[Fastest H-Town Realtor]

B-

Sweet truck you have there. Could you elaborate on the "off load" idea? Also, my post of not hitting boost until late rpms is kinda validated with the realization of a 3200 rpm stall convert. It lets the turbo spool.

Paragon-

True, the coating keeps under hood temps more in check, but its primary purpose is to keep exhaust gasses speed up thru the header. This is
a snip-it from the Jet hot site:

"Nevertheless, JET-HOT Sterling will normally boost power when applied to headers for two reasons. First, the coating promotes denser, more potent fuel/air charges by insulating the engine bay from exhaust heat. At the same time, it accelerates the pulsed-vacuum effect on “tuned” headers, resulting in more effective scavenging of cylinders. The increased velocity of exhaust gases produced by higher exit inertia not only clears each cylinder more quickly; it also draws in the next fuel/air charge more efficiently."

The exhaust gasses staying hot keep the molecules more active, a desired effect in the header. To cool the gasses would make them less active and slow down the flow. I believe this is a therm-dyn law. Dont quote me on it,though. The diesel turbos are positioned very close to the exhaust outlet of the head, keeping flow high. Add in a powervalve downwind of the turbo to keep pressure active within the exhaust and a turbo system designed to make boost early, then bleed of excess flow with the wastegate and you have a responsive turbo set up-If the unit was any other way, a turbo diesel would be a bad idea because diesels shut down way early than the gas counterparts. Redline on a diesel is 4K.

A small(er) turbo that will provide low rpm pressures will map out(pressure maps) short of flow on the 6L engine. This will severly limit top end power and overwork a turbo. Any turbo install is a compromise, as is a blower install.

My experience with turbos is limited to systems I have hobbled together from junk yard parts and reading all I can from design gurus like Hugh MacInnes.

The 6400lb/325hp H2 needs low end grunt to make a difference. A 600hp/265ftlb engine would diminish the experience, whereas a 325hp/500ftlb engine would be pure sex(shut up drty ). One major advantage of the turbo system is not sacraficing up to 70hp to drive the blower. For this reason, I think a good turbo system would better enhance the driving experience than a lycholm screw/roots type blower kit, although I'm not willing to hand my warranty over to GM on a silver platter to be voided. I can yank the package off of the engine with little problem, but the turbo will be problematic for re-running exhaust. I also like the intercooler/intake manifold set up much better. Again, opinion.

As I set up to open a 4cyl/fwd perfomance shop later this year, I think the front vs. rear turbo debate will be a fun project to tackle. I will attempt to build both and compare results. Be warned though, I only use dyno testing for tuning issues. My kuddos are handed out on the track/street. Dyno kings and trailor queens dont excite me.