Originally Posted By GLLHG
Originally Posted By NJR
I have replaced the stock filter on my '83 CVH (XR3 n/a) with a nice Pipercross. Sounds good and much improved throttle response, but the car runs out of breath past 80 in top, and struggles to gain further speed. Can I cure this with adjustment or is it a gearing problem?

Many thanks.

I notice that you have taken steps to free up the inlet side ( ie the Pipercross) but what about getting the used stuff out ie the exhaust side

I'm not suggesting that this is a complete fix because the issue is wider and really involves how wide the effective power band is and where it is deliverd, but if you are still on OEM stuff, then a better quality exhaust manifold and a system with a smaller silencer would be worth considering

A s a final point ( and apologies becuase this is a real hobby horse of mine) is the Pipercross situated so that it is giving you a good supply of dense, cool air?

regards,
GLLHG


Breathing is improved at both ends, I have removed the tail silencer and put a straight through pipe ( single silencer box under n/s wing) but using stock exhaust manifold, which apparently is quite efficient. It has a 5 speed box but I get the feeling that top is quite 'long legged'. She pulls very well up to around 80 in top, then runs out of legs, but will cruise happily at that speed.

One thing, there's a small air pipe that that ran from the original air filter box to the base of the carb...should this be closed off, left fully open or remain attached to the small original valve, for best performance.

thanks for your help

rgds
Nick....just waiting for the sunshine...