low boost

[catmandoo]

just got done switching the banks from my 84 1/2 ton 6.2 to my 92 6.5 and now i have very low boost .i really have to be puttin the coals to it to just get 1 lb out of it ext temps run up to maybe at the most 700, any ideas?before in the 6.2 from a stop sign i could get 5lbs out of it within the first 300 feet.

[whatnot]

Did you turn up the pump?

[catmandoo]

no thats the one question i had that i was gonna ask .whats involved,do i need to remove the intake to get to the pump?and what direction do i need to turn the screw and how much?

[catmandoo]

well turned up the pump today and maybe gained 1/2 lb under pretty good load and ext temp went up maybe 50 degrees today i ran 375 at 60 before and after i turned it up 400 at 60 the ext temp comes up alot quicker now and it does have more power i do have a donut leaking on the drivers side which i'm fixing tomorrow hopefully that helps some and i don't like the long stud bolts on the banks air chamber might just run some readyrod in place of those studs i think maybe i have small leakage there too.

[mhagie]

catmando,did you save the washers on top the plenum box w/the neoprene centers off the 6.2?
also the gasket between the box and the intake might be suspect.
Also a place to look is the sides of the intake that are blocked off w/the banks cap they have been known to fail w/age.
I believe you have to have a air leak between turbo and intake.
Good Luck........Merle

[catmandoo]

well thats my basic conclusion for right now the 6.2 it came off of would pull 5lbs of boost in under 300 ft and smoke the tires.also i had to drill new holes and offset the air chamber other wise i had a real bad kink that i didn't want do deal with making a pipe,lots of restriction.i turned the chamber to the left about 30 degrees so i could just pretty much go from the turbo to chamber thats why i think those banks studs are causin me trouble,theres some reinforcing ribs on the inside that i suspect the studs are catching on,ya know i never did like those banks nuts on there you would think for the money you had to spend for the set-up in the first place they could have had better nuts,like a cap nut or something.

[whatnot]

Is the rubber cap on the CDR port (on the intake manifold) cracked? My did within a week of installing it.

[catmandoo]

no i used the hose that was there and pluged it so i know thats ok

[patrick m.]

what kind of turbo is it? What model? is it wastegated?

[catmandoo]

well it's a banks and i did cure some of it today was wasting some time and thought maybe it was the hose into the air chamber so took it off and for some reason blew in it and it wouldn't hold pressure so pulled the hose and it had a little kink in it and a tiny little hole so replaced it and now i can get up to 3 lbs under pretty good load and cruising at about 65 it just comes off the peg maybe 2/10th of a lb.and ext temp about 400 still think it could put out a little more i'd be happy to see 1 lb at 65. gonna pull the chamber and replace the studs and see if that helps.

[catmandoo]

oh it's an older banks pre sidewinder no wastegate

[whatnot]

Did the engine come with a turbo or was it originally N/A?
Does/did it have an EGR system? If so, did you remove the flapper thing on the driver side exhaust manifold outlet?

[catmandoo]

to put on the banks air chamber you have to remove the egr valve and it has a special plate that covers the hole,and the heatriser valve is still in the drivers manifold and wide open.my vac pump died awhile back and i figured since it doesn't control heater or cruise theres no need for it.so went to the parts house for a shorter belt and he even asked me with or without vac pump so figure i'm ok there.

[mhagie]

Catmandoo,My Banks turbo kit was ordered for a J" series to go along with the J manifold on my 6.5 reman.
So obviously the EGR on mine is non existent, you state you rotated the box 30*, that would require drilling new holes in top of box did you plug old holes?(dumb question) save the neoprene flat washers?
I find the studs to be quite adequate so am surprised you don't like them, mine was shorted the nuts so I bought a pair of locking nuts to compliment the neoprene flat washers,worked out fine.
Britannic had a post a while back stating that insulating the cross over pipe and turbo helped increase boost.
it might be worth the effort.

[catmandoo]

ya i plugged to holes with bolts and some rtv sealer ,and i do like the banks studs but when i rotated the air chamber ther is 2 ribs on the bottom side that i think are hitting the studs.just need a little time to check into this.but boy you don't know what your missing when ya don't have it .today i went to pass a car doing 60 and i didn't need a run at him even at only 1 1/2 lbs of boost felt like it had another 100 hp. god i love turbos was doing 75 before i got pulled back .think i'm gonna pull the heatriser valve out and i do have some leftover thermotech that i've put on the downpipe off the turbo that i can use on the crossover. i'll let ya know how that helps.

[mhagie]

I.ve got the 6.5 reman w/6.2 banks in my 80 silverado and I insulated everything as this turbo wasn't made for the older body style but its in and it fits but things are close so insulation was in order. :D

[catmandoo]

well got home early today so decided to dig into a few things.first took the crossover pipe off took out the heatriser valve put thermotech wrap around pipe and put it back on and threw those damn springs out as i couldn't get that side to quit leaking with em in there. then pulled the air chamber and ground out a little on the bottom side so the studs wouldn't hit and while it was off it had its fair share of oil residue in there that wasn't in there before the turbo so trace that down to the pipe on the intake hose before the turbo and put a restriction in the line, when i finally get this set up like i want it will be somewhat like the banks a/c box , i want to put like a wall in the box with holes in the bottom edge to slow down the oil from being sucked up in the turbo.so then i procede to use some sealer and seal the air chamber.after setting for a couple hours took it for a spin ,now down the road i have maybe 3/10ths of a pound whereas before i had maybe 1/10th,and it will climb to 5 lbs under a pretty good load.lots better but then i get back and pop the hood and oil residue is running down the side of the intake under the air chamber not bad but just enough to **** me off, damn i hate them. somebody here posted a while back about an o-ring seal to fit on top of the intake does anybody remember this or have a part number? then as i pull off the rubber elbow that goes on the turbo it has oil residue in it,well if that wasn't enough the hose evidently can't take the oil cuz now its swelled to like 3 3/4 inch inside diameter where it used to be 3 1/4.now i need to dig up a hose as it just wants to slip off now.

[whatnot]

What gear ratio do you have? I noticed on my 95 the other day that if I shift out of OD while cruising at 65 MPH, the boost will almost double.
If you have real high gearing, the RPMs might just be to low to make a lot of boost.

[catmandoo]

haven't checked gears but the guy that bought it new ordered it for highway driving as he put on 1200 to 1500 a week. and i am currently at 1200 or so a week. if i get up over 65 or so it does come up some but i guess it just doesn't need much for boost for cruising down the highway .yesterday with wind at my back maybe 1/4 lb if lucky and with headwind just a hair over 1lb so guess thats probably where its gonna run and just have to live with it.would like another lb or 2 though.just hit 2 of iowas finest pheasants (at least they were hens) today and took out the windshield and grill so might have to rig up my intercooler now that the frontend will be off.

[whatnot]

Do you have a tach? If so, what is the RPM at 70 mph? My 93 has 3:42 and runs about 1950 rpm with 265 tires. It has been a while since I have driven it on the highway and I don't remember the boost numbers.

[catmandoo]

no don't have a tach thats the one thing this guy didn't order when he got this.he even had the original window sticker it was like 18,900 new in 92,now look what they get for these things double that!