Exhaust back box options

[Norbert]

Hi,
My exhaust back box is probably on the way out as it started to rattle. I have been looking for replacement options but can't find a proper one. These are the options I have found:
- I could buy a 2nd hand stock exhaust. There are many on eBay but they don't look better than mine. They all look rusted, even the more expensive ones. This is still an affordable solution but I can imagine it wouldn't last long.
- Buying the eBay style sport exhaust is affordable. I tried it and I was horrified at how bad the droning was. I measured 105!!! decibels around 2500-3000 rpm. That's permanent hearing damage territory in a few hours of drive. Not fun. There may be a way to decrease the drone with exhaust baffles but still not convinced.
- Another option could be a 2nd hand unit from the US. They look much better (in pictures), no rust. Posting cost would be horrible unfortunately and I have no idea about customs.
- New aftermarket exhaust (not eBay style) like Dansk. They cost around 1k, really expensive for a back box. I have seen tons of videos revving to redline with this exhaust. I would be more interested in how much they drone. 
I am not looking for a sports exhaust, I think the stock one sounds nice as is. I am just looking for a reasonable solution to replace my slowly disintegrating exhaust.  I am sure I am not the only one facing this issue. Can you share your view on this? Thanks and happy Christmas!!!

Edited December 24, 2023 by Norbert

[½cwt]

If you think Dansk is expensive, try about £1500 from Porsche for an original one, although it does come with the two U bends and clamps too.  The Dansk systems are largely regarded as a pretty good match for OE in terms of sound and with no droning.  These are pretty big boxes of stainless steel compared to most cars, hence the high price tag to do it properly.

If you do look for second hand, it must be from a 2.5 as the 2.7 and 3.2 back boxes are supported differently under the rear of the car.

[phazed]

I’ve just ordered the Toyosports back box. Car will be used for track days mainly so hope it won’t be too loud used with standard cats.

[ANL]

I had the same problem as you. The car came with a loud Sports Box with a terrible drone. Then tried an ebay one but then failed the next MOT. So in the end I 

bit the bullet and went for a Dansk 986 standard sound S/S sports box which I am very pleased with. It did cost £1229 though but well worth it.

[jonogt6]

15 hours ago, Norbert said:

Hi,
My exhaust back box is probably on the way out as it started to rattle. I have been looking for replacement options but can't find a proper one. These are the options I have found:
- I could buy a 2nd hand stock exhaust. There are many on eBay but they don't look better than mine. They all look rusted, even the more expensive ones. This is still an affordable solution but I can imagine it wouldn't last long.
- Buying the eBay style sport exhaust is affordable. I tried it and I was horrified at how bad the droning was. I measured 105!!! decibels around 2500-3000 rpm. That's permanent hearing damage territory in a few hours of drive. Not fun. There may be a way to decrease the drone with exhaust baffles but still not convinced.
- Another option could be a 2nd hand unit from the US. They look much better (in pictures), no rust. Posting cost would be horrible unfortunately and I have no idea about customs.
- New aftermarket exhaust (not eBay style) like Dansk. They cost around 1k, really expensive for a back box. I have seen tons of videos revving to redline with this exhaust. I would be more interested in how much they drone. 
I am not looking for a sports exhaust, I think the stock one sounds nice as is. I am just looking for a reasonable solution to replace my slowly disintegrating exhaust.  I am sure I am not the only one facing this issue. Can you share your view on this? Thanks and happy Christmas!!!

Having been in the same situation as you several years ago, I'd opt for a used exhaust from a USA dry state, even with postage costs and possible import duties. The one in the photo below looks fantastic with zero corrosion on the outer seams and will probably last another 20 years. Far better than some horrible aftermarket drone box.

[jonogt6]

14 hours ago, ½cwt said:

If you think Dansk is expensive, try about £1500 from Porsche for an original one, although it does come with the two U bends and clamps too.  The Dansk systems are largely regarded as a pretty good match for OE in terms of sound and with no droning.  These are pretty big boxes of stainless steel compared to most cars, hence the high price tag to do it properly.

If you do look for second hand, it must be from a 2.5 as the 2.7 and 3.2 back boxes are supported differently under the rear of the car.

Good point about the differences between the mounting, although it's very easy to fit the later style to a 2.5...you just need the bracket like the one below.

[½cwt]

30 minutes ago, jonogt6 said:

Good point about the differences between the mounting, although it's very easy to fit the later style to a 2.5...you just need the bracket like the one below.

And the cross bar with the two bushes that bolt to the top of the box on it too I imagine, but that might be attached to a salvage box.

[Norbert]

13 hours ago, phazed said:

I’ve just ordered the Toyosports back box. Car will be used for track days mainly so hope it won’t be too loud used with standard cats.

I think it's going to be fine if you only use it on track. You won't be running the engine around mid rev. Actually it was no drone with that style of exhaust when I was accelerating. 

