Testing wastegate opening pressures

[Holden202T]

I'm trying to improve my brothers race car, it barely makes any boost on the start line, i believe mostly due to the converter being too small, but i had a thought about if your making 2psi on the start line, does this also partially crack the wastegate (12psi max boost setting at the moment) or does the wastegate only crack at say 5 or 10 psi ....

my theory is that if it is slightly opening, even if just a small amount, then using a boost controller to pump the same 2psi onto the diaphragm to hold it shut should mean it can make more boost pressure at the same rpms..... and even if we only get another 1-2psi its more than currently.

so my plan to see how this works is roughly as follows, this also serves as some R&D for me setting up my boost control later (im using my wastegate for this test).

i cut my wastegate off the manifold as its easy enough to weld back on and its a straight section.

the below picture wasn't cropped cause then someone would whinge about the lack of reference

The fitting in the side will be for map sensor, and i'll probably use it later on to fit a manifold pressure sensor for monitoring manifold boost pressure, and i plan to weld a plate on the end to get pressure for the wastegate and also feed in pressure from air compressor etc.

i'll then use my FX wiring loom to power up the ecu, connect map sensor and boost solenoid and do some testing.

[delcowizzid]

Depends on pressure in the manifold pre turbo out 7psi spring used to start opening at 12psi even though we had boost set at 18psi our electronic controller has boost on to the top to stop that hehe

[delcowizzid]

We did it the most scientific way we could hand over the 3 inch long screamer pipe and load it up until it burnt our hand and shout yep so the driver could watch the boost gauge lol

[Holden202T]

hahahah thats about as rural as it gets!

yeah and thats my plan, i have a wastegate with ports on top and bottom, the solenoid should direct that pressure to the top side to hold it closed.

i guess its hard to work out what pressure is in the inlet manifold compared to the exhaust but if we assume its going to be higher than the boost, and we know what exhaust manifold pressure opens the gate etc we can at least say that at least its not bleeding that earlier.

i guess as well, it might be the BOV needs tightening too ....

[HQ355]

Nice stubby holder

[Holden202T]

yeah got a few top fuel shirts and stubbie coolers over the years

[immortality]

Turbo Joda was talking about this I believe in one of the episodes of the Bedford van on the Skid Factory. They added an extra solenoid to control pressure on both sides of the waste gate to get better control.

[Gareth]

The fitting in the side will be for map sensor, and i'll probably use it later on to fit a manifold pressure sensor for monitoring manifold boost pressure, and i plan to weld a plate on the end to get pressure for the wastegate and also feed in pressure from air compressor etc.

What do you intend to use to log with? Wired to an aux. of the 808 or something else?

I'm very interested in learning more about boost control (never had the experience with modified turbo systems) I have a pretty built VL turbo with an external gate and eboost controller. It's never been tuned or setup properly, boost control is shite at best, I'd love to make use of the gear controlled boost to make it more drivable. It also doesn't make boost on launch.

[Holden202T]

logging will more than likely be with vl400 data logger .... but you could use 808 input for it there just arn't as many!

the bedford videos is what gave me the idea of using solenoid to try and get more from the brothers car on the start line!

got a bit of time to tinker tonight, this is the outcome.... frankenwastegate!

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20180816_193956_1534414467606_resized.jpg (160.59 KiB) Viewed 5396 times

[Holden202T]

initial testing all good, now to connect up delco and stuff.

[youtube]https://www.youtube.com/watch?v=AWQZ2cRxC64[/youtube]