GP-Infinitas (formerly G-Power), No Boost Solved

[Davisca455]

For you G-Power owners with some miles on your kit.

I was at an HPDE at Laguna Seca a couple of weeks ago with slcook54, and I lost boost toward the end of Session 1.
I could hear the boost leak (WOOSHING) but there wasn't any way to repair it at the track, so I just had to adapt the driving style a bit, but still had a blast (such an awesome track, and a nice mild climate).

How the bypass system works is that all three valves progressively open as vacuum increases (chopping throttle), to release pressure as the blower overruns.
All three valves close as vacuum decreases (mashing throttle), which then allows pressure (boost) to build.

When I got home, I removed the blower pump, airbox and plenum, then performed a bench test with a vacuum pump on the Bypass Valve Assembly.
I discovered that the two small valves were leaking vacuum and were unable to open, and that the vacuum leaks were significant enough to prevent even the large center valve from opening as well.
So because all three valves remained closed when I lifted the throttle, and the blower continued to overrun, the system could not relieve the over pressure into the airbox, which caused the hose between the intercooler discharge and the plenum intake to dislodge and create the boost leak.

Replaced the two small (outboard) valves and all is right with the world once again.

GP-Infinitas is where you can source spare parts for these kits.

[derbo]

Nice job Chris!

One of the few kits out stateside and with tons of mileage!

[Redd]

Seems like an Audi logo on the small blowoff valve. I wonder if it will be worthwhile to replace all the valves with aftermarket metal units. They look like typical OEM turbo recirculating blowoff valves to me.

[Davisca455]

Originally Posted by Redd

Seems like an Audi logo on the small blowoff valve. I wonder if it will be worthwhile to replace all the valves with aftermarket metal units. They look like typical OEM turbo recirculating blowoff valves to me.

Sharp eye!
Yes, the two small valves are Audi/VW diverter valves.
The large valve in the center has a euro spec Mitsubishi part number from a Lancer Evo.

Unfortunately, GP-Infinitas modifies the valves by machining off the hose barb feature for a precision o-ring fit into the plenum.

The cost for the modified valves from GP-Infinitas isn't at all unreasonable, but I just didn't want to wait, so I ordered the two Audi valves from FCP and machined them myself.
If the Mitsubishi valve had been bad as well, I probably would have waited. I just couldn't find an obvious replacement locally.

I did order a new center valve, and all new rubber parts as well though, so spares are on their way from Germany.

[amrazM]

Why are you continuing to use a 710C? 710P is the latest revision of the kayser “710” valve. I used two generic 710P kayser valves and it worked perfectly fine. Instant response and $50 at fcp

[Davisca455]

Originally Posted by amrazM

Why are you continuing to use a 710C? 710P is the latest revision of the kayser “710” valve. I used two generic 710P kayser valves and it worked perfectly fine. Instant response and $50 at fcp

The first reason is out of an abundance of caution.
The kit and the tune are from 2009, and it still works really good just the way it is.
I just didn't want to chance any unintended consequences by changing hardware for fear the software couldn't deal with the change.

The second reason is ignorance.
I'm not familiar enough with Audi valves to know what the differences might be between the "C" and the "P".

The third reason is that the "C" valve was available from FCP for $52.00 each

[DimitrisM3]

Originally Posted by Davisca455

The first reason is out of an abundance of caution.
The kit and the tune are from 2009, and it still works really good just the way it is.
I just didn't want to chance any unintended consequences by changing hardware for fear the software couldn't deal with the change.

The second reason is ignorance.
I'm not familiar enough with Audi valves to know what the differences might be between the "C" and the "P".

The third reason is that the "C" valve was available from FCP for $52.00 each

We have better solution!!

https://www.bar-tek-tuning.de/pop-off-ventil-bar-tek?number=2118t106

[Davisca455]

Originally Posted by DimitrisM3

We have better solution!!

https://www.bar-tek-tuning.de/pop-of...umber=2118t106

That is a very nice looking valve assembly!

At a minimum I would need to machine off the 2X hose barb feature, and I would still need to know some other dimensions before I could determine if it was possible to fit it between the G-Power plenum and airbox.
The valves are modified by GP-Infinitas and they also leverage some of the injection molded features to retain them.

[DimitrisM3]

Originally Posted by Davisca455

That is a very nice looking valve assembly!

At a minimum I would need to machine off the 2X hose barb feature, and I would still need to know some other dimensions before I could determine if it was possible to fit it between the G-Power plenum and airbox.
The valves are modified by GP-Infinitas and they also leverage some of the injection molded features to retain them.

Sent me dm
Your phone number
We have g power group