diesel guys

[woodsracer144]

ok, so i've got a 91 cummins motor in my f350 and im unsure about one thing...

does this motor need back pressure?

there was a 3.5 stainless exhaust right out the front of the rear tire. how ever, I want to put some larger exhaust. and try shorting it up some... I'd like to do a hood stack or something along those lines maybe.

[trick450r]

Usually anything with a turbo you dont really have to worry about it, your creating your own backpressure with the resistance of the hotside.

[bens250ex]

you dont need back pressure on it

[woodsracer144]

awesome!

whats the max size a 12V would use?

5? 6?

[motochamp250]

Most people say 4" will be plenty up well into high horsepower. But i know several who run 5". sounds nice and deep and who doesn't like that :blah:

[400exrider707]

As already said, turbo provides enough backpressure. Is this a competition truck or a daily driver? A hood stack is not a good idea on a daily driver, as it's extremely distracting, but still cool. 4" is more than enough for almost any application. 5" wont hurt though. You'r still only going to be 3.5" more than likely off of the turbo anyways I'd assume...

[KXRida]

Originally posted by 400exrider707
As already said, turbo provides enough backpressure. Is this a competition truck or a daily driver? A hood stack is not a good idea on a daily driver, as it's extremely distracting, but still cool. 4" is more than enough for almost any application. 5" wont hurt though. You'r still only going to be 3.5" more than likely off of the turbo anyways I'd assume...

Exactly, coming off the turbo at the most you'll be 4'' at the downpipe. I run a 4" turbo back on my f350 and it's plenty. 5'' gives you a deeper sound, that's about it.

[woodsracer144]

right now its a DD but i have V clamps from the turbo to the down pipe then from the DP to the rest of the exhaust, i took the rest the exhaust off and put a 90* elbow down just to try out the boost time and **** and it ran alot better all around. I dont like the exhaust right under the cab, it sounds cool but get very annoying going 65 down the Highway.

[woodsracer144]

right now its a DD but i have V clamps from the turbo to the down pipe then from the DP to the rest of the exhaust, i took the rest the exhaust off and put a 90* elbow down just to try out the boost time and **** and it ran alot better all around. I dont like the exhaust right under the cab, it sounds cool but get very annoying going 65 down the Highway.

[Johnny Minehan]

12V's sound good with 5" ;) Lets see some pics once you got it done, sounds good. Best body with best of the diesels powering it, cant go wrong:blah:

[BlaineKaiser450]

No you don't need any backpressure. I am running a 4 inch straigh pipe on my 93 12V and everything is fine. The turbo provides all of the back pressure you need

[woodsracer144]

I like the deep sound, a lot.. I have a vid on youtube I'll post later

[BlaineKaiser450]

2 of my cummins

<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/WrCy_TPHSr8" frameborder="0" allowfullscreen></iframe>

<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/Sg0sPfKtY6E" frameborder="0" allowfullscreen></iframe>

[bens250ex]

Originally posted by BlaineKaiser450
2 of my cummins

<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/WrCy_TPHSr8" frameborder="0" allowfullscreen></iframe>

<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/Sg0sPfKtY6E" frameborder="0" allowfullscreen></iframe>

how do you get away with that in cali? i thought you had to smog em?

[woodsracer144]

You must not have much motor work done do you? And a auto? I like the sound. The low grunt

[BlaineKaiser450]

Originally posted by bens250ex
how do you get away with that in cali? i thought you had to smog em? smog 98 and up, I can do anything I want to my truck and they can't do anything (for now :/)

Yeahh hardly any. I can't afford it because I'm 16 and all haha and yep its an auto! I'm fine with it because it should be able to take 400 hp with a torque converter and a shift kit so if I ever want to do more I'm okay

[woodsracer144]

first mods are gauges... best thing imo

[Ruby Soho]

You don't really need gauges until you start modifying really. A Trans temp would benefit either way but..

Open up the intake and exhaust first and go from there, depends how much money you want to waste just to make a 3/4 ton truck go faster than it should.

I got into the diesel thing too, but quickly turned back when I realized the cost of the parts. Good tuning is all I need with my truck. Trans upgrades when the time comes but other than that I'm set.. maybe some DIY mods but that's it.

[woodsracer144]

Originally posted by Ruby Soho
You don't really need gauges until you start modifying really. A Trans temp would benefit either way but..

