My new stainless exhaust system

steve_c

A2OC Donor
I bought my 1.4i A2 in October 2016 aware that it had all the original exhaust and I thought that (barring any obvious problems) I would run the car at least until its next service to get a better sense of whether it was worth investing for a custom stainless exhaust system.

The car had an existing problem in that the Emission Control System warning light (and less often the Engine Management light) would come on from time to time (and the go away of their own accord). This generally happened when I went up to fourth gear before the car was properly warmed up, and I learnt to drive around the problem, but I was pretty confident that a new exhaust would resolve the issue.

My 2017 service left me with an advisory on my MOT for a slight leak from my exhaust (actually from the flexi section) and I decided that I would treat the A2 to a stainless system before my next MOT; the next decision was over who I was going to get to do the work. Nick Paravani was local to me, and had done superb work on my Saab Sports, but sadly I found that he'd retired. I was wary of using any chain franchise (such as Powerflow) as I wanted to be certain that the entire system was built to match the fit of my existing one, so I thought that I would probably use Hayward & Scott. However a careful check on the internet suggested that H&S were no longer the company they had been, and despite their premium prices tales of woe seemed all too common.

Quite a few customers gave Infinity Exhausts ( https://www.infinity-exhausts.co.uk/ ) rave reviews and I approached them for a quote. After I had emphasised that I wanted a full bottom-of-the-manifold back system we agreed an inclusive fee of £700 and fixed the date for the work to be carried out.
 

steve_c

A2OC Donor
This Tuesday my alarm went off at 03:15 and I set off from Norwich at 03:40. It was a very easy journey down and I was able to take a break before completing the journey and arriving pretty much on the dot of eight o'clock.

They started off by warning me that their straight through system would not be able to match my existing one for quietness, but they would make it as quiet as possible. After they put the car up on the ramp they asked me if I was sure that I wanted a full system, telling me that I obviously needed a new flexi but that the rest appeared sound. I assured them that I did.

Apart from being asked what tailpipe design I wanted (just plain) I had no involvement while the work was being carried out, and that was a slight disappointment. But by eleven they'd finished and they put the car back up on the ramp so that I could inspect the result. It all looked very impressive and was exactly what I was hoping for in that it didn't deviate significantly from the appearance of the original. They told me that they'd made the front silencer a little bigger than the original, in order to get extra packing in to keep the sound levels down.

So all that was left was to drive home and see what difference (if any) the new system made.
 
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steve_c

A2OC Donor
Well it didn't take long to get a sense of the change in performance. Before I had even got as far as the motorway, I could tell that the engine had more torque, particularly at lower revs. And noise didn't seem to be any sort of issue at all. It had the sort of noise level that I'd expect of any new exhaust.

On the M4 I found that the engine seemed to have considerably more power, so that I was having to go easier on the throttle, and my DIS display was telling me that I was getting around 70mpg rather than the 50-odd that had previously been the best I had seen. I had a couple of traffic problems on the way back one of which (missing the M25 turnoff) was my own fault, but even crawling round the North Circular the car seemed lively in a way that it hadn't before.
 

steve_c

A2OC Donor
Initial conclusions:

The car has a lot more performance. Probably no more than it had when new, but providing the stainless exhaust retains that performance I'll be more than happy.

The car is probably using less fuel. I know that the DIS isn't accurate, but it does give a useful pointer. I had never reset my average consumption from the day I bought the car and it has always shown 37-38 mpg. When I arrived back in Norwich Tuesday evening it was already showing 42.3mpg. I have now reset the average and it is showing 45mpg for the 60 miles I have covered since.

The car is definitely noisier, particularly at higher revs. But it's not intrusive, and starting from cold doesn't seem any different to what I had before.

The warning lights no longer display, regardless of what gear I'm in and whether the engine is still cold.

I doubt that I'll need to give the exhaust any more attention for a very considerable while. And I'm happy that I've had good value for my £700.
 

Nye

Member
What a result! I had the exhaust renewed from the cat back by ProSpeed in Cardiff on my 1.6. The performance results were similar to yours initially but I decided it was too noisy so I got them to replace the back box again. The improved torque was great fun, probably close to what it should be with working intake flaps, but sitting at speed with it sounding like an Impreza got a bit grating. Also, my partner complained that at idle it sounded like a racing car; it was louder than the neighbour's car which has a badly holed exhaust.
 

