Hi, As above really, i've got a 919 blade engine and wonder if as with some car engines the more cold air over the carbs/intercooler the better it is???? i have fitted a bonnet with a bulge which allows lots more air into the engine and wondered if this going to make any difference over the one without any openings??? Cheers

I think more cold is better for any engine as all that does is allow the opportunity for a better and denser fuel to air mix.

With the blade engine I was told that they do not perform as well with certain types of air filters and that they perform best when they are drawing still air - this should be fine for most people as this will be achieved with a sausage filter, but not as good with sock filters???

If I was doing it again, I think I would go for the RAM air type of scoop and box that AB Performance sells, but I will definitely not be changing anything on this one now unless something breaks!!!

hth,
cheers,
Steve.

If you significantly change the air supply to your carbs, then you really need to rejet your carbs to take any advantage. Going from closed bonnet to open bonnet will effectively feed more air in, leaning out the mixture slightly. Now whilst I'd suspect this won't make a huge difference such as to cause lean running issues, you won't see a real benefit without rejetting to give more fuel to burn.

The reason this works for cars is that modern cars are fuel injected and have air flow sensors which calculate the amount of fuel required according to the air.

Also I'm no expert but I'd guess that there will always be some sort of compromise when having your carbs setup with air directly from the outside. Carbs are setup to feed a set amount of fuel depending on throttle position. Obviously the faster you're going, the more air you get so the leaner the mixture. So if you tune your carbs for high speed they won't be "perfect" for low speed, and vice versa. Can't be a huge issue though because it is quite a common setup...........I'll shut up now