Injector's or 4 " Exhaust

[ray1933]

I would like to help my milage but cannot afford both at this time.

What would do me the most good, Injector's or the 4 " Exhaust.

 

[MUDDY]

4 in exhaust to let out the heat the injectors you add later, will cause

 

[Koa Man]

Since you already got rid of the cat, I would go with injectors. 4 inch exhaust does nothing for your hp or EGT if you are only around 300hp or less.

 

[DBR]

I second Koa Man.

 

[sewman]

I agree w/them get the inj.

Bob

 

[Hammer]

Ray,,Its ultimately your choice,,If it was me I'd first tell you read Joe D's article on Air+Fuel=Power,,There is no advantage to a larger exhaust system as far as hp is concerned,Now with that said it will help egt's in the long run,,If your stock and want to help your fuel milage there are better ways to do that(i. e. =cam plate,better air intake,timing ect,ect),,Money spent on exhaust is not certainly lost money,but,for the meare 7 hp you gain you'll find there are better and more cost efficent ways to help your truck

 

[Cooker]

Why not a small fuel plate, say 230/605. I have heard many guys comment on how their mileage improved (after the initial horsepower shock) from the addition of a fuel plate.



Which injectors are you thinking. I went from 180's to 215's on my relatively stock truck and noticed no mileage gain or loss. It's about the same.



I agree, the 4" won't get you any mileage if your CAT ran away already.



JMHO,

Ryan

 

[Cummins Corvette]

I am going to have to dissagree with Cooker here. I don't want to start anything but all the plate does is LIMIT THE AMOUNT OF FUEL THAT THE PUMP WILL INJECT AT FULL THROTTLE. I see this all the time on this site. If you increase the amount of fuel that the pump can inject, what do you think will happen to your milage? Now if you don't ever go to full throttle, then the plate will have no effect at all. If you want more power, the plate is a very cost effective way to get it. As far as mods that will increase efficiency, I believe that there are very few. I don't tow much so I can't say much there, the only time I have was with a 21' TT and I got 10mpg @ 65mph. Get your timing advanced a little, and keep a clean paper filter in front of the turbo. These are the only things that helped milage on my truck. The increase was very little though and the rest of the mods I have brought it down overall. Drive conservatively and be happy with it. But if you want more power... ... ... ... ... ... ...

 

[HEYBOSS]

Originally posted by Ray

I would like to help my milage but cannot afford both at this time.

What would do me the most good, Injector's or the 4 " Exhaust.

What mileage are you getting now? I noticed from your sign that you have a 12 valver and 5spd, they usually get pretty good mpg.

4" exhaust sounds C L therefore your foot will be further in the go pedal and your mileage will drop Injectors won't do much I think, I'm not familiar with the older Cummins. Your mileage increase can be further enhanced by your driving habits more than mods made to your truck. There was a thread on this subject before, do a search on it. The guy that posted on it had some excellent tips on driving habits to increase mpg.

 

[HEYBOSS]

Originally posted by Hammer

Money spent on exhaust is not certainly lost money,but,for the meare 7 hp you gain you'll find there are better and more cost efficent ways to help your truck

A good coat of wax sure is an efficient way of increased HP

 

[Hammer]

Shine It BABY

I'd bet that HEYBOSS and I if we got the wax cans out and smoothed her over good can pick his milage up for sure,,Only thing is I'll bet he does not have a color keyed set of jackstands and a heated garage to keep it in after we were done,,He may even have to spend a little more for the expensive Oakley sunglasses to protect his eyes from the radiant shine it will have too... ...

 

[HEYBOSS]

Hammer

ROTFLMAO



You PA guys are too much.

 

[Forrest]

Plate

I 2nd you Cooker! The most bang for the buck for more fueling is a plate. The added bonus of the 230/605 is better mileage with the load! There have been many documented examples.



I'd have to say upgrade the injectors only after you've got the biggest plate you can for your setup. Of course, other pump mods may be needed to continue to supply fuel, but whatever size plate is cheaper & easier to install than injectors.



From the table on the link below, looks like the #5 is the largest plate for your setup & you may not need to change clutches @ that rating.



http://www.dieselpage.com/tstpk.htm



oooh yea, advance the timing!

 

[Cooker]

CAnderson



I'm not trying to argue here either, but so that Ray is not confused I think it is important to clarify a few things.



