Temporary Noise Reduction

[Guest]

Got a cup pipe etc and I got refused at Oulton then managed to get through. I think taht was at 105 but on that basis I thing I've got nxt to no hope at Bedford or pretty much anywhere else for that matter?

Don't really want to change the back box for a C2 (mel what would you say the power reduction is...would I really feel it?). Anyone got any suggestions as to perhaps temporary alternatives? I noticed that Easytrack suggest they hire a temporary solution? And I saw a 964 Yellow RSR in a picture from a recent Bedford event with what looked like something strapped to its tail pipe

I seem to remember my 996 having a little button you could press which altered the sports exhaust? or am I dreaming?

Thks

 

[vic cohen]

Jimbers i ve got a couple of Super Trap thingees made up , Mel calls them medeavel mortar launchers , that i havent needed for the 993 s ...........u might have to make up a length of pipe to connect or u can just try one and see , they were the 'gauge ' for Car Graphic .............just bell me if u want to try

 

[Yoda]

I looked into this once as I was contemplating a cup pipe. I saw an ad at a garage outside Castle Coombe Circuit, advertising exhaust noise reduction presumably some sort of SuperTrap contraption as Vic is suggesting. Contact details are as follows, may be worth a call to see if they have something.

The only other thing I could think of was changing the rear silencer for one of those boxes that have an option of two straight through pipes or going via silencer if caps were put on the straight throughs. Looks a bit 70's but seemed effective from a noise point of view. I am pretty sure that I read an article in a magazine or on the web about someone who did this quite recently on an early 911 - unfortunately can't remember where. Give Haywood & Scott a call and see what they say.

Circuit Motors
Castle Combe
Chippenham
Wiltshire
SN14 7EY
tel. 01249 782596

 

[38F3E1]

ORIGINAL: Yoda

The only other thing I could think of was changing the rear silencer for one of those boxes that have an option of two straight through pipes or going via silencer if caps were put on the straight throughs. Looks a bit 70's but seemed effective from a noise point of view. I am pretty sure that I read an article in a magazine or on the web about someone who did this quite recently on an early 911 - unfortunately can't remember where.

It was probably the Autofarm one you saw. They make one for early 911s and have details on their website.

Ian.

 

[Melv]

I have a bolt-on replacement tailpipe silencer you're welcome to borrow, but I doubt worth more than 2db.....

It may also need re-packing. I've got the stuff, if you want to do it and get the top welded back on.

 

[SimonExtreme]

James

I have been worried about this and I have looked for potential solutions. The bottom line is that all but one seem to lead to reduction in power (see below). I also suspect that if you were at 105db, there aren't many trackdays that you will get through so looking for a permanent solution might be the way to go.

Firstly, a little background. My car, a "normal" RHD car, has been de-catted and has a cup pipe. This means that it is totally relying on the rear box for all the silencing. Due to the size of the box, its not really very good at it. In addition, because of the shape, it not only is bad at silencing but its not very good in helping free flow. However, if you put back the C2 box and go for a G pipe, that is worse for power as the C2 is very restrictive. So, the answer is to remove the small final silencer and the cup pipe and get a decent rear box that goes across the back (where the cup pipe is). I have spent a fair amount of time speaking to Haywood and Scott and am pretty confident that a new rear box from them would be quiet enough AND give the same or maybe even better power than a cup pipe. This is because it would eliminate the tortuous twists around the small real silencer.

Is your car a standard car or a cup car. Has it been de-catted? Are there any other factors that make your car noisy? I am trying to judge if I would get the same result noise wise from my car.

 

[Guest]

Simon,

As far as I'm aware I have a de-catted cup piped "normal" RHD.....but it does sound very luvverly. The original pipe across the back was replaced by Autofarm (the orginal was a real heath robinson job) and I think they put on a Cargraphic one. I'm not sure about its decattedness but after the main pipe there is still the G pipe before the stainless exhaust "hole" bit.

Airbox is standard and as far as I'm aware all else is standard?

I was just planning to put on a std C2 box as per Mel's cup car. I can't believe at my level a couple of hp here or there is gonna make that much difference?!

How much are Haywood & Scott asking for their solution?

James

 

[Jamie Summers]

I'm in the same situation - decat and cup pipe (and cup airbox with K&N) producing too much noise on my C2. James, although I failed the static test at Bedford I was fine on the drive-bys, so don't be put off giving it a try.
I have been thinking about going down the Hayward and Scott route, but have yet to make serious enquiries. A full bespoke header to tailpipe set-up would be very tempting (plus a Wayne Schoffield remap to go with it), but I suppose the cost would be prohibitive. So I would be very interested in a 'bolt on' rear section solution - I wonder if they might be interested in a group purchase ??????

