PECO exhaust - noise tests

[TomE]

Has anyone who's fitted a PECO exhaust had it noise tested? I'm thinking of fitting one to my 1991 SE and, given comments here about it being louder, am worried about falling foul of noise limits on the track days I do.

Most recent measurements for me and a bunch of largely standard SEs/S2s was 84-92db static/drive-by at Goodwood versus their limits of 96db ("quiet day") and 104db ("loud day"). Some non-standard Elise/Exige/Esprit got sent home for being over the limit.

I've got a K+N filter and BBR conversion - is that likely to cause boost creep or other problems with adding the PECO?

Thanks in anticipation for your collective wisdom!
Tom

[Dico]

Monty's was quoted ae being 95 at Oulton, that was with the optional second silencer fitted.

[Monty]

Tom

As Dico said mine was 95 db`s static at Oulton. The Peco i had fitted was louder than normal Peco and we put this down to the custom down pipe (stiffy) which replaced the cast iron lump after the turbo. So need a 2nd silencer.
You should be fine, but u could always ask Dave at peco to do u the 2nd silencer.

Are u a member of LoT, i`ve just join this year and got in to trackdays, infact i`m at Cadwell this saturday

You won`t get over boost with a BBR as there little blackbox cuts the safety feature In the near future u may want to got down the ESM chip route.

[TomE]

Thanks Monty, that's useful info. I'm mainly tracking through Club Lotus Surrey Area, who have a regular couple of slots per year at Goodwood, my nearest track. I've done a couple of Brands session with Easytrack but found them a bit too crowded and more expensive/less track time compared to the club ones. Had seen about LoT and wondered about doing something with them - will look at what's on offer now the weather's picking up!

Interested in your comments about ESM chips - guidance on the website suggests it's not compatible with the BBR conversion (FDC issue). Do you know differently?

[ailwyn]

Interested in your comments about ESM chips - guidance on the website suggests it's not compatible with the BBR conversion (FDC issue). Do you know differently?

Monty means replace the FCD/BBR with an ESM chip - 0.9 bar boost but still retains the safety features.

Ailwyn

[Monty]

Yep,

You can unplug the wires on the blackbox and plug the wires back to stock (well u can on Dico`s BBR kit) then it`s just a case of removing the fixed bleed insert which is in the vacumm hose coming from the turbo which also bypasses the BSV which will need reconecting.

The only thing is cause the black box has been disconected u could end up over boost with the Peco exhaust and hit the fuel cut. With the ESM chip u might get away with it as the Fuel cut has been raised slightly IIRC 0.98

[TomE]

Dave very kindly put his own Elan (with this exhaust fitted) through a noise test to help me judge if I needed to order the extra rear box to pass the Goodwood track noise limits.

His figures were: at a steady 5250 RPM, 1 metre from the tail at 45 degrees, 94.7db. Increased to 95.3 db on the overrun. The strictest limit at Goodwood is 98db under these conditions (or 96db at 10 metres on drive by), so I should be fine.

For comparison, my current Quicksilver exhaust measures 86db static and 84db drive by.

[Monty]

I never got black flagged at Bedford and thats 87db drive by.

[TomE]

A further update: I've now got my PECO exhaust fitted and had the car noise tested at Goodwood on Saturday: 94dB static at 5250rpm, near enough same as Dave's results. Great sound and a noticeable performance increase too.

[Monty]

Did a trackday at Donny on Sunday, they never did a static test but Donington has one of the most strict drive by noise testing and i never got black flagged

[Doug]

Did a trackday at Donny on Sunday, they never did a static test but Donington has one of the most strict drive by noise testing and i never got black flagged

had you been black flagged then you'd have to find out if it was the noise or just yer driving skills

hope you got good practice in cause you know we'll be checking to see who does the fastest lap come March!

[Monty]

had you been black flagged then you'd have to find out if it was the noise or just yer driving skills

hope you got good practice in cause you know we'll be checking to see who does the fastest lap come March!

