dds92780

Looks like i need the 0 402 746 852 pump that came out of a 400hp mack. My pump guy says ill be tickled to death with how much better we can make it. I'm gonna have to make some calls and see how much i can get a core for. Its a 19 degrees of timing pump and my pump right now is 11.5 degrees. He said I have a very strong motor being the e7 and that i will just fine with this turbo and injection pump setup. I would like others to chime in though and see what they think. So right now im running 20 percent oversized injectors, a 427-460 turbo and the rack moved all the way forward. Its quick yes, but i think the other pump will allow us to flow match it all and still be healthy. I'm going to drive it a few weeks and try to take it easy and see if the combo i got now still allows more power with less pedal and increased mpg.

Okay so the story is that i had a s300 turbo on my mack e7350 mechanical and i went up to 20 percent oversized injectors and had a pump guy turn up the pump. I made good power and kept fuel economy descent but i wanted to complete the setup by getting a bigger 427 turbo. I put it on with my same fuel settings and i felt i lost a lil power but still not a slow truck. I then wen I need help from anyone that has moved the rack forward on this bosch pump of mine. pump number is a 0 402 746 642 I need to learn how to move the rack forward or backward in case i want to get a smaller turbo housing. Is it as simple as taking the top cover and side cover off and just trying to turn a screw or socket to move the rack forward? I edited the post. It turns out i am maxed out on my pump right now.

The turbo is going to cost me 830 dollars and im picking it up tomorrow. I am confident that it will work with my stock exhaust which is 5 inch inlet from turbo to DP, then goes to the frame of the truck where it goes to 4 inches all the way back. It seems that its a really tight fit to get a full 5 inch in there. I am not sure what is needed but i think 4 inch is enough. Also, would it look cool since i have 5 inch exhaust to just get 5 all the way through and then put an adaptor on just after the flexpipe that lets me get 6,7,8 inch that goes to a muffler / straight pipe or just leave it alone???

Just answered my own question. the turbo im looking at is the 631gc5173. its the same turbo the rd legend used for 460hp. guy at mack was dumb and told me they all had 4 inch exhaust. I called my turbo guy and he said i need 5 inch exhaust. My thoughts right now are to get a 5 inch downpipe made. I guess i would just need to figure out the measurements of it and have a shop make me one. Then i can use 5 inch flexpipe all the way to the muffler and be done?

I'm wondering that even if i stuck with my 4 inch exhaust if they even make a bigger turbo than what i got that would work.

Here is how it runs. I get 35 pounds of boost by1300 rpm, then by 1600 rpm or more i can barely squeeze out 37 pounds. This tells me that the turbo is too small. But should i leave it alone? My goals are to get better mpg. I can drive it with half throttle all day but it still doesnt get better mpg. Not looking for a tractor pull truck either this is a work truck.

I am happy with the power but i want to increase fuel economy. since turning up the pump and getting bigger injectors the truck builds boost FAST but its a tiny turbo and therefore with the amount of fuel im using to spin a tiny turbo, i feel that i would be better off with a larger turbo with the same amount of fuel. I also understand the kiss method too. only reason i would be getting a larger exhaust is because that is whats required to make the turbo work. The more time that goes by though, i just lose interest.

Still looking for useful info on this topic. It turns out that i will need a 5 inch exhaust to get this bigger turbo. I am not going crazy and going with a 460 hp turbo though. I am going for a s400 turbo 400-427 hp with 1.25 EH. is this a bad idea? where do i get a 5 inch exhaust?

So right now i have 20 percent oversize injectors, pump turned up enough to get a puff of black then grey then disappear. My truck is a 95 mack e7 350 MECHANICAL 442 rears stock trans (RTXF1409B) Problem is that im on a stock s3b turbo and i get 32-35 pounds of boost by 1300 rpm. Truck runs great and pyro temps are low and i can get by using half throttle all day long. I was told getting a bigger turbo is going to really help with breathing better and saving fuel. How can it breathe better though if ive got more power and my pyro temps are only 700-800 all day long currently? i was all set to get a s400 turbo that is designed for 400 hp and has a size of 1.25 exhaust size. Only problem is that i was told that i need a 5 inch exhaust to make it fit. In understand that 5 inch will make it breathe better and all that but arent i just making a recipe for the engine to blow up or blow a headgasket? This is my work truck and it has 450k on truck now. If i get 5 inch exhaust, what does it consist of? I need a pipe that goes from turbo to flexpipe, then a pipe that goes to muffler? i'm new to all this and my dad who is older is recommeding against all this because he thinks im just going to blow it up and im wasting my money. I need some positive advice and also some info on how to get a 5 inch exhaust. Only thing i can think of is to use the vin number off a mack rd legend that had the 460 hp in it and i can use the info to at least get the pipes needed for the exhuast. Any other advice?