Open up the intake and exhaust first and go from there, depends how much money you want to waste just to make a 3/4 ton truck go faster than it should.

I got into the diesel thing too, but quickly turned back when I realized the cost of the parts. Good tuning is all I need with my truck. Trans upgrades when the time comes but other than that I'm set.. maybe some DIY mods but that's it.

you can do that, but i personally like to have the gauges and then do the other mods, cause if you start to mod it and push it you may go over the limits and you not know it.

[BlaineKaiser450]

Yeah mines guaged and I did all the free mods to the pump and a 4 inch exhaust and a more open intake, but that's not much haha

[woodsracer144]

Id say a fuel pin as a good buy for ya. Denny t is good ****

[BakerRacing40]

:rolleyes: back pressure, ah overrated... if it were me I'd just unbolt the exhaust at the turbo outlet and not worry about it at all. :macho

[BlaineKaiser450]

Originally posted by woodsracer144
Id say a fuel pin as a good buy for ya. Denny t is good **** Or grind the stocker = cheaper

[woodsracer144]

I dont know how the hell you plan to re grind the stock cone when you dont have much room to work with, you might as well just take a piece of round stock to a local shop and have them make you one with the grind you want on it, thats what i did anyways...

[kyleschonert]

Originally posted by woodsracer144
ok, so i've got a 91 cummins motor in my f350 and im unsure about one thing...

does this motor need back pressure?

there was a 3.5 stainless exhaust right out the front of the rear tire. how ever, I want to put some larger exhaust. and try shorting it up some... I'd like to do a hood stack or something along those lines maybe.

Although hood stacks look BAD, I'm fairly certain they are illegal, at least in Illinois they are, but hey what isn't illegal in Illinois?

Please please PLEASE don't stack it in the bed. So overplayed and its not a Peterbuilt. And so unoriginal. lol

There was a 12V running around a neighboring town that had the exhaust built into the body work and ran out in front of the rear wheel and looked sick.

I'd like to do that to my Duramax but don't want to cut up the paneling anytime soon. lol

[woodsracer144]

so he has the exhaust coming out the qtr pannel?

I couldnt stack it in the box, its gay as **** to me now, all the dumb asses around me have theirs stacked like that,

[Ruby Soho]

dont be hatin on the stacks ;)

home made!


http://img830.imageshack.us/img830/8914/stacksa.jpg

[KXRida]

It's better pouring smoke out of a 5'' pipe all over the place than stacks. I always tell the guys around here with stacks that they have an extra seat for their boy friends.

[trick450r]

Since this is a cummins, I would deffinatly install a fuel pressure gauge immediatly, you dont need EGT or boost or really trans temp (assuming your running a good tranny cooler) untill you start modding.

[motochamp250]

the fuel pressure thing is a huge deal with the 98.5-02 24 valves b/c low or no fuel pressure can burn up the injection pump.. not as huge a deal on the 12 valvers and the common rails. albeit nice to know, but not as necessary as the 98-02's..

[buck440]

let's say you have a gen 2 cummins 12v. you have a air filter, laser cut delivery valves, pretty big injectors lol, over size injection lines and a phat ******* or a aroura 3k turbo, massive sum *****es.

how would it drive?
would it smoke?
if it was a daily driver could you actually drive it and if you wanted to race it could some nitrous spool it up?

[400exrider69]

a 2nd gen like that would suck on street driving it would probly bellow smoke out to 1700 rpm's when turbo lit

4 a 12v best ideal street set up is
slightly built tranny of your choice auto or manual
4gsk
hx 40 or s300 or desired
sdx 5x12's
fuel plate removed
afc set right
bhaf
that would be a decent powerful street truck

[KXRida]

Originally posted by buck440
let's say you have a gen 2 cummins 12v. you have a air filter, laser cut delivery valves, pretty big injectors lol, over size injection lines and a phat ******* or a aroura 3k turbo, massive sum *****es.

how would it drive?
would it smoke?
if it was a daily driver could you actually drive it and if you wanted to race it could some nitrous spool it up?

if you're running bigger injectors don't forget about the fuel delivery system, not to mention a built tranny.

Right now I'm at a stand still on my powerstroke until I stud it and build a tranny. Not sure if I want to go that route or not. If I do it'll be seeing bigger injectors, turbos, EGR delete, and an all new fuel system. Not a bad way to drop about 15K. My truck pours smoke until the turbos light. Under a load it's just as bad.

