BigBully

What size Turbo does the 93 Have? A friend said in 93 they went to a 16. Is that correct? If so Is it good or is there a better size for the 93???

Thank You,
BB........

jw216

stock should be 18.5, I just took mine off today and put on the 16cm from Piers.

Lil Dog

They are 18.5 cm in 89, 90 and 93. 91.5 to 93 were 21 cm housings.

I am in the middle of pulling out my 18 and putting in a 'gated 12 from an HX35.

J-eh

dodgeman01

My 93 has a 18.5 and my friends 90 has a 21 both autos. Mine drives a lot better than his and the 16 is a lot better than mine
DM01

wannadiesel

[quote author=Lil Dog link=board=9;threadid=20593;start=0#msg193274 date=1065417505]
They are 18.5 cm in 89, 90 and 93. 91.5 to 93 were 21 cm housings.

I am in the middle of pulling out my 18 and putting in a 'gated 12 from an HX35.

J-eh
[/quote]
Get ready for the flutter! :'( Mine's been doing it for 3 months now, hasn't exploded yet. Some say it will, some say it won't. I guess I'll find out. I would't give up the instant bottom end response for anything now!

BigBully

Funny you mentioned flutter, Mine does it bad when I get on it hard. I watch the Boost gauge and it flopps around when its makeing the flutter noise. What causes This?

wannadiesel

BB, what size turbine housing are you running? I and several other 1st gen 5 speed owners experience a fluttering sound (and boost gauge for those who have one) at low RPM under heavy load (say the bottom of 4th and 5th at more than half throttle). Most who have this problem are running the 12 cm housing, and we think it's the inlet side of the turbo cavitating. There is some disagreement over whether or not this will destroy the turbo. I'm never going back to the big housing myself, I'll get an HX-35 if the turbo blows.

Alec

Check this thread out . . .

Or just do a search in the 1st gen form on "flutter", as there are a couple of other threads from that time talking about it. Wannadiesel and I both set our trucks up so that we could surge the turbo bad at about the same time -- Monty had been having some trouble for a while, and J-eh was already surging his truck with the stock 18 housing!

Depending on how our truck is set up, and how you drive, it can be more or less of a problem. The only way to get rid of it is to reduce your boost at lower rpms, either by using a larger, slower, housing or reducing fuel delivered, or to get a turbo with Map Width Enhancement -- and I am not really sure how "flutter proof" MWE is, since I don't have it, but I haven't seen anyone complain about surging their Hx35.

BigBully

Well My Dodge Guru Buddy says mine is a 16 But I dont really know. All I really know is this motor is a 93 and it had an Auto behind it. I cant really think of when it flutters but I think it does it in 4th and 5th the Hammer down.

Alec

If it is a 16, it will have the number 16 cast into the back side of the housing by the flange that bolts to the exhaust manifold. Might need a mirror to read it.

Lil Dog

Ya, I'm thinkin this may be a temporary install.

I can surge the turbo at 1500 RPM and full hammer down. I have done it empty and with a load on. It seems to happen as soon as you reach about 13 Psi at 1500RPM and really starts to be audible around 15 Psi near the same RPM band. Once I get over 1700 Rpm it seems to disappear.

We'll see... :-

J-eh

Bushy

If I understand this event properly the issue occurs in the "boundary layer" between the incoming air and the pinwheel edges.
It's very similar to a prop cavitation. The air cannot get into the turbo inlet fast enough so you get that fluttering sound.
Also there are some housings that have poor "seperation" inside the 'horn' which amplifies this problem.
If you are constantly barking the turbo you will eventually suffer some kind of damage...
Correct me if I'm off track here guys...

Pastor Bob.

Lil Dog

Well Bushy,

Cavitation or flutter is a different animal than "barking" or backflowing the turbo. Our cavitation problem is exactly as you described it, the turbo compressor is asking for more air than it can get and the outlet pressure is too high, basically out of the efficiency map of the turbo. The possible problem would be overspeed of the compressor.

Barking is usually caused by very high outlet pressure and the sudden release of drive pressure on the exhaust side. The turbo slows down quickly and air backflows through the compressor. The sudden change in thrust pressure on the internal bearings causes damage to the shaft and eventually the impellors.

The cavitation problem can be hazardous if maintained for too long, but not as destructive as barking.

J-eh

Alec

Excuse me J-eh, but flutter or surge occurs when the mass of air flowing through the compressor is too LOW -- the turbo is "getting" plenty of air, but the engine isn't "taking" enough away -- that is why as the rpms go up, and the mass of air flowing through the engine goes up, the surge problem goes away.

Some students just don't respect their teachers -- if it weren't for Lil Dog, I might never have figured out what that noise was ;D.

Lil Dog

Uhhh.... OOops...

I am getting all turned around.. I must have gotten up too fast from sawing on my downpipe..>LOL>.

The type of surge I was thinking of can happen, but you're right, its not our problem at all.

Thanks...

J-duh