pyro placement (not the usual question)

[Jan-78FJ40]

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.

agreed. wastegates are notorious for not working. In Michael's garage we tested 4 cheap ones consecutively recently, and none worked properly.

3 inch exhaust is perfect, it won't restrict.

jan

 

[cruiser_guy]

The needle on the boost gauge bounces quite a bit leading me to believe that air is escaping somewhere.

Does the needle bounce depending on throttle position? If so that is normal. As soon as you take your foot off the throttle the boost will drop. In my experience the wastegate is either stuck closed or stuck open and neither of those conditions would result in a "bouncy" needle but if it was stuck open it would not boost well.

 

[iron_giant]

I Took all of the inlet and outlet hoses off and re-attached them in case there was a leak there, and, per Jan, I turned the fuel up a quarter turn more... the results: egt's a little higher (950) but so is the boost I'm getting. I get a good 7-8 pounds under load at 3000 rpm's in 3rd, 4th and 5th gear, and about 5-7 in second and first. I'm happy with that as the motor has 330,000kms. on it. My major concern was that the majority of the boost was very high in the rpm range, so every time I up-shifted I was only getting 1-2 pounds of boost and the truck was gutless. I am now getting about about 3-4- a little better. I'll keep tinkering but the truck is way more driveable now- so coool. thanks for the help.

 

[iron_giant]

Does the needle bounce depending on throttle position? If so that is normal. As soon as you take your foot off the throttle the boost will drop. In my experience the wastegate is either stuck closed or stuck open and neither of those conditions would result in a "bouncy" needle but if it was stuck open it would not boost well.

The needle seemed to steady a lot as well. It was reaching about 5lbs and would begin fluttering and wouldn't make any more boost- it was if something wasn't holding the pressure and it was escaping. The wastegate door itself moves freely. The spring feels very taut.

 

[Tapage]

You must need to re-check your hole system for leaks .. in the head to exhaust and exhaust to turbo .. trust me you need to get all your boost around 2k rpm .. no more ..

If you need to rev up your engine up to 3 k you are killing your engine ..