pyro placement (not the usual question)

[iron_giant]

I've got an ARB turbo manifold that splits the exhaust into two chambers all the way to the turbo inlet. It is basically a T3 flange divided in two (I don't have camera or I'd take pictures). I know ideally the pyro is placed somewhere where the gases collect to get an overall temperature but that's obviously not going to work. Would you suggest tapping one of the chambers or going post turbo and getting a measurement there? I am a little nervous about tapping the turbo itself but I think I've seen that done as well.

Thanks as always

David

 

[cruiser_guy]

Personally, I'd tap one side and go with it.

 

[brownbear]

I'd tap the outlet of the turbo and use 200 degrees lower as a Max figure.

 

[bigbrowndog]

 

[iron_giant]

thank you much gentlemen. The manifold I have looks exactly like the one posted by BBB, only mine is a lot cleaner (note sarcasm). I have always preferred to go pre-turbo but in this case I am leaning toward going post turbo... or a dual pyro from an airplane company and a thermocouple in each chamber!!!!

 

[Jan-78FJ40]

thank you much gentlemen. The manifold I have looks exactly like the one posted by BBB, only mine is a lot cleaner (note sarcasm). I have always preferred to go pre-turbo but in this case I am leaning toward going post turbo... or a dual pyro from an airplane company and a thermocouple in each chamber!!!!

I agree with BBB. I could not easily tap pre turbo, and did not want to drill the turbo housing. So I went exactly like BBB, and it works just fine. the sensor is highly responsive in there, just subtract 200 and you'll be fine.
Mine never goes above 900 bnow, even on long pulls under full throttle. You will see how well it responds to fuel delivery changes. When I turn up the fuel a bit, I can easily go above 1000-so I adjusted it below that.

j

 

[Tapage]

why not tap for pyro sender the manifold . ? I thought the perfect place over the turbo flange ..

 

[bigbrowndog]

That was the fitting location supplied by "Safari" for this purpose and I thought their engineers knew well enough. The sender is located only a couple of inches from the turbo and responds immediately. I used a rattlecan of heatproof "castiron" paint to paint it some 12 months ago.cheers

 

[Tapage]

That was the fitting location supplied by "Safari" for this purpose and I thought their engineers knew well enough. The sender is located only a couple of inches from the turbo and responds immediately. I used a rattlecan of heatproof "castiron" paint to paint it some 12 months ago.cheers

you mean the place post turbo ... ?

Those " caps " con the manufold are for .?

 

[bigbrowndog]

Yes Safari placed the fitting for the turbo in the dump pipe that was supplied with the turbo.As it was secondhand and used, the screw out piece could not be undone so I ground it off and drilled it to size then welded the correct sized bush back in for the pyro sensor. As you can see it is less than 3 inches/75mm from the turbo outlet. cheers

 

[iron_giant]

Yes Safari placed the fitting for the turbo in the dump pipe that was supplied with the turbo.As it was secondhand and used, the screw out piece could not be undone so I ground it off and drilled it to size then welded the correct sized bush back in for the pyro sensor. As you can see it is less than 3 inches/75mm from the turbo outlet. cheers

I just did this exact thing. I drilled a hole in the outlet pipe and welded in a bung. My Safari manifold does not have those "caps" so this seemed the best option. I'll post up pics when it's all working proplerly- not that they will be any different than those above- but they will be mine

 

[bigbrowndog]

I just did this exact thing. I drilled a hole in the outlet pipe and welded in a bung. My Safari manifold does not have those "caps" so this seemed the best option. I'll post up pics when it's all working proplerly- not that they will be any different than those above- but they will be mine

Way to go Look forward to seeing the pica and I am quite sure you will not be disappointed.

