Engine/Transmission (1994 - 1998) 12 valve and he351

[Mhannink]

so i am in the middle of swapping out the he351 turbo off our 06 cummins for a s300, the stock turbo was leaking oil pretty bad and needed to be changed out. however i am looking at the he351 and wondering the possibilities of rebuilding and installing on my 97. im looking for opinions and information on ease of rebuilding, reliability, needed modifications for instalation, and how they perform on a moderatly fueled 12 valve.

 

[Nyoest]

There's plenty of info, I don't remember exactly where I just googled it. The YouTube videos I saw were enough that I bought a low mile Vgt for my 96.

Fleece has a controller for the overvalved trucks but nothing for the twelve valves. I asked them about upcoming support at their booth at Indy and I got a snide remark about it being " too old of a truck to really worry about". If that wasn't enough to **** me off later I found a video on their website testing a Vgt on a twelve valve.

I haven't had near enough time to think about the install yet but am looking very forward to it.

 

[Mhannink]

thanks i will look into it. as for the vgt i saw the fleece, vgt, 12v video. i think its something they are in the middle of testing i havent seen any info other than what you mentioned. maybe it'll pop up eventually, im not trying to defend them but they may have said that to keep others from thinking about doing it, industrial espienoge(sp?) sort of thing.



i dont know how the vgt works on the new cummins, however is it possible to set up a wastegate actuator to back the turbo off as boost builds.



another idea i have seen is a double action cylinder, one side had drive pressure the other boost. im not really sure the advantage of that but maybe that guy is smarter than i.



my only concern with boost or drive pressure controlled vgt would be drive pressure. its always going to want to defult to max spool and the drive pressure would always be high, that makes it hard on the engine. my solution to it would be suppling air pressure via my on board air system, but that doesnt work for everyone.



another thought just struck me though im not sure how to apply it, i think there might be something useful with it. what about using vacuum from the vacuum pump? maybe a spring loaded double acting cylinder the spring side vacuum the other boost. boost would actuate the piston to max flow the spring would push against that. then when your cruising you can flip a switch and draw the spring side under vacuum opening to max flow and dumping drive pressure.

 

[Mhannink]

so after doing some research i have decided that as good as the turbo might be on these trucks its too much fab work for me right now. and i am going to go about modifing my current turbo. so i now have an he351 turbo for sale. it was replaced cause it leaks oil and needs to be rebuilt, other than that it seems to run fine.



so now for some advice on my new plan. currently my truck has an hx35 with a 14cm2 non-wastegated housing. it runs ok but i want a little more bottom end. here are my thoughts, i want to find a 12cm2 wastegated housing, im not looking to buy since im sure there is a perfectly good one lying around someone's garage that i can have for cheap or even free. with this smaller housing i want to look at doing some flow work on the housing, wastegate area, and the manifold and turbine inlet. even if i cant do much i want to play with it. next i am going to install the pacbrake maxflow exhaust elbow, heavy duty wastegate, and the 60mm inducer compressor wheel. the only thing i am wondering is would the 6 blade or the 8 blade be better for me? mods are ddp stg 1 fass 95, fuel cooler, draw straw, tork tek overflow valve, #10 plate slid forward, light afc spring set loose, hamilton big stick cam, fully insulated exhaust manifold and turbo housing, afe drop in air filter, afe torque tube, and turbo air guide, i have a full 4in exhaust minus the turbo outlet and elbow, and the timing is about 18 degrees. currently i am able to control my egts very well, but it can get hot if i push it hard enough. my goal with the mods is to flow more cold air on the compressor side, and get the exhaust out the back a little faster, i am nervous about putting a bigger wheel on the compressor as the shaft is not all that strong to begin with. the truck is a daily driver and when i do tow its heavy but i currently can manage egts while still passing trucks on the grades. i am looking for more low end response since that is mostly where i drive at, between 1200 and 2000 on acceleration and 2200 cruise, i am pretty happy with it currently but i am thinking it could be better, all without spending thousands on a new turbo.



so to restate my main question, which comp. wheel would be better, the 60mm 6 blade or the 60mm 8 blade? i do want to hear others opinions and ideas about my thoughts.

 

[Nyoest]

I can't make a comment on the wheels but have you thought about methanol injection? It seems to be a nice kick in the arse for most trucks and helps a ton on smoke.

