Getting my exhaust made quieter

Well a Ring trip this spring with my mates was about to be called off when I realised there was a 95db limit on the track.

I phoned a place called AAS in Newcastle to see what they could do. He did as sound test & it was 105db @ 5000rpm

There were a couple of options, larger silencer, valve in the exhaust. Seeing as I have a HKS Ti exhaust I was a little reluctant to replace the only bit that titanium on it so we came up with a sweet solution.

Basically, as the HKS back box is removable, he's going to make me a larger silencer section, so the HKS back end can be unclipped & removed & the quieter back end can be put on (for when I need to tone it right down). When I feel like being noisy I can put the titanium tip back on

He's also doing me an electronic 4" valve in the exhaust which is adjustable from within the cockpit via a button, then I can pretty much remove all noise at the touch of a button (for when I'm getting off the drive early on a morning etc).

Well chuffed about the whole setup, Nurburgring here we come.

How much is the adjustable valve? As i would be very interested

How much is the adjustable valve? As i would be very interested

Approx £350 for the 4" one bud (pretty sure that includes everything to control it from within the car). He showed me the 3" one they have in, it's a well put together piece of kit, makes the Apexi ones look a bit feeble TBH.

I can let you know what I think about it at the end of the month Jon, get sound clips etc.

I know £350 is a bit steep, but it's that or not taking the Supe to the Ring, so it had to be done

i'm in need of something to tone down the sound of my exhaust , you see i'm only a feeble N/A and combined with a super dragger its quite loud .

I was thinking of trying to do something with my second cat .... Like remove it and get a custome piece made that fits in with a silencer in it but it would need to be a small one or some kind of thin oval to help keep ground clearance , Plus it would give me a few more ponys having the second cat removed .

What do ya think guys does this sound as if it would work or should i just go for one of these valve options .

I'm pretty sure that the valve affects performance as it quietens, where as a silencer does not affect performance as much (if it all) as it is not restricting the size of the pipework. I went for the silencer option to keep as much HP as possible, but then the additional valve to quieten it right down for specific scenarios.

If you go for a valve, I wouldn't like to say what would happen if you went round everywhere full throttle with it half closed, EGT's would be up I reckon.

I'm going a different route with mine, redesigning the whole thing around a Tanabe exhaust. Have you already plumbed the screamer back in? (they have spys around the track with noise testers apparently).

I'm basing my figures on being able to do UK trackdays as well as the 'Ring and will be aiming for sub 95db. I've got the noise tester now so on to the expensive bit

more details on this valve please

the valve is going to increase back pressure and decrease the boost. It will be like having a restrictor ring in there

the valve is going to increase back pressure and decrease the boost. It will be like having a restrictor ring in there

Yeah but if I read correctly he's only going to use it when he needs to be super-quiet i.e. early mornings.

After deciding that adding another silencer to my system wouldn't fit, i have been thinking of of motorising the apexi valve that i have fitted, and using the EMU voltage switching map to control it by RPM or load, just got to find a motor that is suitable, as there is no way I'm going to pay £350 for something that i can probably knock up for £40;)

I was going to use the TRAC motor, bought the Apexi control valve and fitting kit, but just fitted a Tanabe and re-plumbed the 60mm screamer, now its as quiet as stock.

So have a complete Apexi control valve/track motor etc surplas if anyone needs one

Have you already plumbed the screamer back in? (they have spys around the track with noise testers apparently).

Yeah, no screamer on mine, it's routed back in, I'm aiming for a 95db limit too

more details on this valve please

If you're after specifics I'd give Stu a ring at AAS (will dig the no out soon).

the valve is going to increase back pressure and decrease the boost. It will be like having a restrictor ring in there

Hopefully Ill have it full open when I'm booting it, so the only restriction it should cause is the profile of the buteryfly valve (ie a thin sliver of metal). Plus as it's going in the 4" section, it won't be the most restrictive part of my exhaust anyway(my down/midpipe is 3")

After deciding that adding another silencer to my system wouldn't fit, i have been thinking of of motorising the apexi valve that i have fitted, and using the EMU voltage switching map to control it by RPM or load, just got to find a motor that is suitable, as there is no way I'm going to pay £350 for something that i can probably knock up for £40;)

Totally understand bud, I wish I had the skills to make these sort of things myself, would save a fortune.

I have a redundant TRAC motor but thought it might be a pain to wire up, i thought a window motor might be just the ticket;) however i have thought about using a turbo actuator, that way as soon as there is positive boost pressure, it will start to open the valve, so totally load based, heads for workshop;)

Approx £350 for the 4" one bud (pretty sure that includes everything to control it from within the car). He showed me the 3" one they have in, it's a well put together piece of kit

HOLY CRAP fella, this is the one i'm looking at http://store.summitracing.com/egnsearch.asp?N=401127+115

they do 3" and 4" even with import duty you would only be looking at about £120, your man has put some mark up on that unless its with the electronic controller

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group buy anyone ?

HOLY CRAP fella, this is the one i'm looking at http://store.summitracing.com/egnsearch.asp?N=401127+115

they do 3" and 4" even with import duty you would only be looking at about £120, your man has put some mark up on that unless its with the electronic controller

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group buy anyone ?

I may be getting my prices confused here then as that looks like the same one to me , it might be £350 for that & the backbox silencer he's making, will confirm when I speak with him

you also need one of these, only in America http://store.summitracing.com/egnsearch.asp?N=400996+317597+115&autoview=sku

you also need one of these, only in America http://store.summitracing.com/egnsearch.asp?N=400996+317597+115&autoview=sku

Lol,

I tell ya if he is charging me £350 for the valve I'll be seriously p!ssed

I may be getting my prices confused here then as that looks like the same one to me , it might be £350 for that & the backbox silencer he's making, will confirm when I speak with him

This is exactly what I have on mine, 4 " exhaust and massive backbox, custom made by AAS. £350.

They also plummed the wastgate back into the exahust and lowered it off the car a bit - ex was catching on lift off.

It made a massive difference to the noise; now very quiet by comparison.

The existing BL backbox (I gave it to Darryl) was like a megaphone!

It got rid of all the top end exhaust note, but now all I can hear is drone between 3-4k..

I also looked at valves, but after talking to Michel and reading up they looked like a nightmare; most are manual, and prone to siezing.

I could not find one that looked decent, so I started a new tactic; I wrapped the entire front section in heatwrap to kill the drone; it worked well, so I now I intend to double wrap the rest (the biggest drone section) and I'm putting two supporting alloy 90 degree 1/2 box section strips on either side of the exhaust between heatwrap (2 layers) and that should kill the drone. (dampen the oscillatons)

I was going to get aas to mfr a second in line silencer but on a 4" system it's just not possible; no room at all!

I need to find a ramp to finish the work...

ps the box is good; I defy anyone else to get a bigger, quieter box in the space provided.. and the finish is excellent! I was severley stunned at the quality of work.

I wonder if that's where the £350 came from, I should really pay attention when people talk to me

where is this AAS

ps the box is good; I defy anyone else to get a bigger, quieter box in the space provided.. and the finish is excellent! I was severley stunned at the quality of work.

Yeah they do some quality work, they made me a custom manifold for my old MR2, I do find it hard to believe they'd put a 300% markup on an item they've bought in (which was why I was a little bit miffed)

where is this AAS

Newcastle bud,

I was going to use the TRAC motor, bought the Apexi control valve and fitting kit, but just fitted a Tanabe and re-plumbed the 60mm screamer, now its as quiet as stock.

So have a complete Apexi control valve/track motor etc surplas if anyone needs one

which tanabe did you get?