The Scheid pulling truck video on the ATS site has a distinct change in turbo sound as its spooling up. At the change you can see the exhaust go from black to grey to coal black. Is this just twins spooling up? Is the change a stumble in the small turbo as the large one kicks in? Do ALL twins sound like this spooling? If so, that's pretty cool! The Scheid truck is one BMF for sure. Thanks.

Here's what I was talking about

http://www.atsdiesel.com/Video/Schei...20030904_1.MOV

Ben

 

OH MAN I WANT THAT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!

 

I think the change in tones may be some of his other goodies kicking in at certain boost levels. Like some drugs or Water in stages. Thats my guess anyway.

I did hear some feedback on the video.

HE needs a chute!!! The way he was going I thought he was heading for the onramp for town..


J-eh

 

Here is another one with the Bank's Truck. Kinda the same thing. When you hear the inital spool start to die out sound wise the exhaust gets louder and more smoke. Thanks again. Just bored and have been curious about this.

Banks Sidewinder
http://www.atsdiesel.com/Video/Truck...20030729_1.MOV

Ben

 

Fairly certain the Banks truck has a single turbo.

Just a guess, but it seems like:
turbo spools while staging to build boost, then with increase in exhaust note some exhaust is bypassing the turbo ie through a wastegate that just opened? The increase in exhaust note is definitely not going through turbine wheel.

Change from black to gray is indicator of decreased back pressure in exhaust manifold, waste gate popping open - more air getting into cylinder, then back to black on the ATS truck because wastegate pops open closed twice as he's getting into the fuel and Banks truck because he gets onto fuel right at the setpoint of the wastegate.

The second spool of the ATS truck sounds like a second turbo - deeper/throatier whistle, but sounds like there is only the one turbo re-spooling on the Banks truck as they both get into the fuel.

Orrrr.....maybe not.

 

sidewinder doesnt use drugs

 

The white ATS Dodge doesn't have a wastegate.

The Banks truck did use NOS. They hit the NOS blow off valve before they got to the water box.

 

Well, so much for my guess.

 

The scheid truck is mean. I was able to see it pull in Muncie this year. What a show!
-Jason