(G) Stainless Steel Exhaust

Just had a custom stainless exhaust fitted by MIJ Performance in Walsall. Choice of sound (quiet, mid-sport or boy racer), choice of tailpipe (from conservative to dog-swallower), lifetime warranty, fitted and inc vat for less than £300. Took about 2.5 hours all in, and excellent customer service as well. Would recommend them.
http://www.mijperformance.com/
(I know this sounds like an advert, but I'm not on commission, honest! Just impressed by the service from them)

Good news. I think a good company who makes them on the car are well worth it. i went to Bells in Swindon and can recommend them.

Do you notice the BHP gains? or just like the shound enough it feels faster?

One tip I would give it buy an induction kit of you don;t already have one.

Then when all installed reset the ECU (Do a google search)

THE ECU will then adapt to your driving styles and deliver the fuel better with your mods. Really you need a full re-map which is next on my list.

One of the great upgrades for those who can afford it. Got mine for just over £300 after someone crashed into the back of my B and destroyed the original. Looks great and sounds great. Thought I could feel a performance boost but that might be psychological.

Generally the improvements over the standard exhaust are not noticeable. Although the sound and look is nice.

The old orignal Exhaust is very heavy so weight loss helps. I think 20Kgs saving. You get about 10+ ish BHP more, sometimes you can lose BHP if the exhaust is made wrong. The boys who have a 1ltr saxo's and put the dustbin exhausts on actually make the car slower.

The chap who made mine explained his calculations which I can not remember. Something about pipe sizes and gas flows.

18mths later my current one is still shiny! quality materials used. Life time warrenty is also a bonus.

Have to say I bought it mainly for the look and sound (and longevity) - haven't noticed any performance improvement. Need to start saving for a new hood now for when the hard top comes off

Exhaust fluid dynamics is a complex art and what designers try to achieve is optimum volume flow at optimum exhuast gas velocity.

Maximum volume flow = low velocity = no good
Maximum velocity = low volume = no good

Any given pipe structure/design/configuration will produce maximum performance over a specific rpm band. Road cars and performance road cars are a design compromise.

F1 race cars, that idle at probably 10,000 rpm, have a optimum rpm window of about 14,000 to 18,000 rpm (don't quote me on these figures I use them for example/explanation only). Outside of this rpm window the engine is a limp dead dog. One reason why anti-stall kicks in to keep rpms high whilst the driver has lost control and is possibly easily going to stall the engine.

Out of band = out of the running.

Similar problems occur with 'fast' high lift cams.

Exactly! And this is precisely why a new exhaust system will generally not add HP*. Because no exhaust fitter has the information, time or inclination to calculate the precise needs for every engine. I mean, does anyone here know the exhaust requirements of the B engine? No? Well what chance does a guy in a shop stand?

Just be happy with a nice sounding, shiny exhaust - I know I am

*Of course it is possible, and done on racing cars - but it's extremely expensive and difficult... This is real life, not Gran Turismo

Agreed. A reputable big/mainstream manufacturer like Ansa, who design and sell performance exhuast systems in there many thousands of units, can and do take the time, cost and effort to design a decent exhaust upgrade. These may give a 5% or possibly even a 10% perforamance increase. However 5% max is probably all that can be reliably achieved. Some cars may get zero increase!

Big bore, big noise and no go systems are designed for two puposes only. Boost the drivers ego/libido and fleece their wallet at the same time.

I feel a new business opportunity coming on...... :-)

I agree, I was about to write similar.

From practise I have to disagree. Depending on the workmanship you can gain or loose power with a new system.

In a a 4 pot inline engine configuration you can reduce the required parameters to just 3, where one of them is the desired peak power point. The other parameters are easy to find on the net.

I do and so do a number of other specialists I know and know off.

With race cars the situation is most of the time totally different. On a F1 car the designers have to work with many constraints. Space is the worst of all but not the only one.

In all other applications power against a standard system can be gained or lost in many places.

I am using mandrel bends only, which are more freely flowing. At the same time I try to make the system less bendy because the sharper the bend the more power is lost.

The leading edge on manifold junction is crucial as it can loose you with the wrong one a considerable percentage of power.

The shape of the cat housing is evenly important and can loose a lot of power (the number of cpi is less important).

A system with the cat after the manifold will give you generally up to 8% more power than the one in the manifold.

The silencers will loose very little power when properly designed or can loose up to about 12% power.

Wrong calculation of the primaries, secondaries and collector pipe will not only loose power but will also create flat spots.

There is some more points to it, but I think my essay is long enough as it is.

Good to read that to be honest.

My B exhaust was built by a very experienced person who said alot of what you wrote above. The old one sorry DTR was removed because it had some cracks and built of cheap material.

The new exhaust does use less bends, better size pipe, and better meterials, like I said after one yeah the exhaust piping still looks like new. No rust at all.

I do feel the gains in BHP but also know a remapp would benefit the car more.

Also my car has 90K on the clock, so I would presume the millage and condition of the engine would also play a part in it.

And yes it sounds great.



I would always go this way when replacing an exhaust as the life time warranty is worth loads of £££££'s

hi guys and girls
i had my exhaust done 2 yrs now and you do only get a small increase, but the roar factor makes up for it
as for remap had that done by a man who know his stuff and after remap she increased by 25 bhp. that's not a lot but it has improved the drive and gear change is more responsive so go for it.
as for induction kit i am still sitting on the fence like the idea but unsure about the noise they make, my sons one sounds like a dragon.

Who did your remapp?? As I know your not to far from me....

sadly not local had it done at red dot in watford and had cuppa tea while i was there