dds92780 Posted February 10, 2015 Share Posted February 10, 2015 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 thinkHere 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. Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/ Share on other sites More sharing options...
Yoos Brothers Construction Posted February 11, 2015 Share Posted February 11, 2015 I run a mechanical E7-350 that has bigger injectors, turned up pump and advanced the timing. My pyro was running 1200 degrees and had 35 lbs. of boost. Was told to put on a 427 460 turbo So I did. Best thing that ever happened to it. Now I get 45lbs. of boost and pyro never goes over 1000 degrees loaded heavy on a hot day and it blows the doors off of 460s without thinking about it. the turbo don't look much different than the stock one but it is a lot different. It really helps.Thanks, Josh Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278405 Share on other sites More sharing options...
Gmerrill0516 Posted February 11, 2015 Share Posted February 11, 2015 If the "bigger" turbo is capable of more pressure at a given condition than it would be driving in more air when you need it in theory. I'm not sure when things go BOOM. A lack of air should yield lots of black smoke or a rich condition. I wonder how the exhaust cleans up or if it does with the higher pressure unit. I also wonder if anyone has tried the alcohol/water injection systems like Snow Performance makes. They are not cheap ($1000) but drop EGT's and boost horsepower. I know they make systems for the small diesels with great success.Please keep us posted on mileage, EGT's and such. This is great stuff.Greg Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278409 Share on other sites More sharing options...
Yoos Brothers Construction Posted February 11, 2015 Share Posted February 11, 2015 Mine is a 1993 and has 24,000 hours on it and its just got over hauled for the first time. It still had original bearings and they still looked like new. Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278410 Share on other sites More sharing options...
theakerstwo Posted February 11, 2015 Share Posted February 11, 2015 I to have the 427 turbo on a E7 mechanical engine with stock fuel it would build 30 psi Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278411 Share on other sites More sharing options...
fullfuel01 Posted February 11, 2015 Share Posted February 11, 2015 Josh,Ever heard about your setup on a vmac fuel pump?How you haf the timing set if it's not top secret? Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278438 Share on other sites More sharing options...
Refined Trucker Posted February 11, 2015 Share Posted February 11, 2015 I have an etech 427 turbo that I would sell. It will need rebuilt it came off of my 01 CX last September at 530000k. I replaced with Rochester perf turbo. it didn't fail but it was original and I felt it was time. Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278448 Share on other sites More sharing options...
masterwelder Posted February 11, 2015 Share Posted February 11, 2015 My stock E-7 has always made 30psi or more, gauge is pegged at 30, may be making more. I would love to turn it up alittle. This thred is very infomative. Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278485 Share on other sites More sharing options...
dds92780 Posted February 11, 2015 Author Share Posted February 11, 2015 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. Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278512 Share on other sites More sharing options...
masterwelder Posted February 11, 2015 Share Posted February 11, 2015 The only thing I thought I read in another post was that the pistons were different depending on the horsepower of the engine. I wonder if that would contribute to blowing a head gasket if you add to much air? Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278544 Share on other sites More sharing options...
masterwelder Posted February 11, 2015 Share Posted February 11, 2015 Another question DDS, when you talk about your pump being turned up you say you've got another turn of the screw, on my E7 mechanical pump the only turn of the screw that I have is to adjust my puff limiter. To allow more fuel into my engine I have to undo the cover and slide the plate forward. Maybe I'm confused but are you talking about adjusting your puff limiter or adding more fuel to your motor? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278546 Share on other sites More sharing options...
dds92780 Posted February 12, 2015 Author Share Posted February 12, 2015 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. Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278555 Share on other sites More sharing options...
dds92780 Posted February 12, 2015 Author Share Posted February 12, 2015 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. Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278644 Share on other sites More sharing options...
farmer52 Posted February 12, 2015 Share Posted February 12, 2015 Camshaft is not affected by boost or power. The purpose of the camshaft is to time the opening and closing of the intake and exhaust valves. Speed is the enemy of the cam and pushrods. Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278647 Share on other sites More sharing options...
460P Posted February 12, 2015 Share Posted February 12, 2015 See what a 427 piston part number calls for. I will bet it is different. 400's and higher factory engines used a lower compression piston to allow room for more air. With that said if that is case you will be hard on head gaskets if you have your foot in the throttle alot. I know from experience. Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278655 Share on other sites More sharing options...
Dirtymilkman Posted February 12, 2015 Share Posted February 12, 2015 Turning the fuel up can absolutely be hard on the cam. On a lot of engines the cam has a extra lobe that opens the injector. As you increase fuel pressure it can put extra pressure on the lobe and wear them down. Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278659 Share on other sites More sharing options...
farmer52 Posted February 12, 2015 Share Posted February 12, 2015 Turning the fuel up can absolutely be hard on the cam. On a lot of engines the cam has a extra lobe that opens the injector. As you increase fuel pressure it can put extra pressure on the lobe and wear them down.True if you have a unit injector engine. The E7 mechanical has a fuel injection pump...fuel injection pump cam perhaps...engine cam no. 1 Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278661 Share on other sites More sharing options...
460P Posted February 12, 2015 Share Posted February 12, 2015 What year is this engine? Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278662 Share on other sites More sharing options...
dds92780 Posted February 12, 2015 Author Share Posted February 12, 2015 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. Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278673 Share on other sites More sharing options...
dds92780 Posted February 12, 2015 Author Share Posted February 12, 2015 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 Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278694 Share on other sites More sharing options...
460P Posted February 13, 2015 Share Posted February 13, 2015 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278711 Share on other sites More sharing options...
dds92780 Posted February 13, 2015 Author Share Posted February 13, 2015 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? Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278728 Share on other sites More sharing options...
farmer52 Posted February 13, 2015 Share Posted February 13, 2015 I would recommend installing a 5" exhaust system. Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278775 Share on other sites More sharing options...
460P Posted February 13, 2015 Share Posted February 13, 2015 This is a turbo for a 460 put on a turned up 350. It builds good bost but it blows head gaskets when i put the fuel to it. I have another truck that is turned up from a factory 400 (lower compression pistons) with smaller factory turbo blows more bost and doesn't blow head gaskets. Quote Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278794 Share on other sites More sharing options...
dds92780 Posted February 13, 2015 Author Share Posted February 13, 2015 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/RHe 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) Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/38870-e7-350-mechanical-is-it-time-for-a-bigger-turbo-experts-needed/#findComment-278819 Share on other sites More sharing options...
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