bridleman

So I put the new housing on this compressor about a month ago and everything seemed to be working pretty good but as of lately when I'm towing a load of horses around 8000# the turbo starts to make a fluttering sound and the wastegate starts to bleed the boost off around 39psi and won't go any higher, yet when I'm running empty I can build roughly 44psi. Now does this sound strange to anyone else? I always thought that it should be the other way around when you have a load on the motor shouldn't it build more boost? It always seemed to in the past, it's almost like it's building more boost than then the wastegate can handle so the pressure opens it up and the wastegate can't keep it closed to build the boost. Could this be caused by the spring not being strong enough to hold it closed when the boost gets alot of pressure on it with a load? Or am I just getting to critical. It sounds really bad like the turbo is going to let lose, like a tire spinning fast when it's losing air.Thanks

bridleman

So know one out there has any thoughts or ideas on what might be going on?

Big Blue24

I think the increased load of the horses also increases the drive pressure since the engine is not free revving as much so to speak. This increased drive pressure combined with boost at 39psi pushing on the actuator diaphram is blowing open the wastegate. I bet a boost elbow or a few more cranks to shorten the rod length will let you build a bit more boost.

Big Blue24

Do you still have the stainless or did HTT get you a cast housing. The stainless has a bigger wastegate but has the same size spring in the actuator. I think this is the reason for so many HTT stainless complaints. If you double the size of the flapper/puck/wastegate = more area for the exhaust drive pressure to work on and thus a stronger spring is needed, and or shorter rod adjustment, and or metered/lowered amount of boost pressure on diaphram of actuator.

HOHN

Shiny gold star for BB24-- I think he nailed it. The weak spring with the larger flapper is the problem.

You might be able to shim the WG spring a bit and get your boost back some.

JMO

bridleman

This is what I was thinking only problem is that the rod is cranked all the way to the shortest possible adjustment and there is a boost elbow on it with the tiny hole on the 90. So I need to do something about the spring and w/g flap. How would I shim it? Thanks guys. Oh yeah it is still the stainless one.