If your good enough at rev matching you never have to hit the clutch whether shifting up or down. You would still have to cluch in when coming to a stop though. Hard to get used to and don't recommend doing it with the G.

It is much quicker then double clutching, even if it isn't matching the revs for all parts of the transmission.

 

You all are arguing over which term is the "proper" one but you do all realize that you are talking about the exact same thing right?

 

Rev matching does not equal Double clutching.

two different mechanical functions to achieve the same means.

 

This: and pushing in the clutch, blipping the throttle to match revs, downshifting, and releasing the clutch are the same thing. The only difference that I can see is taking the extra step of coming off the clutch while you match the revs. That is pretty much the same thing - just a different method by which to do it. Maybe I wasn't clear in what I meant by it being the same thing.

 

oddly enough REAL double clutching actually helps smooth out the first-second shifts in the G. I never do it as i got shifting in this car down to a science anyway, but it does work.

 

why's that "odd?"

 

Not the same thing, when you rev match you are only matching the revs of the engine with the drive train. This is not the entire transmission.

when you double clutch you are matching the revs of the engine, the layshaft, and the drive train. Basically all of the components in your transmission.

 

Ok, I am *not* arguing - I'm asking for clarification. If I rev match, I push the clutch in, pull the shifter into the neutral position (with the clutch in), blip the throttle, put the car into gear, and release the clutch. How is that mechanically different (in a modern transmission) than your description of double clutching? When you release the clutch in neutral, as far as I am aware, the transmission isn't "connected" internally so I am not seeing the difference. Hopefully I have described that well enough to get an answer.

 

because i dont see why a 40 k sports sedan should need to this to smooth out slightly jerky shifts...it ment for 18 wheelers lol.

i cant lie though i love the 6 speed on this car.

 

Hopefully I'm not coming across as mean or anything, its always hard when reading someone's response to know what they are like especially when you don't know them from Adam, or Eve.

Modern transmissions - sort of simplified - Engine -> clutch -> layshaft -> Gears -> Synchros -> Drive shaft, diff's, wheels.

while in neutral;
If you leave the clutch pedal pushed in, the actual clutch is disengaging the engine from the layshaft, so when you blip the throttle only the engine is matching the revs of the drive shaft.

If you let up off the clutch pedal, the actual clutch is then engaged, and the engine and layshaft are now spinning at the same speed. so when you blip the throttle everything in the transmission is matching the revs of the drive shaft.

 

You aren't coming across as mean. That's one reason that I said I wasn't trying to argue with you - it could have easily come across that way when you are just reading it. lol

I appreciate the clarification of where you were making a distinction. I was trying to talk to Trey about all it this morning but you can only squeeze so much into 5 - 10 minutes. lol

 

If you want to be smooth and quick on the shifts, just about every car that has a decent amount of Torque and HP will need rev matching or Double Clutching for the 3rd to 2nd and 2nd to 1st gear shifts, especially if they have lightened flywheels.

Synchros can only do so much for you, if you want the car to shift smoothly and not rev match or double clutch then you got to get off the clutch slowly and let everything catch up.

Synchros only help with half the power transmission, you want to be smooth and quick, you have to help out the engine by matching revs one way or another.

 

I dropped my car off Saturday (after some problems with the dealer seeing that I had an appointment with them for a loaner) so a tech could come in today and diagnose the problem.

In any case, all was said and done, and no surprise to me, the tech said the clunking/noise was "normal". He didn't exactly experience what I am havng a problem with as it is a problem that occurs under ~60 degrees, and gets worse the colder it is. This morning was a balmy 76.

So with that said and a few random/abstract analogies from the tech trying to explain the bad synchros away, we agreed that I would bring the car in October/November so we can go over the problem when its colder.

I set this appointment up for today with Infiniti US main number and they got me squared away, however my dealership (for which will be unidentified for the time being) isn't really on the same page.

My guess from the tech's request to call the dealership direct instead of go through Infiniti US to set up my next appointment is to avoid me going through the lemon law which in VA means I HAVE to go through Infiniti US. I have around a year to get the problem fixed before the law doesn't apply so I have to get this resolved before next year. They have something like 3 attempts depending on where you look, however the brochure they provide us when we buy doesn't have an explicit limit.

In any case, if (really when) this problem persists/gets worse, I'm going to get a couple certified techs (SAE) to diagnose the problem, get another "normal" diagnosis from Infiniti and approach BBB which is protocol for my state and begin the arbitration process.

On a side note, the tech said that to have an independent certified tech diagnose exactly what my problem is (faulty synchro), is pointless and made the analogy that women in the middle east wearing garbs on their face to cover them is normal over there, but not here. So unless the independent tech can drive lots of g35's, he can't make a good comparison. We're talking apples and VCR tapes here. One thing has nothing to do with the other in any sense. He says its normal for this car to do this and my rebut is that just because its normal doesn't mean its not a problem. So his point in essence is moot. All that would say is that Nissan created a defective product and needs to recall it.

Anyway, my rant is over for now.

 

have you tried swapping out the manual transmission fluid with RedLine MTL? It's known to "solve" synchro issues like this. i know it's preferable for the synchros to be R&R'ed instead but if the manuf. isn't doing it, and if you don't want to deal with the lemon law, try this first.

 

Excellent comment!! As this thread demonstrates, there is a lot of confusion and misinformation on this topic, and I got flamed on another forum some time back by trying to make the point that double clutching/heel and toe, etc. is still a very useful technique for smoother overall driving as well as high performance driving (not just an "esoteric racing technique" as someone called it). Because of that I will not even attempt to discuss it - its a lot easier to demonstrate it than it is to write about it.

There is an article on Edmunds.com under "Tips and Advice">"How to"> "Heel and Toe Downshift" that explains it very well including the driving limitations of NOT double-clutching (just "rev-matching") even on a car with synchros.