Dodge Cummins Diesel Forum banner
1 - 12 of 12 Posts

·
Registered
Joined
·
221 Posts
Discussion Starter · #1 ·
Hand some questions concerning the intake elbow/horn on the factory 12v trucks and what people see in the real world. Been searching and havent found what I'm looking for.

I have moved my boost probe from the actual intake manifold (below the elbow) and above it (tapped the elbow). Saw 38psi below and 42psi above. EGT's WOT top gear converter locked will hit 1250 1300 in the hot weather. Towing I dont get into it enough to barley see 1000.

My question is this, will an intake elbow lower the boost difference (restriction)? Or does the intake heater grid need to be removed plus an elbow to really see any gains? Will this lower my boost pressure and EGT's? I could care less about HP.

How do other peoples trucks start without a grid heater in the cold (below 20)? All our 4/6bt equipment doesnt have heaters of any sort and they seem to start just fine.


I should add some background. I'm not new to the forum, had another name I cant access/use for the life of me.
The truck is a '95 ex cab long bed 2wd auto. Purchased the truck on a whim and its been great. Trans is REALLY stout, no idea what the previous owner(s) did. It has 350K and my observations indicate it has all the original pump, injectors etc. among other parts. The truck came from indiana originally. Mods are a BHAF, 4" mbrp with muffler and tail pipe, 3KGSK, no fuel plate. (Please no fuel plate discussions here.) Thing runs great, gets 17-22mpg consistent and tows 12K trailers with ease. I dont typically drive it hard as you can tell from my mpgs. I like a smooth running truck with a lot of tq. Any power guesses are welcomed. My guess was 300hp and 650-700ft lbs.

My plans are to advance my timing a little and an intake elbow with grid heater delete. J/W if the cummins forum experience could help. Thanks.
 

·
Registered
Joined
·
6,991 Posts
So your seeing a 4psi pressure drop measured across the opening or the "grid heater" possibly even factoring in the intake log. Basically there is restriction between the two points at which you are measuring. Removing the restriction will help.

Edit: may not necessarily help your situation though, when i said help, I meant it will help remove the pressure drop or flow loss
 

·
Premium Member
Joined
·
971 Posts
Going from grid heater and stock air horn to Twin Ram with no grid heater gave -2 HP on the Dynojet.
 

·
Registered
Joined
·
8 Posts
While the other cummins without the heater grid may start ok it would be easier on the motor if you kept it. It does add restriction but not that big of a deal. If you want to lower egt's without spending a lot of money I'd suggest shaving and reinstalling your fuel plate. I understand not wanting this topic to come up,(I don't run one either), it would be the cheapest. If you still don't want to run the plate tune the afc more, add more air and exhaust flow. You could probably drop it some just by sliding the afc back a little. Does your truck smoke pretty good or is your preboost tuned right?
 

·
Registered
Joined
·
221 Posts
Discussion Starter · #6 · (Edited)
Wish I could re-install the fuel plate to play with it. The previous owners took it out.

Under 10 psi it will roll a cloud but clears right up to zero smoke. Essentially you have to try to get it to smoke, it wont puff or roll a cloud unless your @ very low load situation and floor it.

The egt I feel is pretty safe considering how cleanly and well the truck runs, I was wondering if an intake elbow and grid heater delete would remove that restriction, lower boost & egt a tad and maybe help cruising mpgs.
 

·
Registered
Joined
·
8 Posts
In theory it would but remember gelled fuel isn't lubricating anything. Personally I like to play it safe, some people say 1600* is the high side but I don't even like 1400*. All up to preference.
 

·
Registered
Joined
·
8 Posts
Yes but it will heat the fuel in the pump before you start it resulting in non gelled fuel in the pump.
 
1 - 12 of 12 Posts
Top