Last Friday, I purchased the EVO Billet Diverter Valves to replace the factory diverter valves in my 03 turbo (which were starting to make noise after about 4500 miles)

Today, in about an hour and 15 minutes, I installed the EVO billet diverter valves.

Some comments on the installation.

Unplugging the Mass Airflow Sensor; It would have saved me a few minutes if the instructions stated that to unplug the MAF Sensor connector, all you need to do is push the connector release on the right hand side of the plug. The plug has some extensions on the front and rear (relative to vehicle) sides which *look* like they should be the release catches to remove the connector. They are not... and it only took me a few minutes to figure it out.

Removing the intercooler hoses; I was ABSOLUTELY amazed at how dry the o-rings were. I used some high quality (read; SCUBA Gear quality) silicone grease to lube up these o-rings before re-assembly. Even though I didn't need to remove the right hand (us-passenger) side intercooler hose... I did just so I could lubricate the o-ring.

Installing the new diverter valves; Using the aforementioned silicone grease, I lubricated the outside of ALL the diverter valve-hose interface tubes (two per diverter valve), put the factory clamps (not the new clamps provided by EVO... I've had bad experiences with clamps like these coming loose over time, so I re-used the factory clamps which I think are MUCH more secure over time) back on the hoses and then, using a pair of needle nose pliers, squeezed the clamp and slid in the diverter valves... they went on EXTREMELY easy AND there is no chance that the clamps will come loose.

All in all... the instructions were top notch. Armed with a color printed copy provided by Todd... I had absolutely NO problem installing the diverter valves. It was actually quite relaxing just tinkering with the car for a little while.

During the test drive, I noticed that I no longer had the "honking" noise that one (or both) of the factory diverter valves were emitting. I didn't really notice any change in boost pressure or turbo lag/throttle responsiveness... but this might be because my factory valves only had 4500 miles on them and really hadn't degraded sufficiently to cause performance issues.

When you look at the new billet diverter valves and compare them side-by-side to the plastic factory valves... you will shake your head and wonder what the heck the factory was doing putting such cheap-quality plastic parts in a performance sensitive application.

EVO's Billet Diverter Valves are really works of art.... and I am extremely apprecitive to be rid of the noisey factory diverter valves.

I'd say that this installation is a good "first start" for anyone interested in doing a little work on their Porsche, but who have limited knowledge of vehicle mechanics. The instructions are top notch, the product is high quality, and the time to install is very reasonable.

Joe West

 

Thanks

 

Check out www.evoms.com under products for the 996TT - it will answer all your questions
Dump valves are what holds/relieves your boost pressure between shifts...

 

Q: What is a diverter valve and what does it do?
A: A diverter valve, also referred to as a "pop off valve", "blow off valve", "boost re-circulation valve", "air/boost bypass valve" is designed to re-circulate the boost pressure that gets built up in the intake manifold in between shifts. The valve at idle (under vacuum) will remain open allowing the air to circulate freely through the intake to the turbo (s) fresh air side. As soon as the the throttle is cracked, ie: the accelerator pedal is moved, the valve will be forced shut stopping the re-circulation of intake air to the turbos and allowing all the boost pressure to enter the motor.