Post Cat Exhaust Diameter - Vrs Standard Exhaust

[mrburdon123]

Am looking to remove the middle silencer from the vrs standard exhaust system. I have measured the pipe to be 2.25" (57mm) but it was dark and only had an old verynear caliper which wasn't best.

Can someone confirm that the diameter above is correct before I start ordering the tubing and clamps.

Merry chrimbo to all.

[stu_mcl]

Yeah im pretty sure it is 2.25 or atleast it wont be fsr away

[mrburdon123]

Sorry, "fsr" - far?

Thanks.

Edited 23 December, 2013 by mrburdon123

[leevrs180]

Good luck mate if you can keep us posted would be awesome soo many guys doing mods and very few guides etc.

When the warranty runs out on mine will be very tempted to make this the first mod apart from spacers ive just ordered

[mrburdon123]

I will post on this thread how I go about it.

Fyi, here are the parts I'v Ordered.

I'm not going for welded flanges as I can see after the middle silencer, a clamp is used to joint the final exhaust section.

I've gone down the route of a flexible section clamped at each end.

Parts ordered in below links.

http://www.ebay.co.uk/itm/111086606652?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648#ht_3009wt_1164

http://www.ebay.co.uk/itm/320487835854?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648#ht_1650wt_1178

http://www.ebay.co.uk/itm/261145373628?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648#ht_2131wt_1052

Total cost + PnP £69

[leevrs180]

How long is the centre silencer?? Just being cheeky cant be arsed rolling under the car in this weather maself.

[OzFabia]

It's about 42cm long. How do I know? I have one sitting in my garage. I kept it in case I found the need to re-install it, but so far that's not seemed likely to occur.

[mrburdon123]

Had a go at replacing the middle silencer on the VRS.

 

Observations first.

 

Starting the car on the drive and standing behind the car - the exhaust is clearly heard, with an added burble to it.

 

On the drive, in the car, at idle - just a bit louder than stock.

 

Pulling off the drive - exhaust can just be heard

 

Motorway/cruising  - Same as standard, no increase in noise at all.

 

Giving it the beans, mid to high revs - Spot on, exhaust can be heard over engine noise now. not even close to these boy race exhausts, but a nice growl. (windows down is better)

 

Heres my attempt and findings while doing it.

 

First thing iv got to say is make sure you've got time when you don't need to use your car and not to try and do it between the afternoon of Christmas eve and the afternoon of boxing day as I did! 2 full days would have done though. That was also on the drive with nothing but ramps and bricks behind the back wheels.

 

Second thing, the exhaust isn't, 2.25" or 57mm, its smaller, I got a accurate measurement of 55.24mm. This difference in tube diameter wouldn't have mattered if the straight through pipe was to be welded to the standard exhaust but it made for a real PITA when trying to get a gas tight seal using clamps to join the sections together.

 

From the car

 

 

Ordered tube

 

 

 

Finally, I initially just tried to use a straight section of tubing and a flexi join replace the silencer but soon realised that doing it that way doesn't allow the exhaust tips to sit square to the bumper and it also ment the exhaust would rest on the cross member in the centre of the exhaust channel.

 

I had to have a re-think and decided I had to make an 'S' bend. The picture of the removed silencer shows the 'S' which I would need to try and copy

 

 

Now, heres where I'll get people cursing me to death.  

 

I had forgot I needed to take the VRS over to wales to see the family on boxing day, so, I took the silencer out at dinner time chrimbo eve and realised later that evening that the straight section of pipe wasn't going to work. This left me Christmas evening to fab a, 'S' bend out of the section I bought.....without a bending machine......and fit it back to the car on boxing day morning before the 170mile drive.

 

This was my only option   

 

 

I know that corners in any flowing system will make it more restrictive but as there are already flexi sections in the standard system, I didn't think that having corners would really restrict it in any noticeable way.

 

All I can comment on this is using fuel consumption as an indication if something was up. 170 miles - 45.6MPG with a car full of stuff, the dog and the Mrs. Trip was, A38, A5, and M54, a few country roads, then back the same way.

 

So after all the sections of the straight through tube where welded together, it was time to fit it to the car. This involved a lot of swearing and a number of attempts to get it to sit right.

 

I used the flexi section I bought as the clamps hadn't arrived so I had not other way of joining the sections together. I used the OEM clamp (originally it was in the centre of the stock exhaust system) to fix the front pipes together (under the sub frame) and a 'u' clamp to fix the back sections together.  

 

After bolting it all together and getting it all lined up. I started the car and found that the joins between the new section and old weren't gas tight and there was nothing I could do as the diameters were different. The picture below shows what happens to the clamp when one end is larger than the other the thin yellow lines show how the sleeves of the clamp sat, not square. And as I only had an hour before we needed to leave, the desperate times called for me to use exhaust putty to seal the joints for the time being. In all fairness though, 170miles and not a leak! Inside im crying that its now officially bodged!!!

 

 

Overall this is how the exhaust is now. All rubber mounts are used, no change to the original system apart from 1 cut to remove the silencer. I left enough straight at thefront of the silencer so it can be clamped back on when needed, with no need for grinding or welding (ref 3rd pic).

 

 

When the clamps come, I will be removing the flexi section and replacing with a straight bit of tube as I don't really trust the u clamp. I may order a pre made 'S' bend to replace the stepped section. And also, I have a sheet of ,60mm SS which I will be cutting down and rolling to form a gasket to make up the difference in tube diameter. Or, alternative buy the right pieces in the first place and take more time to do it properly.

 

But, it works, its given me what I was after, a bit more noise when pushing on but nice and quiet when driving normally. but also the opportunity to return to stock when needed with out a load of work.

 

I know I used welder to make mine but I do believe that all this can be done with 2 purchased clamps, 0.5m of 56mm tubing and a 'S' bend giving about 40cm in length and 20cm in rise.

 

Ahhh, views? :/

 

[OzFabia]

Good on you for giving it a go. I wouldn't know where to start on something like this (I was more than happy to leave it to the experts at an exhaust shop). I agree with you on the noise assessments. It really is perfect "sound-wise" in all aspects - not obtrusive unless you are going for it, which is when you want a little extra sound.

Edited 28 December, 2013 by OzFabia

[leevrs180]

Without increasing exhaust size you can buy 55mm exhaust pipe and felxi's on ebay.

But without the ability to make the s bend you would have to cut really close to it (between silencer and s bend) and have to get silencer welded if it was to be re-used.

One things I did find was a flexi called 'truflexi' or tru flexi, it looks pretty smart but dont know if I could justify the price and the fact it wont fit due to them only being able to expand to 2"

Shame its such a pain diameter,

[Ootohere]

Bump.  for Mathew.

[matthewl]

Bump.  for Mathew.

Cheers George, saved this in my favourites.