Torque screw

[Fozz]

Maybe Agnem can pimp his pump builder for some info for us. I've played with mine before only to notice more or less smoke, no power increase noticed. Also the torque screw is on pumps from 92.5 on up.

 

[high psi]

I will probably wait until I have new injectors and the timing set before I mess with mine. I do believe I found it though. The screw on my pump sticks out at a 90* angle just above the round part that all the lines come from and has a anit-tamper cap on it. I think thats it anyhow.

Nope, that's a totally different screw. If you have one it would be above and to the drivers side of that screw pointing towards the firewall and the bottom of the hood at a 45* angle.

 

[high psi]

Yes, but it only limits the metering valve until the RPM's reach a certain point.

What?? It's a fixed screw that limits it's maximum travel. It doesn't move outta the way at a certain RPM. Like Black Dawg said the m-valve will eventually be pulled off of it by the governor, but that doesn't mean it's no longer limiting it. The m-valve just isn't reaching that limit at that point.

There was a Stanadyne Tech article posted here a year or so ago. The Low RPM Fuel Limit was explained in it.

The pic is of a DB4, but the header clearly states DB2 & DB4.

I'd be interested to see that article. DB2 technology has changed over the years, just because some newer DB2's have a certain feature doesn't mean our pumps do. I've been there when they've calibrated these pumps and seen how it responds to this screw being adjusted. It's a true torque screw and creates a torque rise as I explained before.

I'm not trying to be an e-thug or argue with you. Just trying to get the facts straight. Too many of these pumps are being adjusted when it's not really understood what's being done. Sometimes there was purpose for things being built the way they were, sometimes not so much. It's good to know which is which. Understanding how things work is the first step to making that determination.

 

[Goofyexponent]

Well, I cranked mine out a fair bit this morning. didnt make a difference around town except more smoke when I walk on it. Tonight going down the highway my truck had way more get up and go at 130-140kph compared to how it used to be.

I noticed a little seat f the pants change too. I haven't installed my butt dyno or anything, but I would like to see what it does on a set of rollers.

It smokes too much and raises the EGT's to be of any use towing, or racing...unless you had a cyro cooled intercooler and some compound turbos. Then I am sure you could play with it just a little.

I am going to set mine where I had it yesterday and take a video of what it does, so everyone that doesn't know, can see exactly the amount of smoke we are talking about here. It's definitly bad for the engine!

 

[f-two-fiddy]

it limits the metering valve till the gov starts pulling it away from the screw.

Exactly. The rotary pumps are all controlled by centrifugal force. Just opening the cover, and looking at it does not tell the whole story. Things change dramatically when the engine is running thru it's RPM range.

I've experimented with it. The only thing You gain is higher low RPM EGT's, and smoke. NO perceivable increase in boost, or earlier boost. It actually slowed My low RPM boost.

So unless Your a 16 YO trying to look like a fool with Your pants on the ground.....

 

[f-two-fiddy]

I noticed a little seat f the pants change too. I haven't installed my butt dyno or anything, but I would like to see what it does on a set of rollers.

I call Placebo Effect on this. As stated, the Low RPM Fuel Limit is totally defeated above 1100 RPM, or so.

 

[Goofyexponent]

...or trying to impress a bunch of 16 year old with their pant on the ground in a burnout competition...lol

 

[93cc7.3]

i adjusted mine 90 degrees made a coniderable diffrence i think but nealy no smoke still i might do some more later

 

[matt-jenkins]

I noticed a little seat f the pants change too. I haven't installed my butt dyno or anything, but I would like to see what it does on a set of rollers.

It smokes too much and raises the EGT's to be of any use towing, or racing...unless you had a cyro cooled intercooler and some compound turbos. Then I am sure you could play with it just a little.

I am going to set mine where I had it yesterday and take a video of what it does, so everyone that doesn't know, can see exactly the amount of smoke we are talking about here. It's definitly bad for the engine!

I'm going to turn it out even more and take a video

Then i'll screw it back in to almost stock because I'm sure my gas mileage is really suffering at the moment.

 

[Sycostang67]

Ok, I dont think my pump has a torque screw.

You must be registered for see images attach

 

[dyoung14]

Ok, I dont think my pump has a torque screw.

You must be registered for see images attach

It looks rebuilt so it was probly traded for a pre 92.5 core pump

 

[Jake S.]

The screw would be above where the injector lines come out. I can't see that area in your pic.

 

[jw674]

my truck is a 92 so i dont have torque screw right

 

[Sycostang67]

The screw would be above where the injector lines come out. I can't see that area in your pic.

I believe there is a screw coming out directly above the area where the lines come out, but I was told that wasn't it. I will take another pic tomorrow when I have the airbox off and can see it without a mirror.

 

[matt-jenkins]

my truck is a 92 so i dont have torque screw right

My truck is a 92 and I have one. Look on the timing cover on the front of the motor and it should say what year your motor is, either a 1992 or a 1992.5. If its a 92 then you do not but if its a 92.5(like mine) then you do.