dds92780

Ok so i started the truck at 430am , let it idle for 30 mins ( i dont usually let it idle this long) got to the pit, sat in line for 10 mins, then took my first load, then talked to the redimix manager for 5 mins, then went to another pit, was in there for 20 mins, then got stuck on interstate 55 for 20 mins, then everything was going smooth, then i got stuck at another road under construction for 15 mins. I babied the truck all day. I would use the method of pretending there is an egg between my foot and use literally .35 throttle or so, but when the rpms are low around 11 i would give it just a lil more to get it up to 1200 at 25 psi or so and then just hold 15-20 psi to 1500 rpm then shift. I did this all day long. The truck makes good power down low with the new injectors that i can give it just enough fuel to get the turbo spooling and then baby it. My results were 284 miles with 49 gallons. I ended up with 5.79mpg today which i don't think is bad considering all the stop and go and traffic jams i dealt with today. I am going to try for 6 tomorrow I also came to the conclusion that 350 hp is all you really need. It is good to have bigger injectors though i think but you really only need 15-20 pounds of boost to get work done. The injectors help it get there faster though. I wonder what would happen if i turned down the pump halfway to what it is already. You think it would help or just leave it the way it is?

I'm going to be doing stop and go driving again tomorrow and i will try to keep the rpms low and see what i can muster out of the dog. I'll post tomorrow

Ok, I know i will never get the right answer because it all depends on the engine, the gearing, the traffic, the weather etc but lets at least try to get some real world scenarios here. Try to do it in the same format as me. Mack RD 688s e7 350 mechanical (turned up, prob more than it should be , oversized injectors) 442 rears grossing 73000, running empty back to pit or next job Mixture of stop and go driving from 0 to 50 I feel that i am getting anywhere from 5.0 - 5.5 I will say that since i have turned up the pump and put bigger injectors in, the truck is a beast but i think i pay for it at the end of the day (im guessing another 4-5 gallons) (which is why i think i should get a bigger exhaust or just turn the pump back down at least half) Lets hear what you got

Let me know if your mpg goes up at all. Mine sure went down from bumping up pump and doing bigger injectors.

I know you can turn up an e7 with no problems but that e6 is already running as good as it is gonna from what i hear. I would call Antrim diesel in Penn.

You can delete this

So i have my pump turned up 1 full turn and the aneroid spring messed with. I then went and got 1125 injectors which are 20 percent over stock. The truck runs great and pyro temps are still normal. I noticed a little issue today and i need help. It seems that as i am building up boost in lower rpms to mid in the high gears, my boost gauge is shaking a lil bit and i hear a slight miss. I called the place that sold me the injectors and told me that if its not missing at idle or anything like that, then its not injectors. Keep in mind, I still make good power and full boost but something still seems like its missing. So his conclusion was that now that im throwing more fuel at it, The governor springs may be going bad. I think he said something about there being three of them. 1 is idle, another is mid, and another is high??? Anyways, he says there is a kit by bosch that i can install and that will most likely fix the problem. What do you all think? I am tempted to just put the stock injectors back in turn the pump down a little but its alot of fun to drive now and seems to run great. e7 350 mechanical, I am able to get 30 psi by 1300 rpm now, my turbo gets maxed out at 1600 rpm now. Could the turbo just be going bad? Pump was rebuilt two years ago. I have videos if you would like me to post them as well. Also, are there any places in chicago that deal with performance? This is still a work truck, but i just like to have a little fun too And i just had injectors put in. They ran great for about 4 days and now i have that slight miss but not at idle and only in higher gears where its more noticeable. Could debri just have clogged an injector and i need to take it all out again and clean them??? I still have the stock ones and might just throw them back on but i need to be pointed in the right direction and also dont want to be stock because stock sucks

Keep up the Good work and keep them elbows dirty

Ok so two days now doing some 75000 gross runs putting on 360 miles then running back empty. I am shocked that the first day i only got 5.66mpg. So today i made sure that i was only going to go 55mph tops. build boost with quarter throttle at 25psi by 1100 or so, i would shift at 1500-1600. I am capable now of getting 30 pounds of boost by 1300. I would NEVER floor it even once all day long (took a ton of will power) The pyrometer never even went over 800. It was at 700 most of the day which i think is real good. I get home and excited to finally see what kind of mpg i got. 5.35. WTF??? Did i baby it TOO much? Doesnt the pyro being low indicate i had plenty of power and wasnt wasting fuel? Boost builds quick when i want it. Truck runs great. Im just not sure how to get the mpg to improve. I though with bigger injectors and turned up pump that i could get better mpg than stock because i wouldnt be wasting fuel trying to build up boost. I dont know anymore. I'm confused. Bigger turbo maybe???

Eaton Fuller 9 spd RTXF1409B

So i got the injectors installed today I used to get 30 pounds of boost by 1500 on 1% bio on a 80 degree day. I have only driven it empty but i can already tell its way quicker. The needle just flies up on boost now. I easily get 33 pounds of boost empty now which i have never done before. I have seen 33 pounds of boost on a 60 degree day in the morning pulling a load around 1600-1700 rpm but thats it. I can't imagine how good its going to do when its loaded. That is all for now

How much boost are you getting?

They are 450 horse with alllison automatics and they haul ass!

