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ATT Update

That is good to hear Slim Shady. I don't know what is wrong with it. I know the ATT flows more air at lower boost but starting in 1st and running through 4th, I can only hit 4psi maximum from start to finish. Something is up. I don't know what. But I am about at the end of things here. I can't use the ATT intake since it won't even come close to being useable with my GM so I can't even run stock turbo. This has gotten me fairly demotivated. If worst comes to worse, I want to scrap it and see if I can't buy a 12V Cummins. I really want to salvage this 6.5 project though because it is cheap to repair, I like the body and it doesn't even have a dent or rust on it, I love the one ton 5 speed single rear wheel. I have done a lot trying to make this my dream truck. I'd hate to just scrap it.
 
Don't give up, there is probably a simple solution.

Do you have lots of black smoke? At WOT and 4 lbs boost you would. Could the boost gauge be nfg?
 
A new engine and a new injection pump is a considerable investment.

A cummins 12v swap will be around 3-4000 if you're a good parts scrounger and then there's the down time and work involved.

The cummins will have better power potential and the promise of better reliability, but there are some down sides to it: Weight being the biggest one.

I would work with slim for a little while longer to see if it can't be sorted out.

I know it's disheartening when the truck still won't work right after you chuck a lot of money at it (trust me, I KNOW that feeling..:rolleyes5:), but I'd say you're a small step away form getting it running.

Be it a replacement turbo (which I'm sure slim will make right if your'e is bad) or some other small tweak.

The only other thing I'll leave you to consider is that the 6.5 is only ever going to be able to produce power to a certain level (IE: around 300 HP tops), If that's enough to make you happy with it then stick to your guns.

But, if you need more (multiple horse trailer and such), I'd seriously consider stopping putting money into it and decide if it's not better spent on a cummins conversion or even (gasp) another truck.

It sure sucks when you've got so much money into a truck you can't really stop pouring money down that hole........:(
 
The DB2 puts out alot less fuel then a DS4. My 93 with a TM did not make boost as fast as my 98 with the vac system. Even with the TM cranked up running a GM4 which is the snappiest of Gm series It struggled to hit 10-12 psi and the truck was in good order. I think the point I am trying to make is being that I owned the exact same truck you have my experience is the DB2 made the turbo react differently than an equivalent truck with DS4/GMxx. I got a bit of smoke when shifting gears as the NV4500 has a bit of a gap in the ratios as well. In fact what I was told by Bill Heath when I talked to him was that I may actually find the truck more responsive if I did not turn the IP up..I would imagine based on this the ATT will react differently as well.
 
NVW said:
Don't give up, there is probably a simple solution.

Do you have lots of black smoke? At WOT and 4 lbs boost you would. Could the boost gauge be nfg?
Click to expand...

X2, whats the smoke and power like? Once discussed with someone that they didnt have any boost so they key tightening the TM, because they kept only getting like 6psi of boost. Then realized the line from the intake to the gauge had melted through and had a big hole in it. Fixed that and realized he had about 20 psi of boost actually.

If you have lots of smoke and low power then its not spooling well. At the same temperature, the flow is all the same at the same boost. You get a difference in mass flow if the larger turbo maintains a large difference in temperature, but even a 30 degree difference is not a whole lot, to where 1 psi may be the difference. As the IAT difference grows then the pressure differential can grow, but not likely to get a huge IAT difference. I just mean you need at least 10psi even with the ATT.

Real sorry to hear about your horse, thats too bad.
 
Shake the spurs slowly,
Beat the drum lowly.
For today a horse that was all horse has passed!
Swing them gates wide St. Peter,
For my horse is galloping on them clouds.
Bound for the greenest, sweetest pastures.
There to graze in Gods glory,
Waiting for the day.
When I shall have need of a steed,
For that final ride.
Walk in beauty,
Till that day does dawn!
 
I didn't see it earlier but sorry about your horse.

Horses and dogs are special animals.
 
you can reuse the upper manifold. the cut off piece can be smoothed out and using 2 connection hoses, 4 clamps, put it back together. it will look good.
when you removed the upper manifold, did you damage the gasket? or cause a leak from the surfaces hitting something?
 
Mix up some dish soap and water in a windex bottle. Spray everything that the intake air goes through after the turbo. Any leaks will show up as a bubble. The wind off the fan will have to be shielded.
 
I got a new gasket where the top intake goes on when I got the motor. It is fine. I managed to scrounge up another upper intake. It was off a electronic motor so I will have to remove the doo-dads on top, and plug the one side and adapt the other fitting down to the size my boost connection is.

I should be able to do that and get my stock turbo on today and see where it runs. I checked the boost line yesterday.

All is well. And I wouldn't do a 12v swap. I'd just get a 12v dodge.

Cummins is way to much weight for what my truck is designed to handle up front. Shit would wear out 3x as fast I bet.

As far as smoke and power goes, the power seems alright. I think having the new engine with basically new miles on it and good compression brought power up a bit. The actual motor runs amazing. Burns the fuel great.

For as little boost as I'm running with the ATT at the moment, there isn't a nasty amount of smoke, but still a good deal.

Motor is doing good and burning it now. Like I said, I don't want to scrap the project. I like the 6.5L.

I am just trying to get maybe around 200hp or so at the rear wheels and leave it alone. I bet even if I got the ATT working I'd still only be around 180rwhp but still I don't need mass amount of power.

I just want a decent amount that will tow when I need it and be reliable. Like I said, I really like this truck. it's a dream diesel for me, especially at this age.

It just gets to me sometimes when so much shit has gone wrong in so small amount of time. I hope I can get it running with my stock turbo today.

Another thing is that at idle with the intake and everything off, no filter, the blades inside the compressor housing were barely moving.

I mean barely moving, yet when I gave it throttle then they picked up.

Shouldn't they be spinning at idle still?

I couldn't believe that there isn't enough exhaust flow at idle to get those blades moving
 
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The turbine blades should spin quite freely at an idle, at least mine did anytime I looked.

Did you pre oil the turbo before the first start up?
 
Yeah. The turbo was pre-oiled. I really can't think of anything that would make the blades not spinning freely at idle. I can see the blades moving. they creep until I apply throttle.
 
I did get the stock turbo on today. Runs 15psi like a champ. Runs good. so i doubt it is the motor. Who knows. I got the turbo ready to box up and be sent away to be checked.
 
Just the stock GM-3. She rips fairly well with it. Just no top end power past about 2500rpm lol oh well. I usually grab another gear between 1900-2000rpm anyways when I'm not having fun
 
what i'm running now. mpg is good, boost is low, power is same as the gm3. i do have an exhaust leak on the crossover that i can't seem to stop though. going to try and put studs instead of the bolts, see what that does.
 
6.5L, did you already try changing the timing a little, maybe retard the pump if its pretty far to the drivers side of the timing mark. Or advance it if its not now.
 
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