Exhaust back box options

[phazed]

Received my Toyosports rear box today. Still in the cardboard as busy with other things, but will open it tomorrow and may fit depending on how my extended sump goes.

 

Just received my Toyosports rear box today. Still in the cardboard as busy with other things but will open it tomorrow and may fit depending on how my extended sump goes.

 

Just watched a YouTube video regarding the same rear box and it is 10.4 kg lighter than standard! 

[02boxster968]

1 hour ago, phazed said:

Received my Toyosports rear box today. Still in the cardboard as busy with other things, but will open it tomorrow and may fit depending on how my extended sump goes.

 

Just received my Toyosports rear box today. Still in the cardboard as busy with other things but will open it tomorrow and may fit depending on how my extended sump goes.

 

Just watched a YouTube video regarding the same rear box and it is 10.4 kg lighter than standard! 

I have been that soldier, avoid Toyosport that product is absolute rubbish and not fit for sale!

I had one fitted to my car for 1 week only after it blew fibreglass packing all over the rear of the car and started to rust after just 7 days. Sent back and got a refund luckily I was not paying for labour.

 

 

[02boxster968]

[ATM]

10 hours ago, Fat Rat said:

Reading all this has given me the kick up the ar*e to finish putting my box back together that I chopped open months ago. New Years Resolution. Get it finished next year. 😂🤙🏻

What you doing to it?

[ATM]

18 hours ago, Norbert said:

I would still prefer to play with J-pipes to be honest. 

What's a J-pipe?

[ATM]

5 hours ago, phazed said:

Just watched a YouTube video regarding the same rear box and it is 10.4 kg lighter than standard! 

Yup

 

I still have my droner in the back garden and it's much much lighter than the OE box. We all like a bit of weight saving but only you can decide if the constant noise is worth it. Mine was absolutely ridiculously loud but the U bends were blowing on both sides too. The PO didn't fit it right, he didn't fit it well at all. And yes it had a clunking noise too because of this. The pipes from the box didn't slot into to U bends and were only just sitting in roughly the correct position. I still can't believe I drove it round like that for a few months thinking it was funny. But I'm glad I got the original box with the car and returned it back to standard. Now I know more about where they go at the seams I'm still thinking about some better rust prevention measures like gunk or oil or higher temp grease or anything really which is water proof but can deal with a bit of heat. I asked my powder coating guy and he said no because of the heat problem. There has to be an industrial solution to cover and protect simple mild steel in temperature changing environments. 

 

[edc]

I think it's the heat cycling as much as anything else that gets to the exhaust boxes. They get very hot so moisture in normal use once engine up to temp.

[Fat Rat]

7 hours ago, ATM said:

What you doing to it?

Basically cut a good box open and threw out the centre silencers and cross over pipes. I have done a thread on it. I will try to add the link. I need to get back on to it. It has progressed. Welded up and and old oval pipe cut off. Modifying to except the facelift changeable tips. Also replace the studs for the front mounting bar as rotted. Then find a mounting bar as mine is not fitted on my car. 🤨. Than a clean and paint. Nice job of yours by the way. 🤙🏻

 

[ATM]

10 hours ago, edc said:

I think it's the heat cycling as much as anything else that gets to the exhaust boxes. They get very hot so moisture in normal use once engine up to temp.

Moisture inside?

 

I was assuming they rot at the seams from the outside due to being open to the elements.

[ATM]

11 hours ago, ATM said:

There has to be an industrial solution to cover and protect simple mild steel in temperature changing environments. 

I just remembered you can get some form of coating applied to tubular manifolds. This helps keep heat inside them and therefore keeps the engine bay cooler. I can't remember what this coating is right now but it could be suitable for the back box. I don't care about the heat reflective properties for the back box, I'm just trying to recall what the coating is.

[½cwt]

12 minutes ago, ATM said:

Moisture inside?

 

I was assuming they rot at the seams from the outside due to being open to the elements.

Water is a product of combustion, that's why you get visible steam when an exhaust is cold, add in the NOx and you get dilute nitric acid inside.  Chuck on some salt on the outside and its is a metallurgist's nightmare for the iron in the steel.

