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FYI- Proper shifting of the NSX

i never skip shifts up...but i often drop it from 6-4 or 5th to 3rd to get a boost...is that bad???
 
dlynes said:
i never skip shifts up...but i often drop it from 6-4 or 5th to 3rd to get a boost...is that bad???
I think what experts agree is "bad" is shifting into 1st gear when a car is still moving! Basically, transmissions aren't designed for that. It can be done, I know, but that doesn't mean it's a good idea.

Other downshifts are optional and a part of the car enthusiast's enjoyable experience. When they are done properly, the clutch and synchros will last 10,000s of miles; in my Porsche experience 100,000 +. I downshift my cars 5th to 3rd a lot and don't find "premature or excessive damage" to either synchros or clutchs. I am sure that it adds a minimal amount to wear but I haven't had to replace those parts "early". We'll see in my NSX which has 47,000 - so far, so good :wink:
 
I would think this only matter if its your style of driving to skip gears and you do it every day. If you just do it on downshifts sometimes, I would think you have absolutely nothing to worry about.

Side note, I know one of the engineers who developed the Integra Type-R said changing the oil in the transmission is almost more important then in the engine. Obviously thats overstated, but overstated to drive home the point. Change the oil in the transmission!!!
 
jond said:
Side note, I know one of the engineers who developed the Integra Type-R said changing the oil in the transmission is almost more important then in the engine. Obviously thats overstated, but overstated to drive home the point. Change the oil in the transmission!!!
I agree. I change the trany oil once a year; it is not expensive. If you ever grind the gears ---> change the oil. Those circulating little metal particles aren't good for the synchros and gears.
 
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OLDE GUY said:
I can advance N to 5 by adding that I have frequently skipped gears going up, most often 3-->5 or 2-->4, in my cars for decades without having a problem with synchros or clutches.

'92 Honda Accord to 65,000 miles
'96 Honda Accord to 105,000 miles
'82 Porsche 928S to 103,000 miles: high torque V8, so frequently 1-->3-->5
'88 Porsche 944Turbo to 67,000 miles: new owner says 80K and no problems

The 928S had 7 or 8 track weekends on it and the 944 T had 25+ weekends. I have never had to replace synchros or clutches. But I don't make these shifts FAST. As DutchBlackNSX said if you do it slowly and give the primary shaft time to wind down, I think it isn't too harmful. Also each time you skip a gear you save one useage of the synchros and the clutch. It may even out on the synchros and saves the clutch.

I do the same thing, skip gears when I shift, and I have never replace any clutches before I sell any of my cars, and I put some serious miles on them too. However, one incident on my current car about three weeks ago; I redlined first gear and shifted into fifth (subconsciously), and the clutch did not grab, the engine reved to redline with the shifter in fifth gear position, and the car did not accelerate. That was an interesting experience. Lots of burn smells afterwards! Never do that again!!!
 
The gist of the TSB is that abusive shifting, particularly hard shifts & engagements from 2nd/3rd to 5th can accelerate syncro wear within the transmission. This is in fact correct, and obviously manufacturers do not wish to warranty such repairs unneccessarily, which obviously are entirely outside of their obligations- hence the TSB. If you have driven co-pilot with enough M/T drivers, it is not difficult to form a similar opinion on these behaviors particularly with the 'speed shifters' whom are apparently otherwise entirely oblivious to syncro operation.

As a general guideline- if you are smooth with your up-shifts, rev match your down shifts, use common sense- avoiding excessive drive train shock / gear grinding, and regularly change your fluid... your tranny will likely live a long healthy life for even the most avid of motorsports enthusiasts.

In practice, enthusiasts using short throw shifters, fully synthetic fluid, drag racing, etc.. can go farther towards syncro wear than most of the driving scenarios mentioned on this thread.
 
yea iv never believe in shifting into 1 w/ any kinda of transmission...I always put in neutral, stop then 1st and go....i was watching a Top gear show and they were driving a yellow 05 lambo, and he said in the particular hair-pin you had to drop to 1st gear...but i never would!
 
I'm reviving this thread since some posts state that it is bad to shift into first gear without first coming to a stop. Some posts in other threads, found while doing a search on this topic, indicate that with a double clutch and proper rev-matching, a shift to first while moving is perfectly fine and will not lead to premature transmission problems.

I frequently take sharp corners where I must, due to the tightness of the turn or the presence of other traffic, slow to a speed where engaging 2nd to accelerate results in less than optimum revs for spirited driving. I've got to admit that at those times I miss my good old American torquey V8's.

So, which is it - is downshifting to first while moving a bad thing to do, or ok with proper technique? Any knowledgeable advice will be appreciated. Thanks!!
 
John@Microsoft said:
In practice, enthusiasts using short throw shifters, fully synthetic fluid, drag racing, etc.. can go farther towards syncro wear than most of the driving scenarios mentioned on this thread.

Are you saying that a short throw shifter and synthetic fluid are bad like drag racing? I don't get that. How does a SSS negatively affect the trans? isn't the same as if you had the standard long throw and just shifter faster? Also isn't synthetic fluid preferable?
 
