6.2 compound turbos

[otisd85]

okay guys ive been looking into compound turbos for cummins and it got me thinking why cant i do it on a 6.2? i have a banks kit on my truck now but honestly it just aint enough to push around a 8500 pound crew cab 4x4. with the banks kit the most boost i have ever seen is about 9psi and i have to be in fourth gear running about 3400rpm to hit that with my egts in the 1100* range. so i have been thinking about ditching the banks kit and getting a 6.5 kit so i have a waste gate and i can adjust it to about 15psi (thats what i have heard is about the limit in the safe range). but i figured if im going to do the work of changing out my turbo i might as well take it a step farther and put a smaller turbo on top of it not so much for more boost but more for quicker spooling and more boost at lower rpms. i dont know what turbo to go with but i have a buddy with a trashed 1980s chrysler conquest with a turbo hed sell me for 100 bucks and with scrap prices the way they are id be ahead about fifty bucks after i paid for fuel. but that turbo is tiny and i dont know if it would be to small. i dont really know what im askin hear im just kind of thinking out loud. let me know what you guys think. thanks for taking the time to read this and for your interest.

 

[towcat]

imho compounds make a engine compartment too busy. it's already bad enough on the GM diesel, half the top ends has to come off to pull valve covers. thanks to "oliver engineering", I parked a IH 6.9/7.3 banks TE06H wastegated turbo where the factory GM turbo used to be at. between the turbo, turbo IP and marine rated nozzles, I have built a C20 2wd that can run like a banshee. take a look down in the 6.5 section, there's plenty of pics of the build.

 

[otisd85]

my truck is a non a/c model so its really not all that cluttered i have a 6.5 turbo and a hx-35 off a cummins at my disposal i know either of these would be a nice upgrade and easily make the 15psi im looking for but i think it would be nice if i can get more of that power at low rpms and i think it would be sweet to be able to say "yeah its a 6.2 and she has twins!" and it would be all the better if it was practical.

 

[towcat]

the factory 6.5 outlet is a convoluted mess. you're better off with the HX35. I ran my downpipe outside the frame and went back inside in the pocket right behind the lower control arm. I'm big on functional stuff, the TE06H pushing 10psi at 1500 rpm eliminates the need for twins. with a HX35 you can top out at 40psi and that's plenty enough to blow the heads off the block. If you still need the bragging rights for a working pair of twins, I can't help you there.

 

[otisd85]

twins would be cool but 10psi @1500 rpm! thats exactly what i am looking for. do you know if turning up my pump will get my turbo to make more boost or will it just raise egts?

 

[towcat]

twins would be cool but 10psi @1500 rpm! thats exactly what i am looking for. do you know if turning up my pump will get my turbo to make more boost or will it just raise egts?

more fuel = more boost. fortunately, all we have to do is remove the top cover of the pump in order to access the feul screw. but use caution in re-installation. done wrong and you will have a runaway motor.
as always watch your pyro like a hawk after any fuel tweaks. know where you pyro is so you can determine where you should top out at. i like mime in the exhaust manifold as close to the valves as possible.

 

[otisd85]

thank you that is the kind of info im looking for. i installed boost pyro and tach at the same time as the turbo last summer. my pyro is in the manifold just before the turbo flange(that is where banks has a pre drilled and taped hole for it in their manifold). i turned up the pump as per the banks sidewinder kit instructions, and this is where it got me. i dont remember reading anywhere in the instructions that more fuel will make more boost, just gave you a starting point and if your egts are to low turn it up more if they are to high you have to back it off.

im not looking to go crazy here, ive read several places 6.2s can handle 17psi but thats pushin it 15psi is safe. they can handle 1200* on long pulls but hitting 1300* even for short periods of time can be detrimental to its health. ive seen about 1125* on the longest steepest hill around here running 75mph at 2100 rpm but half way up im down to about 55mph and i have to shift into 4th.

i want to be in the safe range around 15 psi and 1200* because i will not rebuild it if decides to scatter, i know there are better investments in my time and money for example a cummins(to drop in this truck of course). i guess i just assumed that tearing into my pump again wasnt worth the extra 75* and minimal power increase, but if my boost will increase along with my fuel i might get more than i expected and its worth a try. thanks again and ill let you know my results.

towcat your setup looks a lot different than mine your upper intake plenum is held on by 4 bolts on the corners, mine is two in the middle. also your turbo looks like its further back on the engine, mine is much farther forward. i know you said the turbo your running is from a ford kit but what about the rest of the parts? 6.5 turbo? why didnt you run the turbo that came with your kit or your parts were meant for?

