I have been holding off on asking this question myself for a long time. I have had a noise from the turbo that i suspect to be surging but due to inexperiance am not sure. The turbo seems to flutter when i lug it in fifth. I can get it to do it in third and fourth but its most noticable in fifth. I usually try to back out of it till around 1500 rpms when its gone. Is there a difference in the compressor housings from the h1c and the hx35? I swear i have an hx35 on it but the compressor housing says h1c on it. The turbo is wastegated and looks like all of the pics i have seen. I could use a little advice on this. I have already done a search on turbo surge and flutter but most of the stuff is on 1st gens or bigger turbos. Thanks
Jake

 

You say your compressor says H1C, H1C's from a 1st gen did not have a MAP width enhancing slot cut in them. WH1C's and HX35's did. The difference between them is construction, H1C/WH1C's are bolted and clamped together. The HX35 has a big snapring holding the compressor housing on.

If you take the intake hose off and look into the intake of the turbo you should be able to see a slot that allows any compressed air that wants to escape past the compressor wheel another way out to the intake side.

It sounds to me like compressor surge and if you in fact do have a H1C off a 1st gen then you'll either want to upgrade that one or get a different turbo. Or you could always adjust your driving habits a little too, low RPM's high boost is when it usually occurs.

 

Is the wastgate stuck open? Pull the hose off the back of the afc and blow compressed air in it you should be able to hear the gate open and shut. I would lose the h1c if in fact that is what you have.

 

Preaty sure thats what ive got. There was never a silencer ring in the intake side and there is no slot for the excess air to return to the intake side. I will have to go look at it again to make sure but i think it was only clamped on with a band. Will an H1C compressor housing fit on an HX35 turbo?

 

No, the method of construction is different as I described, the exhaust housing will fit.