Torque curve or slipping clutch?

[hyperion500]

I just bought my 325, and am used to the very linear pull of the turbo on my Viggen. I find that the power seems to level once at around 3000 and once at a little past 4000. Are these flat spots in my torque curve, or is my clutch slipping? Everything else about the clutch and gearbox seems extremely solid, and there are only about 60k mi (100 000 kms) on the car.

Thanks for your help.

[540Rob]

You would definately know if your clutch is slipping.... it wouldn't be on off on off... it would just slip under hard accelleration expically from low rpms.

[hyperion500]

Does that mean that these are flat spots in my power curve? Has eanyone else felt the same thing, or is something else wrong with my engine/driveline?

Also, I've just ordered a Remus system. Purely aesthetic or should I expect some performance gain?

Thanks all.

[Anfanger]

You might be feeling the VANOS... almost no power below 3500rpm, until VANOS kicks in and you get slammed back into your seat. It is a flat spot down low in the powerband, but it should be relatively smooth.

The Remus is exhaust does give a few extra hp and ft/lbs, but only ~5/10 of each I'm betting. People mostly just like the clear tone of the engine through aftermarket exhaust instead of the stock swoosh-quiet exhaust.

[hyperion500]

There are two flat spots, so I don't think it's the VANOS kicking in. It pulls moderately well up to ~3000, lulls, pulls to ~ 4000, lulls briefly and pulls hard to redline. Strange. BTW, thanks for the info on the Remus. I'm looking forward to it.

[Hyperion]

Could it be your intake sucking in hot air until your car gets up to speed to get fresh air? Hot air will make you lose HP, and I noticed on another post you did have a home made Cold Air intake. If you were not experiencing this problem before the intake, there could be your problem.

Or I have heard about flat spot problems before, so that may just be it. Basically its the engine and transmission gearing nothing you can really do about it.

[Stockman]

if you are REALLY interested in whats going on I suggest you get a dyno done.. it will show your powerband instead of guessing

I have seen them go for as little as $25 to as much as $100+

I dont however think its your clutch.. thats not how the clutch acts

[hyperion500]

Problem existed before the intake, too, and the lulls are too regular to be that, but good thought. Actually, it pulls much better now, hot air at idle notwithstanding. If you'll recall from that other post, there was a bird and some peanuts in the airbox, so it could only get better.

Probably just the gearing and engine. Until my driveshaft falls out next week. :

[Kos-motate139]

Could be just the torque curve compared to the turbo car. I don't know Saab's at all, but the 'typical' turbo curve is less power on the bottom, and a huge load on top, a steep curve.

I say 'typical', the only turbo car I've driven regularly was a I-5 turbo volvo. It pulled like a truck off the bottom, tons of torque, but really flattened out when revved up.

The I6 is typically good down low, and power rises with rpms, but I'd guess not as steep a curve as the turbo.

See if you can find someone else that's got a 325 and compare.

[hyperion500]

O2 sensor had no signal, but didn't trip Check Engine light. I replaced it when the Remus went in today, and the problem is gone.

[Hyperion]

Originally posted by hyperion500
O2 sensor had no signal, but didn't trip Check Engine light. I replaced it when the Remus went in today, and the problem is gone.

Thats good...

So what killed the O2 sensor? The peanuts, or the bird...