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DIY Exhaust brake
Posted: Mon Sep 19, 2005 9:21 am
by dani4JB1T
G`day all
any idea in how to build a mechanic exhaust brake ??,...i own a 2.8Td Rodeo with 2.5" exhaust pipe.
cheers
Posted: Mon Sep 19, 2005 10:50 pm
by murcod
A relation built one for his Patrol using the mechanism from a truck exhaust brake and a compressor to activate it. It's controlled via a switch he built into the gearstick knob.
The Patrol is a GQ 4.2 diesel with Safari turbo kit.
Re: DIY Exhaust brake
Posted: Mon Sep 19, 2005 10:54 pm
by Gribble
dani4JB1T wrote:G`day all
any idea in how to build a mechanic exhaust brake ??,...i own a 2.8Td Rodeo with 2.5" exhaust pipe.
cheers
Uhh, why?
If you really wanted to, get an exhaust brake of an NPR200 isuzu, they are around the 2.5 inch mark and run off the vaccum pump on the alternator. Then all you have to do is wire up the solenoids and some brake light switches to your clutch and accelerator.
It might be cheaper just to go through brake pads.

Posted: Mon Sep 19, 2005 11:12 pm
by BigMav
I've heard of it being done before but confused as to why the hell you would want to. Each to their own.
Posted: Mon Sep 19, 2005 11:52 pm
by bogged
weld a hinged flap on to the end of exhaust and a bit of wire running to it to block exhaust

Posted: Tue Sep 20, 2005 8:29 am
by ausyota
BigMav wrote:I've heard of it being done before but confused as to why the hell you would want to. Each to their own.
Exhaust brake would be great on steep decents.
Posted: Tue Sep 20, 2005 10:10 am
by chimpboy
ausyota wrote:BigMav wrote:I've heard of it being done before but confused as to why the hell you would want to. Each to their own.
Exhaust brake would be great on steep decents.
I was thinking the same thing...
Jason
Posted: Tue Sep 20, 2005 11:06 am
by bogged
Ask the REAL MEN DRIVE UTE crowd of wannabees, since none of em can drive real trucks, they do things like put stacks on a HQ, or Datto 1000 ute, their BOUND to have this gig on there next to the 239023098230948230948 clearance lights on a mightyboy.. wonder if they have seen the roadranger thread yet....
Posted: Tue Sep 20, 2005 12:03 pm
by J Top
One of the advantages of a big bore exh is to get heat out of the "Prone to Cracking" cylinder head. An exh restrictor will keep the heat in there.
J Top
Posted: Tue Sep 20, 2005 12:22 pm
by mkpatrol
It would be good if you were towing a trailer all day, not such a silly idea. The NPR one sounds like the go, I would just hook up a switch on the gearstick instead of stuffing around with pedal switching.
Posted: Tue Sep 20, 2005 3:34 pm
by dieseldude
Yeah for sure!
Coming back from Kogan on the weekend and heading down the Toowoomba range with a loaded Patrol and trailer full of motor bikes, I wish I had one!
Would save your brake pads something fierce!
There would be no reason why I wouldn't run one if they could be had easy enough!
Anyone got a good system sorted out?
what the
Posted: Tue Sep 20, 2005 5:44 pm
by LuxyBoy
How does it actually work?
Posted: Tue Sep 20, 2005 5:50 pm
by runnin4life
it works by flipping a little "butterfly" out which restricts the exaust gases and thats about all i know
im not 100% sure what effect it has on the engine all i can think is it gives more compression pressure cus the gas cant escape
but im no expert but does any one know of a mechanical one that is run from a cable or linkage of some type, it would make it alot easier you could use an old hand brake cable or sumthing or have a servo connected and control the servo from a switch
Posted: Tue Sep 20, 2005 11:22 pm
by bogged
there used to be ads in 4b mags for em, $1100 is why they never really took off!
Posted: Wed Sep 21, 2005 10:34 am
by Shadow
runnin4life wrote:it works by flipping a little "butterfly" out which restricts the exaust gases and thats about all i know
im not 100% sure what effect it has on the engine all i can think is it gives more compression pressure cus the gas cant escape
but im no expert but does any one know of a mechanical one that is run from a cable or linkage of some type, it would make it alot easier you could use an old hand brake cable or sumthing or have a servo connected and control the servo from a switch
id have thaught an electronic one is easier.
it will have the servo built into it already.
Posted: Wed Sep 21, 2005 2:11 pm
by rlaxton
It is a little more complicated than that I think. The goal of the exhaust brake is usually to maintain a specific pressure in the exhaust. When turned on, the butterfly closes until the desired pressure is reached then the butterfly reopens a little.. exactly like a big turbo wastegate really.
Not all engines are going to survive the stresses of having an exhaust brake fitted. I would say that anything that was optionally found in a mid sized truck would have the best chance so some of the Isuzu and Nissan 4.2L diesels would probably survive while the Nissan ZD30 or Toyota 2L would probably not.
Richard.
runnin4life wrote:it works by flipping a little "butterfly" out which restricts the exaust gases and thats about all i know
im not 100% sure what effect it has on the engine all i can think is it gives more compression pressure cus the gas cant escape
but im no expert but does any one know of a mechanical one that is run from a cable or linkage of some type, it would make it alot easier you could use an old hand brake cable or sumthing or have a servo connected and control the servo from a switch
Posted: Thu Sep 22, 2005 11:29 am
by CheesePony
Your best bet is to get a setup from an Isuzu and modify it. It's a fairly basic setup, sensor behind the accelerator, and i'm fairly sure it runs a servo at the butterfly itself.
Posted: Thu Sep 22, 2005 6:11 pm
by whoneedsbitumen
Exhuast brakes can also be fun...
3rd gear slowing down with the exhuast brake then u hit the accerlerator pedal hard and u'll get a big black cloud of soot out the side exiting pipe

