Cherry bombed Chim - whats the bd at idle and load?

[Zippee]

My Chim is cherry bombed and I'd love to start doing a few track days. Has anyone measured their cars both at idle and under load (3/4 rpm I think is whats tested) as most track days seem to have 105db limits.
How much do track silencers bring the volume down buy?

[Seasider]

Not alot of bd i reckon

[Vixpy1]

Generally... Too loud for track days!

[WazzaL]

Probably need a couple of track day silencers on it.

Had mine db checked (similar thing done) Went well above the limits..

Sounds good though...

[E1DJH]

Vixpy1 said:

Generally... Too loud for track days!

oh learned, masterful one, not necessarily so.

I have Cherry Bombs, but stil have all the cats in place.

I went to Castle Combe earlier in the year with some "insert" silencers from TVR racing. Without silencers i was 107 db. With the inserts, i was 103db - still too loud. So i bought a set of external silencer "cans" from merlin motorsport down there, and the combination of the two got me down to 97 db.

However:

I then it to Brands Hatch in the summer, and without any silencers, they reckoned it was "borderline". They let me on, with a proviso that if i "seemed to loud" on the track, they would bring me in - which they didn't. I did however take my silencers just in case.

So, although i can't give you a definative yes/no answer, it woudl probably pay to get some silencers "just in case".

HTH

[monstergrowler]

I was under the impression that cherry bombs would actually lose you power due to the rv8 likeing a certain amount of back pressure. Is this the case? Does anybody have any evidence to suggest an argument either way?

[CaptiV8ted]

I can't offer any evidence to back up my claim, but I RECKON that I have lost a tiny bit of power after fitting the cherrybomb exhaust. I don't have any figures to back it up, but it seems a tad less powerful. We are talking peanuts though.....

[Zippee]

CaptiV8ted said:

I can't offer any evidence to back up my claim, but I RECKON that I have lost a tiny bit of power after fitting the cherrybomb exhaust. I don't have any figures to back it up, but it seems a tad less powerful. We are talking peanuts though.....

I had mine on Vixpys RR the other week and got 228.9 at the fly and 180 at the wheels, my Chim is a standard (apart from the cherries) 1997 P plate 400 with 54k on the clock.

[raceboy]

Mines got straight through pipes and no cats, did a track day last week that was a 98db limit, surprise surprise I got blacked flag on the 1st session, not sure what the reading was though.
Fitted a pair of ACT trackday silencers to the back and was below 98db for the rest of the day.