way to test wastegate?
 

is there a way to test factory external factory wastegates? my dad kicked the ---- out of mine and now im not sure if its ok, the actuator arm thing got bent a little

Re: way to test wastegate?
 

Hope you meant internal wastegate, anyways you can use a bicycle pump connected to the vac port of the wastegate, as soon as you apply enough pressure the actuator arm should move or pull out(if it's still good).

Re: way to test wastegate?
 

If you have a gas cyl(non flammible), you can set the regulator and see when it is opening too. I just took the CO2 off my HMT keggerator.
Erich

Re: way to test wastegate?
 

what a crappy dad.

matt

Re: way to test wastegate?
 

I used a hand pump & my fuel pressure regulator gauge. Hooked it all up to the actuator head and slowly pumped.

Re: way to test wastegate?
 

the vacum line on the bottom of the external wastegate goes to the carge pipes, but where does the vac line from the top of the wastegate go?

Re: way to test wastegate?
 

the bottom is usually left open unless running an EBC and the top runs to a vac source

Re: way to test wastegate?
 

ooh ic, where is the best place to get the vac source for the wastegate?

Re: way to test wastegate?
 

aright thanks guys. how you rig a bike pump to the vac fitting anyways?

Re: way to test wastegate?
 

hahahaha, i agree

Re: way to test wastegate?
 

With fuel line and vacuum line. It's not going to be that reliable/accurate. The best way to do it is with an air compressor and a regulator. Set it to less than 20 psi and guesstimate as the needle moves up.

Re: way to test wastegate?
 

Use an air compressor with a regulator.

1: Turn it to about 15psi (no factory one should be higher really)
2: Hook you WG to it
3: It should be wide open
4: Slowly turn down the regulator releaving pressure.
5: Watch both the WG and you Guage on the regulator
6: Once the WG starts to close find the sweet point where it just opens and just closes.
7: Look at the guage on the Regulator and that is what you WG is maxed PSI at.

You can do it in reverse increasing pressure also. Most Regulators are High PSI (Accurate from 10psi to 150psi) so You may want to use a lower guage. They re only 99cents at a surplus tool store.

Re: way to test wastegate?
 

I used a small airbrush pump to testa few today. IHI RHF55 VF39 (STI) starts at 8 psi and is completely extended at 14 psi. Then I tested my used Bullseye Power that I bought on eBay for $1.00. they retail for $100 but this one had a dent (superficial and was purely cosmetic) that opens at 18 psi and is completely stretched at 30 psi. I'll simply change the armature and be happy holding 18 psi all day.

Re: way to test wastegate?
 

remeber that exhaust gasses are pushing on these things, so im not too sure calculating this way is gonna be very accurate

Re: way to test wastegate?
 

Wrong. Boost pressure from the compressor is what is used for internal wastegates. PSI is PSI is PSI and 8 psi on a bike pump will still be 8 psi on a turbos compressor.

Re: way to test wastegate?
 

Yeah. Mine was off by a pound.

Re: way to test wastegate?
 

i guess its internal then? i was confused because its on the outside of the turbo, but ya its bolted directly to the compressor so...

Re: way to test wastegate?
 

Wait a minute. Are you talking about one of those arcaeic OE recirculating valves? If so there is a big difference between a recirculating valve/bov than a wastegate. Wastegates are found on the exhaust side and internally would mean that the flapper in integrated within the exhaust housing. Externals are mounted in the exhaust tract to stall the turbine.

One works with vacuum and the other works with pressure. Big difference,.

Re: way to test wastegate?
 

you misunderstood me sir...i know how an internal wg works, but what i was saying is not to forget that exhaust gasses are pushing on the flapper and that may skew your results when tesing via a pump, since that element is left out.

Re: way to test wastegate?
 

Fair enough, but that isn't the point. The wastegates actuation would/could be skewed while installed on the car. Using pressure to the wastegate while it's off is going to give you the most accurate account of when it actually opens, not the other way around.

Re: way to test wastegate?
 

ghettoturbo is right, its gonna change somewhat when you have 35psi of hot ass exhaust gas pushing on the wastegate flapper. Remember, exhaust manifold pressures can normally be 2.5 x the psi of boost you are running...

Re: way to test wastegate?
 

No ---- Sherlock. Nobody is arguing against that. The point isn't what the wastegate is doing while it's on the car. The most accurate way to see how/when your wastegate is opening is to remove it from the car and used pressurized air to visually see when it moves. This number is obviously going to be absolute when done this way. 8 psi is going to be 8 psi whether you use a bike pump or fish pump with a pressure gauge. You're right that 8 psi might be 6 psi when the wastegate is installed on the turbo and the car is moving. This can be from sheer force of the engine combined with boost pressure combined with heat combined with age of a tired wastegate spring. The easiest way to check when it's opening while installed on the car is to use two boost gauges, better yet two pressure sensors and install one at the compressor outlet to wastegate vacuum line, before the intercooler so pressure drop doesn't come into play, and to be absolutely sure, one at the manifold and watch the difference between all three gauges.

Figure out your manifold pressure and go from there. I had a car once that my manifoold showed somewhere around 35 psi, but the pressure ratio stayed the same acrossed the turbine with the stock exhaust or aftermarket. I added atmospheric pressure of around 15 psi (14.7 if you're a stickler) which gave me in the neghborhood of 50 psi of backpressure in the manifold.

Stock, I tested around my cat and got roughly 22 psi (which would be 7 plus 15) and a pressure ratio of about 2.25:1

Where it gets interesting is that in doing a turbo back, I took out 4.5 psi from the exhaust. Add atmospheric pressure back in 5 + 15 + 20 psi X 2.25 and I got 45 psi. Subtract atmospheric pressure and I now had 30.5 psi a drop of arounf 4.5 in the manifold....where it matters.

Do yourself a favor and make yourself a backpressure tester.

Re: way to test wastegate?
 

that is exactly the reason im open dp :P