Did you just install the larger tube over the recirculating port on the silicone intake or install something inside the silicone so it doesn’t collapse?

I just picked up a used S2000 last week that has a similar setup and flutters like crazy as well. My charge side is coming from after the intercooler though.

 

So I had the work done by a pro, but I did ask him that question and believe he said he installed something in there to make sure it is solid, like possibly some metal tubing with a flange. But I do not know for certain.

 

Did you leave the spring that it came with in or change it out for another one? I am hoping to get mine mostly plumbed up tomorrow. I was worried about the existing 1” ports sine the supersize is 1.5” so I just ran a test where I disconnected the hose on the charge side and let it vent to atmosphere. After letting it warm up I gave it some revs and no flutter . While I was testing that I also hooked up the vacuum line to the Forge and it looked like it was working but not sure if it is opening all the way.

I ordered the spring kit when I bought it so I could always try a lighter spring.

My other question is on which way it should be installed. As mentioned earlier in this thread someone pointed out that the original Bosch one installed was backwards (charged air coming in at the side of the valve). I didn’t find any documentation on how it is supposed to be installed. Obviously if the charged air is facing the valve it will help push it down and open it up. Any feedback would be appreciated.

As a side note it sounds like one of the bearings in the supercharger needs to be replaced. Any suggestions on where to send it for a rebuild besides Paxton?

Thanks for the help, the urge to drive the car is killing me!

 

I did not use the spring it came with. I spoke with a couple people about it, including John at LHT, and everyone said to use a soft spring. John said to use the softest one I could get. I spoke with the folks at Forge and they said I should use their blue spring. So I bought that with the valve and swapped it out before install. It's been working fine. Not too soft from what I can tell, and the guy who did the install for me said it was good too. As for which way to install it, you are in luck. Forge's US location is located right here in Orlando where I live, so I went to pick up the valve in person with them. The guy there was great and incredibly knowledgeable, as you might expect. I had him hold the valve in the correct install orientation for me and took a picture of it which is below (assuming your set up is the same as mine, which you can see in the other pics in this thread). Good luck with the install. Let me know how loud you think yours in when it releases the air when you are off throttle or cruising. As to your last question, I've got nothing for you on where to get the SC rebuilt. Maybe someone else knows that.

 

Thanks for the help. I’ll let you know how it goes.

 

I have the same set-up, also installed at LHT. After driving the car about 1000 miles I'm exhausted of the chirping/flutter. Thank good I found this thread. I'm honestly shocked that John would consider this normal.

SuprchdAP2 would you mind sharing the link to the valve? I can't seem to find that model on forges website.

 

The Forge Supersize seems to be discontinued...should I go for the TiAL QRJ with a 1.5psi spring? I can't seem to find the port size.

 

I have a tial QRJ vented to the atmosphere and running around 15 PSI of boost. I opted for a higher PSI spring because the lower 3 PSI springs would allow the valve to partially open at light throttle and it would make a really annoying metal on metal ringing sound. Fixed with the heavier rate spring although it restricted the air flow a bit. I don't hear any weird noises so I think I'm still good.

 

Thanks! What's the PSI rating on the higher psi spring you ended up using?

 

Hey, sorry I have been out of town and could just now reply. If I had not used the supersize Forge valve, I would have used this one from Turbosmart with the soft blue spring - https://www.turbosmart.com/product/k...cZ-dEUd1MC7P42. This is still significantly larger than the plastic Bosch valve that comes with the SC setup. I personally think the Forge may have been overkill, and as I said below the sound of the venting air is loud with my uninsulated vented carbon fiber hood. If I had the time and the inclination, I would try different valves and see which produces the best result. But for sure the larger, better quality valve will get rid of the flutter. What I don't know is if a slightly smaller valve would make a little less noise.