straight pipes?

i'm kinda curious as to why the op would even both with a truck that he doesn't even own.

i certainly wouldn't be spending my money and time on company equipment.

 

I understand where he's coming from. I have a company truck but Ive spent quite a bit of money on it for polishing the tanks, lug nut covers, and waxing it with black ice turtle wax on my home time. It may be company equipment, but it's assigned to me and its gonna look good.

 

The turbo will provide all the back pressure. And how in the hell does a muffler change cam timing?

Maybe you need to study modern cam grinds on modern engines. Valve overlap has been the norm for sometime now.

 

Please explain the increased turbo lag when going to open exhaust on these big diesel engines over an exhaust with a proper flowing muffler on it. I have seen it in smaller diesel engines that are used in pickups all the way to the larger 15 liter engines used in the heavy trucks.

 

Backpressure in any engine is a bad thing. The turbine wheel and housing on our engines generate way too much back pressure by themselves, so adding more with a restricitve exhaust system only hurts power. No theoretical model (The otto cycle, diesel cycle, carnot cycle, etc) has any input for backpressure that is needed for the cycle to work. The restriction to flow is only going to cause pumping losses and thus sap power.

From a spoolup point of view, you want the large pressure difference across the turbine to help it spool faster. This means straight through exhaust and properly sized pipe is a must. Why is 5" better than 6" and much better than 7" on a stock truck? It comes down to exhaust velocity. The large sewer pipes on a stock engine will cause the exhaust to cool too quickly and stagnate in the pipe. This stagnation causes the exhaust to slow down too fast and instead of flowing out it has to be pushed out. The 5" to 6" expansion will keep velocity up leaving the turbo. Higher speeds means less pressure, so the turbo works even better.

It becomes a balancing act between restriction and exhaust velocity when choosing an exhaust system. There is nothing at all wrong with straight piping a turbo diesel, BUT, you must have the correct size piping. You don't wanna just take a stock truck and through 8" piping from the turbo back. You'll need the correct sized piping for the horsepower application you're going to be running, the higher the horsepower your engine will produce, the bigger the pipe needed.

 

Darn right. Not everyone that has straights is out to get on people's nerves

 

No you may not be killing babies but you might be keeping them awake at night when you come rolling into a town or bark them pipes as you leave town.


I know that I absolutly hate it when I am parked and a sleep and some dimwit with straights decides to crank it up next to me and idle it up to 900 rpm. Then I have to get up and go try to find another spot to sleep only to find all the spots taken up. Then I end up going back and nosing into the spot which pisses alot of drivers off because they can't see around your trailer.

 

still goes back to the shot gun. you wake me or my baby up. i'm chasing you down.

as for looking good. i wash my truck. BLUE beacon does a good enough job for me. i've got better things to do with my time then wax the company truck that's just gonna get dirty the minute it rolls down the highway.

we all like a clean truck. but let's not go overboard. my tanks look good. my chrome looks good. and it's a beautiful day. i'm riding my bike over waxing the already nice looking chrome.

it's bad enough keeping the bike looking good. i'm certainly not adding the truck.

besides, most companies don't really care. you certainly don't get paid for your time. and your lucky to even get reimbursed for the wash.