Frank Catt Exhaust now fitted.

Just wanted to post to let you know how pleased I am with the services of Frank Catt. I have a 'slightly' modified 396 engine and am concerned about how to get under the 99dBA noise limit for IVA. I decided Frank's experience of building repackable silencers for GT40 race car's was what I needed, so the car was shipped down to Hailsham and Frank worked his magic. While the car was there he (and his colleague Geoff) did a few other smaller pieces of work on the car, all of which I am very pleased with.
Unfortunately we were unable to start the car to check the noise level because we had a problem with the starter motor while we were trying to start it. All being well the starter will be fixed later this week so I hope to start it soon. I will post video if it is successful.
Here is photo of Frank's exhaust on the car.
 

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That's a neat looking exhaust.
I've been to frank a couple of times and it's always a pleasure to talk to someone who's as driven as myself and also is trying to improve himself.
can't wait to see the video and hear the sound
keep us posted Lee

Frank
 
OK. The starter motor is fixed and works and the car now runs. I have recorded a video but I cannot upload it. It is a MOV file and is less than the 19MB limit. I have converted it to AVI and still cannot upload it. I can upload pictures no problem. Any ideas why I cannot upload movies? Thanks.
 
Cos Frank's exhausts are too bloody loud for the forum!! :laugh:
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Only kiddin'! (don't fall off your chair Frank :laugh:)

On checking I suspect that the size and bandwidth implications to the forum prevent this. Several thousand people possibly downloading the file via the site would be very heavy on traffic.

As a solution, how about posting it on YouTube.com and then adding a link to this thread. People can then listen / view without the site bandwidth being hammered....:thumbsup:
 
Yes Paul, they are loud ! or as soft as you want, they are fully tuneable which gives an advantage to individual requirements and performance, Frank
 
Lee, might pay you to pull a few degrees of initial timing back out, sounds like its trying to kick back on the starter just as it fires up .
 

flatchat(Chris)

Supporter
What Jac says -- but most importantly after all these years, "its going"
now lets see the rest of it -- the one and only, legendary UK DRB--lets celebrate :drunk:
 

Kelly

Lifetime Supporter
Yes Paul, they are loud ! or as soft as you want, they are fully tuneable which gives an advantage to individual requirements and performance, Frank

Sounds nice. Interesting approach as well. Sure would like to see the lay out inside that muffler. Is there still something that approximates a colllector that maintains similar scavenging/extraction to 180s?

Best,
Kelly
 
Hi all.
Another small update on the exhaust. I got the car out onto the driveway and did some noise measurements. Frank still has some work to do, but he is already on the case.

0.5m from exit at 45 degrees at 3500rpm we measured 108dB. Needs to be down to around 95dB for most track days! (99dB for IVA registration test).

Lee
 

Keith

Moderator
Jim, up until recently there are no noise levels measured on road cars (except for SVA), only track cars. How mad is that.

I have zero silencing on my 4x4 as I am trying to get the turbo to spin up faster and reduce lag for the off road bit.

I took the vehicle for it's annual MOT inspection and the tester issued me an advisory about the "excessive exhaust noise". I asked what the recommended level was and he said there wasn't one, so it's in the hands of the individual tester in the UK, but he did say, quite logically, that If I was ever stopped by the Nasties, the lack of any silencing device might well work against me!

So, here in the sensible UK, you can legally drive around the streets as noisy as you like but go to a race track near a Wimpey Estate and you're screwed.

Brave New World!

PS didn't mean to diss anyone on a Wimpey Estate. I'm sure they've got nice kitchens and things and are very quiet inside.. :)
 
I have no intention of using silencers on my P4 when it ventures out on to the open roads with its new ferrari V12. It's a bloody shame we have to use silenceders on the track, but hey ho.
 
Wouldn't it make sense to weld flanges onto the collector outputs and then either fit some small straight-through race mufflers for the street and then some "turbo" style baffled mufflers for the track? Or use a V-band clamp system?

Or slightly restrictive mufflers that you can bypass with electric cutouts both going into the same tips out the back.
 
Guys, beside the noise issues, be cautious about temparatures in the system as well, we have measured in excess of 900C in the collectors, 1018 exceeded 1000C in 2 laps at Goodwood, so not running an insulated silencer box means you need plenty of air space around the pipes and any part close to the bodywork. Frank
 
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