I just got a 16cm. housing from piers to put on a HX-35.I was a'wonderin if there was anything I could do to improve it before I install it.I have never ported a housing,so I dont know how hard it is.Is this something I could do my self pretty easley?And,is it worth the effort?

 

Geez, you need some serious fuel just to keep the lag down, and you want to port that?

I haven't heard of anyone porting an exhaust housing before, so I wonder if it would do any good. Not that I'm an authority or anything, but it just seems like you'd here of that being done more often if it was really a good solution.

Chris

 

polishing exhaust ports, manifolds, turbine housings, etc. keeps heat in the exhaust which spools the turbo quicker. only way to do it right is to Extrude Hone it, but you can clean it up as far as you can go.

Forrest

 

Forrest,

You and others have talked about modding a stock 12cm housing. Could you please elaborate on what to do, I am not trying to hi-jack this thread, but rather discuss what can be done to improve housings. I would like to find a 12 that I could work on without my truck being down, as I have alot of blending equipment available along with a full machine shop and would like to stay with a stock turbo and go as high as I can with horsepower before changing it (350 - 375 hp???) out.

thank-you very much

 

I appreciate that and may take you up on it.. First I need to locate one and i would like to study some then drill the hole for the waste gate etc.. It would be good to know what the expected max hp is with this set-up. thank-you

 

I have a 16CM housing on my hx40 that has been extrude honed. It costs around 100 bucks and months of waiting from the place in Paramount, CA. Might have helped a little bit but nothing major. Not sure if i would do it again or not. The best thing you can do is to port the outlet on an ATS 3 piece to match the inlet on your exhaust housing. Meaning port that both out more. You can get a gasket without the divider in it so you can go pretty skinny on the divider. (can't quite remember the exact name for it) This will give you good results in loss of heat and maybe a couple of HP. As anything that helps keep backpressure down on a high horsepower motor is good.

 

Anyone else have any more ideas??


thanks everyone

 

bump,


Anyone have any ideas?? thanks

 

I disagree with Forrest on this one. While polishing will *very* slightly reduce the surface area exposed to heat (thus reducing heat transfer), it's negligible.

Furthermore, keep in mind that polished exhaust surfaces won't stay shiny. Any improvement gained from the "reflective" insulating of polished internals is quickly negated by the layer of soot that it deposited. Soot is an insulator anyway, so whether what's underneath that layer of soot is polished or coarse is of infinitesimal significance.

What you WILL see gains from is cleaning up the casting. There's a lot of core shift on these things, and the ports are commonly mismatched by alarming amounts.

Just this weekend I undertook this project. I removed the turbo and put it on the bench. The inlet flange has a lot of room for improvement. There are "bumps" that intrude on the flowstream, not to mention that the port volume inside the scrolls is just tiny. I opened up the inlet to within 1/8" of the gasket line, and deep blended this all the way down to where the volutes begin to turn.

I also opened up the manifold outlet (at the turbo flange), but not quite as much. There's a tiny "stepdown" as the flow enters the turbo, letting it expand a bit and helping to marginally combat reversion when drive pressure exceeds boost.

Finally, I opened up the exhaust manifold ports where the flange meets the head. Here, I just opened them up about 1/8" all the way around for about 3/8" into the manifold. Then, I blended this into the rest of the manifold runners. A cone-shaped grinding bit is ideal for this, as you can point the die grinder at the manifold exit to get the taper angle right to help steer the flow towards the turbo.

It's a good idea to confine most of your metal removal to the flange areas where the manifold meets the head and the turbine inlet and on the turbo where it meets the manifold. The castings for the manifold and turbine housing are very thin, and removing metal from the majority of the areas isn't a good idea IMHO. Just focus on the flanges and getting smooth transitions (exception: turbine housing is meaty in a lot of places, so you can make a pile of shavings).

One last area to address- the stock exhaust elbow. Mine had bad core shift resulting in one wall being especially thick. I opened this up to help smooth the transition to the downpipe.

My own personal results were good. NO change in peak boost (32psi still), and a drop of over 150° peak EGT. Now, I can only get my truck to hit 1200° when I'm over 85mph on an extended WOT run-- AT 6100 feet!

Lag seems to be increased by the tiniest amount. It's still very minimal, and I can drive my truck in this elevation with no smoke issues at all.

In terms of *feel*, the truck seems to not be working as hard at all. It sounds a lot happier at WOT than it did before. It just...effortless, if that makes any sense.

Big thanks to Forrest and some NW bombers who got me thinking about porting my own turbo as a cheap alternative to a 14cm housing. Mine is probably now about a 13cm housing-- perfect for my fueling and elevation.

Good source for carbide burrs and sanding rolls: www.eastwoodco.com

Justin

 

Ok, thanks a lot Hohn!............now I want to port the 12cm housing on my 98.5 after reading your post!............150* egt drop?!?!.......WOW!..........to me that is worth the work to do the porting........I didn't think you would see that kind of change with porting alone.......sheesh!......one more thing to add to the list!

 

Be advised that Your mileage will vary. It may not be a true apples-to-apples comparison as weather variances like pressure and temp can change EGTs.

I'm confident I gained at least 100° though if an A-B were done.

Justin