Hi all
to run in the "Production" class at BUB Speed Trials on the Bonneville salt requires a "stock unmodified" exhaust system.
After talking with a tech inspector/scrutineer, it appears likely that an added O2 bung may be acceptable, but that is it. No gutting of silencers, no removing catalytic convertors, etc. Even ceramic coating is not permitted, apparently.
so, I have yesterday put a stock unmodified complete exhaust system back on the bike (with an O2 bung ahead of the catalytic convertor in the 08 exhaust header in the location used on the Euro ZX 14's), and temporarily gone back to a "Zero" map in the PC 5. I also temporarily hooked back up the "fresh air" system to inject fresh air into the exhaust ahead of the cats, which unfortuatley skews the reading from the wide band O2 sensor.
First question: to get an accurate reading of the actual air/fuel ratio, I need to plug the fresh air sytem. How long will the cats in the header and the silencers survive with the fresh air system plugged? Minutes/hours/days/weeks etc? I am not clear on how badly the cats need the fresh air system, but I at least need the cats to survive say 2 to 3 hours on the dyno while I try and optimize mid range and top end fueling for absolute best top end power at 100 per cent throttle. Does anyone know for sure one way or the other? I would hate to have the cats plug up during tuning and restrict the exhaust flow.
Second question: for best top end I don't see pulling the secondaries (flies) or a TRE as being a whole lot of help. What else can anyone suggest for top end performance enhancement for a bike forced to run a stock unmodified exhaust system? I have already done the Speedo Healer/ ceramic wheel bearings/ smaller rear sprocket selection/ non O ring chain/ PC 5 with Autotuner and accelerator pump feature enabled.
I actually cut a spare stock silencer apart on a bandsaw to see what I was dealing with, and in fairness to Kawasaki the silencers actually look pretty decent for exhaust volume. Similarily I sectioned an 08 header, removed the cat, welded it back together and ran the gutted header on the bike with no noticeable increase in power (but a noticeable decrease in heat).
So, stuck with the perceived restriction of a full stock 08 ZX 14 exhaust system and its three catalytic convertors, what would be the best tuning route to go for best top end wide open throttle tuning for a run on the salt at Bonneville?
Paul