How should power torque curve look like after tuning?

by **capske** » Fri Mar 14, 2014 7:59 pm

Hello,

I have a question about how my torque curve should look like after a tuning.
2years ago i had my Laguna3 2.0 Dci 150 chip tuned by a company to 180Hp.
Immediately after the tuning I put the car on the dyno and saw that I had a nice straight torque curve.
It rose to 400Nm at about 2000rpm and stayed about the 400Nm all the way to 4500rpm.
I had nice power gains and even under 2000rpm I felt a power difference.
I had the chip tuning removed because when the car was idling I had a strong exhaust gas smell inside the car.

Now I had the car tuned again somewhere else. I'm very impressed about the boost I now get at 2000Rpm.
But below 2000rpm, I don't feel difference. Instead, I have the impression I have less power below 2000rpm.
On the dyno I see that the torque curve is actually the same as the original torque curve, on the exception that it's about 60 to 70 Nm higher than the original. But it's nog nice and steady like the previous tuning.
On the other hand I don't have exhaust gas smell inside of the car.

I must have the sheet from the dyno from the 1st tuning somewhere but I can't find it right now. But I think you must be able to visualize what I mean.

Could someone tell me what is actually the better tuning of both?
If it's better to have a straight curve or like the original but higher?

Thank you.

Best regards.

by **zok** » Sun Mar 16, 2014 9:32 am

The second one is a "percent" tuning with probably standard setup below 2000 rpm, and that is ok for flywheel, ecology. economy etc.

It is nicer to have a nice smooth curve, but too much torque below 2k rpm can seriously threathen dual mass flywheel's life.

It's all a matter of personal preferences.

I personally like a car that pulls off well at 1300 rpm, but because of a flywheel max torque is developed at 2500+ rpm. :? I drive below 2000 rpm most of time.

by **sparco** » Sun Mar 16, 2014 2:39 pm

And dont forget, high torque at low rpm possibly kills the gearbox as well, happened to me, font want that to happen twice ;)

by **capske** » Mon Mar 17, 2014 8:25 pm

Dear Sparco & Zok,

Thank you for your posts. This is pretty obious and clear.
Thank you for this. So i don't have to worry about the fact that I don't have big gains bolow 2k rpm and it doesn't mean that the tuning is less good.
Now i know I can keep working with the second tuner.

Thank you very much guy's!!!