[Norbert]

4 hours ago, ANL said:

I had the same problem as you. The car came with a loud Sports Box with a terrible drone. Then tried an ebay one but then failed the next MOT. So in the end I 

bit the bullet and went for a Dansk 986 standard sound S/S sports box which I am very pleased with. It did cost £1229 though but well worth it.

Why did it fail MOT? 

[Norbert]

3 hours ago, jonogt6 said:

Having been in the same situation as you several years ago, I'd opt for a used exhaust from a USA dry state, even with postage costs and possible import duties. The one in the photo below looks fantastic with zero corrosion on the outer seams and will probably last another 20 years. Far better than some horrible aftermarket drone box.

Thanks! I just found this yesterday. I am checking the import duties now. 99% buying this.

[iborguk]

Ballpark £2100 for a brand new one, part 996 111 152 02.

 

[Norbert]

4 hours ago, jonogt6 said:

Having been in the same situation as you several years ago, I'd opt for a used exhaust from a USA dry state, even with postage costs and possible import duties. The one in the photo below looks fantastic with zero corrosion on the outer seams and will probably last another 20 years. Far better than some horrible aftermarket drone box.

I bought this. Thanks for recomminding this. Import duty seems to be only 4% (shipping excluded).  

[danb]

1 hour ago, Norbert said:

I bought this. Thanks for recomminding this. Import duty seems to be only 4% (shipping excluded).  

It will be 4% plus 20%vat

[Norbert]

37 minutes ago, danb said:

It will be 4% plus 20%vat

I think eBay already charged me VAT.

[danb]

Ah maybe, fingers crossed

[iborguk]

https://www.gov.uk/goods-sent-from-abroad/tax-and-duty

[Boxsum]

Be very interesting for me and sure everyone here what the total cost is if you don’t mind when you have received it and paid all duties just for reference 👍

[zagamuffin]

If buying from the states buy on global shipping programme. All paid for upfront so no nasty customs surprises. 

[iborguk]

7 hours ago, zagamuffin said:

If buying from the states buy on global shipping programme. All paid for upfront so no nasty customs surprises. 

https://www.ebay.com/help/global-shipping-program/default/global-shipping-program?id=4646

[Everywhen]

On 12/24/2023 at 6:05 PM, Norbert said:

 Buying the eBay style sport exhaust is affordable. I tried it and I was horrified at how bad the droning was. I measured 105!!! decibels around 2500-3000 rpm. That's permanent hearing damage territory in a few hours of drive. Not fun. There may be a way to decrease the drone with exhaust baffles but still not convinced.

The dB Killers do work, I have them in my Toyosport back box, I couldn’t detect any loss of performance when fitted and the car is fine on the Motorway but still sounds good when revved out on a B road blast.

This arrangement is a lot cheaper than any other solution, which for me would have been approaching 50% of the car’s purchase price. 

Spend the big money on suspension, and brakes it makes far more difference.

 

[jonogt6]

On 12/25/2023 at 2:13 PM, Norbert said:

I bought this. Thanks for recomminding this. Import duty seems to be only 4% (shipping excluded).  

Providing its as good as it looks, I think that's a good deal, even with possible import duties. Let us know when you receive it👍

[kdh]

I think you've made the right move Norbert, I hope you don't get clobbered too much on tax etc. You're right about the dross on ebay, I think people have such a cheek. I was looking for a Boxster S exhaust and they are about £300 with rust, splits, mountings cut off etc. Chancers and chavs.

As a complete exhaust anorak, ANY aftermarket exhaust is going to have some form of drone, usually between 2-3000rpm - it's the nature of the beast. DB killers will help reduce it but they can take away the 'nice' sound further up the rev range.

Good luck with yours I hope it works out.

[phazed]

I should receive my ToyoSport cheapie back box in the next 7 – 10 days. Won’t be able to test it for many weeks as I have a lot of other stuff to do on the car first.

Looking forward to trying it out. It looks like it will be a lot lighter than a standard item which is a definite positive. I don’t mind the drone as I will not be sitting at a constant RPM. What I am concerned about, is that the noise level hopefully will remain below 100 dB with using the standard cats. I am also using the Toyosports s/s manifolds. Don’t know if that will make any difference to sound.

[danb]

Has anyone got a recording of the drone? I’m wondering if you could vastly reduce it with a suitably tuned Helmholtz resonator but would need to know the primary frequency of the drone  to calculate what might work.

I know they are not uncommon on some exhausts to combat droning but I’m wondering if one could be made to sit in the cabin to tune out the noise - would make experimenting much easier than welding stuff to the exhaust….

[McDonald]

2 hours ago, kdh said:

As a complete exhaust anorak, ANY aftermarket exhaust is going to have some form of drone, usually between 2-3000rpm - it's the nature of the beast.

I replaced the whole exhaust with Dansk - no detectable drone.