weber trumpets

[StewartG]

I think I remember a pearl of wisdom from Roger King suggesting that standard length trumpets with K&N filters allowed less than ideal clearance between the end of trumpet and the filter cover.

What improvement might I expect with a change to shorter trumpets.

Anyone tried this?

[Roger King]

It depends which carbs and filters you have. Normally, 40s are fine with the filter that Caterham supply, but 45s generally have longer ram pipes and the standard Caterham filter is really too short.

 

Ideally, fit deeper K&Ns, but this is usually not possible with full length wings. In this case you may be better off with shorter pipes, but this will depend on engine spec to some extent.

[StewartG]

Yhanks for the reply Roger.

I have 45s and the longer trumpets ( sticl out about 60mm from the carb face and the filters are 80mm deep) so I need either shorter trumpets, longer K&Ns or maybe to space the filters out from the carbs somehow.

Would I be right in thinking it would be better to keep the lomg trumpets and space the filters rather than fit shorter trumpets which might not be too good for torque.

I've got cycle wings so space is not a problem.

[Roger King]

Generally, it is best to keep the long ram pipes and fit deeper filters, but engine spec can play a part in this.