[400exrider707]

Originally posted by KXRida
if you're running bigger injectors don't forget about the fuel delivery system, not to mention a built tranny.

Right now I'm at a stand still on my powerstroke until I stud it and build a tranny. Not sure if I want to go that route or not. If I do it'll be seeing bigger injectors, turbos, EGR delete, and an all new fuel system. Not a bad way to drop about 15K. My truck pours smoke until the turbos light. Under a load it's just as bad.

Is this for a 6.4? Have you been keeping an eye on WOP's single turbo setup? Looks like it's gonna be a sweet alternative to guys running big tunes and wanting to get rid of their drive pressure issues. What tunes are you running now? Having issues with EGT's and drive pressure yet?

[woodsracer144]

Originally posted by KXRida
if you're running bigger injectors don't forget about the fuel delivery system, not to mention a built tranny.

Right now I'm at a stand still on my powerstroke until I stud it and build a tranny. Not sure if I want to go that route or not. If I do it'll be seeing bigger injectors, turbos, EGR delete, and an all new fuel system. Not a bad way to drop about 15K. My truck pours smoke until the turbos light. Under a load it's just as bad.

you have a 6.0?

[spanky101]

Originally posted by buck440
let's say you have a gen 2 cummins 12v. you have a air filter, laser cut delivery valves, pretty big injectors lol, over size injection lines and a phat ******* or a aroura 3k turbo, massive sum *****es.

how would it drive?
would it smoke?
if it was a daily driver could you actually drive it and if you wanted to race it could some nitrous spool it up?

Those are quite the different turbos there! haha But like someone else said, it would be pretty laggy and smokey. I would suggest running a s300 based turbo, modest injectors and other supporting modifications including transmission. I have a 12v that ill proboly run a 62mm turbo on mine or actually run twins for towing purposes.

[woodsracer144]

agreed^

[KXRida]

Originally posted by 400exrider707
Is this for a 6.4? Have you been keeping an eye on WOP's single turbo setup? Looks like it's gonna be a sweet alternative to guys running big tunes and wanting to get rid of their drive pressure issues. What tunes are you running now? Having issues with EGT's and drive pressure yet?

Yes for a 6.4. I've kinda looked at the WOP single turbo's but don't know if I'd want to drop the coin in them at the moment. Only EGT issues I have is under long WOT runs. Going to run a bigger cold side pipe with some bigger rails and see what that does. Right now I'm running a 310 tune.

[woodsracer144]

fuel question?

what are your thoughts about running used motor oil. filter it down to remove all inpuritys and crud.

[CJM]

Originally posted by woodsracer144
fuel question?

what are your thoughts about running used motor oil. filter it down to remove all inpuritys and crud.

When I used to tow we would take the used oil and just dump it in with the fuel. Never hurt the engines ever and we did it everytime we changed the oil-like every 10k.

[woodsracer144]

you filter it out?

[buck440]

i never headr of using motor oil for fuel, interesting.

[BlaineKaiser450]

Yeah you dont run it straight, but a little but when filtered can help lubricate everything

[woodsracer144]

I know there is a guy in PA that ran straight trans fluid. he had a pressure system that cleaned and filtered it out, started on diesel then switched over for highway use, he said you can use it in the city but it smokes alot from what im told.

[finsteratv]

so is the point to lubricate im guessing. when i was talking to a texas refinary co. guy at the annual logging convention he said with the new diesel being filtered so much and with the crap they add it has less lubricity?

[buck440]

that sounds correct. the diesel you get today is ultra low sulfur. sulfur helps lube the motor. my dad has a aluminum tool box but he put a custom fuel cell in it to hold off road fuel which is better for older trucks, (04 cummins) and tapes into it and runs off that.

[KXRida]

With the newer diesels running the low sulfur diesel its a little harder on the injector o rings as well. Running a good quality fuel additive is never a bad idea. I usually pick up a name brand additive and add it when I fill up.

[buck440]

from what i read they even cleaned up the the fuel additives. but it's better than nothing.

[kyleschonert]

Make sure IDOT doesn't catch him with that hidden fuel cell. Lol, that would be one hell of a fine if they caught him running off road diesel.

From what I've been told though, is off road and on road are the same, its just a different dye and its all for tax purposes.

[buck440]

depending where you get it, it has more sulfur in it which is better for older trucks and yah it's also red and tax free.