Turn up the IP for turbo or not?

[WildWilly]

This is the IP I am running on my 6.5 TD "DB2831-5088 10229115 1994-97 HD P & G Van - N/A (170 hp)" I will be putting my motor in this week but need to know whether or not to turn this pump up. It will be alot easier to turn up while it's on the engine stand but I'm not sure. I'm using the stock turbo from a 93 K3500 and have no plans of higher boost but heard that a NA pump needs turned 1/4 turn for the turbo. I am also getting my injectors rebuilt and everything will be stock on my motor.

 

[bison]

There is not really much to turn up in a electronic controlled IP,..its all in the programming.

 

[WildWilly]

It is a mechanical pump from a 95 P30 chassis, sorry I wasn't clear on that.

 

[WarWagon]

You should knock the heads off and change the NA precups out for turbo precups. With stock 1993 turbo this is not very critical, but, push it with a bigger turbo and you will regret the small precups.

You can go 1/3 to 1/2 turn if you will run up to 14 PSI of boost. 1/4 turn is standard for going turbo.

I'd almost stay NA vs dropping a POS GMx on the engine. You MPG will suffer for very little power increase. This is why I suggest better precups for when you put a better turbo on the engine. Yes, it will be a challenge to do this with a van center turbo mount. It may be 30 HP, but the choked feel in the upper RPM plain sucks with the factory turbo's.

 

[WildWilly]

Thanks for your response WarWagon. I'm not planning on adding boost or anything for a while. If & when I ever do I'll install head & crank studs and pretty much go all out to do it right. The NA motor is a 98 GoodWrench 506 casting and the precups look like the larger ones for a turbo motor. I have 3, 4, or 5 6.5 motors laying around for future build. I really appreciate everyone's help on this forum. Now back to work I am in need of getting my truck running by this weekend, my Camaro is on its last leg but I don't want to take shortcuts with my 6.5, just need it going. So do you think I'd be better off or just as good running NA? I was getting around 15 MPG with my 93 TD that locked up and plenty of take off & pulling power. I was pretty happy with its performance.

 

[WildWilly]

I take that back on the precups. I see that the square ones are used for NA following this link. http://www.thetruckstop.us/forum/showthread.php?11778-6.2-6.5-precups&highlight=precup

 

[WarWagon]

My 1988 NA 6.2 4x4 suburban would get better than 18 MPG. My 1993 TD hasn't broken over 15 MPG with a GMx. Yes, turbo is a little more power but you trade economy for it. My economy did not change on the 1993 TD when I turned up the fuel and boost. The power went up.

NA and choked turbo feel the same in the top end - just out of pulling power.

 

[L98TPI]

My 1988 NA 6.2 4x4 suburban would get better than 18 MPG. My 1993 TD hasn't broken over 15 MPG with a GMx.

For what its worth :hihi:
My 86 Sub 1/2T 2WD got 21-22 at highway cruise. My buddy's got a 96 Sub 3/4 ton 4WD he swears gets 20 on the highway. IIRC it has a GM-8 on it, straight piped and is stock other wise.

 

[6.5L]

When I was running my GM-3, I was getting 19mpg highway at 65mph with 4.10 gears and my NV4500. Running 5psi. However, with my closed wastegate if I went above about 10psi, my mpg went down to about 13mpg.