I have a 1995 A4 Z28. It has very few mods but over 130K miles, 3.73 gears and a Hypertech programmer with 160 t-stat.

The tranny seems to hang the shift at anything close to half throttle or beyond. I am wondering if this is because the fluid simply needs to be changed or is this how these trannys just shift. I tried the option on the programmer to firm up the shift, but then it just surges everytime and that sucks for driving in traffic or when I am not wanting to drive like Billy Bada$$.

Questions...

• What exactly does the shift kit change?
  
• Will just changing the fluid and filter possible increase the hydraulic pressure due to new fluid?
  
• I know I should use a cooler... which one?
  
• Which shift kit is best and why?

Thanks for participating in this education. Any and all submissions will be reviewed for spelling and content. All responses will be greatly appreciated by someone who is generally concerned to know everything so that one day I too can be as smart as the woman I live with.

 

Your tranny just might be getting old and needs a freshening up. But its always worth while to try the little stuff first.

If you change your tranny fluid yourself, odds are you'll have to drop your tranny oil pan to get to it, especially if you want to change the filter in it. If you get it done at Jiffy-Lube or something, they pump it out, and pumo new stuff in from the dip-stick tube.

A programmer or "shift-improver" will just up the line pressure. Its the absolute worst way to do things. When I put in the torque converter, I put in a TransGo shift kit and left line pressure at stock levels.

I'm not sure what mechanically changes inside the tranny when a shift kit is put in (I had a friend of a friend who was a reputable tranny mechanic do the install), but I do know it speeds up the shift (as in takes less time to shift), and it shifts harder because of it. Since the pads and stuff engage quicker, less friction happens and the tranny generates a little less heat.

If your tranny fluid is low, it could change things. I'd change the fluid first before doing anything else.

You could get a cooler for safety of mind, I've got a little shrimpy one and I need to upgrade. Unless you've got a big stall torque converter, you don't really need it.

Best kit? TransGo. But you've got to drop the transmission to install it. So while its dropped, you might as well put in a little better torque converter and get the tranny refreshed anyway.

 

First, Thanks for the reply.

What gains did you notice with your converter and shift kit? My commute is hellacious thru Houston traffic. I drive over 130 miles each day. Soon it will be less because I will not have to drive from one airport to the next each day but it still will cover almost 100 miles.

Will the converter affect the cruise speed or rpm? Forgive my ignorance, this is the first automatic car I have had in 12 years. My GN had a 4800 stall and was strictly for street racing... it was never a thought to drive that car any further than needed to kick someone's A$$.

Thanks Again!!

 

No problem man,

I gained A LOT from the converter. But its all from a dead dig on ET Streets. See updated sig for times. MPH will suffer a bit, but your ET will drop like a stone, considering you have enough traction. On stock cam with bolt-ons I went from a 1.99 60' on auto-x tires, then added the converter and gears an went down to a 1.77 60'. But the converter was a little too big for the stock cam and I was passing up all the torque. With the new cam, its a bit better.

The bad thing is, your gas mileage will take a hit. I went from around 22 around town down to about 15 with my 3200 stall, but its real loose and flashes around 4000. If its stop and go traffic, you'll get used to it, especially with a smaller converter. My friend had a 2400 stall put in his when he was rebuilding his tranny. It was a stock cam car too, and it felt more torquey off the line than mine did.

Another bad thing is, OBD1 cars (your 95 is probably a OBD1 car, only a few rare late 95's were true OBD2) don't like stalls over 3000 rpm. Some of them (mine was lucky enough not to have this problem), won't shift at wide open throttle on the 1-2 shift. The PCM doesn't update fast enough, some people think it has something to do with how the VSS is mounted in the tail shaft. There's a few work arounds in programming like having your car shift off rpms and disabling the mph tables in the PCM. Mine did it once when I started launching 1.6 60's, so I'm ditching it and going for a TH400.

Cruise speed on the highway won't suffer, because the converter will lock up at a certain rpm (that is if you get a lockup converter). It'll drive like stock. City driving you'll cruise a little higher because the converter is shearing. With your GN, you know what its like with the converter, except it'll just lockup when you hit whatever your stall speed will be, or the highway (unless you had a non-lockup converter in your GN.)