Yes thats what i did!

I will have to look but from what i remember DO NOT run it into the intake side on the left. It will cause bad readings and shaky bouncing needle on the gauge. If i remember correctly i put it on the passenger side somewhere on the top of the engine area. I can look later for you though and take a picture.

I just spoke to a guy named rich and R and A turbo main. He rebuilds turbos and is very knowledgable about it. ( 30 years in business) I told him what turbo i had ( i bought my turbo from him when my last one blew up due to oil starvation) (learned a lesson there) anyways I have the S3B which is a small S300 and he asked what size exhaust i have and i told him stock and he did some research based on me telling him i have 20 percent oversize injectors and my pump turned up but doesnt blow black smoke. ( i get a puff of black kthen it goes to grey then its gone) Even today , i know its cold out but i can get 35 pounds of boost by 1300 rpm then its just wasted fuel from there on out to get 38 pounds of boost. He was impressed that i told him my pryo was at 700 or under all day long and in the summer never goes over 875 even with my mods. I drive my truck from the moment i get it rolling with only .25 to half throttle and it runs good. Long story short he DID recommend the 400 hp turbo. He says my stock A/R is 110 and the 460 turbo is 1.45 the 400 hp turbo is 1.25 A/R He said that some 427s' and 460's use this turbo but there are all kinds of S400 turbos out there. I feel that he is getting me the perfect size turbo to give it a modest power gains and still be quick to spool and safe and most importantly good fuel mileage. With the amount of fuel ive added with this S400 turbo i think its going to be the perfect setup. ( Now if i can just to grips with reality and realize my truck is never going to be air ride then ill be happy ) ( im sick of 44000 pound springs in winter lol)

Sorry to hear about all that, keep your head up and like the others said you have many good friends here to help.

Thanks for the link but this doesn't really answer my question. I was going to put a newer borg warner turbo that is fit for a mack 427/460 to my truck and was just wondering if it was safe. All this shows is that the compression is lower on the 427 and 454, but they also have electronic fuel injection right? I might just call borg warner about it. I m sure there have been others out there that have done much worse than me. Only thing is that i didn't do the typcial 350 mack to 427 mack conversion by just turning up the pump , putting in 427 injectors and a 427 turbo, I have a mechanical pump and i have 30 percent oversize injectors with the stock s300 turbo, also my exhaust is the stock 4 inch. Can more people with real world experience chime in on this please. So ive been reading further into it, I think the turbo i need is the borg warner S400S069 or S400S073. Anyone know the difference between the two?

I'm still needing some real answers here. I don't see why it would be a problem because im not adding some hotrod turbo. I am still going to be in the power range of 1200-1800 rpm

its a 95 with bosch mechanical pump. Fuel is not the issue as you can from my video. I just want a bigger turbo to benefit the extra fuel i am using. Truck runs great and never sees 850 on the pyrometer even in the summer on a hot day.

I guess i am still wondering the answer to this question. Would adding more air and pressure to my existing fuel setup be bad for the engine ( camshaft, pushrods,,etc) My piston numbers on the truck is the 240GC2250AM and timed at 11.5 degrees. My dad says that i will blow the engine because the camshaft is not designed for even the amount of boost i am currently pushing. Im confused.

I was talking about adding more fuel. I don't have a puff limiter on my setup, I have an aneroid which has also been tweaked by weakening the spring. The pistons that i have are two piece according to a source i have and the cradle is aluminum. It's the perfect setup to add more power to from what i hear.

These are all good answers so far. How in the heck did your truck last with the timing advanced and pyro at 1200? With my current setup it pulls perfect even at .25-.50 percent throttle and if i work it hard even in overdrive going up an incline for a minute straight my pyro never even sees 900 so i guess im happy with that. The guy that turned up my pump (BEFORE i had injectors) said that i still have a full turn of the screw to go. I don't blow that much smoke. Sure it comes out effortlessly but its like a gray color (Starts out with a tiny puff of black then goes gray) and only lasts a second or two then its gone. I have not messed with my pump at all since the bigger injectors but i just feel that the 427-460 turbo is really gonna complete the setup. I have 450k on the odometer today. I am working on ordering it now. I just hope that it doesnt blow a headgasket or blow something up but based on reading other peoples setups in here, i feel that i am not pushing it as hard as some others are.

