Exhaust brake on twins ?

roachie

roachie

Taco Master
Joined
Nov 2, 2007
Messages
11,133
What are yall doin with twins and exhaust brakes?

Im thinking a 2nd gen OEM Jacobs brake between the 35 and the 471.

Or maybe a inline after the twins.

Not sure which route to go.

Thanks for some help:thankyou2:

(this is for the ford)
 
shoot - a prxb will stop that thing no matter what is behind it

but, pac brake does not have perfomance in mind

their 4" prxb is no wheres near 4" - and they dont make a 5

so you are pretty much stuck with the BD

it will work, and its huge so it will flow

don
 
Brake

I had the Pac brake 4" on my truck and loved it, but now that I have the twins I am putting a 5" in line Pac brake on next week.
 
think you could throw a tape measure across it and snap a pic?

when it shows up i mean

thanks, don
 
Ive heard the inline's arent as good as the turbo mounts because of their distance.

Anyone know it you can clock the Jacobs turbo mount model?
 
It would be pretty tuff to fit the turbo mounted brake between turbos, but if your custom building your twins, Im sure somehow they could fit. I had a jacobs before my twins and never even thought to try and make it work when I build my twins. You can clock it but the whole assembly will move together, maybe you can move the linkage like with some wastegates on clocked turbos?
 
Achillies said:
As soon as I get it installed I will post a picture. :Cheer:
Click to expand...

how are you gonna show us how small the i.d. is once its installed?

last i checked pac didnt have a 5" brake. they shipped their 4" with reducers. that may have changed. if not the 4" is not 4", it is smaller...
 
roachie said:
Ive heard the inline's arent as good as the turbo mounts because of their distance.
Click to expand...

think thats a wives tale. have had a few brakes. manuf and model is what determins how well they work

its kinda like "how much lag would you have if you mounted the turbo under the truck at the x-member?"

no more than if it were mounted on the ex housing
 
Exhaust Brake

The shop has the brake now, just waiting for the injector to return for the install at the same time. I was going to run to the shop today but got sidetracked. You bo have my interest up now and I am wondering the I/D size is. I will try to make it to the shop tomorrow and post a picture of the size tomorrow night. :Cheer:
 
pacvsbd4inch.jpg


thats a 44060 4" prxb from pac above

and a 4" BD below

rut ro
 
Pac does make a 5" inline! I believe it was one of Piers' projects while he was with them!
No first hand knowledge but as I understand it works very well!
 
i know of the project but last i heard it was still not avail to the public

hopefully that has changed

as much i as whinned they should send me one if it is

don

ps - pac told me that the other customers dont care about flow - just me...

lol

pps - i was also told that they couldnt make it (the 5") retard anywheres near as well as their 4"
 
Interesting, they make air operated brakes in 5".

On the inline working less than the turbo mount: The engine has to pump enough air to pressurize the piping between the valves and the brake. You have that between them to fill, plus the coushin effect of that amount of space.

But, thats just my theory.

Somebody got a pic of a 2nd gen exhaust brake?
 
Why does it have to be 5"? I doubt the people who actually have the airflow required to warrant a 5" will not be using an exhaust brake. I highly doubt many would notice a difference between a 4" and 5". $.02
 
White Knight said:
I highly doubt many would notice a difference between a 4" and 5". $.02
Click to expand...

if you spent a grand on a 4" brake and it showed up 3.5" bet you would be thrilled

its not like i went thru any lengths (or spent any money) to have my ex system 4" from the back of the turbo to the tip or anything...
 
No, probably not. However its still not likely that I would notice a large enough difference in performance to warrant causing a large fuss about. Sure the manufacturer would hear about my dislike but its not worth much more of my time.

Considering the original poster was asking about a hx35 over 471 I would not worry about the 3sqin area loss. If you were majorly concerned about it you could externally wastegate around it.

Does anyone have any experience with US Gear's brake? Maybe someone has looked into larger GVWR vehicles brake systems?



It seems that when the topic was previously discussed a number of members were able to incorporate brakes into their twin setups.
 
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White Knight said:
If you were majorly concerned about it you could externally wastegate around it.
Click to expand...

majorly concerned no

it is the smallest part of my ex tho

and its also the most expensive part

if you bypass the brake i dont think it will slow ya down much

lol
 
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