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Discussion Starter #1
Thinking about part exing my manual 2.3 stg1 for a 2.3 auto FPT. (with a view to upgrading at a later date)
Any inherrent problems with more horsepower or torque going through an autobox?
Cheers
Alyn
 

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Any inherrent problems with more horsepower or torque going through an autobox?[/b]
I assume you mean inherrent problems with a 9000 auto and more power/torque?

Yes there are a few. More torque slighly changes when the box wants to change.. so it can change at odd times in my experience.

Also it will wear the clutchpack and torque convertor faster..and indeed there are few aftermarket strengthening parts that can be used on the ZF box.

The upgrades I have on my 9000 were part of the reason why I wiped out my autobox. Reconditioning an autobox properly isn't cheap.. and getting an auto specialist to further strengthen it, isn't cheaper either... look at around 1300 pounds if it all should go wrong.

Having a fairly heavily modified 9000 auto myself I can see the benefit of an auto especially in stop/go traffic and in town - it's very relaxing. However for back road fun it's ultimately frustrating, because you have to really alter your driving style to avoid the box shifting when it shouldn't.
 

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Speedparts drop the maximum torque by about 10% for their 9000 2.0lpt automatic upgrade. ChipCentre do a special upgrade for autos - don't know whether this is just a torque reduction or if there is something else special about it.

It is clear from this that the tuners are definately taking the weaknesses of auto boxes into consideration.

I'm going for Speedparts (due this week) because they have arranged that the extra power does not come in until higher revs - this means that for trogging to work and round town it should not increase the wear and strain on the box.
 

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Originally posted by Mike Hunter:
[qb]I'm going for Speedparts (due this week) because they have arranged that the extra power does not come in until higher revs - this means that for trogging to work and round town it should not increase the wear and strain on the box. [/qb][/b]
Is this standard practice for speedparts when suppling an ECU for an auto, or something you have arranged yourself Mike?
 

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Standard practice.
I found out by chance that Chipcentre had the special auto upgrade and asked the Elk if Speedparts did one too - the answer was yes.

Speedparts have a form to gather the info they need - this includes gearbox, traction control, cruise control and VSS
 

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I think that, if anyone is ever interested in making a Saab that's quick in a dragrace I think you'll find an Auto can actually in certain cases be a slight advantage. Gary Donovan has a 10 second K car auto at this site:

http://www.thedodgegarage.com

It broke recently on the dyno ... but he and Gus Mahon, who died last year, found that at least in Chrysler cars the auto was faster than the manual with the same motors. Because when you shift a turbo car the intake manifold has to go under vacuum, some boost is dropped, and the turbo slows down you get lag between gears. Hypothetically if you had a 5 speed auto like in the aero's ... proerly tuned it could blow away a 5 speed manual in a turbo car. Gary's auto is a 3 speed and still was far far quicker than with the 5 speed manual. Granted it wears down much more quickly, and I'm not reccomending anyone go out and buy and auto just for this reason, but don't diss em! They can really be made to run quick. Food for thought eh?
 

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Discussion Starter #8
Thanks guys,

I shall go and look at the auto today and see what its like. My manual is running in nicely at the moment - the auto will have to be something special and a good deal offered to sway me.

Alyn
 

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Discussion Starter #9
The Griffin was a nice motor, but- well I guess I actually like the car I've got. If it was an Aero it might have been different. My running in is progressing and I am starting to get all
again.

Alyn
 

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Same story here...I went with the auto just because of the deal I was offered. In hindsight, I wish I would have waited and just looked harder for a manual trans. The auto is very convenient and comfortable but you cant dump it at 3k rpm so some lag is inevitable. If you truley love driving, you dont just want but need total control over the car. It is very easy to feel like you are fighting with the auto over what gear to be in. The newer 5spd auto at least has a manual shifting mechanism but even this is not the same as working a clutch. A buddy of mine who has been a Saab tech for many years told me the 9000 auto trans fails regularly in Aero trim due to the extra power. He also told me he has never had to replace a 9-5 autobox that was properly serviced in any trim. Just based on that, I would not tune a 9000 Aero with an auto trans. I figure I'll stop tuning my Aero when torque gets close to 300lb-ft.
 

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Saab tech for many years told me the 9000 auto trans fails regularly in Aero trim due to the extra power.  [/b]
The 9000 aero auto is exactly the same as 9000 2.3 Turbo non aero autos I'm afraid.. 200HP and 296NM torque as standard...

The ZF 4 speed transmission is not really designed to cope with higher torque outputs than 296NM... in the case of chrysler etc, the popular US auto boxes have a full tuning industry behind them, with strengthening kits etc available to handle the big increases in torque and stresses that come with tuning an engine and using it for sprints.
 

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Originally posted by XAAMOTTOMAAX:
[qb]A buddy of mine who has been a Saab tech for many years told me the 9000 auto trans fails regularly in Aero trim due to the extra power.[/qb][/b]
I must agree with Mark - the Aero auto has no more power than the other 2.3T autos. Chances are that the Aero, being the "sporty" model, has been driven harder. The ZF unit in the 9000 is specified up to 300Nm. As Mark says, the 9000 2.3T auto output is almost at the design limit.
 