As too the Vgt I plan on a mech setup that is springloaded close with boost to open. It will take some fiddling with to get perfect but I can stand that. I figure if I use a high idle plunger like off an old idi 7. 3 as a "stop" I'll be able to have exhaust brake as well.

 

[Mhannink]

I can't make a comment on the wheels but have you thought about methanol injection? It seems to be a nice kick in the arse for most trucks and helps a ton on smoke.



As too the Vgt I plan on a mech setup that is springloaded close with boost to open. It will take some fiddling with to get perfect but I can stand that. I figure if I use a high idle plunger like off an old idi 7. 3 as a "stop" I'll be able to have exhaust brake as well.

personally im against water/meth, propane, and nitrous. i have enough to maintain on one truck besides making sure those things are full and ready for use when needed. the smoke isnt really a problem, with all my mods i will smoke a little on the bottom end but its not heavy and clears up pretty quick, though the mods i want to do are also aimed at reducing that some. i do like big black clouds, but i dont use it like i used to and its just wasted fuel. my new mind set is to get the engine to lean out as much as possible. that means as much air flow as possible.



thats what i was thinking about too on the vgt, hence the wastegate actuator. i am wondering though wouldnt drive pressure spike like crazy when you let off to shift of coast? it would automatically engage the "exhaust brake" function as soon as you let off the throttle.



what about opening the turbo off of drive pressure, as the engine revs the drive pressure will rise, opening the turbo for more flow. i know there is still a problem here and i need more time to figure out what i am thinking. ill get back to you on my thoughts, hopefully your finding this helpful not just annoying.

 

[KBurgoyne]

the newer turbo will have an electronic wastewate, but if you want it can be plugged for 40 bucks. the he351 has a tiny exhaust housing, like a 9 or so. egts would get spicy after about 350, but it will spool instantly. sorry dont know about the blades. heres a link to a rebuild with picktures.

Holset HX35 Rebuild with Pics! - Dodge Cummins Diesel Forum

 

[Nyoest]

Nobody likes meth until they use it.

All your questions are likely answered in this thread: HE351VE on a 12 valve - Competition Diesel. Com - Bringing The BEST Together

That feller eventually did a compound setup that looks really nice.

 

[Mhannink]

yeah i read that thread along with some others, i have decided that while i could rebuild the turbo no problem, it is going to take a lot of work to get installed, right now the money can be better spent on other parts of the truck and other trucks we own, not to mention i have been busy as all get out, and simply dont have time for a project like that.



im now leaning towards the hx35/40 hybrid with my own twist. i think between that and the other mods i have i can push almost 400 and still be ok on the egts.



kburgoyne, the housing is 9cm but my understanding is the new technology on turbos it can be that small and keep the egts in check.

 

[Nyoest]

Keep us informed! Inquiring minds want to know.

 

[KBurgoyne]

a super b would cost a little less than a new hx35/40 new. as for the 9cm housing being able to work because of new technology, the point of a 12valve is that you dont need to rely on technology. a 12v specific turbo work better, and be much easier to put in. what is your budget aproximately.

 

[Mhannink]

when i say new technology, im not talking about computers, the new housings from what i hear, and the performance numbers seem to back it up, flow a lot more then the 12cm housings of the hx35. is it true? i dont know, but the guys that have put them on their trucks show some real improvments across the board, so it could be possible.



as for budget, im thinking about 6 to 700 bucks, gillet diesel has all the parts i need minus the exhaust elbow. if i can find the exhaust housing that i want thats 500 or so off, the total price and puts me in the range i like. i think i had it roughed out to about 610 or so.



so far the parts list is as follows 12cm2 w. g. turbine housing 525, gds high spring rate w. g. actuator 100, hx upgrade compressor and housing 275, gasket and seal kit 7, pacbrake max flow dodge elbow 231. 25, boost elbow 25. total is 1164 minus 525 for housing (i know i can get one free or at least cheap) total is 639, call it 650 with shipping and small extras for final install.



