Gen 5 ZX10R gearbox shimming.

Hey all,

I switched to a Gen 5 ZX10R last year.. Has the QS and Autoblip gimmicks.. I mostly just used it for coaching and track days in 2021. For 2022 I'd like to focus more on racing again and I plan to contest the full North Central schedule.

However, I had multiple issues with the gearbox. Upshifting and downshifting. I believe some of it may be electronics related, but I also believe it may have been mechanical. Either way, I need this out of my head for racing, so I can be confident and focus on being safe and "fast", not wondering if I can get it to shift.. LOL

I ended up crunching the gearbox up on the first day. Fortunately, It was covered under the recall. I had them replace all the shift forks while they were in there. I suspect I may have actually bent them again. So, I went ahead and ordered another full set.

The issues I've been having with back shifting are as follows: On my ZX6R, I was able to basically come off throttle with a free backshift (by slightly holding pressure on the lever right before I closed the throttle) Then I could blip with my hand, have just a little pressure on the clutch and be able to absolutely rip back down the gears into whatever I needed with no issues. Only times I ever hit a false neutral were when I didn't do it as fast as I usually do (likely because I wasn't being smooth)

However, on the ZX1oR, if I come off the throttle and immediately start trying to bang back the gears while keeping the rpms high, I will usually jam up in 4th gear, or 3rd gear.. I then have to wait for the the revs to come down more, pull in the clutch and MAYBE it will let me back shift more. Sometimes I have to even just live with it and finish the corner in that gear. BUT if I come off the throttle, wait for the revs to drop THEN backshift I usually don't have an issue. This issue is relatively the same even if I use the clutch.

I have also had issues upshifting, but I think its electronics related. Considering where the problems have happened. (wheelie hill coming onto front stretch at Road America stuck in 5th, then popped out of 6th, and sliding coming out of final turn at ACC North TC kicking in and wont let me shift into 4th, then again into 5th sometimes)

So, this winter I am changing the clutch from stock with judder spring, to KIT spring plates with fresh everything. I think I will cut the spider plates as well. Engine braking on this bike has been a weird challenge for me. Without the ECU assist I feel likes its bit too much and for some reason the first 1-5% of initial throttle is really jerky. WITH the ECU assist I feel like I'm being pushed into the corners, but initial throttle is butter smooth.. I can tune the EBC somewhat as i have the FTECU suite or whatever. I think I want to just upgrade to the KIT ECU though and have someone really go through it for me.

ANYWAY (sorry for yet another novel)

I plan on just pulling the trans for inspection. While its out, I think I am going to try and shim it to nominal specs and see if that maybe helps with the shifting.. However, the KIT Racing Manual seems to be very confusing to me.. (its obviously translated from Japanese) when regarding the shims there is this singular paragraph that is confusing me the most.

"Use the kit input shafts of the racing kit with the washer adjustment since their sizes are,
different from the standard shaft, designed taking the washer adjustment into account in
order to make the dog lengths of the 3rd-5th & 2nd-6th input gear dogs equal. Adjust the
dog length of each gears to smooth gear-shifting to the 5th and 6th gear."

So, if I want to use the KIT Shims, do I need to change the input shafts as well? I'm hoping I am just confused by this translation due to my smooth brain or something. I feel like it would make the most sense to just be able to swap out these washers/shims with the kit ones and get in within the 0.3mm-0.4mm..

I am fairly comfy with dogbox style transmissions, due to my time racing cars, but this singular paragraph has my face sort of twisted.... I want to be sure I have the right parts before I start ordering a bunch of $14-$40 washers..

If any of you are in the know, please help lol.

Quick sidebar, I am also considering sending all the bits out to get coated/treated. I have heard the ZX10R LOVES to munch up the gearboxes.. Do any of you know of a good source for that in the midwest?

Thanks so much for the help. This forums rules.

 

Hopefully the kawi guru @DDK732 can chime in. Personally I haven’t had any gearbox issues on my 2016 that I’ve been racing for several seasons. I run the kit exu with an aftermarket cordona sensor. Took a little fiddling to get the shift up and shift down voltages just right but it’s been pretty flawless. No problem downshifting/autoblipping while leaned over even. I have always been interested in doing some shimming as well to see if I can even further improve the feeling but I don’t have a clue what I should be measuring based on the instructions in the manual.

 

I also took out all of the Y springs except one, and run the kit judder spring plate. I made a post about preferred stack heights here a couple years ago and derek gave some of his feedback on what worked well for them in motoamerica a few seasons ago if you want to search for that.

 

I dont have a kaw nor do I have experience with them. But maybe you have a clutch thats still engaging, meaning to many shim plates. I had this issue with my R6 4th gear would stick and it was a pain to go into neutral. Turns out it had a racing clutch and it was just too thick, slapped an oem clutch set and it was all good.

