ok i did some searching on porting and clipping a turbo and only found help about porting it. i know porting allows for more airflow so what does clipping a turbo do?

I would also be interested in the process, and performance gains. The only thing I saw it would help on is boost creep. How many of you guys experience this?

Clipping is done to the turbine wheel. The idea is that the fins are clipped to allow more exhaust gas flow. What does this do? It allows more exhaust gas to pass through the turbine - at the cost of a higher boost threshold. Most people will call this "more lag", but lag is different then threshold. The boost threshold is the RPM at which the turbo can attain maximum boost. Turbo lag is the time it take to achieve full boost from 0 boost when you're already beyond the boost threshold RPM. Ok. Strictly speakin - it will eliminate boost creep in certain cercumstances - but why? Because it allows more exhaust gas to pass through the turbine. Think of it this way - bigger turbines flow more exhaust gas but have a higher threshold because it take more exhaust gas to accelerate the turbine wheel. In the same respect, a smaller turbine that has been chopped away will flow more exhaust gas AND it will also have a higher threshold.

Pushing the turbine pushes the compressor, which generates more airflow to the turbine. When a wastegate is too small for the application - a boost level/turbine flow limit is attained - that is, the wastegate is wasting as much as it can but it's not enough. Therefore, the turbine has no choice but to spin out of control. Boost creep.

The real solution to boost creep is to have an appropriately sized turbo and wastegate. If you like the turbo - change the wastegate. If you need more power - change the turbo.

Clipping is a hack.

My n/t $0.02...but I'll be turbo someday.


95 Eclipse RS : 5 speed
15.7 @ 87.9mph
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

Originally posted by MetalJim
Clipping is done to the turbine wheel. The idea is that the fins are clipped to allow more exhaust gas flow. What does this do? It allows more exhaust gas to pass through the turbine - at the cost of a higher boost threshold. Most people will call this "more lag", but lag is different then threshold. The boost threshold is the RPM at which the turbo can attain maximum boost. Turbo lag is the time it take to achieve full boost from 0 boost when you're already beyond the boost threshold RPM. Ok. Strictly speakin - it will eliminate boost creep in certain cercumstances - but why? Because it allows more exhaust gas to pass through the turbine. Think of it this way - bigger turbines flow more exhaust gas but have a higher threshold because it take more exhaust gas to accelerate the turbine wheel. In the same respect, a smaller turbine that has been chopped away will flow more exhaust gas AND it will also have a higher threshold. Pushing the turbine pushes the compressor, which generates more airflow to the turbine. When a wastegate is too small for the application - a boost level/turbine flow limit is attained - that is, the wastegate is wasting as much as it can but it's not enough. Therefore, the turbine has no choice but to spin out of control. Boost creep. The real solution to boost creep is to have an appropriately sized turbo and wastegate. If you like the turbo - change the wastegate. If you need more power - change the turbo. Clipping is a hack. My n/t $0.02...but I'll be turbo someday. 95 Eclipse RS : 5 speed 15.7 @ 87.9mph Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

awesome info man. cleared a lot up for me. points for you.

Originally posted by MetalJim
Clipping is done to the turbine wheel. The idea is that the fins are clipped to allow more exhaust gas flow. What does this do? It allows more exhaust gas to pass through the turbine - at the cost of a higher boost threshold. Most people will call this "more lag", but lag is different then threshold. The boost threshold is the RPM at which the turbo can attain maximum boost. Turbo lag is the time it take to achieve full boost from 0 boost when you're already beyond the boost threshold RPM. Ok. Strictly speakin - it will eliminate boost creep in certain cercumstances - but why? Because it allows more exhaust gas to pass through the turbine. Think of it this way - bigger turbines flow more exhaust gas but have a higher threshold because it take more exhaust gas to accelerate the turbine wheel. In the same respect, a smaller turbine that has been chopped away will flow more exhaust gas AND it will also have a higher threshold. Pushing the turbine pushes the compressor, which generates more airflow to the turbine. When a wastegate is too small for the application - a boost level/turbine flow limit is attained - that is, the wastegate is wasting as much as it can but it's not enough. Therefore, the turbine has no choice but to spin out of control. Boost creep. The real solution to boost creep is to have an appropriately sized turbo and wastegate. If you like the turbo - change the wastegate. If you need more power - change the turbo. Clipping is a hack. My n/t $0.02...but I'll be turbo someday.

I thought clipping was mainly to make the turbo spool slower ? thx for clearing that all up jimbo :thumbsup


#333
www.dsmlife.com

I thought boost threshold was the rpm in which boost was beginning to be built...sorry Im prolly wrong I was reading maximum boost...pretty good book..~shrug~ Im probably wrong..