Holset 16? or not..

[IRoss]

Okay, so I was hoping somebody could tell me if my turbo housing is a 16cm or not... . The type no. is H1C, ***'y no. is 3528894, and serial no. is C0035648. I was told when I bought the truck the housing had been downsized, and I always figured it was a 16, but lately i've been wondering. Cruising at 2000-2100 it pulls about 15-20psi. . Any help is appreciated. .

 

[Philip]

Look on the side of the exhaust housing. It should be cast in numbers.



The numbers you listed are from the tag on the intake housing. That won't give us any info on the exhaust side housing.



That much boost at normal cruise sounds like something smaller than a 16 cm.

 

[IRoss]

How right you are... . upon closer inspection it has 16 stamped on the outside of the exhaust housing... . maybe 'cruise' might be a bit of an exaggeration for those boost levels,i live in the mountains and use the go pedal quite liberally... . another question i have for those members who have 'swiss cheezed' their airboxes, after i ventilated my stock airbox last weekend i noticed, along with an increase of the boost system whistling sound an actual fluttering in the boost whine coming from the system itself when the pedal goes down hard, at around 15 psi plus... the boost gauge does not flutter with the sound... i drilled a series of 2" holes in the box... anyone had this happen before?

 

[JLEONARD]

I have an "enhanced flow" airbox as well... . the other moniker sounds so cheesy... .

I had turbo flutter after I made some intake changes (non I/C), but the boost gage fluttered as well. Yes it was around that same boost level. It was not related at all to the enhanced flow airbox as far as I'm concerned.

When I installed the compressor housing out of a 94 WH1C that has the Map Width Enhancement groove, the flutter stopped.

From what I have read the jury is out as far as whether flutter is really that bad. Personally I can only imagine bad things from it.

Jay

 

[IRoss]

So let me get this straight... the compressor housing is on the inlet side of the turbo unit, and the H1C that is in there now might be responsible for the fluttering sound by some sort of restriction inside the housing? To me it definitely sounds like an intake noise. . thanxs

 

[JLEONARD]

I think the fluttering is the compressor wheel "stalling" as the wheel is pushing more air than the engine can use. The MWE groove relieves the pressure the opressure on the wheel and allows it to keep spinning.

At least that is my simple understanding.

 

[Greenleaf]

I cut my own into an H1 and that thing screams. Never any flutter like Jay has described with his previous turbo on the non-IC engine. But then I won't hear the flutter over the loud piercing shrill-cry of the MWE slot



I use the aFe filters open to the engine compartment so it's getting plenty of air and nothing to muffle the noise.

 

[rlyons]

I cut my own into an H1 and that thing screams. Never any flutter like Jay has described with his previous turbo on the non-IC engine. But then I won't hear the flutter over the loud piercing shrill-cry of the MWE slot



I use the aFe filters open to the engine compartment so it's getting plenty of air and nothing to muffle the noise.

Greenleaf, any pics?

 

[JLEONARD]

But then I won't hear the flutter

I think you would if you had it.

But I think flutter is more a manual trans issue.

 

[rlyons]

I get this flutter very badly. So if I get a 94 Turbo it should cure this? I have a spare 92 but I could look for the 94 I guess.

 

[JLEONARD]

So if I get a 94 Turbo it should cure this

That's what did it for me.

But it's the MWE groove in the housing that does it.

Perhaps Greenleaf can divulge how he cut the slot into his housing and you can try that. You've got the spare to play with.

I vaguely remember someone else doing that maybe a year ago ... . I believe there was a pic posted in the thread. Perhaps a little archive searching will help you out.

 

[TWorline]

IRoss:



Check this thread out. https://www.turbodieselregister.com/forums/showthread.php?t=130253&highlight=MWE+groove

 

[IRoss]

That thread is indeed very informative, and I think I will have piers take a look at it in the spring, since I am planning to install a 4" downpipe as well... . I can well beleive the shaft bearings may be worn as well... . my only other question (it might be a dumb one)is if my H1C housing isn''t a Hx35 what is it exactly?