Tilasin sitte tuollaisen, kun tuolla jenkkilän puolella kaikki tuntuu kohkaavan siitä...
FPR
Testien perusteella pitäs olla tosi hyvä hankinta.
Tässä testauksen tulos:
Fuel Pressure Regulator Test Procedure and Results for ’99 Honda CBR1100XX Super Blackbird.
50psi Regulator.
Two identical ’99 CBR1100XX were used for a comparison test, one red, one blue.
Both bikes are stock with the exception of K&N airfilters.
The following pretest maintenance was performed. Starter valves sync’d (throttle bodies) and idle adjusted to 1250rpm by the bike tach. The fuel pressure was checked as per the Honda service manual and found to be 46psi on both machines. I believe the slightly higher pressure is due to the test port being located at the discharge of the pump and the FPR being at the end on the rail. Also the Honda procedure completes the test with the manifold pressure tap disconnected, when reconnected the pressure reads as per spec.This discrepancy was evident with the new regulator also. These checks were completed to rule out any issues that could skew test results. The muffler exits were polished (Blackbirds are notorious for sooting the exhaust exits, various theories abound as to why, my choice is poor atomization at low speeds).
The 50psi regulator was installed on the blue bike. The idle speed adjusted to 1250rpm once warmed up. Again a pressure test was performed as per the Honda service manual and found to be 52psi. (see comments in previous paragraph).
89 octane fuel used, OAT approx. 80deg.f. The test route was 100 miles (just worked out that way by accident) and was a mix of city and country two lane. I made effort to ride both bikes equally through the test route.
Observations: Blue bike.
- The idle exhaust note was noticeably crisper.
- Low speed throttle response much improved and smoother. Much easier to ride through residential streets.
- The 1-2 shift clunk is eliminated (Blackbirds have a reputation for having a clunky 1-2 shift unless above 7000rpm) and the rest of the shifts much smoother.
- The rough spot or surging in the 3000-4000rpm range at cruise and light power loadings is eliminated.
- Power roll on at highway speeds seems smoother and more responsive.
- The Blackbird engine is one of the smoothest running you will find but with the fuel pressure tweaked it is now comparable to a rotary (fair comparison, my wife drives a Mazda RX-8)
- Absolutely no evidence of sooting on muffler exits, although I realize this was not a lengthy runtime.
- 38.6mpg.
Observations: Red bike.
- The idle exhaust note now sounds blubbery.
- Low speed throttle response is as I remember, snatchy and jerky.
- The 1-2 shift clunk is there 9 out of 10 shifts and the rest of the pattern is not as smooth as the blue bike.
- The 3000-4000rpm surge is very evident.
- There is slight signs of sooting beginning on the mufflers even with the minimal run time.
- 39.8mpg. The better fuel mileage from the bike that doesn’t run as nice has me a bit baffled as most of the improvement could be attributed to better fuel atomization but the 100 mile test route isn’t really that long and there may have been a little more spirited throttle application on the blue bike due to the improved response.
Conclusions:
- Overall driveability much improved, especially in the lower speed ranges.
- Much smoother shifting, completely eliminated the 1-2 clunk.
- Mid-range surging is gone at lightly loaded cruise speeds.
- Appears to have reduced the tail pipe sooting.
- Fuel mileage may have suffered approx. 1mpg. But the test distance was not long enough for accurate results.
- My one concern is if by increasing the fuel pressure the fuel pump is operating outside of its performance curve. I notice that even though Honda used the same fuel injectors for the different pressures the fuel pumps are different part numbers for the different years. I realize this is not a given that the different pumps are different curves but it is all the information I have to go by.
- All in all, a favorable mod.