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Discussion Starter #1
I know that 9000's with an auto box are factory limited to 200bhp - and most people are reluctant to tune much beyond this.

What about ng900's, 9-3's and 9-5's with auto - are there similar factory limits - and what are the thoughts about stage tuning these?

Alyn
 

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I heard many comments about auto box/BHP limit.
I have 9k autobox + maptun stage1. (going for stage3 by this weekend )

I try not to push the car too hard in low gear and avoid hard kick down. WOT is used for higher speed, +100km/hr. I think these will help my auto box to last longer.

Any suggestion about what to do or what not to do to make the auto box last?

Cheers
POM
 

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Gearboxes know nothing about power. They only feel torque. The 9000 box is designed for 300Nm. I think that some of the tuners provide different ECU reprogramming for automatics which limits the maximum torque, but boosts the torque at higher engine speeds where it normally starts to tail off.

The general advice is: be gentle in first & second gears (the box is partially locked up in third and fully locked up in fourth, so they are more robust), and change down by hand before overtaking rather than using kickdown (gearchanging at full throttle is serious stress for the 'box). Change the fluid more frequently than normal.
 

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The (early) 9-5 4-speed autobox is, IIRC, different to - and rather stronger than - the 4-speed 'box in the 9000. Leon has his in rather an impressive state of tune, and the 'box doesn't seem to mind. Not sure about the later 9-5 5-speed 'box, but I'm assuming that it, too, has a higher torque threshold than the 9000 box.

As for the 9-3 and NG900, is this the same as the 'early' 4-speed 9-5 box? Or is it the one that's in the 9000? Or neither?

James (who knows very little about autoboxes)

BTW, where's MarkA? Didn't his 9000 have various strengthening mods to the autobox?
 

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The 4 speed in the 9-5 is different than in the 9000. I have an Aero stage 1 with a few other mods and I do not drive it mercifully. After 6 months the transmission fluid is still nice and rosy with no signs of overheating (smell or darkening). Too much torque will cause too much heat and cause failures. If stage 1 is not enough, installing a stand alone transmission oil cooler will provide better cooling and, yes, more power capacity. If you are looking at stage 1, you should have no problems.
 

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Discussion Starter #6
Cheers chaps,

I have a manual 9000 at present with a stick shift and stage 1. Its getting a little long in the tooth and I will replace it soon.

9-3's and 9-5's seem to be more common with an auto so I am starting to research what can be done.

Thanks again

Alyn

 

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The problem with the auto is that there is a torque limit on the gearbox. You can tune the engine in various stages to increase the torque output over the rev range. But, if "Stage 1" is enough to reach this limit across the rev range, any higher stages will not give any benefit.

Don't forget that Horsepower = Torque x Revs. So you need to look at the published torque curve (usually for manual transmission)and compare the tuner's one with the standard. But draw a straight line across where the curve goes above the auto box torque limit.

In practice I think that Stage 1 (or 2, which is usually Stage 1 plus a big exhaust)would give most benefit. The benefit of higher stages will only be available in an auto at the top end of the rev range.

Bear in mind that in a Saab the peak torque is at quite a low engine speed before tuning (1800 rpm or so), so tuning an auto would give least benefit at these revs.

Because they start from lower torque, the 2.0litre auto engines can show a greater %age increase at lower revs as there is more "headroom" before you hit the torque limit.
 

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The 9-5 autobox does appear quite a sturdy unit, with specialist breakers unable to sell units on the shelf!

It's up to you to look after it, as with anything, when you push the design envelope, an increase in maintainence frequency will pay for itself over and over, saab recommend a fluid change every 60k miles of so.. for the sake of oil, I'll be doing it every 20k miles or so, and keep a close eye on condition.
 

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The later 9-5 5speed auto units are solid I'm led to believe. Because overhere They are sold in the hirsch performance 9-5 with 305 BHP. with official warranty.
 

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The torque on these cars is limited to 400 Nm instead of 420 Nm for manual gearboxes. So you might say an automatic box is still limiting tuning possibilities, however to a less extent as in the past.
 

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Okay, so does anyone have a figure in Nm of how much a 9-5 autobox (4-speed) can withstand?

Is 9-5 Aero 4 speed box different that LPT? And if it is, then what is the difference?

I'm thinking of Maptun Stage 2 but have no idea whether the guys restrict the torque.
 

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Leon is correct


But theres a problem with the MapTun stage 2
..........when I get into 3rd gear and the after burner (full boost) fires up, I always run out of bl**dy road!
 

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Originally posted by Cosmic Blue 9-5:
[qb]Leon is correct  
 

But theres a problem with the MapTun stage 2  
  ..........when I get into 3rd gear and the after burner (full boost) fires up, I always run out of bl**dy road!    [/qb][/b]
Then find a longer road or work on that suspension!
 

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Anyways, due to the weakness of the autoboxes, I think most tuners have a separate program for them that limits low end boost. They can tailor the boost curve so that lower peak torque is achieved but still make similar horsepower numbers.
 

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So do you think Maptun is going to issue their T7 programmes with PPC-like device (no ECU replacement needed)?

When mounting the new ECU (i.e. Stage1) is TechII marrying needed or is it a straight plug and play?
 

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Originally posted by Adam 9-5 2.3t auto:
[qb]When mounting the new ECU (i.e. Stage1) is TechII marrying needed or is it a straight plug and play? [/qb][/b]
Yes -plug and play (alot!
) - provided you have given the correct details from your existing ECU
 

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Well, tristian, it appears to me you should probably start another topic. The question you are asking warrants it, and you may get more responses that way.
 
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