Turbo questions, what's best for MY rig?

[Mark Nixon]

Theoretical engine:

1990 Non-Intercooled, stock injectors with a timing bump, stock pin turned to the deep side, starwheel a few clicks looser, full power screw a couple turns tighter.
3200 governor spring.
Stock '91-'93 Intercooler.

Which of the following turbos will do the job the best for a truck with a 5 speed, grossing 16,000, with 4.10 gears:

HX35W, 12cm e/h, wastgated, 7 blade compressor.

HX35W, 12cm e/h, wastegated, 8 blade compressor.

HX35W, 16cm e/h, non-gated, 7 blade compressor.

HX35W, 16cm e/h, non-gated, 8 blade compressor.

HIC 18.5cm e/h, non-gated.

H1C 16cm e/h, non-gated.

I'm wanting the best performance without mileage suffering too drastically and without breaking stuff.

Anyone want to give ideas on this?

Mark.

[peobryant]

I'd use one of the HX35's with a wastegated 12cm housing. Fast spool up, and you don't have enough fuel to make it too hot. I don't think the difference between the 7 or 8 blade wheels is enough to matter, so use which ever one is in better shape.

[Mark Nixon]

Is manually or electrically operating the wastegate an option?
Also, is the longevity any less on a turbo with a tighter housing and does a tighter housing make the turbo turn a higher top rpm?

As I understand it, a quicker spooling turbo helps torque, smoking and also helps EGTs, is that correct?

Mark.

[Richie O]

Smaller housings mean higher egt's at higher rpm's. Not sure how much a 12 gated will flow once the gate opens compared to a non gated 16. The 12 will light sooner. My 16 spools nice in my 93. I was also happy with a 16 on my 89 before I updated.

[Mark Nixon]

Okay.
Buy Pyro FIRST, then play.
See? I DO get it!

Mark.

[peobryant]

I've never heard of a smaller exhaust housing having an affect on turbo life. I've seen multiple 400-500K HX35's, and we've towed quite a bit with my Dad's '97 (turned up a little bit) and she never got hot.

A quick spooling turbo wil help torque and smoke, but generally, the smaller the housing, the hotter it will get. This only matters when you have a lot of fuel (a mild pump tune shouldn't have a problem) otherwise, the smaller housing is a better option, especially on a manual truck where you lose boost with every shift.

Mark, I've seen a few posts about controlling the wastegate over on DTR, I'll see if I can dig them up for you.

[Richie O]

With you actually using power I would go with the coolest running setup. Its not going to mean much if the turbo takes a second longer to light. Your going to be running power for long periods of time not shifting like drag racing. The boost difference between a 16 and even a 18.5 is going to be maybe 2 or 3 psi. With your application flow is your friend. Need more input from a smarter guy then me. Maybe with your fuel settings a 12 gated 35 would be the best. Its all about the fuel setting to what you need for a turbo.

[ford69557ci]

a 14cm housin would be best with the hx 35. Still get quick spool and keep the egt in check. Your best bet would be a s300 series turbo.

[dpuckett]

I vote 7-blade HX35 with a 16. Faster spool than stock, yet big enough to flow well at higher load and RPM. My experience with a 12 is that it's great for a daily empty driver, but tow 10-20K with it, and things choke fast. The 1stGens like to breathe, and the 16 allows that.

I went from a 12 to a 16, and actually LOST peak EGT in my W350. Emtpy cruise EGT went up maybe 50deg. Spool was real close to the same. Loaded acceleration difference was negligible.

Dan

[MMeier]

I'm very happy with the Super B I put on mine !

[peobryant]

What happened to "Mad Max?" I remember he would tow his Ramcharger with a PDR HX35 and 12cm housing and loved it. I don't remember what the rest of his setup was though.

Well Mark, I guess you'll just have to try both and see which one you like more.

[Mark Nixon]

Well, there's a few small hills around here, and I have plenty of heavy stuff to put on the bed to work it with.

I'll get a pyro and baseline it as it is, bone dead stock w/o intercooling, then bump the pump settings non-intercooled, then intercooled and work up on the turbos from there.

I'm really curious to see the difference in EGTs between Non-I/Ced stock and turned up, then I/Ced and turned up.

I could use a cohort, where's Pullit with my flashlight?:D

Mark.

[Ace]

IC'd injectors don't flow enough fuel to make a significant difference in any aspect of performance WRT the turbine. 12cm goes better with a stick in a lightly modded setup. Non IC'd, dunno. I'd use the 16cm for towing, either way.

14's like half a cookie. Do I eat one cookie, or two? Hmm....

[unixcowboy]

I'd look around and see if I couldn't find a Super HX-40 - the one with the 7 bladed compressor. And a 16cm turbine.

I found an 'off' model with a 17cm turbine and an HX-50 flange. Shipped to my door under $250.00.
Simple adapter and it's on. I love it !!

Starts spooling as fast as my H1C w/18.5 cm turbine and sounds much better. Whistle starts at ~ 3psi ( just off idle ) and by 10psi it's really screaming.

I've got somewhat larger sticks than you, but cc gets me ~ 750 - 850 at 70mph and boost runs from 4.5 - 18 ( up larger hills ).

[bgilbert]

Sounds like not too many nonIC'd to IC'd stories. The nonIC injector is a total different animal when compared to the sissy IC'd injector.

I've done some towing ~18k pounds both before and after the IC swap in my crew. With no IC and the stock baby h1c, I couldn't even come close to using all my power. I would drive by the pyro. On hills I would have to back out of the fuel and many times drop to 4th and keep the rpm's up. This is with very conservative fuel settings. Ie not set to kill.

Swapped in a 1st gen IC, hybrid 58mm hx35- had it laying around. I had the choice of a 16, 18 and 12cm wastegated housing. I choose to use a 18cm housing that was on the stock h1c. This is a tow rig, not a hot rod so I'm a believer in the top end breathing ability of the bigger 18cm housing. Now if you're just in a hurry and floor the fuel down low, sure, you'll get some bottom end smoke. But considering the getrag doesn't like low rpm throttle smashing, nor does the rest of the truck, just keep the rpm's up before shifting and getting into it and that will limit low end smoke.

Now I can use all the fuel. Pulling the same loads and same hills that previously the pyro would get out of control, it wouldn't get over 1250*f.