Hey guys its been awhile since i have been on here. As some of you may know, i have a mack e7 350 mechanical engine with bigger injectors and a turned up pump. The truck is a lot faster than it was in stock form. I feel like the missing link to everything is that i am shoving a ton of fuel to spin a tiny turbo. The turbo i have is a Schwitzer S300 and according to specs its only supposed to see boost levels from 24-32 psi. I now get 30 psi by 1300 rpm which is great because the power is effortless now but i feel that i am maybe just wasting fuel. I have experimented with using half throttle all day and only taking it to 1500-1600 rpm on the higher gears but it didnt seem to really matter on fuel economy. It only makes sense to me that if i am already using a set amount of fuel based on injector size and amount pump is turned up, i would get a benefit to adding more air by getting a bigger turbo. I was told to get a borg warner 427-460 turbo and i would be happy. If i am already quicker than 427-460 hp mack then i think a bigger turbo would do the trick in fuel economy and more power. I have noticed that with having bigger injectors and a turned up pump that my pyrometer never goes over 750-800 so i know i am good there. Is there any risk in adding a bigger turbo if i already am using the fuel i am using? would it blow a head gasket? I would basically be just getting a bigger turbo that already comes on a mack. I guess what i am trying to say is that i dont see a problem making the turbo bigger when i already have the fuel required to spin the 427/460 turbo. Now if i wanted a bigger turbo and i had stock pump and stock injectors then i could see it being a bad thing but i feel that i am setup for a bigger turbo, boost levels are good, pyro is great so i say why not. What is the difference in a 350 mack and 427? I have bigger injectors than what come in a 427, i think the 427 has a larger turbo too. So if it already takes a set amount of fuel to spin that bigger turbo on a 427 and im already faster with a smaller turbo then it only makes sense. I was told i can get a borg warner turbo for 1600 and i would need a new oil return line and different intercooler pipe and thats it. Let me know what you all think Here is a video of how you can see i need a bigger turbo. I was going about 45-50mph one gear before overdrive. Prob 1300rpm to 1500 in this video.

44k rears are 10 inches thick and 38k are 7.5 inches. I forget what 34k are. Prob 5 inches.

Ok so i think i figured out the problem. Oh and bullhusk i have the pump that doesnt have washers. There is something called a lift supply pump. It is connected to the injection pump itself. If you have a faulty one you will notice longer starts and if you change your fuel filters you will have to keep giving it some pedal till it has enough to keep it going. So the symptoms i had were that under 1400 rpm i would get the boost gauge shaking a little bit trying to build boost, i got worse in higher gears. Well, today the problem went away on its own. Yep, i don't know how but it did, Truck is a joy to drive again from even 1100 rpm. I am guessing that air got trapped in the pump??? I know there is a check valve or something like that in it. Maybe someone can explain what the lift supply pump actually does cause i would like to order a replacement one.

The problem fixed itself today. Hear is what i think happened. There is something called a lift supply pump on the side of the bosch mechanical pump. If it is faulty you will notice longer starts in morning or when changing fuel filters you will have to give it some pedal to keep it running till its full enough. I believe there was air trapped in the pump somehow or something. Either way, all the fluttering of the boost gauge and the feeling of it missing are gone now. I get a smooth 32 pounds of boost by 1300 again. Long story short, I drove it fairly easy and had a ton of traffic and hills but kept speed at an average of 40-50 along with crawling speeds for traffic and still averaged 5.7. I shift to 1200 only in low gears and 15 in high gears. I try to build up boost and then hold it at 20-25 and i still walk away from other trucks lol. They dont know i have more bark in the dog if i want to too. I am happy with that I still think i need to order another lift supply pump though.

Keep them results coming guys. So today i had a TON of hills, and even some offroad work was involved but i still only used half throttle and let it get up to 25 pounds of boost at times on the long hills. 800 on the pyro was my was on a long climb. I even got it to hold steady at 600 while loading and cruising at 50. Still can't figure out why my boost gauge is fluttering under 1400 rpm while building boost at only partial throttle or full throttle. It sounds like a miss but i still build boost. It goes away after 1400 rpm. I do have a small exhaust leak just under the muffler and the pipe that connects to it. You don't think this could be causing the issue do you? I just changed the fuel filters and that didnt fix it. Anyways, back to the topic. I ended up going 277 miles and burned 50 gallons. The total is 5.54 which i am actually pleased with considering how many long climbs i had and the amount of offroading driving i did