Can I use an ex-Race BEC Fury on track days?

[MikeE]

so I used the new silencer at Rockingham last month and the static value was 95DB (down from the 105Db at Brands, with the old exhaust).

I'm not sure I believe the new exhaust (1" bigger diameter and 24" perforated tube length versus the old 12" perforated tube length) would make 10Db static difference?

I'm booked to do Bedford Autodrome in 2 weeks and ther's a 101Db static limit (should hopefully be ok with my 95Db achieved at Rockingham) but only an 87Db drive-by limit

So question is, does anyone have any insight into what level static will give you a good chance of passing the drive-by? I'm assuming the drive-by is lower than other 101Db static circuits values simply because the microphone is further from the track?

[E-bmw]

As (you correctly say) drive by is lower due to distance unless anyone has exactly the same static as you with the same engine & drives past the mic at exactly the same revs/throttle opening, it is virtually impossible to answer that.

As a comparison, I was with someone a few years ago & he was told to short-shift 10m in front of the mic & then he was fine.

The track doesn't want to send you home, equally they don't want to flagrantly flaunt their rules, so they will normally tell you where to short-shift/back off briefly to keep everyone happy.

[xjay1337]

Bedford there is usually a microphone on the pit straight and one around the back of the circuit after the chicane braking into the sharp left.
If you can blow your exhaust to the "left" of the car rather than out the back or to the right then that would help there.

[Order66]

If you have a flatshifter it is often the bang of the gearchange that causes a drive-by fail. I have a side exit exhaust for my current car which passes static tests no problem at about 101db but can reach over 110db on a drive-by if the microphone just happens to coincide with a shift point.

[MikeE]

Thanks guys. The tail pipe comes out of the left hand side sill just before the rear wheel so should be optimum to avoid the two drive by mics if they're on the right.

Haven't been to Bedford (GT Circuit) for 8 years or so but understand there's a new pit block now. Is the drive by on the pit wall of the new or old pits?

And the other one, you mean on the long back straight (with the earth Bank on the right) after the mid-point chicane?

[Steve H]

There's four mics round Bedford, two each side.

[xjay1337]

I've only done SEN so don't know about the GT circuit :-)

[MikeE]

So after fitting the new exhaust and sorting the drive shaft and Quaife diff I ventured to Bedford Autodrome yesterday....and had an absolute blast!

The new exhaust has taken the static down from 105db to 94db (well below Bedfords 101db static limit). I then enjoyed a full day at Bedford on the GT circuit with no noise issues at all, which is great news and I must say I'm surprised it was that easy to get it through.

The rear end noise is now much better and whilst there's still some noise from the diff area I'm told this is normal for a BEC which tends to send vibrations from the engine down the propshaft and into the diff.

These Fury BECs really are very good, cheap trackcars. I was overtaking many much more expensive and more powerful cars much to their annoyance I'm sure

[MikeE]

Now I've made all the improvements to turn this into a very useable and fast trackday car (or could be road registered) I've decided to sell up as my wife wants me to get something more practical (she's thinking V8 F-type convertible).

So it's up for sale in the classifieds on PH.