a slight bit less pronounced but it was definitely still there.

swoope

iTrader: (5)

if you are good you can cause the tc to go off on the 3 to 4 shift..

another tsb to think about..

http://www.finishlineperformance.com...4-06-1641a.pdf

beers

Senna

Yeah I saw some info on the DSC possibly being a factor in this when I searched and have been planning to do some runs with it disengaged (long press) but have been too damn preoccupied/busy with other stuff. Will give it a try tomorrow. But I do know the DSC indicator never came on and it was a much more subtle "bogging" than when I've had the TC activate on launches etc. Will post the outcome. Thanks for the input.

Senna

I could be wrong but I don't think this TSB applies to my issue. The big difference is I'm shifting at about 8500 RPMs or higher into 4th and then into 5th.

I'm also a little doubtful as to whether a dealer technician is going to be keen to take the car up to about 80-90 MPH to duplicate this symptom.

Gotian

Quick question, my car falls under the vin numbers for the 2nd TSB should I be concerned and take my car in to be checked out or wait till a problem occurs?

Subdivisions

The techs at my dealer don't have a problem "pushing" my car.
At least two of the techs own an rx-8.

When I was having a brake shield rattling problem, my tech let it slip that they were doing doughnuts in my car to duplicate and resolve the problem.
I thought to myself, this isn't all business ... they were having fun too.
I was a "little" pissed at first, but then I realized I would rather have them test the car in both extreme and daily driver situations.

9291150

I noticed this too, and talked about it in other threads;

https://www.rx8club.com/rx-8-discussion-3/analyzing-8s-acceleration-what-happens-90mph-115028/

It's something that kills the trap speed, but try shifting higher (just before fuel cut-off) and you may not notice the lag. Also, I noticed that it's no longer there after I installed my flywheel.

RX8Maine

Wow. You are forgiving.

TimzSI

Yah, thats what I was thinking.

I have this...issue, I guess we're calling it, as well. Except, its not only at redline, but if I shift over 6.5-7K into third, and sometimes into fourth, I can feel the engine hesitate. Feels almost like its re-synching itself for the next hard charge, it's a strange sensation to describe because it happens for less than a second and then its back on full song, no problem. I think it might just be some quirk in the current guise of the 13b, but I don't have enough rotary experience to make that determination.

While we're discussing high rpm issues, my car takes on this metallic shriek at the top of the rev range, before the fuel cut. Sounds *similar* to gear-grinding in something with a tight gear box like a 911, or a lotus, but without that panic feeling you get when you don't grab the correct gear, just the sound, not the feeling in your palm. No loss of power is associated with this, indeed the engine seems to be making its peak power, as it should, at this time. Not marbles in a can, more metal on metal.

Senna

^^ If I was getting the hesitation at 6-7K I'd definitely be taking it in. I push the car but I try not to get into that speed range where I risk being arrested with my ticket. I had it at 105 (in a 55 zone out on a rural road) this afternoon testing the issue with the TC/DSC disengaged. And yes, it's still there.

I guess I'll live with it for now or at least until someone tells me this is the result of some kind of problem and not just a Renesis characteristic.
"re-synching itself for the next hard charge"-is a good way of describing what it feels like.

GT34

I've had the same sort of problem. But I get it when I shift from 1st to 2nd with the tcs/dsc off. It's almost like I shifted faster than the car expected and when I plant my foot to the ground it takes a split second to react. It happens when I've been driving the car around for quite some time.

KuzuRyuuSen

have you tried to wait for a second after shifting before flooring the accelerator? I used to get the same thing, but it's actually caused by the way i shift. If I really need fast shifting, I would move the shift **** pretty fast. Before the rpm drops too much, dump the clutch and floor it at the same time. If you do it properly the rpm will be like being sucked by the clutch (dunno if I describe this correctly ). That way I never feel any hesitation in my car.

mikeferz42

i don't know if these will work but it's worth a try.

1. resetting ecu
2. checkin/cleaning/replacing air filter
3. spark plugs inspection

i had bad throttle response and my problem was an oil soaked air filter.