32 replies to this topic

[Matthew Bentley Racing Ltd]

Hi All,

 

Thought I would put a post up to get the ball rolling and see the interest. Some of you may know I have been working on Bill and Graeme's car for some time to come up with a track friendly full 3" exhaust system. It has been a long process for a few reasons and in the middle of it I got to a point and just didn't think it was possible with the space constraints. 

 

I am on about version 9.7 now  but think we are there. The system spec is:

 

- Full 3" pipework
- Twin 3" Flowmaster silencers
- Single or double lambda bosses
- Single or twin outlets
- No cat option currently

 

The static noise figures are using the only others I could find, they are from Bargi's system which I believe is the quietest other option??:

 

Bargi/DH VS mine:

Tick over         84db vs 84db
2000rpm       90db vs 87db
3000rpm         91db vs 88.4db    
4000rpm        95db vs 90.2db
5000rpm        98.5db vs 93.4db

 

Most traditional silencer systems silence the low-mid frequencies from the full range of frequencies travelling through the system. The silencers I have used silence the higher end of the frequency range, the 'peaks' of these higher frequencies are the ones that set off noise meters. 

 

I am also working on a trick twin outlet that should help even more, this will be available very soon (with any orders placed).

 

We are out track testing on the 2nd May for driveby readings. 3 people have already placed orders and are in build.

 

Prices will be: around:

 

£1150+vat for single exit

£1225+vat for twin exit (trick outlet)

 

Any interest? Thoughts? Questions?

 

These photos are of the MK1 version, the pipework is routed differently now, but gives you an idea of the design. I will upload more once the second system is made.

 

 

 

 

Thanks

 

Matt

[Exmantaa]

Repackable?

Performance of the system on long term will be interesting for the big SC's...

 

(Thought of a similar system with 2 mufflers, only would use longer ones and route the pipes differently with wider U-bends for flow; Downpipe > wide U (with possible cat) > rear muffler > tight U > front muffler > 90° >To back middle or side exit. But no idea of such can be made to fit...)

[techieboy]

Any numbers for drive-by's, Matt?

 

Those are my real problem as I've never had an issue passing static tests (even at Bedford) but the soon as the car is driven in anger, it all starts to go wrong and I can see the marshals dusting off the black flag.

 

Maybe wise to make allowance for some kind of plug-in DB killer with the tailpipe(s), just in case.

[Matthew Bentley Racing Ltd]

- Silencers are sealed - but can cut and repack if needed in the future

- Can get these silencers any longer or I would have and just used one - the twin silencer was the hardest part to make fit

- The pipework actually enters the other end of the silencer from the one in the photo to make it able to fit in a completely oe setup (std head shields etc)

- No long term knowledge yet as no-one has had one yet, but in general I thing all high hp SC cars will struggle with long term durability because of the temps. On the race SC 2-11s we had to repack after every race. 

- Plug in db killer is easy

- Drive by figures will be available on the 2nd.

[WrightStuff]

Any numbers for drive-by's, Matt?

 

 

He wants to be able to go WOT at Donington ! 

[Matthew Bentley Racing Ltd]

Donnington do noisey days...................... 

[techieboy]

He wants to be able to go WOT at Donington ! 

 

I'd like to be able to go WOT, full stop.

[The Batman]

Out of curiosity, can you not spin the system around to get rid of the first long pipe in the system? Would mean the first u bend wouldn't be that tight then? Or is this needed for peak noise thingy majigs?

[Duncan VXR]

Looks nice Does it fit with clam on? Is the price inclusive of fitting? What was the db with twin tailpipes? Be interesting to see both systems tested on the same meter, not sure if spec differs much between bargi and your one? I do love a good bit of data and found historically when doing upgrades most did not want to test back to back or had any data which is boring lol With track noise levels becoming ever more of an issue quieter running cars is the only real way forward it seems DG

[FLD]

Looks good, nice to see some effort going in.  If its of use you can buy custom end plates from Birchills to make up silencer boxes whihc would make experimenting with larger or repackable boxes easier.  Happy to help out if you need me to. 

 

IIRC flowmaster used to do plated boxes (packing free) that I guess work in a similar fashion to milteks.  It would be interesting to see if they work better than a traditional packed box.  I appreciate someone has to bank roll this R&D so it may not happen but it was a thought that ran through my head when I saw the flowmaster brand.

