Track Day Exhausts

[sweetmate]

i thought the quiet silencer had no packing in it built from the factory just chambered.

[baja1969]

sweetmate said:

i thought the quiet silencer had no packing in it built from the factory just chambered.

what ever was in there originally had turned to glass and was rattling about in my old track day silencer that came with the car, Wayne sliced it open and repacked the areas that he could, it is a 3 chamber exhaust silencer though

[baja1969]

passed noise test at Oulton park today 104 just scraped though, had a great day was running in the mid 1min 50's before lunch coming down to quickest lap of 1m 46.7 all was good until about 4pm when it looks like a piece of the cam chain or from round that area has come off and punctured a hole just under the rocker cover gasket and cylinder head. time to put it on the trailer.

looks like its off to the big R to give my bank balance a good spanking

[BertBert]

ouch, that's not helpful. Hope it's not too big.
Bert

[baja1969]

Engine now back in the car, picked it up from BSD Engines near peterborough, they've done a great job from what i can tell, the list of the parts replaced was lengthly, but without boring anybody the short story is that if i hadn't got the engine in for rebuild when i did it was not far off blowing itself to bits. Mark from BSD found remains of the timing chain and tensioner in the bottom of the dry sump, all the big end bearings were nearly through to the white metal, so now after a rebuild cost that was over half the cost of RPE i can wholly recommend BSD to anybody who is looking to get a rebuild done without the big R costs, only down side is the lack of "R" seal for the club mans cup and challenge.

[jpivey]

Good to read you got it sorted, feel sure you can run it in big R races just need to get it on there rollers to have a power run they will then seal it, I could be completely wrong on this though!!! Or bikesports it's cheaper...

[baja1969]

jpivey said:

Good to read you got it sorted, feel sure you can run it in big R races just need to get it on there rollers to have a power run they will then seal it, I could be completely wrong on this though!!! Or bikesports it's cheaper...

Hi JP I'm hoping to do the bikesports round on the 23/08 at silverstone, think you will spend a lot of time lapping me though LOL

[F40LOUD]

If you are all out if ideas and have no problems with the driveby but you're struggling to get past a static test you can fit a speedo healer to the wire running to the tach and temporarily calibrate it so that the tach overreads during the noise test, effectively reducing your true engine rpm (and therefore noise) while the tach still shows 3/4 max revs. I've only seen people do this a couple of times when they'd already spent a lot of money on exhausts.

[Blatter]

I had the same problem as dptdpt when I turned up at Castle Combe a couple of years ago with my Radical "Extra Quiet" Trackday Silencer - 103dB!

I've now finally got round to getting a custom made silencer fitted and when I tested it myself ( 8,000 revs) I was getting between 97-98dB which is better than what I'd asked for. I wanted to get under 100dB, but didn't think I'd get that good a result.

When I went to Castle Combe last week for a track day, I tested out on their noise-ometer at 95db! (Mind you, they did only ask me to rev to 4,500........)

The guy who built and fitted my silencer is Neil Handbury at Neil Handbury Racing in Taunton.

Photo below of the Silencer after two track days with it fitted.

It took Neil a bit of time to route it and fit. He also had to weld a small bracket to the rear left of the bodywork support frame to provide enough support for the cans. A good, neat job - and it works!

[Sigmamark7]

That looks very impressive and the dB readings even more so. Since my year's budget has been blown on fixing a broken gear drive unit, I am going to be limited to track days only and need something that will pass the noise test at most circuits, so can you answer a couple of questions?

1. Does it have any significant effect on performance/engine breathing?
2. Will I need to sell my soul to get one?

Neil is only about 40 minutes away from me, so it looks like a great solution if it is reasonably affordable.

[Blatter]

Sigmamark7 said:

1. Does it have any significant effect on performance/engine breathing?
2. Will I need to sell my soul to get one?

Neil is only about 40 minutes away from me, so it looks like a great solution if it is reasonably affordable.

1. Didn't notice any drop in power. Neil has maintained the same bore throughout the silencer system. I guess the only true way to find out is to stick it on a dyno?
2. Nope - £350-ish

Where do you live? I'm in Bath if you wanted to have a further look at the finished 'zorst

[Sigmamark7]

Blatter said:

1. Didn't notice any drop in power. Neil has maintained the same bore throughout the silencer system. I guess the only true way to find out is to stick it on a dyno?
2. Nope - £350-ish

Where do you live? I'm in Bath if you wanted to have a further look at the finished 'zorst

£350 in the Radical World counts as almost free!!

I'm in South Glos - a few miles from Michael Wood Services on the M5 and it would be good to come and have a look at your system. I have messaged you my contact details.

[Zuluracerx]

Here's mine. It's not too loud, just right. Short vid below the pic.




https://www.youtube.com/watch?v=KwHCzYdQ5ZI

[Coldaswell]

Short of making the car electric, does anyone reckon they could get the car quiet enough to get round Bedford?

Where did you get yours Zuluracer?

[splitpin]

Coldaswell said:

Short of making the car electric, does anyone reckon they could get the car quiet enough to get round Bedford?

A few years ago we did it in our quiet teapot equipped SR4, the SR1s were there the other day doing 'How Fast', various Rads have held the fastest lap over the years and it's currently held by an SR8 driven by For Flux Sake?

[Zuluracerx]

Had it made locally by Burns Stainless owner, Jack Burns. There shop is right around the corner from my shop and they specialize in race exhausts. It sounds great but I was joking about it being quiet. Not sure what it blows but it's way over 100 db. We tested the single "reverse cone megaphone" against this dual set up (shown below). The duals I use are actually short resonators made from 304. The duals are quieter than the megaphone but my lap times show they take some power away. I have not dyno'd either. John

[Steve27]

Coldaswell said:

Short of making the car electric, does anyone reckon they could get the car quiet enough to get round Bedford?

Where did you get yours Zuluracer?

In reply. We managed to get our 1500 SR3 running on carbs out at bedford. Had to fit one of merlins mufflers, and short shift by noise meter after first corner as we were getting close (although they would say how close) but ran fine. will post pics of system we have if anyone interested.

[Blatter]

Coldaswell said:

Short of making the car electric, does anyone reckon they could get the car quiet enough to get round Bedford?

Where did you get yours Zuluracer?

Bedford should be do-able with mine now as I'm under 98dB and they work on <100dB static and 96db drive-by don't they?

[Sigmamark7]

Blatter said:

Bedford should be do-able with mine now as I'm under 98dB and they work on <100dB static and 96db drive-by don't they?

And mine in a couple of weeks after a visit to Neil Handbury! Couldn't get the price down and the system for mine is going to cost me £450, but the difference is less than it's cost me in lost track time while I have messed about with add on silencers which didn't work, so all in all, I think it is money well spent. It will also avoid the necessity to lift passing the drive by meter at Bedford, which will make Bedford even more fun. Maybe see you there Adrian!

[jensenradical99]

HERES MY SYSTEM, YET TO TEST IT THO !!!!