Bliue dm Posted February 18 Share Posted February 18 (edited) 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. Edited February 18 by Bliue dm Quote Link to comment Share on other sites More sharing options...
Popular Post R.E.D Posted February 18 Popular Post Share Posted February 18 (edited) First let me start out by saying that if you're coming from a cat or a Cummins, a 12 liter Mack engine will feel like a mut. Someone correct me if I'm wrong but I don't think the XT program was offered an RD chassis.the s400 is stock yet there could be reasons why truck would be lagging. Dirty fuel filters, low fuel pressure to the injector unit pumps or could have fault codes hindering power. Edited February 18 by R.E.D 2 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Joey Mack Posted February 19 Popular Post Share Posted February 19 These trucks are slow and deliberate.. This truck will pull.. yes change the fuel filters.. also keep in mind that the V-Mac III system reads the trucks movement and delivers fuel as needed. When you are empty, and you push the pedal to 100 % throttle, and the speed sensors see a quick rise in road speed, the computer sees that you are empty and cuts back on fuel delivery... when the throttle is at 100% and road speed gains slowly, then the computer thinks you are loaded and delivers fuel accordingly.. Seat of the pants acceleration may seem the same. however, you will move the load effectively.. It aint no Cummin's . sometimes setting the governor setting from 'min-max' to 'allspeed' can perk it up, but......... it's still a Mack. Slow and deliberate... Jojo 3 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 19 Share Posted February 19 its also not an XT... and the Schwitzer S400 SO41 turbo was what I saw on most applications... jojo Quote Link to comment Share on other sites More sharing options...
Bliue dm Posted February 19 Author Share Posted February 19 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? Quote Link to comment Share on other sites More sharing options...
JoeH Posted February 19 Share Posted February 19 Pictures would be nice. 1 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 19 Share Posted February 19 There is a ton of info stored in the brains of the members here.. I believe that when you start working this truck you will be happy with it. So for now, thats all I got. jojo Quote Link to comment Share on other sites More sharing options...
SICSEMPERTYRANNIS Posted February 23 Share Posted February 23 Is there any way to hack the speed limiter from 65 to 75 on a 2000 Mack RD688s ? By hack I mean add a resistor in line on the sensor and make it think it's doing slower than it actually is..... I own this truck and want it to go faster than 65. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 23 Share Posted February 23 I dont know about that, and would not introduce a future issue.. Just take it to Mack or someone with PTT for Mack or a ProLink 9000 with a V-MACIII pmcia card... you can set road speed and cruise speed... jojo 1 Quote Link to comment Share on other sites More sharing options...
Bliue dm Posted February 26 Author Share Posted February 26 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 Quote Link to comment Share on other sites More sharing options...
Bliue dm Posted March 11 Author Share Posted March 11 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? Quote Link to comment Share on other sites More sharing options...
Onyx610 Posted March 11 Share Posted March 11 (edited) You won’t make a lot empty, I’d change the air filter/fuel filters and pressure test the whole charge air system. Also check for exhaust leaks pre turbo. Edited March 11 by Onyx610 Quote Link to comment Share on other sites More sharing options...
Bliue dm Posted March 11 Author Share Posted March 11 Let me see if I can load pic of turbo tag Quote Link to comment Share on other sites More sharing options...
Bliue dm Posted March 11 Author Share Posted March 11 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted March 11 Share Posted March 11 30-32 lbs .... jojo Quote Link to comment Share on other sites More sharing options...
Bliue dm Posted March 11 Author Share Posted March 11 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 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted March 12 Share Posted March 12 I dont know.. sorry.. but I do know when I drove 400's in the construction company back a while. the 400 i drove out pulled the 427's.. same tranny's and rears. and I was a new driver pulling away from vet's.. never saw boost pressure. but when I worked at Mack, i'm pretty sure that 32 PSI was it.. Sorry, I forget some thing's even though I work on trucks everyday..... jojo Quote Link to comment Share on other sites More sharing options...
fjh Posted March 12 Share Posted March 12 (edited) Depending on the year 33 was max spec in 2003 A good running 460 is in the 35 neighborhood 98- 2001 pre that seen em go to 38! That being said Rd had limited cooling it was hard to even get a 460 in an RD at some points in time ! Edited March 12 by fjh 2 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted March 12 Share Posted March 12 'F' I'm so glad you showed up, I find that I'm forgetting a lot of what I used to know, 'just like that' .... jojo 1 Quote Link to comment Share on other sites More sharing options...
Onyx610 Posted March 12 Share Posted March 12 If your at 28 loaded you have something to look into. If your hitting 33 like the other guys said your good to go. Besides 2 psi isn’t going to be a noticeable difference. 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted March 12 Share Posted March 12 Ok.... I'm going to throw out, what may be a dumba$$ question... do you here this info on the C.B. Radio? or from mechanics? sorry, I started my 'Period' today so I pull out some B.S. Jojo 1 1 Quote Link to comment Share on other sites More sharing options...
Onyx610 Posted March 12 Share Posted March 12 3 minutes ago, Joey Mack said: Ok.... I'm going to throw out, what may be a dumba$$ question... do you here this info on the C.B. Radio? or from mechanics? sorry, I started my 'Period' today so I pull out some B.S. Jojo Damnit I’m out of reactions….anyway 🤣 1 Quote Link to comment Share on other sites More sharing options...
fjh Posted March 12 Share Posted March 12 6 minutes ago, Onyx610 said: If your at 28 loaded you have something to look into. If your hitting 33 like the other guys said your good to go. Besides 2 psi isn’t going to be a noticeable difference. They started ripping people off for hp when emissions tightened every year a new regulation a lower hp SEEN IT HAPPEN since the 80' s Quote Link to comment Share on other sites More sharing options...
Onyx610 Posted March 12 Share Posted March 12 5 minutes ago, fjh said: They started ripping people off for hp when emissions tightened every year a new regulation a lower hp SEEN IT HAPPEN since the 80' s Good point! Quote Link to comment Share on other sites More sharing options...
Bliue dm Posted March 12 Author Share Posted March 12 16 minutes ago, Joey Mack said: Ok.... I'm going to throw out, what may be a dumba$$ question... do you here this info on the C.B. Radio? or from mechanics? sorry, I started my 'Period' today so I pull out some B.S. Jojo 🤣🤣. No jojo. I read it hear. 1 Quote Link to comment Share on other sites More sharing options...
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