thats called a car having plenty of power.... try driving a supra, evo, sti and they all have the "thump"

 

The "thump" only occurs in manual mode because in full auto mode, the TCU can perfectly adjust for the power going through the tranny at any given time. It knows when its going to shift and it can regulate everything during the shift.

When in manual mode, the thump primarily occurs when you are pressing the pedal more aggressively and usually the shift would occur at 5k-6k. But if you short shift it, the tranny isn't prepared to shift at that point but you are forcing the shift. It shifts but can't regulate all the conditions as effectively so you get a more forceful (waaay less smooth) "thump". Now the other gears don't thump but they still shift way harsher than left in full auto mode.

 

I wish my 03 had this problem

Anyhoo, it's probably the TCU telling the tranny to shift at a higher line pressure. It's assuming when you are in MM, you are going to drive it more agressively thus a higher line pressure is dialed in.

Why can't anyone offer a TCU mod like the ECU mod? There's only about 10 gazillion G35 autos running around. UGH!

 

Is it true that the TCU and the ECU are for the most part mated together? Probably because of VDC and such it makes it hard to decouple the two.

 

As far as I know, they are two seperate boxes. But later TCUs are INSIDE the tranny!

 

hmmm... inside the tranny?

Good thing I am happy with the way mine shifts for now

Just get a VB mod if you want harder shifts

 

The the shift firmness I don't have a big problem with. It's the shift logic that chaps my butt. I'll have to arrange to have the latest tcu flash done from Infiniti to see if that does anything.

Plus VB mods are what? $800-$1200??? Here is a clue. I don't think a VB mod on a RWD auto is that much diff than an FWD auto tranny. Now remember what the maxima VB mod used to cost??? MARKUP anyone?

 

I never got down to test driving an early G35 with the older tranny software, but I can imagine... slip the infiniti tech at a dealership some $$$ and he'll probably hook you up when the service writer gives you the blank stare when you ask him about it.

I was looking at how much a VB mod costs... it's pretty bad. I remember Don in Texas doing them for cheap if you sent in your VB. As far as I know, there are two methods to the VB... replacing the internal springs with stiffer ones or changing out some pressure plate to increase line pressure... $1k for a VB mod is a lot...

 

This happens to me ('05 X) and to me it should NOT be considered normal. If it was "normal" then it would do it in all gears changes but it ONLY does it when going from 2->3. All other upshifts are not effected.

Man, if you are hard on the gas and upshift to 3rd it feels like something hit the bottom on your car.

 

Found this out a long time ago. Either leave it in D or before you go into 3rd, take foot off gas, shift, then gas (at least that's what I would do when I drive MT anyway). But the lagging on the automatic is horrible so I leave it in D almost all the time now (except on highway when I use 4 or 5th gear back and forth).

 

My 05 auto doesn't have a hard 2-3 shift but you can feel a "thump" when you shift between 4-6k, it's perfectly normal for this to happen in my opinion.

 

https://g35driver.com/forums/g35-coupe-v35-2003-07/125122-figured-out-2-3-shift.html

 

Actully I just installed the gen2 Stillen exhaust lastnight and the thud is hardly noticable at any RPM range. I will do more testing.

I normally use the manual mode in heavy traffic so I don't have to break/gas all the time with the stop and go.

Lol, if you have to shift at a certain RPM range or have to lift and then shift, that's hardly what I call "manual" :P

 

I don't call myself a pro driving manual cars but as far as I've driven m/t cars for the last 15 yrs, to shift I let go of gas, clutch in, shift, clutch out, gas. So to just let go off gas in manumatic mode, shift, gas is a piece of cake.

 

Mine bumps sometimes during the 1-2, sometimes during the 2-3. I don't worry about it. As long as the tranny doesn't splatter itself all over the street, I'm good with it. It's done it since day one and it'll probably be doing it the day I send her away.

Not a big deal - I call it normal.