Engine/Transmission (1998.5 - 2002) E-brake effect on EGT's?

[jmeehan]

While I was south on vacation I stopped by the Diesel Dynamics shop to talk trucks and buy my truck a TTPM.



I had planned on going with their stage II injectors in the future, but was advised that my turbo mount exhaust brake will cause to much of a rise in my EGT's.



What kind of temps are those of you running stage II or III injectors with an turbo mount E-brake seeing?



I love the Power Module, I got better then 20 m. p. g. on two tanks, and over 19 the rest of the time. I got a steady 18 m. p. g. before adding the box.

 

[bighammer]

Are you talking for warmup?



Not sure that injectors should make any difference otherwise. You aren't injecting any fuel when coasting with the brake on.

 

[jmeehan]

No, I think the theory is the brake causes some restriction in the exhaust while it's not applied.



I'm just curious how much restriction as measured in EGT's.

 

[emjay]

My Pac Brake will keep the pre-turbo EGT at about 500 to 600 degrees at idle on a mild day. As soon as you touch the accelerator, it opens up and has no effect on EGT. The butterfly valve and cavity is larger than the inlet and outlet to compensate for the presence of the open butterfly. Turn off the exhaust brake and it'll drop to 350-400 pretty quick at idle, somewhat longer if you're towing or pulling hard (goes without saying. )

 

[DEZLPWR]

Originally posted by 85CJ

While I was south on vacation I stopped by the Diesel Dynamics shop to talk trucks and buy my truck a TTPM.



I had planned on going with their stage II injectors in the future, but was advised that my turbo mount exhaust brake will cause to much of a rise in my EGT's.

Hmm... Diesel Dynamics told you that? That makes no sense whatsoever.....

 

[Ramboy]

I have had my Pac brake in for about 7 months and I don't notice any difference in EGT's whether towing or not.

 

[jmeehan]

DEZLPWR:

The man I was talking with said they prefer the US Gear Decelerater since it mounts further down the pipe and disrupts the flow less. It's also available in a 4".

This makes sense to me but I prefer the turbo mount for a variaty of reasons.

I know from veiwing others sigs here that others are running bigger injecters with turbo mount E-brakes, I'm just curious if anyone checked EGT's before and after mounting their brake.

DD may have also been assuming I wanted to build a high HP engine, where as I'm just trying to opitimize what Cummins already built.

I don't want to have to go to a bigger turbo and I would prefer to keep the stock exhaust for now. I'm not worried about the clutch since I'm planning on pulling the transmission myself to fix the third gear grind someday.

 

[Ram4Sam]

No difference on mine...

85, I didn't notice any change after installing my BD brake. I have towed up the same grade with my 5er both before and after the install of my brake. Egt's, power, etc. were the same as far as I could tell.



Sam

 

[Roger rodbolt]

If I remember correctly a stock Jacobs/Cummins/Mopar exhaust brake measures 2 3/8" diameter, in the elbow. Subtract the additional area from the shaft and valve and the restriction increases. Even though the elbow is short, it HAS to have an effect on a bombed engine. Several folks have made fun of Banks advertising a hp gain with their e-brake and the replacement elbow that they sell to improve flow without and e-brake. On a modified engine I don't doubt them, fuel, air in + air out=hp. I don't use Banks myself but just used this to make the point that DD did. If you can benefit from a 4" exhaust then don't restrict it upstream and expect egt reduction. I use a 4" BD inline e-brake and would change to 5" exhaust if I could get a 5" e-brake. HTH's Larry

 

[CFAR]

I think alot depends on the type of brake you have, some like bd and banks both tried to make sure they didn't take a stock elbow dimentions and add restriction (ie butterfly), I run a jake, i will try and let you know when I get my pyro hooked up this weekend. Then perhaps on 11/9/02 when I install my bully dog III's.



I screwed up by not completely researching my purchase, what I should have done was wait and buy a remote 4" brake.



Woody

 

[Steve St.Laurent]

I have a BD turbo mount brake on my truck (275 injectors and a hot custom Powermax3) and my EGT's didn't increase at all with the installation. I didn't/don't want a remote mount because I live in Michigan and they salt the roads so heavily here that a remote mount would be toast after one winter I'm afraid. My guess is that their reasoning behind telling you that is because of the ability to later upgrade turbos. I've been researching turbos for a couple of years because of this very problem. If you go with a turbo mount exhaust brake your stuck with an HX35 or an HX35 hybrid (Piers makes a modified HX35 and you can also get HX40's with an HX35 exhaust housing). JMHO

 

[Roger rodbolt]

Steve,



Did you measure your BD turbo mounted brake? What is the diameter of the housing and outlet? I know the PacBrake is larger then the Jacobs but havn't measured the hard mounted BD.

Larry

 

[MikeR]

I didn't have any egt diference either....

I had a certain power level before I ever installed the Jacobs I used to have. My egt's were the same before and after the brake install... hp was the same too. Then when I sold off the brake (for a future HX40 install) I still saw the same temps and everything.

This was with a set of stage 2's and a Powermax3 (as a matter of fact I also ran a set of supermentals with this brake installed, no problems).



-Mike

 

[Steve St.Laurent]

2. 4" at the inlet and 2. 9" at the outlet. Which is the exact same dimensions as the stock elbow that came off the truck that I have sitting here.

 

[Roger rodbolt]

That helps!

Thanks for the dimensions, Steve.

 

[roadranger]

I just put an E-brake on this past June.



Installing dealer called it a Pac Brake, but it says Jacobs on it



Dealer said Jacobs bought out Pac Brake



This brake has the wire connected to the ECM which delays e-brake application for about 2 seconds- thought this was a Jacobs feature



ANYWAY, I tow across the Rocky Mountains with a GCW of 18,000 running an EZ box on a HO with a BHAF and stock exhaust... ...

I see a 100 to 125 degree increase in EGT's pulling uphill hard ever since the e-brake install.



Think a 4 in exhaust will help???

 

[MUDDY]

Originally posted by Steve St. Laurent

I didn't/don't want a remote mount because I live in Michigan and they salt the roads so heavily here that a remote mount would be toast after one winter JMHO

could ya spray the heck out of it w/ wd40 and preserve it. i sold my pac and ordered a bd remote as i went to a pdr40. steves post has me worried now as i drive in mud often and wonder if mud will play heck w/ the brake, as well as the various substances they spray on the roads in the winter.



after havin an e-brake for the past few years im not enjoying going w/o one while i wait to get the bd from piers and install it.

 

[Ron Bissett]

Just a thought Some think that increase in pipe will in it self improve flow of exhaust gas from the engine . The turbo mount All have a small effect on the gas flow but it is almost nil . when gas comes out the manifold it is under pressure and will expand to the size of the brake or pipe and when restriction is in line the psi is increased to cause a increase of speed of the gas as the pipes increase in size gas will expand and slow the same thing happens with all fluids and gas is considered a fluid when comp rest all things considered the brakes restriction is all most nil moving to the larger down stream is not going to improve the movement of gas any more than a turbo mount , but if it increases the flow it will slow the flow do to increase in volume . Just a thought to stir things up . Ron in Louisville ky Putin on my flack jacket and Pot. :-{}

 

[Roger rodbolt]

Ron,

Okay, I know that a lot of guys say that size doesn't matter . If a short restriction doesn't affect flow then why the huge difference in drive pressure between housings on a HX35. Try a 12cm, 14cm, 16cm, 18cm, and 21cm. I have all of them and there is a linear change. LC

 

[jmeehan]

Speakin' of housings, I understand the bigger housings flow more hence lower EGT's but how much slower is the spool up? Would a bigger housing compensate for the E-brake?