tial 44mm wastegate how much power

[hodge]

does anyone know how much power 1 of these are good for.

cheers

john

[Chris Wilson]

Hmmm, you can't rate them on power, say you have a huge compressor housing being spun fast by a small turbine housing, in order to keep boost sane the WG needs to bypass a lot of gas, although BHP levels are modest. You would need a big WG for this. Take a turbo that is sized to have to be worked flat out to make the boost you need, the WG may never even open, or if it does it need flow little bypass exhaust, yet the engine is making big HP. You could run a tiny WG then. You need to ask a turbo expert for an opinion really, giving them all the details they ask for. There are very few REAL turbo experts the like of you and I can approach. Turbo rebuilders are often far from turbo sizing experts.

[hodge]

I'm looking for something around the 700 to 800 hp mark Chris. I'm running a GT42-76 turbo with a 1.28 A/R. I may be downsizing to a 1.01 A/R.

[johnny g]

An article I read said:

 

For purposes of this discussion we will reference two very popular wastegate sizes, 38mm and 44mm.

 

The purpose of a wastegate is to vent exhaust gas pressure away from the exhaust wheel of the turbo in order to control shaft speed. The more exhaust gas the wastegate vents, the slower the turbine wheel will spin.

 

For a turbocharged car that sees primarily street use, most people think the smaller 38mm wastegate would work best, and although it is not a bad choice, ultimately the 44mm would work better for most street applications. A street car will not be running the turbocharger at its peak efficiency all the time. Because of this, boost will be kept on the lower end of the turbo’s efficiency range. Since the boost will remain generally low, a larger volume of exhaust gas will need to be vented prior to the turbine exhaust wheel. That is why the 44mm wastegate would be a better choice for this application than the 38mm. It can more efficiently vent excess pressure from the system with the same valve lift as the 38mm.

 

If you were sizing a wastegate for a race application, a smaller wastegate would generally be a more efficient choice. In race applications, boost pressures are higher, so a turbo is more likely to be operating in its peak efficiency range for longer periods of time. That means you would want to keep more exhaust pressure going through the turbo, which means you are venting less exhaust gas. In this instance the 38mm wastegate, since it is smaller, will vent less gas and keep more pressure in the system to spin the turbo.

 

Hope that helps

[JamieP]

Im running somewhere between 850-890bhp with a single Tial 44mm WG, no boost problems, if you are worried Tial do a 60mm WG.

[hodge]

Interesting stuff cheers johnny.

[johnny g]

I had a 46mm on the MR2 with a 4094r

[hodge]

Im running somewhere between 850-890bhp with a single Tial 44mm WG, no boost problems, if you are worried Tial do a 60mm WG.

 

Not really worried Jamie I just don't want to have to buy another wastegate a little down the line.

Think I may give the 44mm a go.

[Chris Wilson]

If you are having to buy one I'd go for the 46 mm to have a bit of leeway. I would say a 60 mm one is OTT.

[hodge]

I wonder if Johnny might sell me his;)

[johnny g]

Mine is in some breakers yard mate!

[hodge]

I thought you would have stripped the car and made some cash back.

Where abouts is the car.

[johnny g]

I thought you would have stripped the car and made some cash back.

Where abouts is the car.

 

In Chesterfield at the moment - not had a chance to get it back... I will strip it though, probably at Woodsport

[hodge]

Keep me in mind buddy.