i think this will provide the spool i want on the low end, with the cooling ability for higher h. p. im thinking that with the 4in outlet right at the turbo the extra room for expansion will provide a greater tempurature change across the turbo and that will drive it up better. also the whole thing wastegate too can flow better and is less restrictive increasing air speed increasing spool and lowering egts. on the cold side the bigger wheel will push more air through a wider range keeping intake temps down and there by lowering egts while increasing power. what i keep tossing back and forth is whether the 6 blade wheel is better or the 8 blade. i tend to think that more is better but thats not always true.



part of my reasons for this besides the already mentioned desire for better mileage/power, is i dont have the funds for a new s300, turbonetics, garret, or some other high end turbo. 700 i can swing, 1400 plus i cant. i also kind of like the thought of being able to get the "stock" (i. e. modded but stock base) turbo to produce 400 h. p. without pushing the bitter edge of the turbo's reliability. this last reason is why im concerned about the heavier compressor wheel.

 

[Vaughn MacKenzie]

Going to put in my two cents if it's helpful at all, I had both a VGT turbo then a HE351 (off an '06) on my 2001 auto. Between the two I liked the HE351 (the non VGT turbo) much better. It drove better and felt more efficient, it felt like it was breathing quite a bit better and didn't have the often "corked up" sensation the VGT caused.

Yes the HE351 has a small exhaust housing but with the large wastegate I don't think drive pressure is that bad. And it can be reamed out quite a bit larger. I had 75hp injectors (I was close to 300hp to the ground) and EGTs were no problem (maxed out at about 1150 preturbo). With the 60mm compressor it is a considerable improvement over any stock 2nd gen turbo. I would say it could handle up to 350hp pretty well, great selection for the mildly bombed.

Installing one on a 2nd Gen means you have to clock it which renders the wastegate control useless, I used a tab bolted onto a drain bolt and hooked a brake spring on it. Presto worked perfect, spooled great and limited boost to about 30-32psi. I was pretty happy with this turbo on my '01, drivability overall was quite improved over the stock HY35 and the VGT setup with Fleece Controller.

Vaughn

 

[Mhannink]

Going to put in my two cents if it's helpful at all, I had both a VGT turbo then a HE351 (off an '06) on my 2001 auto. Between the two I liked the HE351 (the non VGT turbo) much better. It drove better and felt more efficient, it felt like it was breathing quite a bit better and didn't have the often "corked up" sensation the VGT caused.



Yes the HE351 has a small exhaust housing but with the large wastegate I don't think drive pressure is that bad. And it can be reamed out quite a bit larger. I had 75hp injectors (I was close to 300hp to the ground) and EGTs were no problem (maxed out at about 1150 preturbo). With the 60mm compressor it is a considerable improvement over any stock 2nd gen turbo. I would say it could handle up to 350hp pretty well, great selection for the mildly bombed.



Installing one on a 2nd Gen means you have to clock it which renders the wastegate control useless, I used a tab bolted onto a drain bolt and hooked a brake spring on it. Presto worked perfect, spooled great and limited boost to about 30-32psi. I was pretty happy with this turbo on my '01, drivability overall was quite improved over the stock HY35 and the VGT setup with Fleece Controller.



Vaughn

so your wastegate was opened by drive pressure? im no sure im totaly ok with that. i really like have the consistency of boost pressure controling it.



i do like the way it seems to run, accoring to those who have one.



im really leaning towards, my idea of the 35/40 hybrid, would it not be about equivelent to the he351? how does the 351 spool on the bottom end?

 

[Vaughn MacKenzie]

Yes by drive pressure, worked A-OK for me, couldn't tell there was any drawbacks to it. The main pain was hooking plumbing it to the intercooler, and I had to get a special flange from Source Automotive and "blank" downpipe to weld it to since it's an oddball outlet. Here's a post I made about it with link to pictures HE351 Installed - BOMBER Board

 

[Mhannink]

the more i read about it the more im thinking this is something for me to do much later down the road. i just dont have time for all the fabrication, and the related adjustments and fine tuning. between school, homework, catching up on 300k combined miles of poor maintenece, dealing with horses, customers, and interpersonal relationships i cant be worrying about my truck needing adjustments and tuning. i want a turbo i can bolt on and it works no adjusting, no tuning.

 

[Mhannink]

i read your post. have to say it looks good, nice clean setup. still thinking its not for me. im looking at about 650 675 to mod my turbo exactly as i want. which is what your post said you have into this one. i really appreciate your input however i think i am going to stick with the 35/40 hybrid.