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So, one of the secrets I've been alluding to in other posts arrived today:
A fresh set of stacks from Felix Delwood.
The set came in today and I am pleased to say they fit the box and look pretty good. On a plus side I've been working on a cheaper alternative for a flow control setup for the main air bleed and with these stacks I'm able to route hoses more easily. What I've done is simply run a 4mm id hos to the main air bleed then into a "Y" and then into a Festo flow control. What this does is move the inlet for the air bleed to a less turbulent area and allows for better control ove a lean condition without re-jetting. The cost for the flow control kit would be about 40$ shipped. The stacks from Dellwood are 140 US shipped. Take about a week to arrive. I will update with a dyno chart with the new stacks.
OEM air box with oem stacks, PCV, and flow control fitted. This is the flow control all by itself, only on 12mm is drill in the side of the airbox. Everything else is push connect. My airbox with no PCV, FDW stacks and a flow control nestled underneath. FDW stacks all alone in there, fits just fine. Fit and finish is a little rough and requires some gentles massaging to fit.
Running the Dellwood stacks for 6 months. I polished the lip of the bell and about half/inch down into the cylinder, thinking it will speed up the flow of air over the lip. Seat of the pants dyno says stronger pull everywhere. Previously running two tall stock.
Last edited by HawkRider98; Sep 12, 2020 at 07:02 PM.
Ace, could you post better pics of which is the main air bleed and a link for the flow control unit plz? Which I presume comes with all required parts including hoses.
Also, why is one of your sub air filter inputs blocked off with Hi temp RTV silicone?
Sure, I can add more pics later. As for etc silicone, that's a spare airbox so I really have no idea. No silicone is needed anywhere. Only vacuum caps, 1 small hole, 3 sections of 4mm tube and a festo flow control valve...or smc...or any brand you prefer.
Without checking my notes I have to say that I'm running 180/185. But I suspect that I could go up one or two and put the needle back on 4.
Av
Cool, thanks. Have you opened-up your airbox/race filter? I am making my own flow-controller, as you have, with less intake restriction (opened airbox & Pipercross race filter) I am concerned that I may have to go down the HRC road and eventually block the main airbleeds and run smaller mains (currently 190's)?
My current experiment is, I have shortened the float needles from 19mm to 18.75m, this has raised the float level measurement from 16.50 to 15mm, this has fixed the 4500 rpm lean spot, meaning the pilots had to go down to 40, hoping a big decrease in fuel consumption.
I have fitted a lambda probe in the exhaust, with the display taped to the fuel tank so I can observe what is happening while I ride.
