I realize I am opening the old can-o-worms, but anyone had a good experience with a particular size turbo over and H1C framed high pressure unit (in my case, hybrid 62/86mm H1C/14cm3)?
It is possible that, at my altitude and very thin air that I should use my existing turbo as the low pressure unit because my turbo is a little lazy on the bottom end, and a rabid beast on the top end.
Thoughts?

 

Altitude is only part of the equation. There is a thing called density altitude that is the hurtle to conquer. It's a combination of altitude, temperature, and barometric pressure. Something we leaned in pilot school. With out knowing it, you may not get airborne before the end of the runway or melt you engine shortly after. The same effect determines performance in pretty much any fueled engine. When I worked in Arizona's high desert (7000ft, 112°), I saw density altitude as high as 12000ft on a low pressure day. The reverse in Alaska (0ft, -40°), I saw density altitudes of -7000ft on very high pressure days. I ran a big HTT turbo on my 91.5. I can't remember the specs for sure, but it was like a 68 compressor, the exhaust housing was a waste gated 13cm3. My boost never got above 35 and EGT barely hit 1200° with the 7X.010 injectors. In contrast with those same injectors on my 92, EGT control is a big issue especially when I hit 45psi boost with the modified H1C (see my sig). 91.5 was a 5 speed, the 92 is an auto. The 92 auto has instant boost while the 91.5 you had to give it a boost to spool before it would take off, otherwise it would basically stall. I see 2 things that could help with your altitude sickness is; 1, the PODs have the wrong spray angle. 2; go back to a stock fuel pin. Too much fuel too soon.

 

My Density Altitude factors at over 12k most of the summer. The drag strip down in Albuquerque usually factors at over 10k, which is why our race cars tend to run hard everywhere else.
My setup ran 15's axle hopping a foot off the ground before I went up to a 7 blade 62/86 wheel with a 16CM exhaust housing. I had Gillette upgrade to the largest wheel and compressor housing possible in the frame and lost all my bottom end. Switched to a 14cm housing and had it ceramic coated, that only helped marginally.
I don't want to go to a 12cm and kill the top end charge, it's really fun, but was thinking maybe an H1C closer to a stock wheel with a gated 12cm might be a good high pressure turbo to help light my current one.
As far as POD's, I run the thinnest copper seals I can to bring the spray pattern down into the bowl the farthest I can, and I have the star wheel adjust to cut down the smoke, and I lean into it to avoid "the prince of darkness" cloud.
Exen with all my mods I still average over 18MPG driving up and down 2,000ft, and over 20 on the freeway if I keep the speed down.
It was the perfect setup, now not as much, but still serviceable.

 

The real question is, if I go with a larger atmospheric will it help spool my current turbo, or do I go smaller on the high-pressure side... my mind says go smaller on the high pressure side, my heart says bidder atmospheric..

 

No air pressure!

 

Watching this thread with interest. You are at a similar altitude to me, so am curious about how much smoke you make and under what conditions does it smoke the most? Mine smokes like crazy at low RPM's (below about 2,000 RPM) and a heavy foot. It is also much worse before the engine reaches full operating temps
Mine is 3rd gen, so that may be quite different to yours..

 

My POD's turn the day into night if I floor it at low RPM, so I try to avoid that as much as I can, cokes up the rings. If I lean into it gently I make hardly any smoke once the turbo lights.

 

That is my experience too. Need to barely tickle the accelerator at low RPM's, but even then there is slight haze. Wish I knew how to stop the smoke without sacrificing performance.
BTW, my truck lives between 6,000 and 8,000 feet altitude. Often go from 6,000 to 8,000+ in under an hour...

 

Mine is the same way. Ease into it, it's fine. Quickly push it to the floor and I can do 4 wheel burns and cause a solar blackout. This summer I plan to "detune" my truck back to a safer level. Turn down the pump and different injectors. Haven't decided which injectors yet. 6X.010 or 5X,011.

 

I live in Northeast OK and the elevation is around 700 ft IIRC. I swapped out my stock H1C for a wH1C with a wastegate. I then got a boost fooler to tweak it up a bit so it hits about 34 psi.

Edwin

 

Maybe I build this with my M90 blower to get it lit, then bypass at higher flow. I just sketched this up, just goofing off, so don't flame me!
But I would have nearly instant boost with only a puff of smoke... just thinking.

 

I was at 40 psi with the 60mm 6 blade wheel and the stock intercooler, then I sucked in my air cleaner, so upgraded to 7 blade 62 and a much better intercooler, so am now around 30-32PSI

 

What did you use for the "much better intercooler".

 

One of my clients is a local radiator builder/supplier for everything from tiny units to giant mining radiators, and they built me a new heavy duty unit, much thicker and beefy, guaranteed not to blow loke the stocker (which I blew up) and less restrictive.
Independent Radiator Service Company in Albuquerque, Mike is the owner. I built and maintain their computer network.

 

Cool. So they re-used your 1st gen intercooler and re cored it? Or built something custom for your 1st gen.?

If you have a picture of it that would be nice to check out. I find most of the '92/'93 intercoolers I test, leak at this point.

I have been using 2nd gen intercoolers on some of my builds but there is some cutting, welding, grinding and fiddling around to get them to fit. They are much bigger, thicker and the inlet and outlet are larger. It is just a hassle to get them to fit cleanly and by the time I am done everything from and including the turbo to the intake horn has been swapped around.