Jamie

 

[Yoda]

Jimbo

My car is standard except for the filter/airbox cover and I must admit having driven several RSs - some standard and some lightly modified(eg chip, exhaust etc), including yours I think the difference is pretty negligible. Agree the fruity noise is fantastic but I am yet to be convinced that extra bhp is going to make a noticeable difference for an everage driver. Switchable exhaust would be perfect, but expensive.

Only way to tell would be to have a dyno day and/or trip to Santa Pod for a run-what-ya-bring event.

Mel - there was a Dyno day at JZM a couple of years back, what are the chances of them inviting us back again? Not sure re details of previous event but if you want to give me a call, I'm happy to ring them and try and arrange something. WOuld be good to have arange of cars in std - modified state to see what the real differences are.

Regards

 

[Guest]

.....Jamie, thanks for the insight...I spoke to GT3's Glenn Mc today about his difficulty at Bedders....his prob was the other way round....sailed the static and failed the driveby when his new Manthey setup got going.....!

So I'm going to give it a go Friday and see how I get on.

F'oz you know I agree with you.....all this chasing little bits of BHP ain't gonna make a fat lot of difference to me....so I'm saving up to to buy a either a 3.8 RSR or a 993 RSR...oh yes you know it makes sense!

So until then if I pass on Friday then so be it.....I'll wing it everywhere until I get bounced somewhere! If I get bounced Friday I'll just go for a C2 box be done with it.....

anyway.....the less BHP you've got the more incentive you've got to get better at going round the bends quicker! yippeeeeeeee!

 

[Yoda]

Jimbo - will you have a C2 silencer for the 23 April if you don't get through on Friday (I like that you are having a cheeky practice session before we all go, John is there tomorrow doing a Palmer day).

Good luck.

 

[Guest]

If I get bounced matey then I'll be on the phone to Steve at Jaz for a full service, new disks and pads (pagid something or other) and that blue stuff, C2 box and possibly a cup air filter on the basis that I'll take it (BHP) off one end and put it on the other! Probably doesn't work that way but as I've said it doesn't really matter at my level!......though I have to say I was pretty pleased with myself when I bumped into Bruce Attwood and he told me his dad thought I was OK but crazy!!!!!! []bt thats probably why I managed to end up in the gravel with your mate in the car at Donnington? ooops...he is ok isn't he?....so I toned it down at Oulton and had a much better time!

also mel & vic thx for the offers of various bolt on goodies....as always much appreciate the offers of support!

 

[Melv]

Jim -want to borrow my Tudor mortar? -worth a couple of decibels....five min. job to replace the tailpipe.

 

[Guest]

Mel, yes as a precaution.....bt where are you the rest of the week?.....I'm down in town Thursday bt clearly let me know your movements and I'll see from there?

 

[vic cohen]

Tk Heavens , working from home Thursday.................dont ask Steve to use blue B Fluid he hates it and has much better stuff!

 

[RSR]

Jim I'm a bit confused as to what your car is running. You mention Cat and cup pipe, but also mention the one at the rear was replaced by Autofarm for a Cargraphic. A cup pipe means there is no silenser across the rear and it is just a straight through pipe. a Cat bypass means the cat behind the left rear corner PU is replaced with a pipe and there should be a final silenser behind the right rear PU, if that is missing and you have a big space then you also have what they call the G pipe fitted.

 

[Guest]

Paul, Let me take a butchers and whats there and I'll post it up!

 

[SimonExtreme]

Jim

Sorry for the delay in replying. I am assuming from what you say that you are running a cup pipe, probably decatted but have the final silencer in place. I the exhaust is from H&S is about £750 and this goes across the rear of the car and then straight out to the rear. It doesn't follow the route of the rear box and does away with the need for a G pipe.

Because of the less tortuous route, it should be rather good on the power front. I believe that it will be better than a cup pipe and the standard rear box combination as the rear box is very tortuous. I also don't think you are talking about only a few bhp. I would expect that the difference between a system with a C2 box and the "G" box and the H&S single box will be about 15bhp. What I am uncertain of is how much of that you would unleach without a remap. I would expect most of it.

Based on other cars, I would expect to get 15bhp from this, 5-7 bhp from the air filter and up to another 15-20 bhp from a chip remap.

 

[Laurence Gibbs]

I'm as confused as Paul on just what silencing you have if any. Sounds to me from your description that you are not running any silencing at all!!!! which would explain the noise test failures.

 

[Guest]

As a follow up to this post....after 2 tests on the gate at Bedford I got the red sticker at 106dba static....and guessed I was in for an early bath. However one out I didn't trip the drive by's anywhere....unlike poor old shaun in Dessies beauty with that twin pipe exhaust...poor chap was having to short everywhere.

I now have pictures.....but in the meantime I have a pipe coming from the engine into what I guess is the CC to a straight pipe across the back which then goes into a small box on the drivers side and out to the exhaust?

What's the static drive by procedure at other tracks. I thought the process of suck it and see at bedford was good....and similar to Oulton. Are goodwood, snetterton, brands and castlecoombe the same?