..... fun for people standing on median strips
the thing we get up to in council trucks

Posted: Thu Sep 22, 2005 6:11 pm
by whoneedsbitumen
Exhuast brakes can also be fun...
3rd gear slowing down with the exhuast brake then u hit the accerlerator pedal hard and u'll get a big black cloud of soot out the side exiting pipe

..... fun for people standing on median strips
the thing we get up to in council trucks

Posted: Thu Sep 22, 2005 6:12 pm
by whoneedsbitumen
Exhuast brakes can also be fun...
3rd gear slowing down with the exhuast brake then u hit the accerlerator pedal hard and u'll get a big black cloud of soot out the side exiting pipe

..... fun for people standing on median strips
the things we get up to in council trucks

Posted: Thu Sep 22, 2005 6:13 pm
by whoneedsbitumen
how the hell did that happen
Posted: Fri Sep 23, 2005 7:50 am
by mkpatrol
whoneedsbitumen wrote:how the hell did that happen
You must have pressed the post button tree times thinking "jeex this thing is slow".
Posted: Fri Sep 23, 2005 8:24 am
by dani4JB1T
I agree with pick an Isuzu N series light truck and modify it. From my shop manual the 2.8 NKR has one, so that`s what i need.
I think this device could be a great help for fully loaded down hills oof road conditions at mountainous places like the one where i live.
cheers

Posted: Fri Sep 23, 2005 6:09 pm
by Rainbow Warrior
Anyone know if they would work on a petrol engine, I suspect the pressure build up would not be good if it got back to the carby, fuel injection might be ok. Then again you are just restricting the exhaust not blocking it completely.
Posted: Fri Sep 23, 2005 6:34 pm
by Vulcanised
regardless of the comments of some..... i think an exhaust brake would be a good investment off-road..... especially steep declines..... i often have to drive off-road in a 7 tonne Canter fire truck... and the exhaust brake works very well, even in a slightly higher gear than you would have chosen without it. Only a diesel specialist can reliably inform you of any engine problems because of it..... I would have one by now if it weren't for the cost...... maybe a call to a truck wrecker would be beneficial

Posted: Fri Sep 23, 2005 7:05 pm
by HJ60_HEATHUS
RoeDao wrote:regardless of the comments of some..... i think an exhaust brake would be a good investment off-road..... especially steep declines..... i often have to drive off-road in a 7 tonne Canter fire truck... and the exhaust brake works very well, even in a slightly higher gear than you would have chosen without it. Only a diesel specialist can reliably inform you of any engine problems because of it..... I would have one by now if it weren't for the cost...... maybe a call to a truck wrecker would be beneficial

obviously exhaust brakes off road would be usefull for a fire truck, but on an 1800kilo ute, i'd be sticking to low-low down hills, and keep a foot ready on the brake.
just imagine going down a 40 degree slope: your engine revs up, hits the rpm where the exhaust brake kicks in, the exhaust brakes will knock you right down to the rpm where it opens up again, and this will happen over and over (i'd give it once, maybe twice before you flip onto the roof)
Posted: Fri Sep 23, 2005 7:50 pm
by Vulcanised
auto exhaust brakes? hrrmmm i wasn't considering that..... i have never driven a truck, fire truck or otherwise where the exhaust brake cut in and out...... once activated.. it stays on until you touch the clutch or accelerator..... driving down a steep grade... even 40 degrees.... you can touch the accelerator every now and then to gain a bit of speed and let it engage again to slow you up...... i can't see it being any more dangerous than hitting the brakes just as your engine is about to bounce a valve from over revving..... i guess it would be ok if you have crawler gears, but not all of us can afford them unfortunately.