Just noticed my driveway where I park car has black chalky dirt trail which was exhaust. It's quite a bit and just started happening. Is that normaL?

Just dynoed car and it's running decent. AF range from 12-14. Only thing was my trq was way above up at 467trq and hp down to 320hp. Not sure if it's the guys dynoing wrong or if I should have someone look at it in more detail? I was tuned at 401hp and 415trq.

 

might be some pieces of the catalytic converter

 

Double check your AFR at idle. Sometimes tuners make the AFR richer at idle and very low rpms to make the car smother in that rpm range. That may be what is causing the dirt trail.

 

Unfortunately my gauge is not working as o2 sensor is burnt out due to rich start (according to dyno tech). but it wasn't shooting out the black dirt till I recently had to put in new test pipes and took out catalytic conv. thinking there is oil or turbo leak....??

 

There is only one measurement a dyno measures and thats torque. HP is just the torque multiplied by some constant which is done in the dyno computer.

Just google the equation for HP and then calculate your HP at various RPMs based on your dyno torque to see if it makes sense. Maybe the guy had the conversion factors screwed up or something.

 

That is incorrect as Inertia dyno's measure HP and THEN calculate the torque.

OP..you may have this problem now because it finally collected enough inside the exhaust that is shoots it out now.

 

Sorry, thats wrong.

HP is always calculated. It is impossible to measure HP or any other type of energy directly. You can only measure the effects of that energy.

In the case of a inertia-based dyno, HP is calculated by the measurement of angular acceleration from the drum and its inertial moment.

But you're right, in that inertial dynos do not measure torque.

 

This.

There is no way to measure HP, you measure torque and derive it.

Horsepower = (torque*RPM)/5252

 

Well...you are correct in this case. I'll call that one 50/50 because you said:

And inertia dyno's don't do it this way...but then again they also don't directly measure HP as I stated so I'll give you that.

 

Black streaks are normal. Welcome to rich start up conditions and no cats. Enjoy!

 

+1 Enjoy it...my driveway has that $hit all over it LOL!!! Totally normal.

 

Not having the black streaks before and the loss in power....that's not a problem? I guess I assumed the two are somehow linked. Even before when I had pipes on the exhaust didn't smoke as much as it does now.

I guess I'll start with replacing the o2 sensor first and see what my AFR actually is.

EDIT: It seems the busted o2 screws up the my FCON. So i guess that messes up the AFR.

Hopefully that fixes.

 

hmmm, I have seen black streaks occasionally.
op, which o2 sensor burnt out? pre-cat (connected to the manifolds), or the ones connected to the cat's? Were you throwing any codes with the burnt out sensor?

 

The black streaks are because you got rid of your cats and went to test pipes thats normal...the loss in power is weird. You should have gained power with more flow with the added test pipes.

Guessing it has something to do with your 02 sensor. Change that and see what happens. Thats where I would start.