External wastegate, what size

[hodge]

Any opinions on what size wastegate i should use.

I will be running a GT4276 turbo, 1600cc injectors and a veilside plenum.

 

Thanks

john

[Terminator]

Huge

[JamieP]

My little tial 44mm is doing just fine controlling the boost on my 76mm turbo.

[Miguel]

I ran a single HKS 50mm gate on my GT42-76RS with no problems. HTH:)

[Wez]

I run a HKS GT 60mm gate on mine but only have a little tiddly turbo

 

With wastegates I would always say fit the largest you can

[Chris Wilson]

Fitting FAR TOO big a wastegate can make boost control a bit jumpy, and tends to burn the valve and seat as they only ever open a fraction.

[hodge]

Think I'll go for a 44mm gate. It's Gina be hidden away so if a small gate will do fine then I'd rather have a small 1.

[MartinBattye]

Fitting FAR TOO big a wastegate can make boost control a bit jumpy, and tends to burn the valve and seat as they only ever open a fraction.

 

plus 1 on that..

 

although then you can get away with a smaller ex housing. then over gate it and have the best of both worlds.

Edited May 3, 2010 by MartinBattye
speeliingng (see edit history)

[hodge]

The turbo has a 1.28 A/R

[MartinBattye]

hope youll be revving it hard..!!

[Rinus]

Maybe some good info here??

 

Across the broad array of message boards we see a large amount of misinformation. Sadly this bad info can lead somebody into purchasing the wrong part. One common bit of internet hearsay is "The bigger the turbo the bigger the wastegate!" So is this fact or myth? This write-up may influence your next wastegate purchase.

 

Generally speaking running lower boost levels, requires a larger wastegate. The theory is more exhaust gas needs to diverted (wasted) away from the turbine wheel during low boost conditions. While running high boost levels, a majority of the exhaust needs to be directed into the turbine wheel to spool the turbocharger.

 

Example A: A GT42R turbocharger on a 1.6L engine would require a smaller wastegate because a majority of the exhaust flow from the engine would be required to spool the turbine wheel.

 

Example B: A GT25R on a 3.0L engine attempting to run low boost pressure would require a large wastegate because a majority of the exhaust flow needs to be diverted away from the turbine wheel to keep the turbo from boost creep or over boosting.

 

check;

http://www.fftec.com/WastegateSizing.html