The bypass valve supplied with the kit is too small. Has a 20mm valve in it. So part throttle around 6k rpm it flutters causing the bike to jump back and forth between boost and vacuum. Well the ecu tries to adjust accordingly but it can’t, so the bike shutters real bad.
I’m putting a 38mm valve on it and that should cure the problem.
Here’s some pics of the process of modding the plenum. I cut out the valve that acts like a wastegate as it was cranked shut anyways.
But the new valve is on, and took it for a test ride. The fluttering problem is now fixed, however I need to put it back on the dyno to tweak the tune. The new valve flows so much air that now in areas where the ecu was starting to see a little boost, doesn’t anymore so the throttle response is a little muddy in some spots now. No big deal, I was expecting to have to do that anyways.
The owner was in town, so he swung by to check out the bike, and even took it for a little ride. He came back with all smiles.
He did also give us the green light to change the gearing per my suggestions from 18/48 to 18/45. We are also installing a progressive methanol injection kit, and changing the pully to get some more power out of it.
I’m suspecting a serious power increase from the methanol kit alone. Blowers by nature produce extremely high intake temps. This being non innercooled I had to combat that in the tune by pulling timing, and keeping an overly fat afr ratio (10.5afr) which puts a big damper on power output.
With the meth kit, in theory just from the intake temp drop alone it should pick up substantially. But then factor in being able to lean it out a bit, and put more timing back in it, it should really come to life.
I also made a nice little mount for the AEM failsafe gauge.
I’m happy to repor with the 45 tooth sprocket, it REALLY woke the bike up. It pulls way harder now, and we can now run 80mph without the exhaust screaming. It was turning around 5800rpm before.