External Wastegate Plumbing

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AFR Tuning

Member +
This may have been covered, but if not then I thought I'd chuck it up. Had a few cars of late come for mapping with no wastegate plumbing.

An external wastegate has two input ports. The middle port must have pressure, ideally from the compressor housing. If there is no pressure to this port, you will overboost !

The top port is generally for boost control pressure, so with pressure applied here the wastegate wont open at spring pressure.

You can also raise boost by bleeding off pressure from the middle port, but you need pressure to middle of the wastegate to run wastegate boost levels :)
 
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shane01

Member +
AFR Tuning said:
This may have been covered, but if not then I thought I'd chuck it up. Had a few cars of late come for mapping with no wastegate plumbing.

An external wastegate has two input ports. The middle port must have pressure, ideally from the compressor housing. If there is no pressure to this port, you will overboost !

The top port is generally for boost control pressure, so with pressure applied here the wastegate wont open at spring pressure.

You can also raise boost by bleeding off pressure from the middle port, but you need pressure to middle of the wastegate to run wastegate boost levels :)
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i have a tail wastegate with it only the middle of the wastegate piped into the turbo housing, with a 10 psi spring which is just sneakin over to 12 psi and im hittin fuel cut?, would that be a wastegate fault or could i fix with a manual boost controller to keep levels stable?>
 
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glanza97

UNTRUSTED SELLER
shane01 said:
i have a tail wastegate with it only the middle of the wastegate piped into the turbo housing, with a 10 psi spring which is just sneakin over to 12 psi and im hittin fuel cut?, would that be a wastegate fault or could i fix with a manual boost controller to keep levels stable?>
Click to expand...

electronic boost controller you need not a manual
 
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shane01

Member +
glanza97 said:
electronic boost controller you need not a manual
Click to expand...

would it stop the over boostin? its iv experimented with changein the pipe sizes from the turbo to wastegate and the smaller size brings on the fuel cut more quicker and harder the bigger one delays it for longer.. im thinkin the wastegate could be over boostin for some reason.!

would anyone suggest what i could do?, i could buy a fcd and fuel regulator to keep up with the over boost or buy a diffrent wastegate or try an eletrionic boost controller.
. im gonna buy them all over time but i need something to buy this weekend to stop the fuel cut
 
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shane01

Member +
Texx

Texx

Super Moderator
shane01 said:
easy enought!, so im thinkin fcd fprr and a manual boost controller? would that stop the wastegate from boostin over springrates?
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Not really! If your over boosting then the wastegate probably isn't opening fully and would indicate a wastegate or boost pressure supply problem.

What colour is the spring in the wastegate?
 
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shane01

Member +
when i first had the wastegate the diafram was broke so i replaced that but it was a bastard puttin it back together and i think it was a yellow 10 psi spring.,
i did inbox you texx with abit more information.

also would any sort of leak or if the pipe was 2 small cause an issue?


cause cant make sense the smaller pipe makes me hit fuel cut faster then the one thats bigger.
 
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shane01

Member +
Texx said:
Not really! If your over boosting then the wastegate probably isn't opening fully and would indicate a wastegate or boost pressure supply problem.

What colour is the spring in the wastegate?
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its yellow mate?, what do you think is happenin?
 
Texx

Texx

Super Moderator
If it's definitely fitted with a yellow spring then I would say either the actuator is sticking, the diaphragm is leaking or there's a boost leak between the turbo compressor outlet and wastegate pressure port.

Did you tuck the edge of the diaphragm in before tightening the top bolts down?

The only way to know if the wastegate is operating properly is to remove it from the car and apply regulated air pressure to it. You need to check if it opens fully and how much air pressure it takes to open it fully. A mountain bike shock pump with a gauge should be accurate enough, however an air compressor with an adjustable regulator would be ideal.
 
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