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Discussion Starter #242
I've been toying with more code mods in the megasquirt ecu. I've changed the way the supercharger boost control works such that it is basically always on. I setup the supercharger boost to follow the throttle position. It's working great so far. It's almost like having a big NA engine because the boost level is nearly instantly targeted and reached. The servo is set back to full speed and the computer seems to love it. Datalogs shows the lag between commanded boost level and reached is only 200ms.

Megasquirt has many ways of doing traction control. It can reduce boost, retard timing, add fuel, whatever I want it to. So that'll be down the list of items to get working soon.
 

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Discussion Starter #249
Is it really that quiet? I expected it to be . . . whinier. LOL!
Ya, in an early test video on here it was noise from the gears that whined. I hadn't put anything but penetrating oil on the gears just to test. You can hear the supercharger but it's pretty quiet. So if you like supercharger whine just don't put oil in the gearbox!
 

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Discussion Starter #251
I found something quite interesting and upsetting. My wastegate has been leaking this whole time. Too weak of a spring caused it to not build boost or even reach its full potential. Even with the boost controller pressurizing the top port it wouldn't keep closed.

I suspected something was up so I capped off the wastegate flange and went for a drive. It was night and day difference on the turbo boost build. I found that the spring out of and old dead wastegate fit in there and was much stronger. It worked. However the spring was over compressed and didn't allow the valve to open much at all. The boost would come up to spring pressure and then shoot up after 6000 rpm.

Another wastegate is on the way with a 14psi spring. I'm sure it will keep closed like it should but I hope it isn't too much boost for low pressure settings. If all else fails, I have an idea to control the bottom port so there is no boost pressure trying to open it.

I may regret this. The supercharger/turbo transition is finally tuned in and I'm going to screw it all up.
 

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If your wastegate valve doesn't stay shut with boost in the top port, you probably have a leaky diaphragm. It's not uncommon for chinagates to be installed with the diaphragm pinched. If you put air in the top port, it should not leak out. If you put it in the bottom port, only a small amount should leak via the valve seal. If air from the bottom port leaks at the seal between the halves or thru the top port, it's likely the diaphragm.
 

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Discussion Starter #254
I think that"s half the fun :p
Yep!

If your wastegate valve doesn't stay shut with boost in the top port, you probably have a leaky diaphragm. It's not uncommon for chinagates to be installed with the diaphragm pinched. If you put air in the top port, it should not leak out. If you put it in the bottom port, only a small amount should leak via the valve seal. If air from the bottom port leaks at the seal between the halves or thru the top port, it's likely the diaphragm.
I didn't spot any problems with it taken apart but I got a new one anyways. I'll take it apart and check it before I use it.
 

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Discussion Starter #256
This new gate barely fit. I had to chop off cooling fins and mash the hood down to latch it. I should have gotten the same model I had before with a 10psi spring. I think that would work better for both fit and low boost tuning.

I did a bunch of tuning with the new wastegate today. Spring pressure alone is right on the edge of spinning the wheels in second gear. But I did get close loop boost working well on the turbo. The boost control to the supercharger was a bitch as usual but it's working well enough for now. There is more potential in it now that the wastegate works properly.
 

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Discussion Starter #259
All better now. Running great. I took it out for a beating (the best way to break in an engine) and it is doing it's thing. Also the engine is nice and quiet now, hmmm. I'm glad I did the bottom end because the rod bearings were shot. I think those were almost 4 years old and race bearings don't last like standards.

The shop touched up the valve seats and had to cut .005" on the damaged seat. No big deal.

New pistons, rings, pins, rod bearings, and valves.
 
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