Air Filters & Odd Noises

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Wildfire
Posts: 295
Joined: Fri Nov 17, 2006 9:12 pm
Location: Derby

Post by Wildfire »

I may be being dumb here (quite probable I have had years of practice :lol: ) but why does swapping the trumpets over increase the velocity of air, given that the air box volume is fixed?
I can grasp that making both the same (larger) size would help but swapping front to back still leaves you with the same overall volume/velocity ratio :?:

Also with the sub air filter thing - When I had done the CCT's and first ran it it was very rough feeling - I noticed that the carb breather that goes to the front one of these had not seated correctly and that it vented outside the airbox. Put that back on and it seemed a lot better even without the sub filter. I presume this is some sort of back pressure thing :?:
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alan
Posts: 1349
Joined: Tue Mar 07, 2006 1:22 am
Location: leeds
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Post by alan »

maybe having longer ones creates more pressure i dunno but in my original post i said i couldnt remember if you swapped the front with the rear or for the same size, after having some time to think :lol: im almost positive you swap for the same size trumpets either 2 long or 2 short, various other mods have been done in the airbox too ie removing the divide in the snorkel (air intake vent) aswell as removing the strip that the oe filter connects to im not convinced these 2 mods work though but others who have done say so
tony.mon
Posts: 16290
Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Post by tony.mon »

Well, we're about to find out, ladies and gentlemen!
Because I've wonderd about this for a while, and tried two long ones, though I could feel more torque but can't be sure SO:

I'm off to the Bulldog Bash on Thursday, and will be running the Storm up the drag strip. (It's a yellow one in case anyone else is going, with carbon straight-throughs).

I'm planning to run with the two long ones on Friday, then the two short ones on Saturday, say five runs each day, that should give me a reasonable average result.

But there's also a mobile dyno, and I thought it would be interesting to have a run on that each day as well, so it's not just my clutch control, how hungover I am, or other factors.

So-

I'll post the results and let you know how I get on.
Last year the best I managed with one of each size trumpets was 11.6*, any better this year and we'll know for sure, won't we?

* but I've just fitted a 15 tooth front, which should help, and a chain and rear sprocket as well, and a much better condition clutch, so that might make a contribution- we see..... :?
It's not falling off, it's an upgrade opportunity.
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