Anyone got any specs on race cams for a MotoFXR? Can I just get the standard cams reground?
Anyone got any specs on race cams for a MotoFXR? Can I just get the standard cams reground?
Read the far kin rules, geez.
Oh and specs on a race pipe too, would be handy, thanks.
And, errrr, your input won't be required Mark, so please run along .....![]()
Basically you can do whatever you want with F4 four strokes, the basic limitations are.
Naturally aspirated, ie. no turbos or superchargers (Ram air is OK)
Must be running on petrol, Av-gas is OK but no meth or Nos
Engine must have started life as a non-competition engine. that is trail bike OK, motorcross bike not... Street bike fine, GP bike not...... etc. Some of the Derby 2 strokes are on shakey ground with that rule as they come from the factory in dedicated race bikes etc, check out Metrokit.....
Outside of that you can do pretty much whatever you damned well please which is half the fun of buckets as opposed to Street Stock 150s. The really fast bikes have spent plenty of time on home-made dynos working on compression ratios, exhausts, cams, cam timing, ignition timing, porting etc, etc, etc The sky is the limit if you've got the time and the money. Won't do you anygood at Mt Welly though cause it's all about the corners and power hasn't got a lot to do with it
The reason that some of the CB125 twins go so well is that they've had 30 years to figure out what makes them go faster and stay together. The FXR's have a long way to go till they're in the same league.
Don't take too much notice of some of the BS on this site, half the people on here haven't read the rules and have never touched their engine short of putting oversized carbs and exhausts on them which probably make them go slower.......
I don't know much about the cams that FXR150 sell except that they are new race cams out of Malaysia (definitely not regrinds).
When I can afford some for myself I will get them profiled so we know what we're dealing with.... Apparently they are longer duration but that's all I've been able to find out.
There are probably cheaper/easier ways to get some extra HP out of an FXR but first you need to decide what sort of power curve you want which is dictated by the track......
Actually, we're talking about an FXR150 and as far as I can ascertian (and I've read the rulebook a couple of times) that's a no go. The rules state "All engines must be normally aspirated except F4 4 stroke engines of less than 100cc capacity, which may be turbo or supercharged."
Last time I looked, the 150 in FXR150 stood for the capacity of the engine which is quite clearly well over the stated max of 100cc for blowers.
In saying that, I've heard a lot of people talk about blowing 100cc engines and in theory you should be able to get some serious hp but never seen anybody do it with reliable success...... It would be fun if I had the time!!!
There are currently 1 users browsing this thread. (0 members and 1 guests)
Bookmarks