Bliue dm

21 minutes ago, Joey Mack said:

30-32 lbs .... jojo

That's it?  Why does everybody say 460 make 35lbs of boost? It definitely pulls better than my boys 400 but not much and it gets 30lbs all day

Let me see if I can load pic of turbo tag

So i started to look over the truck. I realized that I had a ripped boot off of turbo and boost gauge was disconnected. I replaced the boot and plugged up the gauge. It honestly feels slower now 🤣.  Either way it raised a few questions. First I realized it wouldn't make much past 25lbs of boost. I heard they should be making more like 35. Is it because it's empty? I saw 30lbs once and that was after hitting a bump in the road. You could feel it pull harder but it began to back off to like 28lbs. Now I haven't serviced this truck since I brought. Is it possible that air and fuel filters are that bad that it's holding back on 10lbs off boost? What are yall thoughts?

Pickup pump maybe. I would also revisit solenoid on pump idea. If there is no fuel coming out of injection lines then pump is not pumping fuel. Are fuel filters dry?

I've seen worst when it comes to blowby.  Loader does use some hp but I'd run it. She'll let you know when she is tired 😫 

I have a few pictures. I ran Vin number. It has 4.30s in the rear. I will get some more info on Monday. I'm out of town this week

I actually don't have any complaints.  I have yet to drive truck loaded. Was looking for more general info than anything else. Are the 460s a little smokey before boost? I don't think it's leggy yet? I also see there is more than 1 s400 turbo? Our am I making a mistake?

So I brought a 2000 rd 688s. It's a mut. Mack 460. Mack 18spd. Hendrickson suspension and meritor rears. I must say. It runs amazing but being a 4th or 5th owner truck I don't know much about it. I haven't had it loaded yet but seems to have plenty power. First it rolls some coal. Is it possible it has xt program? It has a borgwarner s400 ; is that stock? Some help figuring out more about this truck. It's factory built the way It's is. I ran vin.

Where there any 2000 rds that came with the xt file? If so. How would I know?

So.. I have a 97 rd688s. E7 400 with 12sp. Triaxle. At this point it has 2 new rears but aluminum dump is shot. Motor has 543xxx on it and front head gasket is leaking bad. Frame rails are stuffed and waffled bad but. She does as a mack does... she still runs well. Does some leaking from gasket other than that. No complaints. Issue is.... the reality is needs motor and refurbished dump body on top of frame rails. Is it worth re railing or move on. 12spd was redone in 16. I really love the truck especially with the 4.17 rears but truck is at the point we're it's time to really invest in it or move on. What's yall thoughts

Ok. 6 degrees it is. 

So don't advance for better running.(more power) like 8 degrees 

Anyone?

I know the timing spec is one the valve cover  but I want to know what the experts suggest the timing spec should be on my 97 e7 400?

Is the jack brake heads themselves leaking? 

If my grandfather had an old quad that ran 62mph. That was flying then.

3 hours ago, terry said:

I once had a DM dump put a overdrive 12 speed with 4.17 rears and loved it, was on 22.5 rubber, but the pump was set to 2300 RPM'S would not push it that hard very often, just surprise another truck or two!! it would bury the 80MPH. speedometer.    terry

Family had 5 70s dm800 673t

One 85 685sx with a 675 tip turbine with a 6spd. It would do 67mph. But for the setup.... pulled like a savage.

Yes. Seems to be pretty accurate too. I think I'm gonna do 4.17. If it was a bigger motor I wouldn't be so concerned with the loss of tq but I think 3.87 is gonna be a bit much in terms of loss of pulling power. So now that I have the mph figured out let's talk about loss of pulling power. I guess experience is gonna have to answer this questions.

15 minutes ago, Joey Mack said:

3 minutes ago, Lmackattack said:

https://spicerparts.com/calculators/transmission-ratio-rpm-calculator

Thank you sir

3.87 is a big jump from 4.17. I was going to do 4.17 but 3.87 would be great if it doesn't kill the torque all the way.

2 minutes ago, Joey Mack said:

You can park on a clean floor. mark the tire and the floor at 6 O'Clock. roll the tire until the mark hits 6 O'Clock again. mark the floor, measure the distance between the marks and divide it into 5280... thats your revs.. jojo

Ok. Understood. What is 5280?

1 minute ago, Joey Mack said:

ok.. only reason i posted is because I have done many Mack rears and 4.17: 1  and 4.42:1,,, were the most common by far...  Someone who knows more than me will post for you..jojo

If I go 4.17 with 78 final with the 11r 24.5 where would that put me

How to I calculate that math?

5th gear is 78. Yes it pulls very well. Have a little timing thrown in there as well. Problem is we( as time goes on) are running more highway. At 65mph its up around 1700rpm ...1800. I want to get those rpm down. I would also like to be topping out around 80mph. It's not necessary but I would like. As I said before...the tires are 11r 24.5. Again. Any help.is appreciated