turbo surge?????

[JQuam]

i get turbo surge around 10-12 under loaded conditions. it is a 93 12valve motor. Any ideas before i break sumpn? thanks

 

[JGrefenstette]

what exactly do you mean by surge? is the boost spiking once you get to 10-12? auto or getrag?

 

[JQuam]

boost real eractic and a strange noise from da turbo. its a zf 5speed. will do it in 3rd,4th,and 5th

 

[OKish]

sounds like your turbo is going south, is it wastegated? you sure its not a leaky ic or hoses?

 

[JQuam]

no wastegate. it doesnt do it all the time just now and then.

 

[JQuam]

usually under partial throttle,if you back off and then get after it it wont do it. it has 4. 10 gears ,i dont know the turbine housing size. runnin down the road it only runns 3-4lbs of boost unless you step into it

 

[dpuckett]

If it is fluttering around the 10-12psi range, at lower RPM (Say, under 1600), then I'd say you have surge. If it's at higher RPM, I'm not sure what to tell you. It also puzzles me that it's only at part throttle, but not at WOT. You sure it's not just the noise of the turbo? They dont all make a steady whine all the time- sometimes they will sound like they are fluttering just a bit, but it's actually the pulsing of the cylinders (like at idle).



The cure for turbo surge is to get a compressor housing with a mapwidth enhancement slot- it allows some of the air to be recirculated back to the intake, and not try to overfeed the engine at lower RPM.



Daniel

 

[JQuam]

no not at wot at all. this is definite surge sound. where can you find the enchancement turbo housing? i believe i have an 18cm housing. im going to change the gears to 3. 55s, will this change in rpm affect the air flow to the turbo and make that surge go away

 

[dpuckett]

I doubt a gear change will make it go away.



An MWE slot is a slot cut through the inner intake portion of the turbo compressor inlet (inside the 4" wide, about 2" long piece the air filter tube attaches to), perpendicular to the axis of the shaft. Look closley at an HX35 and you will see it. It is about an inch outward from the fins.



DP

 

[JLEONARD]

You can also go to a WH1C... those have the MWE slot.

I changed my compressor wheel and housing to one from a WH1C and my turbo flutter/surge went away.

 

[Greenleaf]

Blown head gasket.

 

[Bob Beauchaine]

I had the same problem with my truck and the original cold side turbo housing running my 14cm wastegated hot side. Since going to the PDR HX35 and adding a boost elbow to the boost sensor for the wastegate it has gone away. The boost elbow is currently closed and loaded temps are up slightly but my Snow W/M stage 2 system with a stage 3 analog controller all is well.



Bob

 

[JQuam]

anybody got sum good pictures of the mwe slot on the compressorr side. I think im just going to machine them into it. sound do able????

 

[dpuckett]

GL- my blown head gasket made the noise at WOT, too. Not saying you'r ewrong, but if it did it at part throttle, it seems it'd do it at more throttle. Unless the engine noise of full throttle drowns out the noise.



DP

 

[JQuam]

not a blown head gasket,the motor pressure test good and no water in the oil. it is defianitely turbo surge. i did sum more searching and found that it is that the motor can wind faster than the turbo and causes the it to go to the surge limits of the turbo(hope that made since). it defiantely needs the mwe slot in it. im not quite sure how to machine it into it yet, looking for sum ideas. i dont think a can switch to a different turbo because of the space i have available isnt much. sorry it hasnt been puttin my sig up. its in a 89 ford crew cab with a 5spd. kinda close quarters.

 

[Greenleaf]

The turbo compressor housings for most of the H1C and HX 35 HX40 are the same. The older one with the 50mm inducer is smaller but also lookes much different.



I cut a slot in a H1 and works really well. However, you really need to upgrade to a larger compressor wheel. The housing will remain the same size externally.

 

[JQuam]

Do you have pictures of the slot you put in? What size did you make the slot?I found a picture on Welcome to TurboByGarrett.com

does this look right?

what size of compressor wheel do you recommend?

THANKS!!!