Teresa

Merchandising Co-ordinator
As you're in Norwich, I don't suppose I could come and have a listen could I please Steve? I desperately need to sort something out for my 1.6 and struggling to get responses from anywhere.
Many thanks Teresa
 

steve_c

A2OC Donor
A few further thoughts.

This exhaust has been made with a joint between the front and back box. This is of course how OEM replacements come, and is pretty much essential for fitting without removing the rear axle.

The exhaust has a 'lifetime' guarantee which excludes the flexi joint and the cat internals. One of the downsides of buying from any single business of course is that they may not be around by the time problems emerge.

I had confirmed my requirements with Infinity in writing ahead of travelling down. I didn't think to tell them about the ASF and the importance of using the original hanging mounts which led to some worried moments as the exhaust neared completion (although of course it was fine).

I remain very happy with my new exhaust; I'm getting used to the additional power on offer and really enjoy the new driving experience.
 

Teresa

Merchandising Co-ordinator
A massive thank you to you Steve. It was great to have a ride in your rather amazing A2. The exhaust sounds absolutely brilliant. Not remotely loud. It is much quieter than mine is at the moment. You can certainly notice the performance improvement as it definately wanted to go and was quick off the mark.
Thank you again Steve ?
 

steve_c

A2OC Donor
It was really nice meeting you this morning, Teresa. I'm glad you were suitably impressed with the exhaust, thanks for the kind words.
 
I have a Sport 90 TDI Re map currently producing 125 BHP mated with a MYP 6 speed gearbox.

I'm looking for small increase in power, any better exhaust note is also very welcome, any of the above done it on TDIs??

Thanks Andy
 

A2Steve

A2OC Donor
I have a Sport 90 TDI Re map currently producing 125 BHP mated with a MYP 6 speed gearbox.

I'm looking for small increase in power, any better exhaust note is also very welcome, any of the above done it on TDIs??

Thanks Andy
Had a full stainless exhaust on my TDI160. One single backbox, 2.5 inch system and a decat. Pickup was a heck of a lot better and it sounded nice too. I am however becoming increasingly environmentally conscious so wouldn't do it again.
 

steve_c

A2OC Donor
One year ago today, I had my 1.4 petrol A2 fitted with a full stainless exhaust, so this seems like a good time to report back in detail, with a year of experience under my belt.

As far as I am concerned, there have been no negatives whatever to the exhaust. The engine, which had felt quite asthmatic before, is lively and free revving, with decent torque right across the power band. The car is an absolute pleasure to drive and I use it more in consequence.

Noise is a potential issue with any straight through exhaust but mine has struck absolutely the right balance. For day-to-day driving it's really quiet, but on the odd occasion iwhen I need to accelerate really hard, it suddenly sounds like a scalded cat!

I'm using significantly less petrol. I had been averaging between 37 and 38 mpg on the DIS, now the figure is up between 43 and 45 mpg This is despite driving the car more enthusiastically. Right now the DIS is quoting a running average of 43.7 mpg, and that is based pretty much exclusively on driving around town.

Earlier this year I started using the Fuelly app. and that pretty much matches my DIS display. There's a slightly wider variation, with figures ranging from 40.5 to 47.4, depending on where I've been driving, but that is what I'd expect.

I don't give any great thought to petrol consumption when I'm driving, and my car definitely isn't set up for economy. I have Conti Premium Contact 2 tyres, 195/50 on the 16" SE alloys, which I fitted when I bought the car, inflated to 29 psi for maximum grip and comfort. If I fitted narrower tyres and ran slightly higher pressures, I'm sure my mileage figures would improve further.

Next up, my thoughts on the options I declined.
 

steve_c

A2OC Donor
This was not by any means my first custom stainless exhaust. My collection of Saab Sport 2-strokes all had them fitted, as did my NSU Ro80, so I had a good idea of what to expect and knew what I wanted.

I didn't want a bigger bore, preferring to stick with an exhaust that matched the original in appearance and hopefully in noise level. I had no interest in fancy exhaust tips which are simply bling, of no practical benefit.

I was offered a high performance replacement for the rear cat which would have had a 400 cell core, but went with the standard 200 cell version, which saved a bit on the cost and is almost certainly all I need. I kept the original cat at the base of the exhaust manifold, but if I ever need that replaced, I'll certainly think about fitting the high performance version.

I'll round out these posts with some thoughts for others considering investing in a custom exhaust, but since it's getting late I'll post those tomorrow.
 
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