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I've always preferred manuals to automatics, in any vehicle. Having said that, I should also relate this story about my good friend JJ. He has a '95 Aero that's slightly modified (by Abbott - he dynoed 220 whp) and also is an automatic. JJ has had this set-up for a few years now and has never had a problem with his slush-box (it has well over 100k miles). JJ is a very bright engineer who works for a local aero-space firm and knows a lot about fluids and mechanical systems. I think his knowledge of the basic principles involved with automatics heavily influenced his driving habits and the corresponding lack of problems he's had with his modified AAA - Abbottized automatic Aero.
He has developed a feel for when the transmission up-shifts and never uses full throttle through those shifts - just lifts his foot up from the loud pedal when he feels a shift coming. On downshifts, he doesn't mash the loud-pedal to force the shift, he manually selects the lower gear with no throttle and only after the gear engages will he add throttle. He also changes the ATF with Mobil 1 synthetic, every 10k miles. I guess my point is the AT does have it's weaknesses but if given a little care and thought, it will handle a little more torque and remain intact.
 

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You guys are right about the Aero auto sharing engines with the non Aero 2.3t and you are probably right on with the Aero tending to be driven harder. I just have Aero on the brain and forgot it didnt get the same power rating with the 9000. Either way the auto in the 9000 is not designed to cope with high amounts of torque as stated, and fails with some frequency. Unfortunately I love the neck snapping thrust of the 4th to 2nd downshift you get flooring it at 60mph
so If there is a trans thats going to go, its probably mine! What is the history of the auto in the 9-5? Is it a GM trans shared with any other vehicles? How much torque is it rated to handle? My Stage 1 ECM has a lower power rating for the Auto trans vs manual trans. I am wondering if this is so because the manual is designed to handle more power than the auto or if experienced Saab tuners figured out many Saabers are a little sketchy tuning autos due to the number of failed transmissions in the 9000 auto. I know I was when I first started thinking about tuning mine.
 

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What is the history of the auto in the 9-5?[/b]
From 2002 the 9-5 has a new auto box, both this one and the previous one are manufactured by Asin Warner.

From 2002, Automatic Aero models are equipped with a new five-speed automatic transmission. Previously, torque was restricted to 243 lb.-ft. with the older four-speed auto,

*this is an important point, since it means that the gearbox communicates with the torque load sensors on the car, and protects its self from higher torque inputs.. and tells the car to limit the torque. So when tuning it gets interesting.. does the box let the car express the full new torque?

The new five-speed auto- gearbox however allows full utilization of the Aero engine's 258 lb.-ft. torque.

Re-calibration of the management system to take greater advantage of the variable-turbo boost on demand was introduced with the auto aero 9-5.

The box is also available on the arc and linear.


As said, the gearbox is capable of handling the Aero's high 258 lb.- ft. torque figure. The previous four-speed automatic was limited to 243 lb.-ft. of torque.

Saab is one of the first European manufacturers to put this much torque through a five-speed automatic in a front-wheel-drive configuration.

Adaptive automatic reconfigures to changing conditions

The automatic constantly monitors its surroundings, adapting performance and shift points to the prevailing conditions. It "knows" when it's in a high-altitude environment for example, or if it's towing a trailer, and it responds accordingly. The transmission also continues to monitor its own shift quality and will alter shift timings and patterns if it detects any change in its performance or in that of the engine. A high-speed CAN data bus provides the continuous flow of information between engine and transmission to enable this to happen.

However, the five-speed automatic transmission isn't driver-adaptive. That's up to the driver to control, with the choice of normal, sport, or winter settings. To choose the sport setting, the driver engages the "S" button located on top of the gearshift handle. In some other applications, the sport mode engages a closer set of ratios by moving the automatic's mapped shift points.

Saab's engineers have engineered a similar result by using an alternative solution. The drive-by-wire throttle becomes more sensitive to the driver's foot pressure - effectively giving him another set of ratios, and providing a sportier response by concentrating the gearbox's best efforts on the engine's mid-range power.

In winter mode, which has a special shift pattern to suit slippery conditions, the engine starts in third gear to ensure a smooth take-off on icy surfaces, and to help minimize wheel spin.

Slipping lock-up clutch gives greater efficiency

The new five-speed automatic transmission also features a clutch within the torque converter. In higher gears this clutch bypasses the torque converter and directly engages the transmission, eliminating some of the frictional losses associated with traditional torque-converter automatics.

The gearbox is a sealed-for-life unit. The automatic transmission fluid, an extremely high-quality mineral oil, has been formulated to last for the life of the car, cutting down on servicing costs and creating less environmental waste. It's also one less worry for the driver.


*** built from various Saab press releases..
 

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Sorry, I should have clarified. I have a 2000 Aero auto with the 4 speed. The factory torque is lower than with a manual, but part of me suspects again this is a psychological tactic to put ease into the minds of previous 9000 owners who had failed auto trans and are considering a 9-5. I could be way off. Does anyone know the ratings/history for the 4 speed used thru 2001? Thanks for the info on the 5 speed! Very informative.
 

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Does anyone know what the maximum allowable torque for this transmission is? They come from the factory with 243 lb-ft but what is the true reason for this? I suspect testing would show the auto could hold up under higher power loads than the stock 243.
 
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