 

[otisd85]

so i turned my pump up, it was a 1/4 turn as per banks instructions i intended to go another 1/2 turn so i would be about 3/4 total. at about 3/8 turn i think my screw bottomed out, or snap on isnt all its cracked up to be, because it stripped the allen wrench. so the pump is set at 5/8 turn now and thats where itll stay because i cant back it off or turn it up more even if i wanted to. i also installed a set of marine injectors for a 6.5.

i took it out for a test run and wow what a difference! itll make about 13 pounds of boost now and i was loading it pretty good and seen about 1225 on the pyro but i never beat it as hard as i was tonight. i guess ill have to keep a close eye on the gauges for a while until i learn how it acts. its going to have to be alright sense i cant adjust the fuel screw any more.

so i have a couple new questions. first is there is what i think is a temp sensor in the head on the passenger side at back with 2 wires, what is it, and what does it do? on mine the connector is melted and one of the prongs is broke off, and i would like to replace it but i would like to know what to ask for. my second question is with marine injectors do i need to have my timing adjusted because they have a hire pop pressure and itll take my pump longer to reach that pressure?

 

[towcat]

what you're seeing in the pics is a factory 6.5 setup with a banks from a ford mounted to it.
where Banks has their pyro mounted is still near the valves, so yes the 1200 max is a good number to work with. on the fords, the pyro is downstream enough to be dropping the threshold to below 950 deg.

 

[towcat]

so i have a couple new questions. first is there is what i think is a temp sensor in the head on the passenger side at back with 2 wires, what is it, and what does it do? on mine the connector is melted and one of the prongs is broke off, and i would like to replace it but i would like to know what to ask for. my second question is with marine injectors do i need to have my timing adjusted because they have a hire pop pressure and itll take my pump longer to reach that pressure?

iirc that sensor of for the cold idle circuit.

 

[otisd85]

when its floored im making lots of smoke for a 6.2 until i get to about 2000 rpm and continue to make smoke until about 2800 rpm it cleans up. i can get it to 13 psi when it governs out in third gear but im still only seeing about 3 psi in fifth under a load and no boost when crusing, and i still cant hold 60mph on a hill without downshifting into fourth.

ive got a buddy with a 95 6.5td that sees 10 psi when crusing at 60 and if he gets on the go pedal he hits 15 psi within about 2 seconds. i would like to see numbers like that but maby the banks kit just wont do it.

i think the next thing i need to do is have the timing advanced to clean up some of the smoke so there is not a constant black haze following me.

 

[towcat]

when its floored im making lots of smoke for a 6.2 until i get to about 2000 rpm and continue to make smoke until about 2800 rpm it cleans up. i can get it to 13 psi when it governs out in third gear but im still only seeing about 3 psi in fifth under a load and no boost when crusing, and i still cant hold 60mph on a hill without downshifting into fourth.

ive got a buddy with a 95 6.5td that sees 10 psi when crusing at 60 and if he gets on the go pedal he hits 15 psi within about 2 seconds. i would like to see numbers like that but maby the banks kit just wont do it.

i think the next thing i need to do is have the timing advanced to clean up some of the smoke so there is not a constant black haze following me.

you might want to check if your turbo is dead. something is very wrong with your truck.

 

[Black dawg]

advanced timing will only make the black smoke worse. I am wondering where the timing is now?

 

[otisd85]

you might want to check if your turbo is dead. something is very wrong with your truck.

um??? what do you mean when you say "dead"? it has no side to side play that i can feel, very little in/out play, the turbo spins freely with your finger, and there are no scuff marks inside the housing or on the blades.

what is it that makes you think something is wrong with my truck? it starts good with a little white smoke out the exhaust when its cold, it holds good oil pressure about 30-35psi at warm idle and 45psi when driving, it has a little blow by when i remove the oil fill cap but not much and i have seen a lot worse.

when i rev the engine in netural it makes very black smoke but at the tail of the black smoke there is a small **** of white. i dont know what that means. if it means anything.

 

[otisd85]

i would assume the timing is stock as everything else on this truck was, but i couldnt guarantee that.

what i have read about advancing the timing is it injects the fuel a bit sooner so it has more time to burn in the cylinder giving a more complete burn, less black smoke, and lower egts. at the cost of slightly lower performance and slightly less boost.

or have i been misinformed?