The plate does not only affect the WOT fueling, but fueling at all levels. If you look at the picture of the plates in this post it is easy to see: https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=23573&perpage=15&pagenumber=1



I'd just like to add a quote from one of Joe Donnelly's post. I think we all can trust Joe when he it talking 12v performance:

"The TST plate changes the shape of the torque curve. It adds more fuel in the mid range than at top end compared to the stock plate. This broadens the usable hp range. "



When I was green around here I spoke with Ted Janetty via email, another person I think we can all trust. I told him I wanted more HP (at the time not crazy HP )and I wanted to keep my fuel mileage the same or if it got better that would be great. He recommended a 230/605 plate. He went on to say that many of his clients are claiming better fuel mileage with this setup.



Like Forrest mentioned, "The added bonus of the 230/605 is better mileage with the load! There have been many documented examples. " I have read quite a bit on here about increased mileage w/o the load as well.



I know what you mean about that heavy foot, it sure is a killer for economy , BOMBed or not.

 

[Cummins Corvette]

Hey Cooker, no disrespect AT ALL, but from what I know about the p7100 pump the rack doesn't hit the plate until full throttle. The plate is what stops the rack. The curves and notches are what the piece that hits the rack follows in relation to rpm. As rpm increases the bit attached to the rack moves up the plate, but only at full throttle. How far the rack moves at full throttle changes as rpm goes up or down unless the plate was totally flat. For example, a #6 plate with the "nose" on the bottom gives much more fuel when the rpms go up enough to allow the bit on the rack to move up past that nose. Untill you give it full throttle, the rack never touches the plate. Now if you put in a plate that doesn't let the rack move much at all this will increase milage by decreasing the amount of fuel that the pump can inject. This would in effect make you keep your foot out of it. If you only have 40 hp available you can't really hammer it. Ya' all need to keep in mind that I don't know it all and could be wrong, but this is what I gathered form my conversations with Piers. I am not saying that he told me this either. I am just trying to tell everyone how I think (pretty sure though) it works. I hope that some guys that do know everything chime in to tell us which is right.

 

[ray1933]

Injectors or Exhaust

Allright guys, I have read all the replies so far and I'm not interested in more HP, have all that I need. Im just interested

in better mileage if that can be done. I do not want more smoke from either tires or exhaust.



If I drive 62 to 65 empty with no head wind I get 19 to 20 and with the camper on it is 15 to 17. Driving close to 70 empty it drops to 16 to 17 , loaded 12 to 15. I have had this truck since day one and the mileage has never vaired much from the above figures



I e-mailed Wheatland Diesel in Milton Freewater,OR and asked their opinion on this subject. Should hear from them tomorrow.



Then maybe, down deep inside me maybe I want to do some mods, so I can have big fancy signature block.

 

[Deezul1]

Ray

The 4" exhaust is primarily for EGT reduction and there is not a lot of HP benefit there. Check my sig, I get 17. 5 around town and 21-22 highway almost all the time and thats exactly what it got before mods but wasnt near as much fun to drive. I got the most power increase from the plate.

 

[Cummins Corvette]

Ya, you KNOW you want more power. What the heck is this "all the power you need" crap. You can be honest here.

 

[Cooker]

CAnderson,



Now I am very confused. I see what you are saying. This is not the way I have understood how these things work.

This just doesn't make since to me.



If it only affects WOT, why why would TST be able to make this statement (on their page explaining the fuel plates), "A few owners who tow heavy loads have reported the ability to tow in a higher gear, obtaining better fuel mileage. " I'm sure they are not WOT, especially if they are getting better mileage. I have heard of others, again as Forrest mentioned, that have gotten better mileage towing after the installation of a fuel plate. If the plate only affects WOT how can this be true?



You may be correct. Whether you are right or wrong, you have sure confused the hell out of me



I'm sure someone will chime in here an put my mind to rest.



-Ryan

 

[Cummins Corvette]

Perhaps more fuel at a lower rpm would be more efficient. I dunno. From the info I have I don't have a friggin clue how it could increase empty milage. When empty and driveng for milage the rack should never touch the plate and take it completely out of the equation. The claimed milage gains could be just another excuse to justify the cost to the wife mabey? I am single so once again I dunno. Like you I really hope someone that knows speaks up and explains how things work if I am wrong.