custom front pipe

[smokeejoe]

Hello recently got my car noise tested as im looking into doing track days, and have found my janspeed to be on the 105db limit.

I already have a good standard backbox so am planning on making up a front section to be cost effective as i resent paying £110 for a front section just to use on track days.

Does anybody know the optimum pipe diameter of the twin pipe part of the front section?
Also what is the correct diameter pipe to use for the rest of the front pipe?

[smokeejoe]

Do you guys think it would be worth me buying a front pipe to canabalise the 2 into 1 section and flexy to use as the basis of my pipe?
cheers

[elbon50]

You say that your exhaust system noise output is at the top limit for trackday use Joe

However, you seem to think that the silencer is not the source of the high noise level ?

What is the problem that you have with the front pipe ?

Peter

[un1eash]

I would of thought a custom backbox that bolts on the janspeeds downpipe would be the best solution to meet track sound limits. The Janspeeds long downpipes i always thought was the key to its slight improved performance over say a mongoose system.

[smokeejoe]

peter i currently have a janspeed fitted to the car and this is the exhaust that is too loud for track use. My reason for wanting to make a custom front pipe is that i have a standard back box that is not on the car at present, so my thinking is that the easiest and cheapest way to get my car track legal is to fabricate a front pipe so i can utilize my standard back box.

unleash i thought it would be harder to fabricate a back box than a front pipe.
Would it be acceptable to make a section of pipe up to join the downpipes from a janspeed to a standard back box so in effect i would have a 3 part system?

Or is this all a complete waste of time??

cheers joe

[elbon50]

Yes I see

If un1eash's theory about the Janspeed header pipes is correct (sounds likely to me) then your idea of a link pipe could be worth trying Joe

Don't know but suspect a standard box isn't very efficient from a power point of view though

Peter

[smokeejoe]

thanks for your thoughts peter.

My main objective is to be cost effective, track legal and to make life as easy as possible, not overly concerned about performance atm.

Im gonna have a stab at making a link pipe when i get the chance will let you know how i get on.