[iborguk]

14 minutes ago, ATM said:

I just remembered you can get some form of coating applied to tubular manifolds. This helps keep heat inside them and therefore keeps the engine bay cooler. I can't remember what this coating is right now but it could be suitable for the back box. I don't care about the heat reflective properties for the back box, I'm just trying to recall what the coating is.

They rot from the inside out in the main.

[ATM]

3 minutes ago, iborguk said:

They rot from the inside out in the main.

Ok - but why do the seams go?

[iborguk]

Maybe something in the welding process  makes that area more susceptible- guessing there.

[ATM]

17 minutes ago, iborguk said:

Maybe something in the welding process  makes that area more susceptible- guessing there.

I'm assuming the weather gets to the outside of the seams. That's how my brain makes sense of it. If the seams rot from the inside that's just not logical. Unless maybe they stay cooler and water is condensing on them inside. Not sure I buy that. 

[BBB]

29 minutes ago, iborguk said:

Maybe something in the welding process  makes that area more susceptible- guessing there.

Good guess.

Welded joints are more prone to rust because the welding process causes the formation of a heat-affected zone (HAZ) around the joint. This HAZ has a different microstructure and composition compared to the base metal, making it more susceptible to corrosion.

Reference: https://www.physicsforums.com/threads/why-welded-joints-rust-faster.683998/#

[iborguk]

43 minutes ago, ATM said:

I'm assuming the weather gets to the outside of the seams. That's how my brain makes sense of it. If the seams rot from the inside that's just not logical. Unless maybe they stay cooler and water is condensing on them inside. Not sure I buy that. 

Maybe in the case of the seams both inside and outside effects get to them more readily if they are a weak point due to HAZ (thanks @BBB).

Edited December 29, 2023 by iborguk

[Norbert]

15 hours ago, ATM said:

What's a J-pipe?

Just a pipe usually welded before the back box (other end closed). If the lenght of the pipe is correct the sound wave will bounce back from the closed and eliminate the drone.

[edc]

13 hours ago, Fat Rat said:

Basically cut a good box open and threw out the centre silencers and cross over pipes. I have done a thread on it. I will try to add the link. I need to get back on to it. It has progressed. Welded up and and old oval pipe cut off. Modifying to except the facelift changeable tips. Also replace the studs for the front mounting bar as rotted. Then find a mounting bar as mine is not fitted on my car. 🤨. Than a clean and paint. Nice job of yours by the way. 🤙🏻

 

I've posted pics previously in my 550 running report but the Carnewal mod is probably along similar lines. You can see the central upper section cut in a rectangle. 

[ANL]

Going back to my comment on the MOT failure. It was down to the eBay exhaust back box an causing emissions failure.

[phazed]

Can’t see how the back box can affect emissions failure. Surely that can only be controlled by the cats.

[jonogt6]

18 hours ago, iborguk said:

They rot from the inside out in the main.

That's not the experience I've had with them. The outer seams tend to go first, probably as a result of dirty water, salt, and all manner of other cr*p being sprayed on them for a prolonged period of time combined with hot/cold temperature cycles. 

[iborguk]

42 minutes ago, jonogt6 said:

That's not the experience I've had with them. The outer seams tend to go first, probably as a result of dirty water, salt, and all manner of other cr*p being sprayed on them for a prolonged period of time combined with hot/cold temperature cycles. 

I’ll defer to your experience and I get that for a UK climate re the seams.

Guess I should have said they can rot internally as well as externally with climate and interaction with salt/rain also being factors.

 

[Fat Rat]

16 hours ago, edc said:

I've posted pics previously in my 550 running report but the Carnewal mod is probably along similar lines. You can see the central upper section cut in a rectangle. 

I did use your pics of the Carnewell to give me the cut lines. 😉

We will find out sometime soon hopefully, if I get my finger out. 🤙🏻

[kdh]

Sort of off-topic but I followed a Maserati of some sort today in traffic - four small exhaust pipes at the rear and boy what a beautiful noise it made. I thought it was the perfect tone and sound for a Boxster, any Boxster.