ExtrudeHone'd Turbo Housings

[KEENO]

Does anyone know of a source that has the capability to "Extrude Hone" our Hot End Turbo Housings?



My confession: I've modified the wastegate on a 12cm2 housing by knurling & pressing a 'plug' into the wastegate hole and then having it welded into place w/ a nickel rod, I also welded the actuator hole closed. I now wish to Extrude Hone the housing to 13cm2 approximately and install it in place of the 12cm2 (w/ wastgated) that I'm currently running on my modestly-fueled First Gen.



I've been warned that this might not be the best approach to eliminating the wastegate "flutter" that I'm currently experiencing. I still wish to evaluate this housing set up and will be cautious w/ regard to overboost & turbo efficency mapping.



I believe that Joe Donnelly has experimented w/ Extrude Hone'ing the cast iron housings and mentioned that no performance gains were realized & it was a waste of time & money.



Any comments? I'm open to all...



Tim "KEENO" Keen

 

[Deezal Man]

Maybe I shouldn't reply, since I am not "Mr. Turbo"... However, it seems to me that extrude honing the turbo would do more harm that good.



It is my understanding that extrude honing serves two purposes. To increase the port size, and remove the casting burrs found inside of a head or intake manifold.



A turbo is nothing more than a high volume, low pressure compressor. Doing so by means of a high efficiency "fan", rather than pistons... such as what you'd find inside your air compressor. the other method uses meshed screws..... which is basically a supercharger.



Increasing the housing would also increase the space between each vane... and therefore a decrease in its ability to force air into the motor. More air is allowed to pass between the vanes and the housing. Sorta like an air leak.



Then you would almost be forced to purchase a larger vane... if that is possible. Seems more cost effective to buy a larger turbo at that point.



As far as extrude honing the intake. Good idea, but rather costly per HP gained.



OMO

 

[NVR FNSH]

Do a search on extrudehone & you'll find plenty of info - most of it saying it's not worth the expense for street driven vehicles.



Brian

 

[Piers]

At what boost do you hear this flutter? The WH1 model turbo that it sounds like you are useing doesn't have a "bleed line" machined into the compressor housing. You need to have one machined in or use an HX35 turbo, which are already set up with the bleed line.

 

[KEENO]

Hey Guys... Thanks for the replys!



More information: This is a Holset 12cm2 cast iron exhaust housing off of a HX35. My interest is to 'remove' the wastegate & actuator (by plugging & welding) and then have the housing Extrude Honed to a slightly larger cm2. In essence, it will be like the non-wastegated 16cm2 only smaller.



My first Gen has the OEM "HIC" (an HX35 w/o the 'silencer ring') and builds 30 PSI of boost @ 1100 degrees Max. w/ the current 12cm2 that I have installed (pressure line diabled). I enjoy the performance of the 12 but @ 20-22PSI it develops "wastegate flutter" and bounces the wastegate valve & boost needle.



I'm experimenting w/ trying to build linear boost w/o the 'flutter' and not necessarily trying to increase my overall boost... Just contol what boost I have & the flutter.



My overall concern is that I'll over-boost the compressor side & take the turbo unit out of it's efficiency map so I'm wanting to Extrude Hone the exhaust housing to a larger size (13cm2 - 13. 5cm2'ish approx. )



Comments, suggestions, concerns by more knowledgeable minds... .



KEENO

 

[Extreme1]

Um...ah....hehehehehe......you said flutter...hehehehe

How about a wastegated 14cm?

 

[KEENO]

Thanks for the reply Extreme1



I have had a Banks 14cm2 on the truck before the 12cm2. With the limited fueling capability of our Bosch VE44 rotary styled injector pump on the First Gen's, EGT really isn't an issue. The 12cm2 works awesome w/ instant trottle response so I would like to stick w/ the 12cm2 but I'm still clinging to the 14cm2 like a security blanket.



This 12 has just been an experiment in eliminating the wastegate to understand the results... . So far I have $20. 00 invested in the project & I'll probably just skip the Extrude Hone idea.



Keeno

 

[KWIKKURT]

KEENO,



I may have the answer. Ken at Turbo Auto Diesel in Phx. Just custom built me a Turbo. It is a HX35 that has had the compressor and turbine housings Bombed to accept larger wheels. The larger wheels give more volume of air with less heat generated and the small housings gives very good response. I have had it in for two days so far and am very happy with it. But still testing the capabilitys of the Turbo.



I want to add that he has done a lot of testing and has Bombed many CTD turbos.



It was also a good price. E me or PM and we can discuss further!



Happy Bombing



Later Kwikkurt