 

AFAIK the bike is currently setup with the OEM stock clutch. I have talked to both previous owners and neither mentioned anything about clutch work. I will be switching over to a thinner pack/higher preload setup once all the plates/frictions/retainers get to the dealer. I'm hoping this setup will allow me to get the bike to be less aggressive with the engine braking, but not push me into the corner like the EBC assist currently does. I can tune the EBC via the FTECU flash, but I would like to dial in the clutch feel first, then mess with the ECU assist.

Another thing I potentially could be overlooking is the actual strain gauge... I never paid much mind to it because unless I was trying to backshift fast like I could on my ZX6R, or if I was trying to upshift while TC/WC was intervening, I never had a problem.

I have been basically been blaming the backshift issue on bent forks/damaged cogs/shim spec. As well as blaming the upshift issue on TC/WC and MAYBE mechanicals.

Either way, if I can get this thing to backshift shift even 90% as fast and consistent as I could my ZX6R (which didn't even have auto-blip and I still used the clutch..) I would be a happy camper.

This bike handles like a dream compared to the ZX6R, but holy shit do those brake markers come up a lot quicker. HAHAHA.. So being confident that the bike is gunna do what i am expecting it to do every time is very important. Especially if I'm gunna get back on the race grids this year. Last thing I wanna do is ass-pack somebody on one of these big bikes.

 

From what it sounds like you're still running stock ecu but flashed, on the kit ecu side there were issues with the quickshifter working properly while tc/wc was engaged. The issue was present in the 1.0 software, upgrading to the v1.1 kit ecu software fixed that fyi, maybe you can ask ftecu and see if they have a similar fix.

 

The FTECU is more capable than the race kit ECU. Graves has a FTECU map you can buy from them but you may have to run their exhaust with it. Definitely worth calling them about it. Their presets for the quickshifter timing and sensitivity are really good.

We never had any tranny issues with the gen 5. There was a recall on the 2018 where you had to replace a couple of gears, but that didn't effect the shift performance.

You could shim the tranny to the kit manual spec and that helps a little. To me it sounds like you might have more of an electronics setting issue. I would look at the sensitivity setting for the quick shifter and then look at the kill/auto-blip timing for down shifts. We had the best performance using the stock shift sensor and dialing in the sensitivity setting.

The stock clutch is pretty good once you get it set up. When we used the stock clutch we ran it between 52.7mm - 53mm compressed with the +40% kit spring plate and one leaf spring. The EVR clutch works better though. Smoother transition on decel and more consistent feeling compared to the stock clutch.

 

Thanks for the info..

When you say the FTECU is better than the KIT ECU, do you mean the stock ECU with the FTECU package VS the KIT ECU?

Or, are you comparing KIT ECU's but one is set up for FTECU? (I believe that is an option)

I think I'm going to pull voltages off the strain gauge and see where that falls. When using the FTECU, did you have a specific "MS" number that worked best for you?

Thanks for all your help, I was hoping you'd chime in.

 

The FTECU is just a flashed stock ECU. Their software has more adjustability than the kit ECU software. We ran the kit software in 2018 and switched to the FTECU with a Graves map in 2019. The FTECU/ Graves electronics just did everything a little bit better.

I would start at 50ms and go from there. For voltages I ran 3.05 on the low and 4.99 on the high for down shift and used level 5 for down shift control. For upshift I ran 0 on the low and 2.0 on the high. I believe those were the FTECU starting points and we never needed to change them.

 

I could be blind, but I don’t see the option to adjust QS voltages or MS times in any of these folders/settings.

 

You might just have the basic license then. I believe they have tiers on their licensing which opens up certain parameters. Maybe call up FTECU and see what options they have.

 

Just to circle back on this thread. I pulled the trans again for inspection recently. I found the output shift fork was pretty banged up again.. this was brand new in June.

Everything else measured out within spec, including the 3rd/4th output gear groove (where this fork resides)

Replaced all of the forks once again because I was in there, and slapped it back together... Hoping this was just a fluke. Planning on getting another box and spending some money/time in getting it setup with shimming and coating.

 

Would like to update this again..

Swapped out shift fork as mentioned above in previous post, and also switched to the KRT spring plate setup in the clutch.

