Loud Exhaust (too Loud!)

[DavidM777]

Hi

I am at Goodwood next week and think I need to quieten the car down.

The exhaust is straight through, except for the last box on the right of the car before the tail pipe (i.e. no cat, and cup pipe). It was 107db at Castle Coombe and needs to be about 105db for Goodwood next week.

I can get a standard main rear box to put in place of the cup pipe.

Any views on if this will take the noise levels down and also if it will restrict the performance?

Thanks for your help and see you there next week if you are going to be there.

David

 

[Jamie Summers]

David,
I have an exhaust tip with a removable silencer core which a friend of mine has put into small-scale production .......
He has a friend who makes bike exhausts and thought it would be interesting to apply a bit of bike science to a car tail pipe. It's a nice stainless tip with a removable core (takes five minutes to install - just one bolt to fit the tip). Then the core itself can be removed with one small allen-head screw.
On his car (a seriously 9m MoTeC tweaked 964 C2) from memory it reduced the noise from 105 to under 100 and cost only 2bhp on 9m's dyno. On my car it reduced noise from 108db to 105db, more importantly it brought the drive by noise (as measured at Bedford) to 84db so I was able to drive flat out all day (my car has previously been black flagged at Bedford for drive by noise !) Basically it means I can effectively get onto any track on anything other than a "quiet" day.
From memory they're somewhere around the £200 mark, and are a bit of a no brainer as far as I'm concerned !

Let me know if you're interested and I'll send you my friend's email address.



Jamie

 

[DavidM777]

Hi Jamie

Sounds good to me. Please would you let me have his contact details and I will get in contact with him. Only problem is I will need something for next Thu!

Thanks

David

 

[Matt]

david

i have one of jamies mates exhaust tips - i can vouch for the workmanship.

my car now 100/101 static with all standard silencers & this tip in place (dependent on rpm) and i've done a castle combe and bedford days with no probs at all

 

[911addict]

How easy is this special tip to fit? Does it just insert into the tail pipe? If so, can I have the contact details too?

 

[Ian964]

ORIGINAL: DavidM777

Hi

I am at Goodwood next week and think I need to quieten the car down.

The exhaust is straight through, except for the last box on the right of the car before the tail pipe (i.e. no cat, and cup pipe). It was 107db at Castle Coombe and needs to be about 105db for Goodwood next week.

I can get a standard main rear box to put in place of the cup pipe.

Any views on if this will take the noise levels down and also if it will restrict the performance?

Thanks for your help and see you there next week if you are going to be there.

David

I had the same exhaust set up as you on my C2 (cat+primary bypass and standard secondary) - just fitting a standard primary muffler brought the noise down enough to be able to get on at Bedford, which has quite low limits.

The cup car I've just got has a primary bypass, normal cat and secondary, and passed a Goodwood 105dB test a couple of months ago (was about 102dB according to the PO).

Jamie, I'd appreciate the contact details for your friend.

thanks
Ian

PS I'll be at Goodwood next Thursday as well.

 

[Steve Brookes]

This should help you guys that are interested in Will's exhaust tip.

http://www.pistonheads.com/gassing/topic.asp?h=0&f=48&t=359516

You'll see that it replaces the standard exhaust tip and therefore should take only about 15 minutes to swap.

 

[Jamie Summers]

Thanks for posting that link Steve ! You can email Will through his profile on Pistonheads. He usually has a few ready to go, so David you might be OK for Thursday if you're quick !

Jamie

 

[Matt]

jamie - hope you're taking a cut on all of these tips you're flogging...or will we see will in a new '64rs at the next trackday []

 

[Stewart H]

Anyone know how the Scart tip performs? It is a similar sort of product.

 

[DavidM777]

Thanks for all your help guys.

I am actually having a primary box fitted tomorrow in replace of the cup pipe for Thu and then will get one of these things from Will and flog the primary box on ebay!

See you at Goodwood if you are going to be there.

David
Purple 964 RS

 

[DavidM777]

One last thing - does the primary box have a negative impact on power? Or is it just noise. My car has neverh ad one whist I have had it and at the last test ran just over 300 bhp.

Thanks

David

 

[Jamie Summers]

Matt,
Sadly no commision, just trying to help out

David,
If your car is putting out over 300bhp then I suspect it's had rather more work than just the Cup Pipe (forgive me if it's all documented elsewhere .....), so as a part of a package replacing the primary silencer will probably cost you a little bit of power.
Accepted wisdom has it that the Cup Pipe on it's own is not worth more than a couple of bhp at most, so whether you have it or not is marginal in terms of power, but is a decent weight saving (where it counts) and makes a nicer noise.
However, the Cup Pipe is vital as a part of a package to maximise other mods (decat, airbox, hot-film, MoTeC etc). When / if you do get one of Will's tips then I would definitely put the Cup Pipe back on.

Jamie

 

[DavidM777]

Thanks Jamie

As you guessed, I have Motec, larger jets, no cat. I have had the primary box put on now and it seems okay, may be a bit less sharp on the uptake - but definitely sounds too mature for me. I'll take it off as soon as I get the quiet track days out of the way and give one of Will's trick pipes a go.


Thanks for all your help everyone!

David

 

[Jamie Summers]

David,
For ref. I have MoTeC (335bhp on 9m's dyno !), decat and Cup pipe, with custom 9m air intake. Without the exhaust tip I'm 108db, with it I'm 105. I would expect your car to produce almost identical figures.

Jamie