 

I wonder if some spectral analysis would be useful to see where the noise levels are being produced.  This may help with sizing silencers (and or resonators) to reduce certain levels.  I have no idea if this would be general enough to work beyond a single car though, its just a thought that ran through my head.  A plus side would be it could save fabrication costs if it steers you well.

 

If it helps I have a full 3" tullet with cat and decat silencer.  I have a stage 2 SC which is fairly common if it helps for some back to back testing.

[ArticMonkey]

I'll ask before Graeme does. Group buy discount?

[Graeme Lambert]

I'll ask before Graeme does. Group buy discount?

No point for me mate... I already have one!

[chris_uk]

at that price why wouldn't you just go for a full 3" tullet inc manifold? it has repackable silencers with the high temp filling stuff, it lasts ages and wont be a problem for a high powered cars so its an upgrade you only have to do once.. and then if you are slightly too noisey on a drive by fit the noise reducer. i think i am about 100db on static at 5.5k with no reducer.

[smiley]

and wont be a problem for a high powered cars

 

Didn't your's have the HJS cat in the middle?

(one of the dutch guys already destroyed the stock cat from his 3" tullett system)

[chris_uk]

yes mine does.. but any cat you get will be destroyed unless its a HJS one (for the high powered lads anyway)

[Matthew Bentley Racing Ltd]

Looks nice Does it fit with clam on? Is the price inclusive of fitting? What was the db with twin tailpipes? Be interesting to see both systems tested on the same meter, not sure if spec differs much between bargi and your one? I do love a good bit of data and found historically when doing upgrades most did not want to test back to back or had any data which is boring lol With track noise levels becoming ever more of an issue quieter running cars is the only real way forward it seems DG

 

It does fit with the clam on as long as you already have the tullet manifold fitted.

 

Price excluded fitting.

 

Have only tests on twin exit with one of the outlets being a dummy.

 

Happy to do back to back readings on any system. 

[Matthew Bentley Racing Ltd]

Looks good, nice to see some effort going in.  If its of use you can buy custom end plates from Birchills to make up silencer boxes whihc would make experimenting with larger or repackable boxes easier.  Happy to help out if you need me to. 

 

IIRC flowmaster used to do plated boxes (packing free) that I guess work in a similar fashion to milteks.  It would be interesting to see if they work better than a traditional packed box.  I appreciate someone has to bank roll this R&D so it may not happen but it was a thought that ran through my head when I saw the flowmaster brand.

 

I wonder if some spectral analysis would be useful to see where the noise levels are being produced.  This may help with sizing silencers (and or resonators) to reduce certain levels.  I have no idea if this would be general enough to work beyond a single car though, its just a thought that ran through my head.  A plus side would be it could save fabrication costs if it steers you well.

 

If it helps I have a full 3" tullet with cat and decat silencer.  I have a stage 2 SC which is fairly common if it helps for some back to back testing.

 

 

Outlets if something I have been looking at a bit. I think something to help stop the outlets resonating will definitely help, along with more work just before the 'y' to cancel even more of the pressure wave.

 

They do quite a lot of plated boxes, I looked though most but they seem to be all for american stuff and all made from Aluminium steel, no stainless ones??

 

Again, happy to do testing. Only created the system to try and solve and issue for a couple of current customers and thought I might as well offer it and see if anyone wants one.

[Matthew Bentley Racing Ltd]

at that price why wouldn't you just go for a full 3" tullet inc manifold? it has repackable silencers with the high temp filling stuff, it lasts ages and wont be a problem for a high powered cars so its an upgrade you only have to do once.. and then if you are slightly too noisey on a drive by fit the noise reducer. i think i am about 100db on static at 5.5k with no reducer.

 

 

 

Pretty much said that to everyone who asked me for a quieter system. Actually I told them to just run a 2.5" system as I don't think it is actually that much of a restriction.

 

Made this system as everyone came back saying they couldn't get the tullet system quite enough for long enough. 

[ArticMonkey]

yes mine does.. but any cat you get will be destroyed unless its a HJS one (for the high powered lads anyway)

Not got a price from tullet have you lately? I just paid £609 for a 3" mani last month. The rest comes out more than the price of this system!

[Matthew Bentley Racing Ltd]

Damn............knew I should have gone in higher.............