Here I am

Anyone tried 35/40 with 60mm wheel and a 12 WG housing??

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? for you Duramax owner's!

Mopar Preheater? PN 82209444AB

I have a DZ on the way & was advised by City Diesel to retain my 12 housing for my rather conservative setup. I should have it installed in a week or two & will be glad to post he results.
 
I thought the HY got the 54mm and the HX got the 56mm. But I get the feeling that they vary more than we think. For example, Van Haisley suggested that I go with a HX35 from a '97 12v, since that year they ran a 58mm. He was very specific about it being from a '97.
 
Well maybe I will go ahead and give this a shot.

I'm thinking that with a larger compressor wheel, I MAY be able to run less overall boost and still keep some cooling.

It's pretty obvious on my engine that the turbo is choking at 31psi or so. I can wind it up to 31 psi, then add some pedal and take it to 35psi. From 31-35psi it starts to make a woofing sound, and it doesn't sound quite right. If I let up a little and let boost drop back to 31psi, then it sounds normal.

Maybe I'm looking at the wrong side of the turbo... I've ALWAYS felt that a larger housing is needed for even the stock compressor.

Given my feelings about the 12CM with a small compressor, I feel that I may be headed the wrong direction with a 60mm wheel with a housing that's already too small.

jlh
 
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That's because the bigger wheel is easier to surge. Especially when fueled heavy with a load and low RPM.



That's why the 58 wheel works well. Better low end performance and less surge.



Dave
 
Hohn, you posted



It's pretty obvious on my engine that the turbo is choking at 31psi or so. I can wind it up to 31 psi, then add some pedal and take it to 35psi. From 31-35psi it starts to make a woofing sound, and it doesn't sound quite right. If I let up a little and let boost drop back to 31psi, then it sounds normal.



I would read that as compressor surge. "Woof" is surge.



So, by using a large wheel, and at low rpm with all other things being equal, you will have more surge. Now, this is not always the case depending on wheel design, mass, trim , ect. But, it gives an insight.



From what I have read about your posts, you don't want to go to a 14cm housing to keep the spool as quick as possible. I am the same way. But, if the wheel is not correct, you'll get tons of surge depending on the conditions. You appear to be at altitude, which is compounding the problem.



My 58 wheel with the box on kill towing my trailer does not surge. Unless I am at altitude and sometimes I get a bark on the 2-3 shift. :eek:



Dave
 
Hohn:

If you remember I had Piers work on my HY. One of his nasty 9's. (larger comp wheel same exhaust side) I didnt like it. While it did give me lower egts on the top end and very quick spool up it came at a cost. Surging and barking went through the roof. It would bark during the 3-4 shift really bad, especially at wot, scary bad. Heck sometimes it would bark between 2-3 shift. I could not drive through or around the 3-4 shift barking. It also barked anytime I was at 1/2 throttle or above and had to let off even just a bit. Also I could hear (hear not feel) it fluttering or surgeing while at cruise say going up a pass where boost was above 20psi. It was annoying as heck. After getting with you on my turbo questions I realized with your help that it had to be the compressor wheel was too large for the size of the exhaust side, in that case 9cm. I do not know what the size of the compressor wheel was though or how much larger than stock. After I switched to one of Piers worked over HX35's all was well. Obviously the exhuast side went from 9-12cm and the compressor wheel was bigger as well. I still get bark sometimes but it is much much less. And really only does it when pulling a trailer though it does do it under some conditions without the trailer. I no longer have any fluttering or surge. In my mind a larger comp wheel without changeing the exhaust side is only ok to certain point. That point obviously changes from one truck to the next depending on mods and how it is driven. It just seems to me that if you do not change the exhaust side but enlarge the comp side the ex wheel is spinning just as fast as it was before but now with a bigger comp wheel is spinning just as fast as the originall size thereby pushing more air and in the case of surge/flutter or barking more air than the engine can use at that time.



My disclaimer, from all the turbo questions I have asked you you know I am no turbo guru just relating my personal experience and observations with my mistake.
 
Dodgezilla

I installed my Dodgezilla Friday morning. I hauled the 16' lowboy to move my son from Huntsville to Houston. I filled up this afternoon with 500 mies on the trip odometer, 150 empty trailer, 150 with a 3100lb car, 100 miles with furniture & ~100 miles empty truck. I was suprised to have averaged 20. 2 because most of that tank was driving 70+ & playing with the turbo to see how much it affected the EGT's & boost. It seems odd to me that a turbo does break in & free up after some time. It just keeps getting better. Now that it has ~500 miles on it, I would'nt know the difference in spool up except when really pushing it, it does pull harderabove 2k than it did.

