2nd gen exh diffuser

[dyoungre]

Is the exhaust diffuser in the exhaust port considered an 'emissions device' that can be removed? I know we can't port, but can this device be removed - and if so, what sort of impact does it tend to make on the performance if left in? My understanding is that it is VERY hard metal.

Thanks for the advice - I'm new to the 13b ....

[mbuskuhl]

Is the exhaust diffuser in the exhaust port considered an 'emissions device' that can be removed? I know we can't port, but can this device be removed - and if so, what sort of impact does it tend to make on the performance if left in? My understanding is that it is VERY hard metal.

Thanks for the advice - I'm new to the 13b ....

No you can not remove and no it is not an emissions device. Yes it is very hard metal and not worth cutting even if you could.The turbo housings do not have the diffuser in the exhaust ports, those who want to open up the exhaust ports where the rules might allow or in a street car just swap the NA sleeves with turbo sleeves or use turbo rotor housings.

You can remove the 5th and 6th intake port sleeves, actuators and actuator rods, as well as wire the VDI (S5 only) open. This is worth doing if you have not and is IT legal.

You'll need to run EP if you want to remove the exhaust diffusers...

[dyoungre]

Thanks Mark. Honestly, I'd prefer to keep the parts in, but wanted to make sure that they are required for ITS.

Wiring the VDI open - does that hurt performance on track, in any way? How 'bout idle, starting, etc? Or was it tuned for below 3000 rpm, or something like that?

[mbuskuhl]

Thanks Mark. Honestly, I'd prefer to keep the parts in, but wanted to make sure that they are required for ITS.

Wiring the VDI open - does that hurt performance on track, in any way? How 'bout idle, starting, etc? Or was it tuned for below 3000 rpm, or something like that?

No. 5th and 6th ports open around 3800 RPM and VDI 5200 RPM. If you are operating in those low ranges there is a problem. Unless you have your air pump or some aftermarket setup hooked up the actuator is not working to open your VDI currently. Fix the VDI to an open position and remove the 5th/6th sleeves, actuator rods and actuators. Plug the ports on the LIM, a dime (10 cent piece) fits in the hole perfectly along with a little RTV if you want a cheap DIY fix.