syncro rev match

travisjb

it's the right question, namir... just haven't found the answer yet

Phenix

The flywheel on the 370z is extremely heavy in order to reduce NVH. The same was the case with the 350z but I believe the 370z flywheel might be even heavier. The flywheel is heavy enough that it will hang on to a lot of revs and sometimes seems to carry its momentum when you press the clutch and jump off the gas a the same time, building a few revs. I'd put money on it that if you got a lightweight flywheel you wouldn't have this issue, although who knows how much, if at all, that would screw up the SRM software...

semtex

Yeah we need a guinea pig to try a lightweight flywheel. I too am curious to know how it'll affect SRM. Most people are of the opinion that it won't screw up SRM at all. But I want someone else to be the first one into the pool.

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ScooterN2

I have only had my Z for a couple of days and limited opportunity to drive, but I have difficulty with smooth upshifts. After reading this thread (and the other that was referenced), I'll pay more attention to what's going on, but my first impression is that holding the revs on upshifting is probably unnecessary for someone who knows how to shift properly.

I guess I will just need to practice shifting until i get the hang of what the Z really wants. Perhaps just a break-in and some hard driving.

!xoible

yah i had a hard time shifting from 1st to 2nd without getting some jerkiness. one way to get this smoothed out is shifting at high revs. which i'd enjoy on those cars

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StackTrack

I'm in the same boat in terms of not owning one ... but I'd venture a guess that with the synchro-rev turned on, you'll have to adapt to what it does. I'd think you can't really drive it the same way you do a traditional manual without the feature.

And I'd agree that the blip-on-upshift seems kinda pointless if the flywheel is as heavy as claimed in the previous post. Having owned a 240Z with an extremely lightweight flywheel, that's something I had to do with that car because the engine lost revs SO quickly.

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RDGR12

The RPMs on my 05 WRX would raise slightly during upshifts too, but it doesn't happen on all gears. It seem to only occur in lower gears.

DannyGT

I too had a wrx sti and it did the same too, almost randomly but more noticable in lower gears..

Musashi

I have noticed the increase in revs especially when shifting from 4th to 5th. When I shut off the srm it's normal. I wish there was a way to edit the parameters of the srm system to match the drivers style and skill level..... I've just been keeping it off.....

Diversion

It was in the brochure for the 370Z that the SynchroRev feature does indeed assist on UPSHIFTING as well as downshifting Granted, before I read about it, I just thought that the flywheel must have been super heavy in the new Z causing the RPMs to float between upshifting. Turning SynchroRev off is night and day in how upshifting feels.. I lovelovelove having SynchroRev and the option to turn it off.. It's a god send for people like me who aren't the best at heel toeing during the twisties!

Edit: I don't think the SR system is blipping on upshifts, it seems to just be holding the RPMs at an equal level you were just in until it sees if you're going to upshift or downshift. But i've never seen it go higher in rpms before I go to the next gear. And to add, it will stop holding RPMs in neutral for about 3 seconds then drop down to idle if you don't do anything (i.e. coming to a red light or stop). I've always had a bad habit of checking to make sure i'm in neutral when coming to stop. Moving left or right while in neutral also blip the throttle when you're over a certain speed.. It's been a hard habit to break, sigh. People think i'm "showing off" when the engine blips when i'm slowing down.

Jay

speedworks

See my other post in the General Section, I notice the holding (or slight increase) of revs in downshifting and upshifting. The holding rpms in a gear can be dangerous - I have taken a few on ramp turns, at near race speed, and when I lifted off the gas a little, it feels like the car still has the gas on - it holds the rpm, and can be a little discomforting. Once you slightly touch the brake, it will not hold the rpm. I have only noticed this on high speed turns, but that is probably only because of the speed mode I am presenting to the street. After driving this car for 4 months, I am not sure I enjoy the Synchro Rev as much, too much computer, and I don't think they have perfected it. On a racetrack, feeling this 'holding of the rpms' will not be something I would enjoy, and I spend many weekends racing at speed in real race cars. On the other hand, trying to drive this car smooth without it (heel/toe), you almost have to be perfect. The more I think about it, it is definately the heavy flywheel maintaining the momentum.

travisjb

speedworks, I think you're right on! With clutch in and SRM on, it holds RPM in anticipation... takes getting used to... I'm still a fan of SRM on the track though, esp helpful when getting used to a new setup, new track etc... an easy way to take out one degree of complexity, and can add it back when you want

All, I have the JWT flywheel and clutch on order from Mike at DDM ! I think I'll be the guinea pig... will report back here and in my car journal once it's done

speedworks

Travis, it should be interesting to hear the results. Since you have taken this car on the track, I have to know..when you come into a sweeping turn, after a long straight, and the correct line is to just lift on the throttle vs brake, to let the car slow just a little (this is similar to turn 1-2 at NH Motor Speedway), does the car continue at the last speed (as I have been experienceing), or does it slightly slow down. If I was in the car, I think it would probably cause me to spin, as I am usually at the limits at that point - and I think it would be very uncomfortable. I tell you I don't think the fastest way around the track will be with the SRM because of this, it would cause you to enter the turn at a slightly lower speed to compensate for whatever (flywheel?) is causing this attribute.

travisjb

Take a look at the track diagram for PIR (referenced here Third trackday! All is good!)... On the NASCAR straight, I'm going about 120... I'm in 5th for a brief couple seconds ---- short shifting at 6500 rpm right now due to concerns of overheating... Downshift to 4th at the end of the straight immediately prior to rolling left... there is a wall to the left on turn 1, I'm about 5 feet from the wall going about 100 in 4th gear and I'm back on the throttle... Then I'm on the brakes and downshifting to third in a mostly straight line heading to the outside of the track on right side... hugging the right side, downshift to 2nd where SRM lands me at nearly 7K rpm... I'm then set up perfectly to steer through a 90deg left hander and make my way through the next couple... it is all SMOOTH AS BUTTER !!! I don't feel any concern about stability b/c of the downshifting... my thoughts tend to be more about dialing in the correct amount of brake pressure so I don't lighten the rear and step it out... which I've done on this turn at 100 - not fun !

travisjb

continuing with thought... my desire for the lighter flywheel is more about having a more control on upshifts, less overreving, etc