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i'm acquiring a new 9-3 arc this saturday. i was looking at the torque chart for it, and was curious about the torque at high rpms. is the turbo just really small, or did saab program a boost cut in the ecu? what have you guys done to overcome this?

also, i see people saying 9-3ss...is "ss" for sport sedan? just courious. i'm new :lol:
 

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yes, SS is for Sports Sedan.

Don't let that torque chart fool you. the 2.0T has plenty of go even at 70 or 80 mph. i am always impressed how easy the car pulls away at high speeds.
 

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turbulence said:
i'm acquiring a new 9-3 arc this saturday. i was looking at the torque chart for it, and was curious about the torque at high rpms. is the turbo just really small, or did saab program a boost cut in the ecu? what have you guys done to overcome this?
Congrats on your new car.

There is a chart here from BSR's website that shows the hp and torque numbers for the 2.0T engine. If you look at the graph for the untuned engine, you'll see that torque on the engine is almost completely flat between 2800-5000 rpms. This is pretty remarkable, but typical of a turbocharged engine. The Saab does begin to cut boost back around 5000 rpms. This is actually a good thing that will help you avoid detonation from preignition.

There are going to be very few cars that you will see a high rpm peak torque, Honda four cylinder VTEC's being one of the few that I can think of. But that's not really desirable for most driving. Most manufactures try to keep the torque peak as low and as broad as they can to provide a flexible engine. Trust me, you'll appreciate the torque output for day to day driving, it really is smooth and flexible.

I am sure there are a couple of things that you could do to improve top end performance. On the intake side you could add a freer flowing intake. Either a drop in, or a cold air intake. On the exhaust side, you could add a lager diameter downpipe and larger diameter exhaust. I am sure that the better the car can breathe, the better the top end will be.
 

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black_linear, i know why they have the torque the way it is :) that's why i'm asking what you guys have done to help the motor pull all the way to redline. nothing is more dissapointing than a small turbo that can't be efficient at high rpms. boost low is nice for everyday driving. boost till redline is kickass ;) at least that's how i look at it. i know though, it'll be nice having almost instant boost. i love the way the arc drives.
 

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turbulence said:
black_linear, i know why they have the torque the way it is :) that's why i'm asking what you guys have done to help the motor pull all the way to redline. nothing is more dissapointing than a small turbo that can't be efficient at high rpms. boost low is nice for everyday driving. boost till redline is kickass ;) at least that's how i look at it. i know though, it'll be nice having almost instant boost. i love the way the arc drives.
It's really and "either/or" proposition. I'm sure one of the SAAB tuners (Abbot, Hirsch, BSR, etc) could help you retune the engine for ultimate upper end performance. Of course, the low- and mid-range would probably suffer as a result.
 

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my 2 cents:
big charger: low torque at low rpm, good fuel efficiency at high load. good for stationary engines with little transient operation (power plants, large merchant vessels)
small charger: good torque at low rpm, wastegate, bad fuel efficiency at high load. good for engines with lots of operation under transient load(cars, yachts, warships etc.)
 

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Spoken like a true engineer. Thermal loads on large compressors are less when compared to smaller units at similar power levels. A larger turbocharger will not need to compress the inlet air as much as a smaller one due to lager internal volume. The higher levels of compression in the smaller turbos leads to an increase in air temperatures which in turn requires countermeasures in the form of intercoolers etc. Back to the topic,IMOP it's difficult to tune cars equipped with small turbos for high rpm torque because of the exponential increase of thermal loading with an increase in engine rpm. Tuners can try to circumvent these inherent failings by adding extra fuel to the combustion chamber but a turbo operating close to maximum operating conditions is just going to run out of steam. I would suggest that you consider freeing up the exhaust thus allowing the turbo to make and hold boost more robustly. I myself have stg.3 which is the open air filter, a turbo back exhaust system and the requisite ecu programming. Good luck and happy modding.
 

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turbulence said:
also, i see people saying 9-3ss...is "ss" for sport sedan? just courious. i'm new :lol:
No, GM made Saab call it the SS... to be like the Camaro and the Silverado. :lol::lol::lol:


j/k
 

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turbulence said:
black_linear, i know why they have the torque the way it is :) that's why i'm asking what you guys have done to help the motor pull all the way to redline. nothing is more dissapointing than a small turbo that can't be efficient at high rpms. boost low is nice for everyday driving. boost till redline is kickass ;) at least that's how i look at it. i know though, it'll be nice having almost instant boost. i love the way the arc drives.
You'll get more top end with a 3-inch downpipe, or optimally, a full 3" turbo back exhaust system with a free-flow catalytic converter. Software is a must too....

Your turbo's exhaust housing is also a pinch point; replace it with a larger one. (I'm not sure whether the Arc has a Garrett 17 or T25, or a Mitsubishi TD04). If it's a TD04, replace your stock 5cm2 housing with a 6cm2 housing...)

Or, you can do a turbo swap, but be prepared to spend serious do-re-mi for that....

EDIT: Just read Oslowly's advice and he's right on the money.
 
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