 

[iron_giant]

Well,
Just got back from a long trip. I turned the fuel up a little and never went got any higher than 850 egt's (post), so 1050 actual temperature climbing a lot. The trouble is that I am still only getting 5 lbs. max boost. I get no boost at any RPM in neutral. In first I make about 1lb. at 3000 rpm. Second, 2lbs. at about 2800. In third I finally start making some boost at about 2000 rpm and about 4lbs. by 3000 rpms. Fourth and fifth are better, keeping about 3 lbs. at 2200 rpms under load, up to about 5lbs. at high rpms under load. I took the manifold in and had it flattened, new gaskets and hardware. I have the watsegate tightened all the way down to preload the spring. I had someone hold the wastegate door closed as I revved the motor and checked the boost but never got any- actually showed a vaccuum through the whole rom range. I am going to look for more leaks in the exhaust preturbo and go from there. I must say however, even at 3-5 lbs. I noticed a huge difference in power and overall driveability!

 

[cruiser_guy]

You will NEVER get boost if the engine isn't loaded. It can redline in neutral and you won't see any boost at all! You MUST load the engine either by pulling up a good hill or whatever you can do to load up the engine.

 

[iron_giant]

You will NEVER get boost if the engine isn't loaded. It can redline in neutral and you won't see any boost at all! You MUST load the engine either by pulling up a good hill or whatever you can do to load up the engine.

well that's good to know. I was under the impression that I would get a small but progressive amount amount of boost through the rpm range under no load. I really pushed it this evening and got between 6-7 pounds in third gear at 3200 rpms- 900 egt's. If I didn't know any better having bought the turbo used from another 2h owner, I'd say the turbo was spooling to late for the 2h. But its a safari unit so i'm sure the problem lies elsewhere. tomorrow I will try disconnecting the wastegate vacuum hose and plugging it to see if boost is being generated. If it is, that will help narrow things down.

 

[cruiser_guy]

You'll want to set the boost first and then once the boost is set you can adjust the fuel.
Do you have a long constant grade hill that you can use?
I find that my temps are a little higher at altitude.

 

[Tapage]

I thought you have enough fuel .. coz your EGT are right ..

My best bet .. you have bad head to manifold gaskets, exhaust to turbo gasket ( show me your flat surface in the exhaust manifold if you can ) or bad wategate ..

I need to adjust really hard ( with 100 PSI compresor to proper adjust the wategate spring ) to get some boost ..

Right now I'm in process ( machine shop ) to make a flange for exhaust manifold and replace my old ( diying sonner now with the turbo bakpressure generation ) head to gastket manifold ..

 

[iron_giant]

I had the manifold machined flat and am using all new gaskets and stainless steel hardware. If there is an exhaust leak, I think it is coming from a union piece that the old safari turbos used (not pictured above) It uses four allen nuts to mate to the manifold then bends downward about 45 degrees where the turbo is mounted. I was a bit tentative to remove the piece from the manifold thinking I might open a huge can of worms as I'd probably have to drill out the allen bolts. But, if that where its leaking then I'll drill them out and have the surfaces machined. Today I am going to plug the wategate to see what kind of boost I get.

 

[Jan-78FJ40]

I had the manifold machined flat and am using all new gaskets and stainless steel hardware. If there is an exhaust leak, I think it is coming from a union piece that the old safari turbos used (not pictured above) It uses four allen nuts to mate to the manifold then bends downward about 45 degrees where the turbo is mounted. I was a bit tentative to remove the piece from the manifold thinking I might open a huge can of worms as I'd probably have to drill out the allen bolts. But, if that where its leaking then I'll drill them out and have the surfaces machined. Today I am going to plug the wategate to see what kind of boost I get.

Hi David,
you would need an enormous leak to lose that much boost.

I get about 2 pounds in neutral at 3000rpm, 7 pounds in 1st, and 10 pounds in all other gears at 3000 under load.

Your egts are about right. however, the egts are not a constant function of fuel. if you have more boost, the egts will actually go down, since you have more movement.
try to adjust the fuel up a bit, and see what you get. do you get any smoke?

my guess would be that something in the governor/wastegate is not adjusted correctly.

what's the exhaust diameter/
cheers,
jan

 

[iron_giant]

Jan,
My feeling is that the wastegate is not working correctly as well. I have the adjustable lever all the way in to increase the preload of the spring. It feels very tight but who knows if "feel" is accurate at all. It could be that the wategate door is not sealing correctly. The needle on the boost gauge bounces quite a bit leading me to believe that air is escaping somewhere. I am currently running a short piece of 3" pipe for exhaust.