Turbo M1008 with 4l80 towing ability compared to gasser?

[shadpeters]

Hello folks, I have an 85 1008 that has the banks turbo system, and a 4l80 od transmission. It still has the 4.56 gears as well. I know that even with the turbo the 6.2 is not making big power, but I figure if its making 350-375 ft lbs at a fairly low rpm with 4.56 gears it should have similar towing ability to something with 425-450 ft lbs and 3.42-3.73 gearing (thought with a lower top speed). Am I expecting to much? it just seems like the truck doesnt quite pull the way I had hoped that it would. I have been toying with the idea of getting newer truck with a 5.3 or 6.0 vortec and was wondering if they would do a better job. It just seems like on paper that the 6.2 ought to pull better than it does with the turbo and low gearing. I am planning to check the compression on the 6.2 as soon as the adapter for it gets it, it doesnt even have 30000 miles on it, so it seems like the compression should be fine, but you never know. If the compression is good maybe the ip or injectors are getting tired, or is it just going to be a sub par puller regardless? I'm not expecting this truck to compare to a modern diesel, or even a 12 valve, but It seems like it ought to hang with a 6.0 or 454 pretty well, and so far it really doesn't compare to my grandpas 94 3500 with the 454, or my dads newer 6.0 truck. just wondering if thats normal.

 

[NVRENUFF]

There's so much to consider. Do you know what your peak boost and EGT is? That can tell you what's going on with power. How about exhaust haze or smoke. Is there any?

Id say if you're @7-8psi and pre turbo EGT under 1150ish, you should be making enough TQ to pull as well as a slightly newer 6.5 turbo diesel, or older cummins (that's not turned up because nothing beats an old 12v) lol

 

[Recovry4x4]

Getting 454 power out of a 6.2 or 6.5 is likely going to cost a chunk of change.

 

[shadpeters]

I've never seen the egts get out of the 900 degree range, I know i've never seen it over 1000, but I don't push it real hard either. Cruising around at 55-65 i run 3-4 pounds of boost which I have atributed to the higher rpms owing to the low gearing, with a heavy load at the same speed probably 5-6 psi, and under accelartion with a heavy load maybe 7-10. acceleration without a load probably 4-6psi... I do get some smoke on startup, it usually clears up fairly quickly and always smells like unburnt fuel. If I am remembering right it didnt smoke like that till after I put the turbo on it. The exaust always smells a bit rich anyway, weather its smoking or not.

 

[Drock]

When you installed the turbo, did you turn up the fuel? And if so how much? With the banks sidewinder I installed on mine the instructions called for the fuel to be turned up 1/8 of a turn. I typically tow around 3000LBS down the highway at 70-80MPH. M1028, Banks turbo, 4.56 gears, 31" tires, Gear vendors O.D.

 

[shadpeters]

I turned up the fuel, I just did whatever was recomended in the banks instructions, so probably an eighth of a turn. i'm generally towing loads closer to 8000-10000 pounds, but not for real long distances, just for moving logs and a small tractor around. I have had 14000 pounds behind my grandpas 454 before and it pulled it easier than my truck pulls 8k. just seems like something is out of wack.

 

[gimpyrobb]

I've never seen the egts get out of the 900 degree range, I know i've never seen it over 1000, but I don't push it real hard either. Cruising around at 55-65 i run 3-4 pounds of boost which I have atributed to the higher rpms owing to the low gearing, with a heavy load at the same speed probably 5-6 psi, and under accelartion with a heavy load maybe 7-10. acceleration without a load probably 4-6psi... I do get some smoke on startup, it usually clears up fairly quickly and always smells like unburnt fuel. If I am remembering right it didnt smoke like that till after I put the turbo on it. The exaust always smells a bit rich anyway, weather its smoking or not.

How old is the air filter? Is flow(cfm) sufficient with the turbo? I'd turn it up more if you haven't seen 1000* on the pyro.

 

[Drock]

When you installed the turbo, did you turn up the fuel? And if so how much? With the banks sidewinder I installed on mine the instructions called for the fuel to be turned up 1/8 of a turn. I typically tow around 3000LBS down the highway at 70-80MPH. M1028, Banks turbo, 4.56 gears, 31" tires, Gear vendors O.D.

*Edit* Banks instructions call for a 1/4 turn.. My bad

 

[NVRENUFF]

Where is the EGT probe? If it's pre turbo, turn the fuel up more. From what I've read over the years, you're safe to 10psi but not much over that. My truck has minor airflow mods and the fuel turned up just over 1/2 turn. I get a light haze at full throttle, but normal driving is clean and much snappier. Over half throttle from a stop will chirp the 36" tires, and pulls 6k as well as it moved empty stock. I don't have a turbo either.

Heavy acceleration ion with a load it does have some haze, but clear cruising 60mph.

 

[snowtrac nome]

you might also try some timing advance my na motor was turned p a half turn and advanced 1/8 inch over static timing ran strong and would start after sitting all night at -20