ST or SP

[Neonacr]

I attended events in I believe 08 and 09 in a rolling road block Hyundai Accent. The Accent is now to tired to do track time, so I am preparing my 08 2.0 Mazda 3. I had hoped to remain in street touring but I have one big issue with the Mazda. The flywheel has so much inertia that shifting at speed is very poor, down shifts with the engine hanging at high rpm are horrible. I would like to install a light weight flywheel but it looks like that would put me in SP. Am I reading the rules correctly?

[breakaway500]

Yes.Lighter than stock flywheel= SP. Maybe try a different transaxle fluid first. I have found light flywheels really don't help shift quality as much as one hopes..

[Neonacr]

The shifting of the trans. is fine, its the over run of the engine that is the problem. Back off the throttle and the rpm just hangs at high speed. Down shifting for corners is akward with all the stored energy of the fast spinning engine trying to feed itself back into the driveline at not the best of times. Very hard to make a smooth corner entry. This seems to be a common problem with the MZR powered 3's. One owners comment was that he felt like he could read a book waiting for the revs to drop between shifts. I think Mazda was trying to make it easier to get under way with a low torque engine but over did it with excess flywheel effect.

[breakaway500]

Not quite sure I'm following you about downshifting into corners and the engine hanging up,,I see that as an asset,as it requires less of a heel/toe blip to complete the downshift smoothly.I actually tune for fuel delivery to remain on at curb throttle, just so the revs don't drop as much on lift. I guess I'd have to ride in the car to experience the issue. I would use the car as it is and get some on track evaluations. The 3 is a great handling car!

[jeffw]

The shifting of the trans. is fine, its the over run of the engine that is the problem. Back off the throttle and the rpm just hangs at high speed. Down shifting for corners is akward with all the stored energy of the fast spinning engine trying to feed itself back into the driveline at not the best of times. Very hard to make a smooth corner entry. This seems to be a common problem with the MZR powered 3's. One owners comment was that he felt like he could read a book waiting for the revs to drop between shifts. I think Mazda was trying to make it easier to get under way with a low torque engine but over did it with excess flywheel effect.

It could also be emissions-related in the ECU. I know of some cars where the ECU will not allow the throttle to snap closed in certain conditions.

You may be able to remap the ECU to improve that.

[Neonacr]

A somewhat elevated rpm might be helpfull during down shifts but this is rather extream. Say the engine is at 5500 rpm in 3rd gear and a down shift to second is selected. The rpm will be close to the 5500 throughout the down shift.I thought it might be a defect in my car but after reading Mazda forums it appears to be common to at least the NA 3's, with a dramitic improvement when using a lightweight flywheel. I bought this car new 3 years ago but only have 2k miles on it, hopefully this spring I can get more time in it and learn to adapt . If not I will either go to SP or skip another season or two untill the Neon is finished.

[breakaway500]

You bought the car 3 years ago and only have 2k. miles on it? I thought I was bad about not using my..toys.. I still think you should try it like it is and see how things go,at least one time.

[Neonacr]

Another case of my poor typing and poor proofreading, actually I bought the car new 4 years ago. Getting to old with to many toys and projects, have started selling off some of the less used items. Hope I will have more time for the car and the track. one of the reasons for lack of use was the steering recall. Had to wait a long time to get the updated pump, hope to install it in the next 4 to 6 weeks. Collecting ST parts and will install all at the same time.

[Neonacr]

Sam, I believe if you speak to the instructors , including those that recomended me for a comscc license, you will find I have no problen with heel toe shifts.As a former motorcycle roadracer I sure know what happens with poor rev matching on corner entry. Perhaps you remember my car a white Hyundai Accent. I may be poor at relating the issue, all I can tell you is that the car is akward and others have found it so also.

[chaos4NH]

I remember the Accent and am sure I have misunderstood the issue. Seems like an odd one to me. Best of luck!

[nateh]

It could also be emissions-related in the ECU. I know of some cars where the ECU will not allow the throttle to snap closed in certain conditions.

I think this is likely to be the right answer. I've encountered this in a number of cars.

[breakaway500]

There may be more than one right answer to this issue.

[WillM]

I could see that problem being a PITA. Whatever the situation, whether the RPMs hang due to ECU control or inertia (both?), the overall feeling is that you are not in control of the motor. My guess is that if the RPMs hang, then the overall engine response is sluggish, and who wants to feel like their engine is always playing catch-up to the driver's input? You already know the two choices you have, but the truth is, (as always) there is only one answer: buy a Miata.

Yes, I remember the Hyundai. Come on back and impress us with the Mazda3. There are have been several of them at COM events...mostly stock.

[Gidyupp]

It could also be emissions-related in the ECU. I know of some cars where the ECU will not allow the throttle to snap closed in certain conditions.

You may be able to remap the ECU to improve that.

I know that in my 2011 Mustang, it's the ECU and can be "tuned out". The RPM hang in the stock tune is apparently good for emissions, but a PITA for heel-toe. The function is called "electronic dashpot"

[Gidyupp]

double post