Just reading that thread from Ed, why would you port the waste gate and who would do that?
Boost
- Thread starter mikey bean
- Start date
Any answers for this?
Boost surge. I had to do it on my 3071.
Ha ha 
Being lazy.
Techy bit from garrett, I expect others on the forum can explain the technicalities better than myself.
http://www.turbobygarrett.com/turbobygarrett/compressor_surge
In layman's terms, my 3071 .64a/r was responding too quickly when coming on boost generating more than it was meant to so the waster gate closes. Wastegate opens again as it realises it's over compensated, compressor overboosts again and wastegate closes.
End result is the GtiR sounds like a steam train when boosting until the amount of air the engine is consuming matches the amount the compressor is generating.
Moving the location of the boost pressure reading to the outlet of the compressor rather than the inlet manifold helps. It makes the measurement of the boost pressure more responsive so giving the wastegate more time to respond. Even now I've tried to get away from this but found it works better with my relatively basic PFC boost controller. As good practice on any car I would always try to minimise the hose length to the boost pressure sensor and from the manifold to the wastegate actuator.
Though this helped, the reason for the surge in my instance was the hole the wastegate lets air out of was too small so it couldn't respond fast enough. Porting the hole on the wastegate 1mm allows more air through so the wastegate doesn't have to open as far to compensate. I expect when it was surging the wastegate was moving from fully open to fully closed and back again constantly. Once ported it modulates as normal.
Porting involves taking the turbo off the car, taking the turbine housing off the turbo and giving it to your local Engineering shop. Porting cost me about £20 but you can imagine the hassle was significantly greater.
Being lazy.Techy bit from garrett, I expect others on the forum can explain the technicalities better than myself.
http://www.turbobygarrett.com/turbobygarrett/compressor_surge
In layman's terms, my 3071 .64a/r was responding too quickly when coming on boost generating more than it was meant to so the waster gate closes. Wastegate opens again as it realises it's over compensated, compressor overboosts again and wastegate closes.
End result is the GtiR sounds like a steam train when boosting until the amount of air the engine is consuming matches the amount the compressor is generating.
Moving the location of the boost pressure reading to the outlet of the compressor rather than the inlet manifold helps. It makes the measurement of the boost pressure more responsive so giving the wastegate more time to respond. Even now I've tried to get away from this but found it works better with my relatively basic PFC boost controller. As good practice on any car I would always try to minimise the hose length to the boost pressure sensor and from the manifold to the wastegate actuator.
Though this helped, the reason for the surge in my instance was the hole the wastegate lets air out of was too small so it couldn't respond fast enough. Porting the hole on the wastegate 1mm allows more air through so the wastegate doesn't have to open as far to compensate. I expect when it was surging the wastegate was moving from fully open to fully closed and back again constantly. Once ported it modulates as normal.
Porting involves taking the turbo off the car, taking the turbine housing off the turbo and giving it to your local Engineering shop. Porting cost me about £20 but you can imagine the hassle was significantly greater.
If you're porting the wastegate, would you recommend getting a port tapped into the compressor side to use as your boost source at the same time? - Seems to me it makes sense whilst it's out of the car, and you're less likely to get swarf in the turbo if it's on a bench.
My tap is a 50p part that fits into the silicon elbow before the intercooler. It's close enough. I only gave the turbine housing to the engineering shop. The rest stayed safely in my garage.
Hmm that's interesting.
I think we will be having a decent discussion before we start the finishing touches to my car :thumb:
On a lighter note, my turbo will be back next week!
I think we will be having a decent discussion before we start the finishing touches to my car :thumb:
On a lighter note, my turbo will be back next week!