Thread: Exhaust Brake for 3.9 Isuzu County

Originally Posted by 123rover50

So whats wrong with putting it on the brake light switch. Take foot off the loud pedal, cuts fuel, tap brake pedal enough to work EB via lights or push harder to work foot brakes as well. Thats why I have the other switch to turn it off if sitting at stop lights etc.

During the day I was out and thought about this.
1. You said in your earlier post 'As it is not used often enough when I want it, it is seized up and wont work. The butterfly rod seizes in the bush if not used often.' That intcates to me it anoying and you turn it off a lot. Not hassling just an observation. The idea is to use it as much as possable to say the brakes. I got it for long down hill runs, but use it heaps now.

2. I have a caravan and it would effect the way the electric brake controler works.(n can go into more detail if you want)

3. The other reason is protocol I may be wrong but I don't know of any vehicle that is wired as you have done. I know of either as I have it or through micro switches on the accelerator and clutch. On the coaster put it is also disabled at lower revs to. Don't know if it work’s through the computer or some other way. It works good but just don't ask me to fit it to complicated. So to me it good to have think wired so someone else can work it out. Eventually weather we like it or not most likey someone else it going to own you car and have to fix it or pay someone else to. You may on a trip and have no gear with you and have to explain how it works to a repairer.



4. Don't know if there are design rule implications with power other equipment off the brake circuit, bit like the answer above. But lot if illegal stuff is done but in a way its the normal thing that wins. But it all goes to crap when your insurance is involved.


It that enough ( can keep going if you want)looking forward to your reply.

Originally Posted by c.h.i.e.f

I had one on there before I turboed it (standard crappy exhaust) it is operated via a switch on the gearstick (being a leco I wasnt going out of my way to hook up micro switches under pedals etc that would mean using to many brain cells ) I found now that I hav a 3inch exhaust I need a butterfly with a 3inch I.D so that I do not restrict flow but problem is finding one tried heaps of wreckers even tried making one out of thick stainless but when tig welded it warped
could go and buy one of the fancy ones off the US racetruck sites but they cost $1200 look very nice though

Thought of making one but I didn't have all the control stuff. The one I got from the wrecker had two flanges that weld to the pipe, with 4 bolts that hold it all together.
If you like you can email me a picture or a drawing of what your idea was and I could machine it up. You have the contril stuff already. It would just be the actual valve butterfly bit and two flanges to weld on the 3" pipe you would need. I would see no reason who you could not hake the main body from mild steel.
landrovercounty@internode.on.net

jackaroo has exhauste restriction on the turbo and they call it fast warm up.they also have a butterfly on the intake to hold the turbo boost.
from memory it only works at bellow 0cel.and has a switch on the dash.it only works at idle.

4BD1T I fitted to 110 all had spring tension to clamp the exhaust as they are out of forklifts and trucks.

nissan has a throttle controlled to increase EGR and help with warm up.

isuzu,hino,mazda has the electric manifold heater.

with VE injector pumps they cut the return hose and this increases the ignition timming.they also have timing advace linkages.the cold climate nissan has a temp controlled valve in line or in the filter to hold hot fuel in the injector pump.

exhauste brake-only works at cut throttle and engaged clutch.good setups also cut out on neutral gear.you could fit a throttle plate in the air intake to help spoolup the turbo when the brake is aplied.

several engineers had comented on alloy cylinder head failures on turbo diesels.when driving along heavy load the air intake is hot.when you decelerate down hill the supper cool air stresses the intakes ports.add inter cooler it can almost freeze the valves.

Thanks Gavo. Its just that I dont use it around town so turn the main switch off. On a longer trip or with a load I turn it on and then the current in the brake light circuit operates the relay that opens the vac controller.
Same as using a trailer brake controller. It does not affect the operation of the braking system. Its simple, much the same as putting a manual switch on the gear knob I suppose.
I have to pull it to bits to free up the butterfly but all I need to do is use it more often.
I dont sell any of the trucks I build, thats why we live in the country and I still have the FC I rescued in Bougainville back in 1972.

thanks gavo i didnt think of machining one up thanks for the offer but ill save you time and machine it up myself.. i priced a 3" butterfly just by itself but it was $410 just for the butterfly and as previously mentioned about mild steel yes it could be used but it might not have as long life span as a cast iron or stainless one due to mild steel laminating due to heat and exhaust polutants but i will probably end up making it out of mild steel due to ease of manufacture

Chief,
If you machine it up our of MS, incorporate exhaust pipe clamp flanges each end (as opposed to weld on fittings) then get the butterfly unit thermo coated... like headers etc.

It would be small and postage cheap so you could send it anywhere for coating.

Hmmm, its got me thinking now! MS tube section. 316 butterfly and shaft. Maybe a sintered bronze bush for the shaft to run on.

Legalities aside, how complicated does the control system have to be.
Flap solenoid 'pressure can' running on brake vacuum. Activated ON by a primary switch (on steering column) activated OFF by switch on accelerator & clutch movement.

Maybe make the butterfly significantly less than full diameter of tube, would give some exhaust braking but not maximise back pressure if you were worried about that?

S

Originally Posted by roverrescue

Chief,
If you machine it up our of MS, incorporate exhaust pipe clamp flanges each end (as opposed to weld on fittings) then get the butterfly unit thermo coated... like headers etc.

It would be small and postage cheap so you could send it anywhere for coating.

Hmmm, its got me thinking now! MS tube section. 316 butterfly and shaft. Maybe a sintered bronze bush for the shaft to run on.

Legalities aside, how complicated does the control system have to be.
Flap solenoid 'pressure can' running on brake vacuum. Activated ON by a primary switch (on steering column) activated OFF by switch on accelerator & clutch movement.

Maybe make the butterfly significantly less than full diameter of tube, would give some exhaust braking but not maximise back pressure if you were worried about that?

S

I think that you have to have a means by which to adjust how much of an opening is left once fully engaged. You don't want to stall your motor on idle when in neutral.

that is also an option getting it coated never thought of that....i have thought of numerous ideas even getting a flap valve of some description that is not exhaust orientated and pull it apart and make bronze bushes for it.... i made a oval shaped flap out of some thick 316 stainless it looks sweet if i must say so myself as for stops to prevent flap closing all the way yes they usually have 2 tabs that go up beside the shaft and have 2 adjusting bolts that adjust the movement of the arm that connects to the actuator rod..only things im not sure on is the affect that the backpressure would have on my turbo seals but i cant really see it being a problem seeing as though exhaust brakes are on turboed trucks