Later!

 

Okay... well this has been helpful.

I plan on keeping this car a simple street car with bolt-ons... LOL!! Just like every other street car I have owned. Liar!!

I would however like to keep some of its nice street manners because it is a convertible and I do like being able to have my girlfriend ride in one car I own.

What would you say for a stall speed then? I was thinking about ditching the 3.73s and going back to a 3.42 to help out with my cruising rpm. I am at 2600@70mph. I would like to get that down a bit so I can cruise at 80 mph at that speed. With a 2600 stall, would that not be the better ratio and stall speed with a 3.42?

 

I figured with your other toys, this was gonna be a convertable cruiser.

For a nice cruiser, I'd say a 2400-2600. That'll lock you right into the meat of the torque band with the stock cam, and if you get a little bigger cam down the line, it'll work out decent too.

I've got a Precision Industries "Vigilante" 9.5" converter, rated 3200, but they're all under rated. Thus mine flashes higher, plus its real loose. A normal 3200 will flash 3600, and a 2800 will flash at 3200. I don't know if they mass make them lower, but you could probably order one. Plus all Vig's have a 2.5 torque multiplication. Another good company is Yank, they've got all sorts of converters in different sizes and torque multiplications. SLP (people who used to make SS's and the like) sell their converters in 2400 and 2600 I think, and they're made by Yank as well. So you might want to check them out. www.slponline.com

Yeah, you might want to drop down to a 3.42. I originally wanted 3.42's, but I heard 28" tall tires hook so much better than 26" (which they do), so I went with a 3.73, threw on the 28" tire, and it brought the ratio back down to around 3.53. I didn't notice much in the way it cruised, except it cruised on the highway at a way lower rpm. At 65 I cruise the highway at like 2200 rpm.

 

I have a 95Z A4 California Model. The tranny shifts at diff RPMs depending on how much I am pushing into the gas pedal.

With very low presure in the gas it shifts into 2n gear almost inmediately, The more I push into it the longer it will stay in gear.

Changing your own Trany fluid is messy. I did it once cause I wanted to change the Filter.

I had to have a professional Shop flush my tranny because when I changed my tranny filter I was only able to replace a portion of my tranny fluid... there was a lot left in the converter. They hooked her up to this machine and it exchanged the fluid with the engine on.... no mess at all. Some people have reported their trannys going bad after they replace the fluid... Mine is due for another one soon and still working fine.. knock on wood. I would recomend a shop that use this type of machine. if the shop only drains the fluid then chances are they will not replace the fluid that remains inside the Torque converter.. and that could be quiet a lot depending of what converter you have installed. I think my car has a fluid cooler in the radiator cause they opened up the hose conection that goes in there and thats where they took the fluid out and injected the new one in.... all in one transaction.


I have 2.73 OEM gears. someday I will swap them for some 3.42s. For what I have read thats pretty much the best compromise. I will do it for the feel of it but dont want to go all out since its my daily driver. I want her to have some city manners left on. She is defenetely not a racer.


well thats as much as I can contribuite...

marvin

 

I have got to stop playing online here and get to work... these airplanes are not going to build themselves.

My main reason other than just making this thing drive right is to save face when my brother is handing me my A$$ with his Evolution8!! His car has been ripping 1.5-1.6 sixty foot times and los 12s with nothing more than a 3" exhaust and lots of computer tuning. It just is not fair!!

Of course then I have to come back with its JUST a convertible street car and throw the Cobra at him.

 

I have the A4 with Transgo shift kit, stock converter and 3.42 rear ratio. Before I instal the shift kit, when dragging I had to let off the pedal slightly to be able to shift before hitting the rev limiter.

Now with the shift kit, I can hammer it all the way and it shifts at 6000RPM all the way upto 125MPH (6000RPM) when it shifts to overdrive. This is the nicest thing about the shift kit. Shifting is firmer and stronger.

I think a 3.73 rear ratio is a way high for an A4 with stock tire size. You would smoke the tires a lot and at every traffic light. And without I shift kit, you will be hitting the rev limiter very quickly every time you hammer it. Also, your crusing RPM will be higher, not good for mpg.