Hi everyone! I own a 08 USDM GD3 M/T

I realized something strange when i do doubling shifting ===> The throttle response.

I seems like the throttle response is weaker from 3rd to 2nd, but very quick/strong from 5th to 4th or 4th to 3rd.

Does anyone has the same situation here?? Or just me have a weak right foot everytime i down shift to 3rd to 2nd.

btw, skunk2 short shift is installed, i dunno if its related or not.

 

While I cant troubleshoot your problem, I can tell you that you are not double clutching.

And Im not sure what you mean by double shifting either....

 

I'm also not sure exactly what you're referring to—rev matching difficulties???

It's worth noting that the hand motions to do a 3 to 2 downshift (and similarly for a 4 to 5 upshift) are more involved and take a little longer, as there are three separate nudges that have to be given to the shifter. The other shifts all involve basically one motion, in some cases assisted by the centering springs for the shifter. Maybe this is throwing your timing or whatever off a bit?

 

^Yeah I think that's your issue. Just not timing everything correctly.

 

Throttle control has a built in lag. Get a throttle controller.

 

smart idea!!!

i think the issue is something about throttle control too.

And my point was saying i realized theres a big difference of me stepping on the gas pedal in neutral when i do double clutch from 3rd to 2nd. Compare to 4th to 3rd. I am saying the throttle response is bad, it will never rev much when i down shift from 3rd to 2nd but 4th to 3rd is really quick. i wonder why

 

Looks like this guy is selling one a lot of people like on here.

https://www.fitfreak.net/forums/merc...roller-27.html

 

thanks brah this is sickk imma get ittt

 

This isn't double-clutching, correct? It's what we in the motorcycle world call "blip downshifting?"

 

well for my understanding of double clutching is this:

say from 3rd to 2nd

1. clutch switch 3rd to neutral then let go the clutch
2. gas to rev match(still in neutral no clutch)
3. clutch again leave gas put it in 2nd then let go the clutch
4. gas to continue

 

Not sure if the mt fits have synchros, but if it does you you are wasting time letting out the clutch. If it doesn't, what decade is this.

 

Living that

 

I believe you are correct but I have no idea why someone would ever want to do such a thing. Just hold the clutch, rev and let off the the clutch. I believe there is something called double declutching which is necessary for certain large truck transmissions but I don't think it's a technique that is relevant for the modern day passenger car transmission.

The rev match I enjoy the most is from 4th to 2nd! I really get great compression and sometimes I'll push the brake a little to help drop the revs from 6k to 4ki.

 

All modern passenger cars that have manuals have syncromesh including the FIT. They have been that way since 1963 or so.

Double clutching is not particularity necessary on modern cars but it does save wear of the syncros and is fun.

 

also im just wondering for the clutch here too, would it be bad for the clutch since its high rev shiftingÉ

 

It's not really hard on the clutch, as there's very little slippage or torque involved. The transmission in neutral represents hardly any load on the clutch and engine. Other driving habits have a much greater effect on clutch life, such as rev matching, not slipping it excessively when starting out, and especially not riding the clutch. (Naturally, city driving is also a lot harder on the clutch than highway driving merely because there's a lot more starting, stopping, and shifting going on.)

 

The only thing that would be subject to greater wear would be the throw out bearing because you are pushing on it twice as much. BUT any increase in wear would be miniscule and nothing to worry about.

There is one big wear factor is be concerned about. The syncros blocking rings wear surfaces.

IF and it's a big if you are downshifting at high speeds and are "forcing" the shifter into a lower gear that will cause increased wear on the blocking rings.

You can tell you are "forcing it" if it takes more force from your hand to get it to go all the way into the gear position you are selecting. You will also get a "delay", though it's just a portion of a second, in the amount of time it takes for the shifter to move all the way into final position because the syncros are taking a longer time to slow down the spinning gear to get it lined up with the teeth on the syncro slider.

Don't laugh but you can also hear the syncros "singing" or "moaning" like they are being hurt if the speed differential between the gears is too high. It sounds like if you run a tape at very high speed. It happens because the spinning gear is going "too fast" (subjective to what your speed is) and when the syncro blocking ring is forced to work too hard to slow the gear down the little "lines" cut into the blocking ring surface are literally being worn down by friction and heat sounding something like the squeal you get from steel brake pads.

If you are flying along at say 60-70 in third and then try and downshift into second and you try and pull the shift lever into second there will be the delay, harder than normal force need to move the lever into second, and the "singing" coming from the trans and if you continue it will finally go into second revving the engine way high. If you do this a lot your syncros will be worn beyond specs in a very short time.

BUT double clutching HELPS with this problem because the gears get "spun up" to a higher speed when you make the clutch out in neutral move. But even if you gas it a bit "rev matching" if the speed is too high you will still get the increased wear.

So if you are out having fun downshifting, making the engine roar, if it takes more force to move the shifter, you get a delay in shifter movement, and your trans is screaming you may want to slow down a bit with the brakes a bit before you downshift or you are going to be replacing the syncros sooner rather than later.

 

Lord knows my 107 hp engine roars like a lion. I'm the king of the road! At least compared to most bicycles LOL

 

Yes this is only really something to think about when doing something like top of 4th to 2nd to get the synchros' speed to match up better.

In any case, I recommend 4-blip-3-blip-2, it will:

1. Save your synchros
2. Avoid money shift (overrev)

Doesn't take that much more time anyway if you're doing it while braking, just have to be confident in your heel-toe.

 

Yep heel-toe is the way to go.. that's if you can do it. My huge size 13 has no problem hitting the pedals but I have alot of friends with smaller feet that struggle. I'm just blessed haha