Life of the Turbo

[mcruz]

"idle down for the correct amount of time" what does this mean? I am new to turbos' so forgive me if this is a stupid question.

[Paw]

I had a 88 Mitsu Turbo before the PT, I had 160,000km on it before trading it in for the mini van back in 97. I used regular 10/30 and change it every 5000km. The most important thing is to cool down the engine prior to shutting it off. I usually let it idle for about 30sec after city driving and a minute after hwy run. I still see the car around town on ocassion.

[Punch]

quote:Originally posted by mcruz

"idle down for the correct amount of time" what does this mean? I am new to turbos' so forgive me if this is a stupid question.

owners manual syas to idle the car for a certain amount of time to cool down the turbo before shutting the car off..

[Turbo Tommy]

*****umm don't all tranny do this? that is why when people install a shift kit, you get slammed into the seat, due to the instant gear change. most people don't want to feal the shifts.

No, only newer computer contoled units do this. I can only speak of chrysler and ford for sure on this, but I am sure other manufatures have similar programs too.

For example,Older hydraulic cntroled units, like say an A-413, when it shifts from say 1-2, it releases the first gear set of clutches/ bands, then engages the next set for second gear, but there is no overlap, but it is done qucikly enough that it doesn't feel that way. The electronic units, when doing the same 1-2 shift the trans will continue to hold/grab the first gear clutches/bands, while at the same time enageing the second gear cluthces/bands, then once those second gear parts were semi engaged, then the computer would disengage the first gear bands/ clutches, so there was an overlap.

The duration of overlap was longer in low rpm shifts, and shorter, or none, at high rpm shifts, causeing it to be quicker, and since the computer can vary line presure, or how hard it grabs the bands/clutches, it can make the higher rpm shifts more noticeable by grabing the bands/clutches more firmly with more pressure.

Like you said most people don't want to feel the shifts, and that is how chrysler attempted to solve the problem. The programing has been relaxed some, I don't think it is ass agressive about holding between gears as it used to be. They made some big program changes in the mid 90's

Shift Kits usually were meant for hydraulic contrled units, in order to make that firm shift, they increased line pressure which meant the bands/clutches engage harder, and usually a kit cause the shifts to be at a higher rpm, makeing that firm shift even more noticeable.

As for idle time, the harder you have been boosting recently, the onger I'd let it idle. If you have been driving gently for the last couple of miles, then probably not as long. If you just tried to set a new record on accelertation, then give it a little longer. I give my cars at least a minute, sometimes more.

[crazyjoe]

quote:Originally posted by Punch

owners manual syas to idle the car for a certain amount of time to cool down the turbo before shutting the car off..

The manual says to do that only after "aggressive driving" I beleive. In other words don't run your car through a 14 mile race and then pull out and shut it off. If you just got done bringing home the milk and eggs, you can shut the car off no problem.

[3BarBoost]

Yep. Turbo cools down pretty quick after you run it hard. Driving around for a minute after pulling into the pits will be necessary, just don't shut off at the end of the straight and coast in. Or for example drag your two jetskis up out of death valley at 80 mph and then pull over at the scenic overlook and shut off.

[Rolo]

That was very informative, Turbo Tommy, thanks.

Questions, questions...always with the questons:

Does the 41TE learn while in Autostick, or only in D? (and consequently, can you "train" it in Autostick?)

Does this AI affect how it shifts/responds in Autostick?

I have 1800 miles total, battery has been swapped once, disconnected another time, and will be again this week. Also, my driving moods change sporadically, so my car is very confused. I prefer it to shift quickly, starkly when it shifts--anything I can do to speed the learning process?

hehe, I see this thing has a PCI bus...can't I just backup my settings to a CD? (nyuk nyuk)

[LAF]

Rolo,
I could not get an answer to this from anyone. I had Stage 1 in but wanted my stock PCM swapped, called the dealer told him it missed and he ordered me one. I put the stock in went to have it replaced and then put the Stage 1 back in. I live like 15 mins from Flight Systems who does the Stage 1 PCM for Mopar. I had mine flashed, and then my brother went down to have his flashed. While he was there I had him ask and they were not sure as it was never asked. I still dont know. I put Stage 1 back in and ran it for awhile, then diconected the battery, and did the quick learn over. Pain in the butt as documented here, but I did it to be sure. So I am not sure, Flight Systems was not sure, so that is what I did.

[Turbo Tommy]

Your right it does have a pci bus, but chrysler calls it something else. Engine pcm, trans pcm, traction/abs are all bused together, so they work very well together, they had this tech way back in the late 80's, pretty cool huh!

Wish it was that easy, just think if you could upload or download info via cdr's through the factory cd deck. Load new calibrations that way!

anyway, it should be learning at all times, d or autostick. As for starkly, if you want it to shift firm and quick, try this.

Disconnect your battery, let it sit for an hour, make sure the memory is purged, and your starting back at factory defaults.
Go out and drive hard from the start, I mean hard, full throttle acceleration, for a while. It should continue to shift that way for a while. However, eventually if you change your habits, it will too.

Autostick shifts are usually firmer anyway, to give it a more manual shift feel.

As for turbomangt's question about life expectancy, change your oil regualrly, with mobl one, 10W30, and allow idle time after driving to let the turbo spin down. Even with s1 I think you could expect the motor and turbo to live that long. Older chrysler turbo 2.2 and 2.5 motors have, with alot of abuse, and this motor is I think more stout than they were.

[Turbo Tommy]

So is it the turbo itself that requires more upkeep? if so, then I would say getting the S2 or S3 (don't these systems replace the turbo with a larger one?) That being the case, perhaps waiting till you get some miles on the turbo would make more sense to replace with s2 s3 later down the road, does that make sense? gary

Ok, the whole motor has more stress on it under boost, each power stroke is much more forcefull than a naturally apirated motor, but the turbo must be maintained too. The only benifit of changeing to a larger turbo is if you are trying to supply a higher level of boost. The stock turbo is capable of 18 psi +or- . A larger turbo can move more air and therefor supply high levels than the stock, however it will have more lag due to it increased size, so it will not spool as qucikly. I would say, if your happy with factory or stage one your factory turbo is just fine. If you want to go to some insane boost levels, get a bigger turbo, and definitly make sure you have upgraded fuel system too, you don't want to go lean.