[cbehnken]

Originally Posted by Kibwe Walker

I still would be worried about pushing them hard because dr650's are clipped turbines.

The majority of the backpressure in our cars has nothing to do with the exhaust, it has everything to do with the turbine and turbine housing. So just play with that scenario in your mind engine bank 1,3,5 is seeing different amounts of backpressure compared to 2,4,6 on the exhaust stroke. At low boost settings, its no big deal but at the settings where the dr650 is doing most of the work and the other turbo is out of its efficency range thats unequal amounts of stress on your crank coming from the different banks.

A engine is harmonic chaos, you don't want to do anything that will break up the harmony and unequal pressures is one thing you can do to destroy the harmony. Not that your engine will fail immediately because it won't, our engines are pretty strong but I wouldn't roll around at 18-20 psi for a whole tank either.

I wish you'd get over it. Your theory sounds great, but not a single person has ever hurt their motor from different turbos. A few have even run 9bs with 15G/DR650 size turbos for some time.

I am going to have to be WAY over 20 PSI to have the DR650 doing most of the work. I easily held 17 to redline before. Maybe if I tried going all out and ran 25 PSI it'd be a problem.

I am totally injector limited and this car will probably NEVER see over 18 PSI or so even when i go to bigger injectors. This is not a race gas car.

If there was a problem it would be easy to feel this out of balance condition your theory suggests at high RPM/ high boost and believe me it is as smooth as ever.

So, whenever a post like this comes up inevitably you are going to post how the theory says boom and I am going to post how in practice there are no problems.



Edit: Oh and the reason for no race gas is I don't see the point of producing track results I can't produce on the street because I drive this car every day. It is my ONLY car.

Edit2: I am sure you have seen the stock downpipe. How's that for equal flow!