ATERPAK said:
Well any thoughts on this?

I think perhaps Acura should lean how to make a better trans :cool: I never hear people breaking their 5-speed tran on the Mitsubishi Evolution and they hold up 6000rpm launches and bumping the torque to 370+ft/lb is common.
 
You can down shift the car into first while the car is moving.

Just double clutch and rev match the speed... i dont see what the problem is.

Do it in my s2k all the time. Since the 1st great ratio is much bigger you need to blip the motor to a higher RPM the lest say 3-2.

Just cause you cant do it does not mean it cant be done.

People say you should not shift to first while the car is moving because 99.99% of the people just jam it from 2-1, the syncros burn up, matches the gears and finally locks.

Ya that wears syncros. If you rev match it correctly, i dont see why it would.

As for the 2-5..... personally i do it all the time on all my cars. I like to feel the acceleration but dont want to the tickets. Wait for the engine rpm to drop down before putting into top gear..... but i have been going from 2-5 with out waiting that long.:eek:

Acturally on the RX8, the factory manual says you cant shift into 1 above like 12mph ..... well guess what? they where wrong. it shifts JUST FINE! :tongue:
 
There should be no problems shifting from 2nd to 1st while moving if you match revs. and don't try to force it. You have to give the stick a little forward pressure and then as you match revs with the clutch in, it should fall into first. You can then let the clutch out and proceed. I've done it a lot in autocrosses and the tranny is still going strong even on the track. It's probably harder on the clutch than on the synchro unless you do it wrong. Remember to have a relaxed grip on the shift lever while doing any shifting and that should reduce most gear shifting problems. Take care,
 
I agree on the slow 2-5th to be better than a fast 2-3th gear change. I do this sometimes.

What I don't do is going through all the gears down to 1st while cruising in 5th and coming to a stop. Doing this will cause unnecessary synchro and clutch wear. I just press the clutch pedal and shift into 1st as soon as the car stopped. If I have to stop anyway. Why should I 'press' the shifter into 1st as there's reason to do so and the tranny is telling me that it doesn't like it.

I don't recall any normally driven NSX gearboxes to have a synchro problem. If so they've been on the track many times.

My gearbox had around 60k miles on it when we opened it to install the shorties and the synchros ALL looked like new. Anyway I installed new synchros as they were ordered already.

I think that the most important thing is to shift very slowly till the oil is heaten up which takes about 10-15 minutes. With cold oil the synchro has to work really hard.
 
Deltron Zero said:
my favorite line from fast and the furious (after the drag race) - "granny shiftin. not double clutchin like you should." hilarious!

Would would you double clutch going up the gears in a drag race??
 
"cool" lingo sells tickets.

I tired to figure that one out acturally and it just didnt make sense! so i gave up. :biggrin:

sometimes i do double clutch up shifting as it helps take the stress of the syncros and acturally will let you gears engage sooner depending on how fast your can double clutch.

Down shift and up shift, the syncros do the same thing, they have to match gear speeds before the gears will lock. So if you double clutch, the engine speed will bring the shaft speeds down quicker then if the shafts where free spinning and you get a quicker shift and less syncro wear. thats alittle excessive tho if you DC all your upshifts. Maybe do it when your really gunning it.
 
Here's my question, sometimes I am able to shift into nuetral without clutching. I usually do this if I am going to HAVE to stop, IOW it's late at night and I'm approaching the stop sign just before my house on that long slowly curving road, I then shift out of say 5th gear in the S2000 into nuetral without clutching. I don't force it out of gear at all. It comes out of gear into nuetral smoothly as the RPMs are relatively low. So, Is this bad?? I've always wondered.
 
BladesNSX said:
Here's my question, sometimes I am able to shift into nuetral without clutching. I usually do this if I am going to HAVE to stop, IOW it's late at night and I'm approaching the stop sign just before my house on that long slowly curving road, I then shift out of say 5th gear in the S2000 into nuetral without clutching. I don't force it out of gear at all. It comes out of gear into nuetral smoothly as the RPMs are relatively low. So, Is this bad?? I've always wondered.

When in stop-go traffic or in regular non-highway traffic, I always do this. I never use the clutch to take the tranny out of gear when coming to a stop.

I have never hurt a transmission and I've never worn out a clutch, even though I've put around 140,000 miles on the oldest one (I usually change cars before the clutch is worn). I've driven about three-quarter million miles over 35+ years doing this, no problems.

On days when my left foot aches (surgery about 10 years ago), I'll sometimes do my entire commute with using the clutch except to start off from a dead stop. I wouldn't do this every day as it taxes the synchros, but simply pulling or pushing the shift lever out of gear when coming down to idle speed (assuming the speed of the car matches the gear's idle speed) won't hurt anything.
 
Thanks dquarasr2 :biggrin: Good to know I'm not the only one that does it and that it isn't harmful to my tranny. Nice to see another NSX owner so close in the S. Florida area.
 
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