Dump pipe pyro install.

[mun60]

Hi All,

Ive read all the threads that i can find regarding the pro's and cons of pre or post turbo pyro installs. I have decided to install it in the cast iron dump mainly as i dont have the time to pull off the exhaust manifold to fit it pre turbo. Can anyone offer up some pics of where they installed the thermocouple in the dump and whether or not they where able to drill and tap the hole while the dump was still fitted to the car.

Not a lot of room in there, maybee with a right angle air drill!

Any help appreciated.

 

[ntsqd]

Post turbo is nowhere near as good as pre-turbo unless you're doing turbo development research. I recently drilled & tapped the manifold on my Cummins 6BT for the pyro's t-couple while on the truck. It's not a big deal if you have access. Mark and drill nearly all of the way thru on a cold engine. Then start the engine and finish the drilling and tapping. Move fast so that it's still warming up when you finish or things will start to get a little warm.....

The running engine puts exhaust gas pressure on the backside of the hole and blows all of the chips out of the hole. Be sure to wear at least safety glasses if not goggles and you may want some gloves as those bits sting a little.

 

[snowboardonsnow]

Hey thats a good idea ntsqd
x2 you want it pre turbo other wise there isnt much point.

 

[Tapage]

The running engine puts exhaust gas pressure on the backside of the hole and blows all of the chips out of the hole. Be sure to wear at least safety glasses if not goggles and you may want some gloves as those bits sting a little.

good idea / move ..

x2 you want it pre turbo other wise there isnt much point.

post turbo will give you an idea how are EGT's but IMOP that can't be used as closer measurement for tunning if that's you idea ..

If you install it post turbo, you should leave plenty ( reasonable ) room considering the EGT's drop cause turbo ..

 

[Tim-HJ61]

Be brave. Remove those covers and drill slightly off centre to avoid the internal webbing.
12H-T power boost | landcruiser | Tim Law

Use plenty of grease to capture the swarf, clean your drill and tap frequently. Your turbo is not a soft and fluffy thing, respect it, but don't fret about it.

Also as a suggestion, post queries about your 12HT into the diesel section.

Tim

Sent from my iPad using IH8MUD

 

[mun60]

That's what I was thinking and really only after a reference point on a totally stock daily driven family car/ 4x4 toe hog, only looking for a mild safe increase in power. I would have thought that as long as I keep them under say 450 deg c at the dump all should be fine. It will be interesting to see what the stock egt readings are back there. The other issue is that I have a dad that's a mechanic/ heavy diesel fitter that works on cats/ GMs/ detroits etc, so I am sort of obliged too listen to his advice on these things. After all it will be hopefully him that fixes this thing if it all goes wrong!

 

[Tim-HJ61]

So what's his advice??

From what I hear, the pro's all recommended post turbo because they reckon it is safer somehow.

And all the self builders recommend pre turbo because it is more accurate. I've never heard of a probe shearing off and ruining a turbo.

Tim

 

[ntsqd]

We did both when I worked in turbo development, but we had reasons for needing both. I've NEVER seen a thermo-couple tip fail that wasn't caused by something else hitting it first. Never.

Other than on misc. forums I've never seen a post turbo install suggestion. The data gathered post turbo isn't nearly as good. In our development work the EGT value was pre-turbo, post turbo was only there to see what the temperature drop across the turbo was, and after a while we kinda quit paying much attention to that data channel.

 

[mun60]

Dads advice is to just drive the truck and not touch it at all. However I bought this truck because I like turbo sixes and I want to play with it and increase my knowledge on these things. His knowledge was that on the cats in the loco's at work they where all in a bend just back from the turbo after an expansion joint. He said that they found some operators would get the engines under high load with not enough revs and the egts would go over 1000 deg c, engines would melt. These little trains pull 300 odd bins four 50-100 km, there not big trains at all. I take all your advice on board but I'm just not sure about drilling into that manifold while it's on the engine! I having enough issues finding the 1/4 not tap here!

 

[Sixty's Guy]

I'm certainly no expert, but the Denco turbo that I installed on my 2H comes with a drilled and tapped port for a EGT thermocouple in the dump pipe.

 

[ntsqd]

I'm certainly no expert, but the Denco turbo that I installed on my 2H comes with a drilled and tapped port for a EGT thermocouple in the dump pipe.

They don't supply the exhaust manifold, do they? If not then they choose the easy way out, makes their kit a total bolt-on. They didn't chose it for it's superiority of location.

If they did supply the manifold, then I'm mystified as to why they would do that.

 

[Sixty's Guy]

Yeh, the whole lot is a kit including the manifold. I'm pretty sure most of the kit manufacturers do this.

 

[mun60]

Anyhow, back on track, didn't really want the argument, I will move it to the manifold if I take it off in the future. Test drove it standard up a 1 km long hill flat in third and egt's got to 550 deg c on the VDO pyro in the cast dump, upped the boost to 10 psi, now I just get 500 deg c. I didn't think the stock reading back there would be that high ? Any thoughts, I know the exhaust is too small, no intercooler either etc.

 

[Simozed]

I mounted mine in the dump pipe also I see similar temps I can push mine to around 550 if going real hard putting a 3" exhaust from dump back will drop egts a bit and give you a bit more room to play with the injector pump and add some fuel. Get it breathing better and wind up the fuel !

 

[Sixty's Guy]

Some info here specific to the Denco system, but this is what mine gets.

http://www.dencodiesel.com/pdf/Fitting/Turbo/TOYOTA HJ60.pdf

 

[mun60]

Cheers for that, I will tune to keep it under 500 deg c.