turbo and IP questions

[bigrigdom]

hey all, new to this forum and i gotta say, i didnt know a damn thing about 6.9's until I found this place. the info here is awesome. I have an '84 f250 with 6.9 and banks turbo. I have seen some posts talking about unhooking the wastegate and turning up the IP. I dont know a whole lot about my turbo setup, or diesel engines in general for that matter. my questions are does the banks turbo have a wastegate and if so how do I unhook it, and were is the injection pump and how do you turn it up? Is it something that can be done to the 6.9 or does it just apply to the 7.3? My boost gauge only shows that im gettin a max of about 7#'s and thats goin over the grapevine in so-cal(a big ass hill) with a ton in my bed, foot to the floor, and was doin about 65 mph(this is my first 6.9 and I was pleasently suprised with how well it scooted, having previously owned a chevy w/a 6.5 I wasnt expecting much ) . egt reads somewhere around 800-900. are these acceptable numbers or should I be gettin more boost? If theres any one that can help me I'm sure that its somone in this forum, and I would greatly appreciate the help.
Dom

 

[towcat]

dom-
welcome to the site The root for any of the mods is your pyro readings. Depending on where your pyro is mounted in at, your max readings will differ. The closer to the exhaust ports, the higher your limit is. Chances are yours is mounted right at the entry point to the turbo. If so, you have a max of 1050deg. If its near the exhaust port, you can max out at 1250deg. Your boost level indicate you have some room left for turning up. Keep in mind though, maxing out the boost is not the best thing to do since the best efficiency for the turbo is right around the middle of its boost ability. I have my ATS set at 8lbs and rarely hit it with my loaded weight of 9k. It's going to be interesting to see what it will do with a trailer hooked up to it. Check your tailpipe smoke output. If you don't have much output, I'd turn up the fuel screw first before messing with the wastegate. Any other questions? Post away

 

[sle2115]

Check out one of our member's web sites - Ziggster's page for fuel screw adjusting!

Keep an eye on that pyro though and go in small increments until you establish a baseline for each adjustment.

 

[Mr_Roboto]

I just have to comment on "unhooking the wastegate". The wastegate is like a fuse to protect the engine from overboost. For the life of me I don't understand why some individuals recommend defeating the wastegate.

When boost reaches the set maximum level, the wastegate begins to open to bleed exhaust gas around the turbo to limit boost to safe levels. The wastegate is adjustable to change the maximum limits.

"Non-wastegate" turbos by their design are self limiting by virtue of their low capacity.

 

[Diesel JD]

I really agree with Roboto on this one, but it wouldn't surprise me if you have the old style Banks non wastegated turbo based on those #s. If it has the square air cleaner box that is the non gated version. At 800-900 egt you might have a wee bit of room left on EGT, Towcat is right the 1250 max EGT number is for pre turbo as close as possible to the exhaust manifold, and if something is not exactly right, pyro is reading low, oil cooler or cooling jets not operating 100% then you will have problems. If its post turbo then you max out around 900. 1250 would be fine all day if it was preturbo close to the manifold and everything was perfect...do you want to take that chance? Personally I want at least a couple hundred degrees worth of fudge factor.

 

[bigrigdom]

thank you for all of the quick responses. thanks to diesel jd I now know that I have a non-wastgated turbo because my filter box is square. that being said, is 7# still a low number or with a non-gated turbo should I make more. IIRC ats's breakdown of turbo design on thier website said that non waste gated turbos would make more boost but wouldnt spool up as fast.
Towcat, I hardly ever blow any smoke outta my pipe so I guess that would mean that I can turn up a bit? will it need to be timed after that? thanks again for all your help everyone, just tryin to get a better grasp on how the old girl works.

 

[tonkadoctor]

thank you for all of the quick responses. thanks to diesel jd I now know that I have a non-wastgated turbo because my filter box is square. that being said, is 7# still a low number or with a non-gated turbo should I make more. IIRC ats's breakdown of turbo design on thier website said that non waste gated turbos would make more boost but wouldnt spool up as fast.
Towcat, I hardly ever blow any smoke outta my pipe so I guess that would mean that I can turn up a bit? will it need to be timed after that? thanks again for all your help everyone, just tryin to get a better grasp on how the old girl works.

Welcome to the site.

If I were you I might give the fuel screw a turn on the injection pump and not worry about the boost numbers being around 7lbs which isn't bad for the IDI. Reliability is more important than power and as long as you keep your exhaust temps in check you should be fine.

The IDI engines aren't going to handle a lot of boost in stock form like the Powerstroke, Duramax and ******* engines simply because of how they were designed so if you have a buddy sitting there bragging his Powerstroke can run 23# of boost just ignor it because it's a totally different animal.

 

[Diesel JD]

Yep, what he said. The PSD has 17.5:1 compression and the 6.9 is 20.7:1. It makes a difference. The most you can reliably boost on a stock IDI, it varies but I've heard anywhere between 13-16psi, personally will try to keep mine around 8-12psi unless I build a high output engine.