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HOLY CRAP! Billet compressor wheel for the factory turbo.

dbrannon79

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I’m actually intrigued about dissembling my old GM4 turbo and looking to see what might be the bulk of the restriction and if anything can be ported larger in there for better flow. Since I have a GM8 installed I have something to experiment with plus learn more about rebuilding one before touching the one on my truck lol
 

dbrannon79

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I feel like the bulk of the restriction that causes the drive pressure is going to be in the t3 flange and in the turbine housing where the exhaust gas exits into the rear section of the turbo "turn down" section or where the wastegate valve is inside the turbo. if there is any meat in that area to grind out without making the inner walls too thin, it might improve exhaust flow enough to make a difference. this theory combined with the WW2 might make buying and installing the WW2 worth it for a budget upgrade.
 

Will L.

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If you are doing it for the enjoyment of the chase - have at it.

But just like building a new and better pmd- this road has been walked many times before. Grabbing any ol hx35 from a junkyard is going to yield better results than the best results of reworking a gm8- the best of the gm turbos and having a ww2 in there.

So if it is trying to save some cash and wanting improvements- you are better off using your time to go deliver pisza and door dash type stuff for a couple weeks in free time then use that profit to buy a bigger turbo. The 10ish hours spent researching where to grind out turbo material and how much, then the 20 hours spent doing the labor of that and rebuilding the turbo itself- it just isn’t worth it.

In hummers, we can get the gm 6 or gm7. Because of limited space, lack of turbo selection with the oil supply and drain being drilled holes in the block- upgrading the gm7 and ww2 is the best it gets for most. Does it help? Yeah. But I am telling you from having seen this vs using junkyard hx35- just get a bigger turbo is so much better that it is nuts.

Peninsular diesel was making a turbo for centermount, and so did Urova. The peninsular is what went on the spec op hmmwvs for USA and Israel, along with their boats obviously. They were both modified s300/s400 hybrid in custom housing from my understanding (matching some of the hx35/40 hybrid numbers). The Urova sells for a shade over 3 grand, but is the only option outside the ww2 in a gm7 which is sold everywhere being called the ‘super77’. The differences are impressive.

I have helped several people now doing the ww2.
My best suggestion is don’t bother with it since you can much easier-fit a proper turbo and don’t have to spend time and the risk of getting the grinding wrong and it not working well, or like a couple guys and do it to only have the housing crack less than a year later from taking out a hair to much.
 

MrMarty51

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The exhaust side housing on My GM8 was already cracked. I dont remember the particulars of the exact location of the crack, IIRC it was only obvious after I got it disassembled. I did post in a pic of the cracked exhaust section and folks in here said to just run it. It was not cracked in a position that it would leak exhaust out of the turbo itself, only from one exhaust section to another.
I think it was cracked in the vicinity of the waste gate port.
I mailed that turbo, WW and all to the guy that I bought this truck from, He has two other 6.5 units. Within the box I explained what I had done to the turbo and that He could easily remove the WW and the OH kit from it and install into his turbo, or, just run it as is.
He was quite surprised upon receiving it and sent Me a text with the most gracious thank You. 😹😹😹😹
As I am most graciously thankful at War Wagon for Him sending Me the ATT unit that He had been running on His truck.
 

MrMarty51

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First I apologize for reviving this old thread. I just read through the whole thing and really appreciate all the info put into it, found the website linked above and located the compressor wheel. I have been wondering myself on purchasing the WW2 for my truck just for a minor budget improvement and to "hear" my turbo other than from the tail pipe. I am questioning the od of the wheel if it's exactly the same or not for installing on a GM8 that has some small amount of shaft side play. currently I have no issues with the side play, the wheel does not contact the compressor housing. if I were to install a WW2 wheel, would contact with the compressor housing become an issue?

Other things I have been looking at is the GMx turbos and the drive pressure ratio issues and wondering if the 4" exhaust kits alleviate some of this drive pressure or is the restriction within the manifold and turbo connection before the downpipe connection?

btw here is an updated link of the site mentioned above with the listed part number.

I believe that Quadstar Tuning explains, in their description of the WW wheel of which turbos it will fit. It seemed it would fit them all.
Dont be afraid to install a kit into Your turbo. It is easy and very straight forward.
The biggest problem for Me was getting a couple of the bolts to let loose, they eventually did but I dont remember what method I used to het them to cut loose. Maybe a couple sharp raps with a hammer and a punch or possibly the torch of the acy/oxygen unit and heated the housing that they were screwed into.
 

dbrannon79

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I have also looked at some of the ebay hx35's wh1c turbos. but I have also heard that the hx35 doesn't spool up at low rpm like the GMx does. is there any input on that or experience on their spool up at low rpm?
 

Will L.

