nats

i have the 4AT and the downshift from 2nd to 1st gear will only change if im going 47kmph (im in australia) or slower. is there any way i can change this to a higher speed with any mods?

chetrickerman

what is 47 kmph like 20 miles an hour? well if it is, in the manual (for MT) it says to not shift into first gear above 20 mph because it could cause tranny failure. so maybe its the same thing with AT's

JTtheDude

I don't know what it is in kmph but in my 4at it's 30mph you can't downshift anymore. I don't know a way to get rid of that

chetrickerman

you dont want to get rid of that. it protects the transmission

thecow135

4AT not 6AT so might be different

Old Rotor

The 4 A/T wont shift down to 1st till it's about 2.7K RPM's in 2nd gear.

JTtheDude

I don't know what it is for a 6AT but here's all gears for 4AT in the US...
Cannot downshift to 1st over 30mph
Cannot downshift to 2nd over 70mph
Cannot downshift to 3rd over 110mph

I too wish you could get rid of that limiter or at least tweak it to increase on 1st gear. I mean if I can hit 48mph in 1st why can't I downshift at say 35-40. I'd be happy with 40 or maybe a little less and 2nd needs to be raised to at least 75 i say. Maybe the torque converter can't handle the shock of the increase in rpm's I don't know. But there doesn't seem to be anything out there currently that can change this like the rev and speed limiters.

09Factor

Even though we can shift from 1st to 2nd @ 48mph, you wouldn't want to down shift from 2nd into 1st @ a speed higher than the 30 mph limit. The sudden centrifugal load placed on the TQ from a high speed 2nd to 1st shift would destroy the OEM TQ.

I don't know about any of you but I don't want shrapnel slung trough my legs.

just be happy with the imposed 30 mph shifting.

tajabaho1

on the 6 ATs you can only shift to 1st below 20mph, and seriously, good thing too, the 6MTs you should only downshift to 1st below 10mph, if not you risk destroying your synchros

just do it

G3tR3DDY2GR3DDY

iTrader: (8)

not with proper rev-matching techniques there is no risk in any downshifting, but i guess not all of us have those skills...

tajabaho1

^ i tried, still in 1st, it really isn't recommended

and for the argument's sake ATs cant rev match =.=

nats

ok thanks for that. Just wanted to know.

R888

2nd gear to 1st gear

Must be under 50km for the tranny to response.

mdw1000

I've found you can do sort of a psedo rev match. If you blip the throttle just after tapping to downshift, it makes the downshift seem a bit smoother. But I've only tried that when I'm downshifting and not on the brakes, or have the time to let off the brakes. Don't trust myself to heel and toe

JTtheDude

I rev match my downshifts all the time in my 4at I've done it so much that it's just habit now and now I"m getting really good at it. going down to first at close to 30mph is the hardest but if you rev match the rpm's up to about 4-4.5k it will be smooth I've done it numerous times.

Spinning Sushi

iTrader: (21)

You can rev-match an AT? Is that even possible?! Please explain.

Jasonawojo

iTrader: (2)

From what I've read, there is enough of a delay in the manual mode shifting that you can blip the throttle after hitting downshift prior to the downshifting actually occurring. Thus helping to bring the revs up as needed for the lower gear.

Spinning Sushi

iTrader: (21)

That's interesting. I'm pretty sure that it's easier with the 4AT rather than the 6AT considering how the gears are longer and not as refined.

JTtheDude

Yeah exactly, you press the down button or use the shifter whatever, then there is the slightest pause where you blip the throttle and depending on the gear depends how much you blip, if you blip it right the gear will grab at about the right rpm and it will be a nice smooth shift. If anyone here is in the Dallas area I'm in Plano and I can show you anytime I do this everyday everytime I drive and I'm quite good at it now. this is in a 4at I've never driven a 6at to try it

09Factor

There is a long enough pause in the 4AT to rev match. I do it all the time.