I thought the relief valve made a "pssft" sound (which it does) when letting up on accelerator. This is an (new)additional low groaning (or, "moo") sound btn. 2,000 and 4,000 RPM whether accelerating, decceleration, or steady. Other members have posted communications that seem to say it's the air pump. I don't need to pass any environmental tests. So, can it be removed? What's involved?
Thanks

 

The charge relief valve (CRV) is venting until around 4000 rpms. It vents off the access from pre-spooling the secondary turbo (so it doesn't over work itself).

The airpump has a relief as well (which is not the CRV or related to it) and that is what makes the "MOO" sound.

The charge relief valve is needed for sequential turbo operation. The airpump is only required for emissions.

 

Thank you. So, can the airpump be disconnected or removed without causing performance problems? I mean, do any adjustments have to be done to the engine afterwords, or will it start, idle, acelerate, etc. just as it did before?

 

If you are trying to get rid of that "moo" sound try this.

http://www.clubrx.org/default.asp?id...ntent=62&mnu=5

If you remove the airpump, you might experience minor idle issues. Someone correct me if im wrong.

 

It's hit and miss with some engines. I disconnected mine with no ill effects to the idle. It's just a matter of unplugging it to see. The air pump cuts out over 3k rpm any way so preformance wise I doubt you'll see and gain.

 

what about the weight savings..... yes weight... must go ultra-diet mode.....

 

if it allows you to get rid of the cat and pump there would be a pretty good bit of weight eliminated with those two items.