I'd like to try a 14 housing just from curiosity, but I'm pretty convinced the DZ/12cm housing is pretty much ideal for what I do with the truck. EGT's are down at WOT about 100 degrees at 100 in 5th. The more I load it, the better it feels. The truck cools off faster at idle than before, gets below 300 at idle very quickly. Bigger injectors? :)
 
Hohn said:
Pretty sure the PDR35 uses a 58mm comp wheel.



I just ordered a 58mm wheel and new machine housing to fit, from Pier's today.

Piers recommends the 58mm but will do a 60mm and I believe he said a 62mm also is an option for the same price.



I have a 14cm on my HX35W already. I don't think there will be a huge difference. Hopefully the same spoolup of a (56mm x 12cm HX35).

I was temped to go to a 60mm.
 
After logging another 500 miles on my DZ , I think you would've liked the bigger wheel.

From what I've read the 58 setup is good through 350hp & the 62 is good through 450.

I'm still usig the 12CM housing, but it spools like stock driving easy & cleared up my smoke completely. I'm not at your HP level, but I can always add the 14CM later if I do add more fuel.
 
Maybe so, I can alway order a larger wheel and housing down the road :rolleyes: Can't do it right the first time... just not my way. :)



Actually Pier's feels so strongly about it, I figured I would give it a try. I wasn't having any issues with the 56mm x 14cm but if I gain a little cooler EGT and a little faster spool that would be good.



However... Hohn's first questions on altitude effect and larger wheels have me curious. I'm hoping someone at altitude chimes in. The surging at 1800-2000 RPM issue at higher altitudes "with a larger wheels and tight exhaust housings" is something I have heard a few times? So many variables truck to truck at different altitudes and humilities some say... But this summer I drove from Colorado to southern Illinois. I disabled my wastegate before I left and still got the same 30-32 psi at 5500 feet and 400 feet?
 
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Actually after thinking about it, with your 14 housing, that might be a really nice setup. My first running empty tank equalled my previous best, which is 1/2 mpg better than my weekly 700 miles commute average. I never expected an improvement.
 
TTT ;)

I'm at the same altitude as Hohn and put on the HTT stage 3 compressor wheel/housing. At the same time I put on 4" exh. and figured I'd try my 16 housing first figuring if it didn't work, it'd be easier to cut an inch off the exh. rather than put it back on. I had the 16 housing on for about a 10 mile round trip. It blew by 1200 deg. on a slow acceleration up to 65. I'm fully convinced the 16 is useless at this altitude. So back to the garage and put on the 12. About an hour later, same road, same temp, same acceleration, it was 400 deg. cooler. I've now had this on since Jan. and it runs great. Temps are down an avereage of 200-300 deg from the stock hx-35. There is no lag whatsoever. It launches up to 35 psi where the wastegate is dumping the rest. Sitting still I can rev the engine and build 15 psi. That's no lie and I have witnesses. :-laf

The major downside is noise. I believe there is some overspeeding going on and I can hardly hear the Cummins. At about 28 psi, a secondary high pitched whir chimes in. Empty it isn't too bad, but on a long trip it was annoying. Pulling trailers it is WAY too noisy. The housing itself is not machined out where I can put the silencer ring in. I did ground my old one down and slip fitted it in there. It would make a loud Tshshshsh noise every time I let off to shift, and it only stayed in place for about a week. We took it up to Whitmore's place in early March and pressure tested the intake side. Found 3 leaks and it runs a little better 'yet'. Any suggestions on making it quieter?
 
TPC, I know you've considered this, but a TAG unit would quieten things down.



Have you had any issues with surge or barking below 2krpm when pulling a trailer at altitude? With a 16cm housing and the HTT stage 2 kit in my 35 I had a really bad case of the surges. I'm now running the wastegated 12cm housing with mods, won't know how it'll work at altitude till this fall when we make the elk trip.



RR
 
Hey TPC,

What Altittude are you and Hohn at? Im really considering doing the 60mm htt wheel in my 35, and I have pretty much the same setup you do.

Im usually between 4800 and 5400' altitude...



thanks,

Jeff
 
We're at ~6100 feet.

I never did do the bigger compressor wheel-- don't need it yet because my clutch can't handle what the stock charger is delivering already.

I'm almost considering ignoring Holset entirely and just going straight to a bigger single like an I. I. turbo... .
 
I haven't done much pulling with it yet. The one time I did pull it was only 6000 lbs or so. The hill I normally had to slow to 65 due to temps, I was going 75 :cool: . East bound from Laramie to the summit for those that know the area. It will bark, but if I let off slowly before shifting, I can control it. No surging, no woofing. I may have to try the tag and I'm also considering the 14 housing.
 
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