First two track weekends everything was working great! All the auto-blip shifts were crisp and smooth, and I didn't have any issues at all. Fast forward to WERA Round 1 at Grattan. Friday's practice day was just fine and I didn't have any issues at all. However, starting in P2 on Saturday I started getting stuck in 4th gear back-shifting for T1, (need to be in 3rd for the corner) and getting stuck in 3rd gear coming into the bus stop after the sweeper. (need to get to 2nd gear).. I had to pull the clutch to get the shifts.. By the time the races started I was having issues in T1 and the bus stop almost every single lap. This happened the rest of the weekend. On Sunday I actually turned the Engine Braking Control off to see if adding more back torque would help with the gear changes. It actually DID help, but the shifts didn't feel nearly as good as the beginning of the year.

I decided to chalk it up to maybe 1st race since 2020 jitters/nervousness/not being smooth/blaming myself. I wasn't running blistering lap times (I think my best was a 1:24.6) I'm just trying to get the hang of things at race pace again after taking a year off from racing.

I coached with STT at Grattan this weekend and I actually still seem to be having the same issue. Its like it doesn't want to backshift if I attempt it while I am in higher RPMs. (like 10k+).. If I brake and let the revs drop, it will blip and shift with no clutch.

Here's some things I know.
FT-ECU flash with the autoblip unlocked.
using OEM strain gage. (checked voltages and it was within spec)
E/T rearsets.
When I pulled the trans, everything was well within spec aside from a very worn shift fork. I replaced that fork and re-installed the trans.
More likely to have a successful auto-blip backshift when NOT using the engine braking assist. (I think the added back torque from full engine brake helps take pressure off the dogs and gates)

Here's some things I noticed.
If I start attempting to back shift right as I come into braking (high RPM) It is more likely to fail at blipping, and the lever feels "stuck" by the time I hit 4th gear. If I let the revs drop, or pull the clutch, I can finish shifting.
Last year, I had problems with upshifts. This year I have not had any. (assuming this was due to damaged fork)
3rd and 4th gear are the trouble spots. (the groove is well within spec on the fork grooves)
When the trans gets "stuck" and the lever doesn't move, I have noticed that there is NO ENGINE BLIP. (possibly electrical issue, or issue with the rearset/lever/strain gage).

FWIW I wouldn't be al that annoyed if it would just stop working entirely.. I'm about to just turn it off.. It's thinking that it is working then scrambling at the last second to grab a shift before turning in is what's frustrating. I could backshift my ZX6R MUCH faster than this ZX10R.. I'm getting annoyed. I like to get all my shifts done as fast as possible and let the bike settle.

Will update again as I try new things...

 

evol tech rearsets with their gp shift knuckle mounted to the oem sensor correct?

 

Also, you wouldnt happen to have a datalogger so that you can verify the sensor is being pressed and transmitting the correct voltage during the time of the issue? Anything from Aim (solo 2 DL, MXS, etc) has the ecu profile and channel to see the shift sensor output

 

I have the Evol Tech rear sets where the shift knuckle mounts to the kickstand boss. And yes, OEM shift/strain sensor.

I have an AIM MXK-10 dash. (the ZX10R specific unit) I have not looked to see the data channels for shift sensor output yet. That's a really good idea though. The voltages check out when testing, but maybe its a combo of something I'm doing coupled with the rear sets that's not allowing proper voltage output to initiate the blip.. I will look into this when I get home tonight.

 

yep, these would be the values you should look at - shifter and kqs dw wk(this is from my buddies bike that also runs an MXK10). Downshifting from 6th to 2nd into turn 10A at Road Atlanta FYI. I'm assuming the kqs dw wk changes from 0 to 1 when the shifter voltage value reaches the specified threshold to engage the blip.

He is also using the same E/T rearsets and OEM sensor, but is on regular kit ecu 1.0 software, not ftecu

 

That is super helpful, thanks a bunch!

 

So I had the auto-blip issue on and off all weekend at Gingerman. Some sessions it would work great, other sessions it would not. I was able to pull some data and do some digging. Here is a snippit of the back straight of Gingerman coming into T11. Its a 3rd gear T10 exit, upshifting to 5th, then down to 2nd. You can see in the graph that it executes the 5th too 4th shift without an issue, but then I attempt 3 more times to get it down into 2nd. It fails to shift entirely, and I'm forced to gather it up and turn in for T11 in 4th... Whats strange is that the KQS UP WK and KQS DW WK channels don't really register anywhere on the track. I've only found a few instances where these channels show any data change from "0" Maybe 1-2 per session and its always KQS UP WK..

I also noticed in your data that the voltage goes UP when requesting a downshift, and in mine the voltage dips DOWN. If we are using the same Evol Tech rear sets then maybe I have the settings incorrect for push/pull in the FT ECU.. However, that would be weird due to it working great sometimes, then not working at all other times... As well as the upshift working every single time.

 

Do you have the polarity settings flashed as standard shift or gp shift? It should be flashed as standard shift when using the evoltech gp rearsets.