Right now I've got City Diesel's "Dodgezilla" HX40/35 hybrid turbo installed. Just down the exhaust stream is the Jacobs exhaust brake sold by DC & Cummins.

So far, the Dodgezilla is a great turbo. Thought I'd ask about something. The Dodgezilla always has the "jet rush/whine" even when coasting. I've noticed that when I engage the exhaust brake, I can hear the turbo "burp" and back off quickly. When I switch off the brake, it spools back up quickly. I can hear it clearly even when there's minimal or no boost.

I know that the HX40 has a tendency to throw exhaust turbine blades, and that the HX35 blades are shorter and therefore stronger. Still, I'm wondering what sort of stress the blades and bearing are under when you back off quickly and engage the brake. Probably worrying about nothing -- but I never noticed the "burp" with the stock HX35 -- I assume it's the big 40 compressor wheel slowing down suddenly.

 

Yes its barking, and yes its dangerous.
Would I worry, not really.

I barked my pdr 40 this weekend with 40+ lbs of boost.


You have less chance of destoying the hybrid over a full 40 when barking.
There is less load on the turbine side.

--Justin

 

My hybrid barks more than I woulld like, but I'm going to make a few changes that should help it. While not good, it hasn't turned into a grenade yet.

I think your problem will mostly go away if you just ease off the throttle before applying the brake.

 

Justin, I have a video of me barking my PDR 40/18 at ~30-35PSI. PM me, or e-mail me LPD@stx.rr.com if you want me to e-mail the video. It's a little large, I'm doing a donut/burnout. About 45 seconds long.

BTW, Yes, you are barking it. With a '35, and barking it at low boost less than 5-10PSI, you shouldn't have to worry about it. It's barking it at high boost that is bad.

Merrick