All you knowledgeable ones out there. Looking for More..........):h ! Will the oil lines need an adapter? How about the Downpipe design, would I want one to connect to the V clamp flange where my Gm-8 exhaust elbow ends? Or just bend a complete new one down to the horizintal? I would have to order it out here in the boonies. I guess I would be wanting the 12cm version? What years?
Thanks in advance!

Judging from your sig and this post -

splayed main caps, arp studs
main-cap girdle
balanced rotating assembly
18:1 pistons
copper head gaskets
ARP studs
diamond pre-cups

Other than that, you'll need to fabricate a down-pipe adaptor, maybe put a restriction in the oil supply line

PM chicagotdp for more............

What gmctd said, cept the copper gaskets and studs, although they would probably be highly recommended. I didn't blow a gasket but never had the boost above 23 PSI at the heads. I am putting in studs this go around but not the copper gaskets........ unless the builder is doing it? Dunno, haven't talked with him for a couple of months.

I'm sure at some point after break-in this time i may be needing a new boost gauge, mine only goes to 35 PSI!:eek:

OK, to get it done right, the turbo needs to be torn all the way down, has to be re-tapped for a 1/4 npt fitting that gets taken out of the stock Gm turbo.

A v-band clamp will not work in the tight space, so I have a jig made to fab a full 3" down pipe with a special flange for the rear of the turbo to work with the stock waste gate. The turbo then needs to be set so that the boost will not blow a stock 6.5 to pieces.

The oil return tube will work, with a little adjustment.

Then, a reducer or adapter will be needed to connect the turbo outlet to the engine and a new intake will have to be made.

Chicago, in your experience, can a HX35 be wastegated to keep boost say at 13-15psi. thinking that a holset at this boost pressure surely must be more efficent than the GM series of turbos. Just thinking about turbo options with stock compression(can't justify 18:1 pistons, not to mention R&R of engine to the other half) My idea is: stock compression,HX35, ATA intercooler. What do ya think. Workable or asking for disaster. TIA

the holset does not offer the efficiency of a GM turbo. This reson being that the holset had a MUCH LARGER exhaust side exudcer that uses more energy to turn. This is my theory right now. I am not sure on it yet. I have still to sit down and crunch some real numbers and get a true energy usage number between the two turbos.

I know that with my 18:1, I had to go to it, the old GM 8 that I had could not bring down my egts enough, which I why I went to the holset with the bigger exducer.

What do you think about the Holset HY35? Seems to me that it has a smaller turbine housing. I hear lots of Dodge guys saying that the stock HY35 is causing high EGT's when they mod their engines. Maybe this one would be a good compromise between low rpm spooling and keeping EGT's in check. What do you think Chicago?

What are the A/R Turbine differences between the Holset & GM-8?

I have run the HY turbo. It still offers a lower egt then the gm8 and it is a nice turbo and probably good size for the 6.5.

I like to run the HX on my truck of course cause of the better boost potential.

I am not sure on any of the A/R ratios for either of the turbos, I just know what works and what does not:D.

Chicago, does the HY35 need the same teardown and tapping for the oil line that you mentioned for the HX35. One more question. Do you think the HY35 can be set so boost is limited to 14-15psi for use with stock compression. Sorry for so many questions but you are the only one that has tried non-stock turbos, at least you are the only one that is willing to tell others what you have experienced. Thanks dude!!

...I know that with my 18:1, I had to go to it, the old GM 8 that I had could not bring down my egts enough, which I why I went to the holset with the bigger exducer.

I would imagine that the lowered EGT's would be coming mostly from the increased efficiency of the HX35 at and above 12PSIG pressure. From what I know of the GM-X series turbos, the efficiency island is centered around a pressure ratio of ~1.7 at a flow rate of ~30lbs/min. Anything outside of this island (really "above" or "beyond") on the compressor map and the efficiency of the compressor drops like a rock. This explains the incredibly high drive pressures to make 14+ psi of boost from them and the resulting decreased rate of EGT reduction when running these boost pressures (with a GM-X)...

Regards,

Hey Chicago TDP,
You wouldn't happen to have a picture of your downpipe?

The HY and HX need the same down pipe and pretty much the same setup.

The turbo could be set to about 14 psi of boost, no problem.

I do no have a pic of the down pipe. there is a pic I think in my garage that shows a little of it.

I kind of keep what I have invested my time in a little secret since I have sold a few setups on here and there are few people that are looking to buy a few setups.

That's fair Chicago,you did the R&D and no one can fault you for not giving it away. I will be in touch when it is time to upgrade the turbo. Lots to do first before that happens though. Intercooler being the most important. Just noticed the infamous GM oil lines have started to drip 1 to 3 drops when truck is parked. Time to get a set from Lube Specialist.