Did you mean poor drivng skills lol

Don`t know about your side of the pond Doug but here there getting strict on the noise level here, if your over the limit you`ll get a black flag they`ll give you 1 chance to quiten the exhaust or back off were the noise meters are but if you get another black flag then it`s home time

Doug, does that mean your coming to Donny BTW there`s no timing allowed on trackdays, anyone caught doing so will be asked to leave the circuit and that includes spectators. Anyways i could always speed up the video footage

[Plus2pete]

I had my PECO exhaust fitted a couple of weeks ago at my local Universal tyre and exhaust shop at the knock down price of £30 and it only took 40 minutes. I also had the opportunity to take a good look underneath while the car was up on the lift.

But I digress, last weekend as the weather was nice I took a blast down to Goodwood to get a noise test as I'll be doing the Surrey area track day in May. To my surprise the test came out at 100dB!! I knew it was loud but not that loud!!

I got on to Dave at PECO who was quite surprised and said it would be difficult to fit a second silencer and to his knowledge doesn't know of a muffler to fit an oval tail pipe. Dave is looking into the problem and I'll post his response, but if anyone has any ideas they'd be greatly received.

':oops:'

[GeoffSmith]

A lot of the high frequency harshness goes after getting a good coating of soot on it. Check it again after you've driven it for a thousand miles.

[Plus2pete]

Thanks Geoff,
I thought that might be the case, I know stainless systems can be a bit noisy at first but will quieten down over time. I like any reason to take the Elan out for a drive. I'd also like to fit an Everest Chip before the track day, so I'll be in contact soon.

[DeeAitch]

I had my PECO exhaust fitted a couple of weeks ago at my local Universal tyre and exhaust shop at the knock down price of £30 and it only took 40 minutes. I also had the opportunity to take a good look underneath while the car was up on the lift.

But I digress, last weekend as the weather was nice I took a blast down to Goodwood to get a noise test as I'll be doing the Surrey area track day in May. To my surprise the test came out at 100dB!! I knew it was loud but not that loud!!

I got on to Dave at PECO who was quite surprised and said it would be difficult to fit a second silencer and to his knowledge doesn't know of a muffler to fit an oval tail pipe. Dave is looking into the problem and I'll post his response, but if anyone has any ideas they'd be greatly received.

':oops:'

Im sure someone on here has fitted a sub muffler in the straight run up from the centre tube to the muffler?
Cant see an Oval taipipe making much diff but doesnt the Peco already have one

[Monty]

But I digress, last weekend as the weather was nice I took a blast down to Goodwood to get a noise test as I'll be doing the Surrey area track day in May. To my surprise the test came out at 100dB!! I knew it was loud but not that loud!!

Now that is loud and i question on how it was tested since TomE is only getting 94dB static at 5250rpm



On a Static test

Noise checks to establish adherence to the relevant limit will be conducted in accordance with current measuring methods as defined by the MSA. Essentially this means that the noise test shall be measured from a position 0.5m behind the exhaust at a 45 degree angle, with the engine running at ¾ maximum revs.

[TomE]

Now that is loud and i question on how it was tested since TomE is only getting 94dB static at 5250rpm

100db seems way off - that's up with Stage 2 Elises and earlier Esprits! Mine was also tested by the Goodwood marshals and my PECO had only been on for two days - less than 100 miles worth of soot.

It might be poor measurement; seems unlikely that poor fitting by Universal would cause that big a difference. Anything else non-standard on the car?

If you look on the demon tweeks site I think they've got some re-packable Supertrapps with either an oval or a split circle fitting. Otherwise it's some bean cans, wire wool, jubilee clips and a bit of DIY. But you deffo need to sort it in advance or they won't let you on the track.

And if you mean the 3rd May Club Lotus day at Goodwood, I'll see you there!

[chris.t]

was it you pete i saw at Goodwood on Saturday? can't believe you had such a high reading, hope you get it fixed by May. I'll see you there if you do!

[drasicjazz]

I follow this PECO sound story with great interest as i'm looking of buying
one ...
maybe a silly question but does anyone knows the Db of the standard exhaust, to have a bit of a reference?

I'm still 5 months away from my car otherwise i could measure it myself