Originally Posted by morris
can any one tell me how far out the back of the sportster you can get the tail pipes without it hitting the "150mm from the effective floor line" rule in the IVA manual?
Working out that floor line isn't straight forward as far as I can tell so I was wondering if someone could measure the distance out on a known passed setup from the number plate mounting space.
I want to use as much room front to back under the tank as possible to increase the length and hence volume of the back boxes without half of it being taken up by pretty chrome parts that don't help silencing.
My Cabrio tail pipes are 70mm beyond the number plate face, and 30mm beyond my bumpers: they passed, but like shares, the past is no guarantee for the future!
Are you aware there are planned changes for IVA coming in soon? - I overheard someone at the Donington Kit Car show saying there were new rules coming in October? Is this right?
Having gone through the steps you are taking with your exhaust design, be careful of the aesthetics: any silencer beyond the back of the tank is very visible, and looks highly obvious. With the Sierra trailing radius arms, I was able to fit a 600mm long box x 150 wide either side of the diff, and finish the main box at the back of the fuel tank. I looked at coming out further to maximise the volume, but it just didn't look like the silencer should be there.
Also at Donington, the guys who are not getting fumes rolling back into the cabin have tailpipes that finish 100mm inside the bumper line - I get quite bad cabin fumes with mine projecting 30mm beyond the bumper line, so plan to cut mine back 100mm, and maybe more.