John Speake

Thanks Steve,
That's an excellent summary - so altering the rpm the kickdown relay sees, (just in second gear) is unlikely to persuade the 'box to kick down at a higher rpm................

It would appear that all the "logic" is in the gearbox hydraulics.

drnick

when the box is warm it will kick down in all gears inclusing first, at higher revs. if the 'effect' of higher oil temp (lower viscosity?) could be duplicated or accentuated within the hydraulic valving...

SharkSkin

So, when in first... what does it kickdown to?

John Speake

Hi Nick,
Do you mean the box will kick down to 1st from 2nd at 30mph ?

If so, it's the only one I know of............

dr bob

As interesting as this might seem, that shift would inflict about the most strain you could ever come up with-- max torque multiplication into first gear, the shock of the downshift, and right at the HP peak on the engine. I'd be cutting up beer cans to make scattershields for the CV joints...

With not very much more speed/RPM's available in first at 30, this is a shift that's not worth the bother. But maybe at <20, that might be nice! I need to experiment with a PKS setup to see what's really available with just the solenoid.

For those "worried" that the RPM sensor will haunt their ability to get the higher-RPM shifts, you can wire your PKS around the relay completely. the little coil on the kickdown solenoid wouldn't strain any decent switch, that's for sure. Relay is there for the logic function, not to increase the current handling capability. Hey, you don't have to worry about voiding any warranties, right?

John Speake

Well, 30mph in 2nd is 3k rpm on my car, and 4k rpm in first.

I don't know if that would break the transmission, but I would be willing to try !

dr bob

I guess I need to go recover the car from storage, and stomp on the loud pedal in first gear to see how fast the engine is spinning at 30mph. I just don't remember seeing anything close to 40 in first gear, but that may be caused by my foot lifting involuntarily.

On a related note, one of the things that really got my attention when the first Autothority chipset was installed was the rather brutal 4-2 downshift when I stomped the pedal at 50-55. I have since removed those chips for other reasons (detonation on hot days, low speeds/sudden loads with AC on). Since then they have been replaced by Autothority, problem solved, then removed for what I thought was a NOx-causing problem. Replacement was mapped for a GT, by the way, rather than using the one designed for my S4. I'll probably put those back in one of these days, now that smog is another two years away again.


Back to work!

drnick

no my car dosent kickdown from first and it wont kickdown at 30mph either!

SteveM928

That's because you've got an '89 transmission. You've got a different first gear and differential ratio than earlier US spec cars if I remember right. You can do right around 55mph in first gear in an '87 or '88 S4 A/T.

dr bob

I knew that the diff ratio is about 10% quicker, but didn't know that the first-gear ratio was changed too. I guess I need to A) drive the car more, and B) spend some more time with the manuals.

Solution to a is coming soon-- the new epoxy floor in the new garage should be "fixed" by the vendor in the next week. I chose the expensive optin, where the vendor sends a contractor to prep and paint. I have a floor full of very hard, very durable fisheyes. Nice fawn beige color, selected by Jim B (thanks Jim) will be great, as soon as they figure out what happened to their paint.

Solution to b may be a little lomger. It's hard to manufacture 'extra' time these days for re-reading the manuals. Hopefully soon the "retired" thing will kick in a little stronger.

ROG100

I don't know if this is new information or not - so just in case.....

If I select 2nd from D and then put the selector back to D my car starts in first gear every time from standstill. Depending how you press the gas it will change to 2nd either at lower revs or redline.

Is this standard or just the GTS?

drnick

roger, it sounds completely standard. what you can also do is shift to 2 and leave it there, starting off in first gear. then when you want 2nd you can shift to 3 and then quickly back to 2 and your car will now be in 2nd gear which it will hold all the way to redline. 1st gear is great for driving around in town with streets crowded by pedestrians. in combination with the RMB the sound sends people scurrying out of the way!