More boost on a No Gate Banks

[Thermal Jock]

Do 6.5 exh. manifolds bolt up to a 6.2? There's a totally junked 6.5 motor in a neighbor's bone pile, but the manifolds could be cleaned up. Seems like GM 6.5 turbos are alot cheaper and probably just as good as aftermarket turbos, maybe you could swap exhausts to mount a GM turbo.

I added a freebie intercooler to my intake. Used exhaust tubing 45's and 90's and silicone tubing to connct everything up. Prior to the cooler, pulling 10,000 ft passes I'd have to gear down and back off to 45-50 to keep EGT's down below 1000. My boost was running about 7. Now I still usually gear down, but can maintain 60-65 if the curves alow, EGT's < 1000, RPM's about 2500.
But now I've lost about 1-2 psi of boost. Seldom see it over 5, punching it I could hit just over 6. Using a Banks non-wastegated turbo, so can't increase the boost there. Really, I like the system better now than before, my overall EGT's are about 150 deg. less. Just wondering if there'd be a way to get a little more boost.
Thanks!!

[Dieselboy]

Insulating the crossover pipe and the impeller housing with thermal wrapping should keep more energy flowing across the impeller, and that equals better turbo response and efficiency. Check out a Summit catalog, and look under exhaust wrappings.

[britannic]

Intercooling will lower boost pressure for at least 2 reasons:

1. drag and inefficiencies in the intercooler
2. lower compressed air temperature, lowers the air pressure.

A 2lb loss is about right.

Some options: optimize your injection timing, increase fuel if necessary, install higher POP injectors and/or 4911 inj. pump to increase boost. Implement Dieselboy's suggestions at the very least.

[grape]

a gm turbo will mount on the banks manifold, standard T3 family exhaust flange.

[Thermal Jock]

Thanks for the info.
Didn't ever think about heat energy supplying boost, just the pressure. Makes sense. Wanted to wrap the pipes anyway just to keep the ambient temp down, this will definitely be my next project.
Have been considering turning up the pump a bit, but I'v e always had adequate power and very little smoke. Problem is the mountain passes and EGT's. Always backing off. It's really rare to see my engine temps above 200, though, even in the summer.
Also: I've definitely got more seat of the pants power at lower RPM's than before the cooler was installed. My boost pressures have always been low <2200 RPM anyway, just didn't change much. She just feels like she wants to go a little more.

Grape: So the GM'turbo will bolt to the exhaust flange. COOL. Time for some homework, I guess. Anybody done it? Time to learn about Turb terminology. Just a crazy thought for now.

Thanks, I know this is old hat for ya, the info is awesome!

[C.K. Piquup]

I wish someone would produce an upper intake to alow installing turbos on pre-88s.I know Banks does,they ought to offer it alone.

[catmandoo]

i did just whaty you are thinking of,my 92 came with a 6.2 n/a and it scored a piston at 260,000 and the only thing the dealer had at the time was a n/a 6.5 so in she went,well after i got the truck got to contemplating the turbo upgrade as i already had a banks on my 84 ,well banks wanted 400 plus shipping for the right side manifold and checked gm and got it for 160.00.if you have the old style 87 down pickup i have a banks right side manifold.if you have the new styl 88 up you can't use it.the only problem i really encountered is the downpipe.the factory 6.5 turbo housing points down out of the turbo whereas the banks goes out the back.so i had to get a mandrel bent 90 degree elbow and cut it and weld my banks flange onto it and then cut the flange off the downpipe and weld there.things are tight back there otherwise works good love the turbo power just wish these banks made more boost

[grape]

the inlet side of the banks is great for over 300 hp's worth of air. The exhaust side is just waaay to big to get the boost up quick. Banks made that deal so it would be at full boost at the rev limiter, therefore everywhere else boost is going to suffer. An .81 or .84 exhaust will deffinately get the boost up quick, yet it will keep building boost right past the 10 or 12 pounds that banks had intended for.

[Dezman125]

Hi
Catmandoo. In your post,you mentioned you had a banks manifold. Is it an extra one? Are you interested in selling it?You can e-mail me at
salecker@yknet.yk.ca. Thanks

[Craig M]

The 6.5 manifolds will bolt up allright to the 6.2, but you may have some problems with the heating box mounted to the firewall on the passenger side on the 6.2 vehicle. The Banks set up misses this area, the 6.5 will cause a problem.

[90LX]

I would really like top see pictures of how you did the intercooler. I'm thinking about fabbing one up for my truck. If you have pics of this, please post em! :D

[Thermal Jock]

Sorry, no pics. Gotta get a digital camera one of these days!
The cooler I found at a mechanic's shop, got lucky, bought it for $25. But it's too big for the application. Measures 33"x10"x5. My front bumper was bent anyway, so I mounted the intercooler at bumper height then built a bumper around it. I made louvers for the intake front to deflect rocks and such, and put a rabbit hutch screen in front of it. After a hot run, the turbo side is***ut hot enough you don't want to keep your hand on it for more than 5 secs or so. About 20-24" away it's cool. I think I've got about 8" of cooler I don't need.
I rotated the turbo intake outlet so it points at the passenger wheel and down. Two 45's (I used JCWhitney 2 1/2"exhaust tubing) ports right out through where the turn signal light is on a '87. I relocated the turn signal lights in the new bumper.Had to cut a short section of plastic out of the grill. That lined up within 1/8" of the cooler inlet.
The outlet was trickier. I turned the Banks intake cover 90' so it aims at the brake booster. The only sharp 90' bend had to be added there.
From the cooler outlet I 45'd it up, cut a hole in the fender well, and brought it up just aft of the battery, missing the oil cooler lines.From there, you'v got lots of room ( amazing what you can do with 2 45's) to shoot in to the sharp 90 at the intake cover. I have 6" of travel on the left front tire (turned all the way to the right) before the tire hits the cooler pipe.
Took 4 hrs or so to mount the cooler, 8 hours, mostly just looking and measuring, to pipe it, and 20 hours to build the bumper. 15 yr old stick welders suck.

[90LX]

Thanks for the description. Sounds like a neat setup. Coolers like that aren't cheap. Sounds like you found a good deal. I like how that setup doesn't block airflow across the whole front of the radiator. I may have to see if I can find something similar. As for the welding part, I have a friend who does it for a living. :D I can bribe him with beer.