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The only point getting the gm to spool better is when you need it below 1000 rpm and you are fueling to do it there. Leaving smoke every time you take off and You have to run out of turbo by 2300 rpm. You will never get it to 3500 rpm doing this. I had a truck set up this way before to help get those 48” tires moving in the rocks.
 

dbrannon79

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that's where I'm kinda torn between the WW2 on the GM turbo and a HX35. I want it to be able to spool low and not have to wrap up the rpm above 2200 to get it going. me not having any experience with the two. just in reading I have read where the HX doesn't spool right off the bat like the GMx does. my end goal I would like to lower my gear ratio from 4.11 to ether 3.73 or 3.42 so my highway rpms are lower since I don't tow anything but once in a blue moon. also hoping to get better mpg's along the way. with everything I've done to the truck including the 4" exhaust kit. my mileage had been floating at 13-13.5 consistently.

right now as the truck is with all the changes and upgrades I have done on a budget, I am happy with the power and take off it has.
I'm almost considering adjusting a tune to use less fuel than stock at below 50% throttle just to see if mileage improves any, or start working on the plans I put together for building a water mist injection system, but that might not be viable right now since with the tune adjustments I have now there is almost no boost while cruising at highway speeds with no load.
 

DieselSlug

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I have also looked at some of the ebay hx35's wh1c turbos. but I have also heard that the hx35 doesn't spool up at low rpm like the GMx does. is there any input on that or experience on their spool up at low rpm?
I ran a WH1C on my modded 94 in the signature. No regrets especially for the cost I had into it! To be honest the MPG increase will be from the elimination of the restrictive GMx cobra head exhaust flange. More boost needs more fuel, thus less MPG. If you are building boost sooner you will need more fuel. There is a balance to efficiency vs power on this one.

The WH1C definitely did spool a little slower but it is really negligible when paired with a good tune or economy type driving.
 

dbrannon79

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I ran a WH1C on my modded 94 in the signature. No regrets especially for the cost I had into it! To be honest the MPG increase will be from the elimination of the restrictive GMx cobra head exhaust flange. More boost needs more fuel, thus less MPG. If you are building boost sooner you will need more fuel. There is a balance to efficiency vs power on this one.

The WH1C definitely did spool a little slower but it is really negligible when paired with a good tune or economy type driving.
Looking at your sig, how was your rpm's and power range with the 3.42 gears? what size tires were you running? I'm just curious if changing from 4:10's to 3.42's will degrade the takeoff power where it would make a dog out of it till it gets up to speed. looking at online calculators going to 3.42's would drop my overall rpm by 400. as mine is now with 265/75-16 tires I see 2300-2400 or so at 70mph.
 

Will L.

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I ran a WH1C on my modded 94 in the signature. No regrets especially for the cost I had into it! To be honest the MPG increase will be from the elimination of the restrictive GMx cobra head exhaust flange. More boost needs more fuel, thus less MPG. If you are building boost sooner you will need more fuel. There is a balance to efficiency vs power on this one.

The WH1C definitely did spool a little slower but it is really negligible when paired with a good tune or economy type driving.

Nah- more boost doesn’t mean you have to add more fuel and less mpg. If you choose to add the fuel and get the extra power- yes you can lower mpg.

But often more boost - if you run higher boost you are just pumping more air through. And if you keep the fuel the same at those rpms, you will accelerate faster using the same amount of fuel. And that improves mpg. Also running bigger turbo means moving more air at the same boost pressure- which helps the same way. Then lowering back pressure is always a win- for more power better mpg and lower egt all at the same time. Thats how like when I went from no turbo to the gm6 my power and mpg improved, or WW’s write up about going to the ATT improved his mpg so much.

Really- get the idea of hx35 having lag compared to gm into the trash can. Yes it is possible if you get a REALLY HUGE unit- but you simply look into which to avoid before getting one. No big deal.
 

dbrannon79

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That is a really old ebay auction link. just look at the link I recently posted or lookup wicked wheel for GM 6.5 to see a photo. I found an ebay item for a complete hx35 for less than the wicked wheel, but it doesn't list the compressor size. still looking for a 14cm so not to go too big.
 

dbrannon79

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DieselSlug

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Looking at your sig, how was your rpm's and power range with the 3.42 gears? what size tires were you running? I'm just curious if changing from 4:10's to 3.42's will degrade the takeoff power where it would make a dog out of it till it gets up to speed. looking at online calculators going to 3.42's would drop my overall rpm by 400. as mine is now with 265/75-16 tires I see 2300-2400 or so at 70mph.

I would cuise at 65 just over 2k rpm. I ran the same tire combo you had in the winter but in the summer I actually ran a set of new take offs in a 17 inch rim that were pure highway tire. I cant remember the size but nothing wild. On the highway I could get 19 MPG, normally around town for me (very hilly 55 mph roads) I averaged 13-15.

IMO unless you do all highway the switch to 3.42 will never be worth it. I would upsize your tire first to to cheat into a different ratio.
 

93detroit

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I would encourage you to NOT chase a super quick spool at low rpm. Unless you have lowered compression, it is a great way to lift the heads off of the block. I've done it with a stock gm8.
 
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