I'm not sure the trans can really handle more than it does already. The turbo is already kinda maxed out. The turbo for this truck is designed to go from 24-32 psi. I get to 32-33 and it doesnt really go higher than that. The upside to the way its setup now is that i get 30 psi by 1600 rpm now, and even 23 at only 1250rpm. 427s are no problem. I even had a well known guy with a turned up 427-460 with 442 rears shaking his head and trying really hard to keep up up. We started at a stoplight and then went up a ramp, the lanes were merging, but he wasnt about to lose to a wimpy 350 lol. So he stays in the right turn lane only and after about 60ish, he finally starts getting ahead, i let off, his truck looked like a steam engine in between shifts trying to do that, im still laughing about it. 475 hp cats are similar to the way my truck pulls now. 425 cat i walk from. This truck is a blast now. I just take off in 1st gently to 14, then 2nd to 16 with a lil more throttle, then 3rd with a lil more to 16 then 4th gear and its cya LOL. Point is, i feel that i am being careful with the trans. SUPERDOG, if i got those injectors, wouldnt i be using even more fuel? The pistons are two piece with an aluminum skirt, so i got a pretty good setup here

Well, so far it seems my fuel economy has dropped but not alot. maybe .25-.4mpg less. I am trying to just take the rpm up to 16 now to see what difference it makes. I might have the pump turned down .25 of a turn or .5 of a turn. I'm not sure yet. I am able to pass loaded RD 350s now its nothing tho lol

I havent really had a chance to check out fuel economy yet. The next day i worked i averaged 5.9 on some tough chicago highway runs. Then the next two days i averaged 4.8-4.9 on some tough hill runs where i would literally leave the pit, make a hard right and climb a hill up to 30 by a stoplight and then more hills 13 times. I think the fuel economy is better than it was before because with the hard driving i was doing last year i would get maybe 4.5 mpg. On the same hill against another RD loaded, i passed him up and he was looking at me like wtf and by the end of hill i had 2 full truck lengths on him lol. There was a vision 460 that used to kill me that i am just a tad quicker now than too. I am shocked that i am run with a 460 now . I just hope the engine is reliable and wont blow up. My pump guy says it should be fine. I have iron pistons and all that. I mean some people go to a bigger turbo and injectors to make a 427 out of a stock 350 so what i did to achieve my power cant be too bad. I went from 27psi to 33. Keep all the questions and comments coming or if you have a turned up 350 i want to hear from you as well. Ill try to baby it more today and see what i can achieve. We will see if i can RESIST

So i was chasing a boost leak for awhile on my truck. I had everything pressure tested and found out that the aftercooler had a bad leak on it. I ordered a new one from rex's. It was fun to install it because the flanges were to long on the top and had to be grinded down. In the meantime my turbo was going bad and had to get replaced. So now i was looking at a new turbo and aftercooler. FYI i was onlyl getting 20 psi of boost and exhuast temps at 900. i knew something was wrong. GOTTA be quicker after that right? I wasn't done. I then went to the pump shop guy that tweaks with these bosch pumps and he messed with the aneroid and did a full turn of the screw. That is also on top of whatever turning of the screw was ever done to it before by the injection place that says they only put it on the high end of factory spec when they rebuilt it last year which is SLOW. This truck FLIES now lol. I mean, i can't believe how much of a difference it makes doing this , I am not even really burning any more fuel than i used to either. Pyro temps are even lower than before too (prob why less fuel being used) Here is a quick summary. 1995 Mack RD688S E7 350 mechanical. 442 rears On 11 percent biodiesel i would get 27 psi on a 80 degree day (pump not turned up) now i get 33 pounds of boost (THIRTY THREE) (still got another full turn of the screw left to go to) EDIT (just got bigger injectors) I now get 36 THIRTY SIX pounds of boost now! So if i do the math, the mack spec sheet for my truck shows 350 hp and 1360 torque on the turbo anywhere from 24-27psi That would mean i am running at least 410 hp now. it is a huge difference and totally makes the truck more fun to drive. I have already walked away from a few trucks that used to be neck and neck with me. I know it might be borderline of what the trans can handle so i never hammer it off the line or even 1st , and maybe toward end of 2nd gear but thats it. I literally keep up with trucks that are empty when im loaded lol. I love this truck Thanks for listening

Very good info. http://www.superiorcooling.co/mack-charge-air-cooler-rd600-cv-granite-rd-model-conventional-cab-1030120-3md527a.html https://www.radiators2you.com/charge-air-coolers/mack-charge-air-coolers/product/114-mack-charge-air-cooler-44mac15a-oem-numbers-44mac15a-17305-cac118b-ca2081-17v9724-374115a-44013001-441109-7091280001-817168-ar443001-btc1118b-madac15a-mk15a-srmmac15a-21030120-204sx278-3md527-3md527a-3md538-4853900001-4853900002-48 Which one would you go with?

How about the difference between an aftermarket one and garrett? I can't imagine its much different.

Hi everyone. My aftercooler is in need of replacing. The truck is a 1995 Mack RD 688S. Mack has an aftercooler for about 1250 dollars and i noticed there are a few companies that make the exact same spec one for about 600 or so. Do anyone of you have any experience using an aftermarket one? I heard that the factory may have defects and sometimes aftermarket is an improvement not a downgrade. Also how difficult is this job for one person? I need to do something soon. I don't mind spending 1200 for a new one but if a 600 dollar one does the exact same thing then i dont want to throw away money either. (yes i have done a pressure test too and it is for sure leaking) Thanks for your help in advance. Dustin

That's the nicest looking "Working" B model i've ever seen!

Here is me at a job I did in naperville for a new UTI building thats going up. I hauled a ton of grade 8 for the paving and then today i hauled grade 8 and 3 inch for the sidewalks. I had to get a picture when i was done

Who is Zimmerman?

I might just try the touch of silicone since you don't really ever plan on taking off steer wheels too often to change a tire right?