Martin J Stirling

I know 'which exhaust?' questions have been done to death, but I posted this on the Drivetrain section with little response.

I have to admit to knowing only the basiscs regarding exhausts. When I changed the exhaust on the Evo, I just went for the loudest one with the highest reported power gains - the Blitz system. Now I understand that max power isn't evrything and that I may have lost low rev torque in the quest for max power. Hence I dont want to make the same mistake again withe P1.
From what I have gathered, the main exhaust contenders are Scoobysport, Scoobymania, Power Engineering, Magnex, Scorpion and BPM, as well as the jap stuff.
Unlike brakes, where thr unanimous opinion is that AP's are the best, with exhausts, everyone has a different recommendation. How do I sift through all the possibilities and choose the best full system for me? I want a really meaty sounding TVR-like burble/growl and the best low down torque/pick up gains possible.
Scorpion and Magnex seem to offer the best in terms of value for money, so what benefits would i geet if i were to spend the extra and go for the ore exotic stuf like BPM? Also, in my opinion although the jap stuff looks by far the best, most people seem to go for the SS system over anything else. Why is this preffered over say an Apexi or HKS system?

Any help or advice in this minefield of options is much appreciated.
Cheers lads,

MS

kav

It's all down to personal choice, matey.

I opted for a Scorpion BB and decat centre section almost by accident and I love it. That's not to say it's better than anything else - I'm just happy with my choice.

If you're really phased by the whole thing, get along to some meets and trackdays and listen to the real thing. It'll be a worthwhile investment.

Cheers
Kav

Martin J Stirling

Thanx for the reply. I realise that ultimately it is down to personal choice, but in order for me to make that personal choice I'd like to know a little more about all the options available and why one is different to another.

At the end of the day they're all stainless steel pipes of some description. What advantages will a BPM or Scoobysport/mania give me over a Magnex or Scorpion apart from a smaller bank balance?

Ultimately I'm not asking 'which is best', 'cause that's a personal thing - more like 'what are the advantages/disadvantages of each?' - so that I can make my own mind up.

Cheers

MS

jon hill

i guess there are four things to consider - peak power, torque, noise (& "sound") and construction.

The pipe that gives you the best peak power increase may put a huge whole in the torque curve somewhere lower down the revs. IMO the area under the graph is more important.

Noise & sound - too loud and you may have problems at track days and the like.

Construction - is it well made, will it fall to bits, etc. (Do they do carbon & titanium pipes for cars yet ?)

jon

ScoobySnack

Hi Martin,

I have the Magnex 3.5" backbox and centrepipe on my car.

Advantages:
Looks good (just the same as the others)
Cost as mentioned, £264 including delivery + fitting
Can be fitted in most areas, i.e Halfords Superstores did the above deal.
Centrepipe comes with a resonator! (not too sure how this is supose to resonate sound, any ideas anyone?)
The sound is bassy but not in your face so much you get a headache.
The only performance gain I feel, is a slighty quicker spinning up of the turbo.
Insurance companies haven't added any premium when I tell then all about it.

Hope this helps a little

Cheers

J

Martin J Stirling

Jon,

thanks. I guess for me the priority is torque and 'sound'. What sort of pipe will offer the best combination of these two factors? Also what are the individual properties of the pipe that allow them to produce different characteristics? Eg, how do larger bore systems (2.5" vs 3") systems compare? In general will all the jap systems give the same type of chracteristics or are they all different>

Jason,

cheers for your exhaust review. I will pop round and have a listen some time this week if that's ok? How about Thurs eve?

Cheers,

MS.

BT52b

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by jon hill:
<B>
IMO the area under the graph is more important.

jon[/quote]

Great! I've been moaning for ages that we should get figures for the area under a torque curve graph, unless people have CVT gearboxes and are permnanently at peak torque/power then it would be far more meaningful for real world driving and a nice measure of flexibility.

I would also like to know the rev range which gives 75% of peak torque.

ScoobySnack

Hi Martin,

I'll be in from the afternoon onwards, until about 9pm....then it might be a quick soiree to Pantiles........

J

cryptwalk

I have a Hks superdraggor on mine

You only have to look at the quality of my mirror polished back box to see the differance between it an the likes of magnex or such.

But alas it was expensive at just short of 600 for the system

But quality comes at a cost.

And it has a 5 inch bore so is not nearly similer to a magnex 3.5 bore m8.

Gridlock Mikey

Martin,

I found an exhaust system purely by accident, it's not one of ya "designer" names but you ask anyone who has heard my scoob at a meet or where ever and they will tell you about it.It's gorgeous.

I have put it next to a Scooby Sport bb and centre, with an impartial crowd and they agreed that it's as close as you'll get to the TVR burble without having a Chimera

It is not in yer face loud, it don't cost the earth, and the chaps that supplied it know a thing or two about scoobs. They sell approximatley 5 per day all over the world. Call this No. 0161 6520920 and tell Dave that Gridlock sent ya.

p.s I don't get back handers for this, I just really like the gear and don't mind telling everyone about it (ask Mike at Scoobymania )

As far as touque is concerned, it's unlikley that you'll feel much difference just from doing Back boxes and centre sections, Down pipes is where torque improvments live

Anyways, Give Dave a bell, you'll not be sorry, I promise.

MIKEY

Mick

iTrader: (1)

There's a lot more to exhaust design than whether it is made in stainless and whether it is quiet or loud!

Backpressure is important to power, but all things being equal lower BP = less attenuation. BUT if you suddenly stick on a low BP system you may upset your calibration and then not be running optimally through the RPM range. There are also LEGAL considerations as regards noise!

Pipe lengths are important to power as in tuning to raise peak power, there is commonly a downside to tuning pipe lengths elsewhere in the rev range. Pipe bore is important to BP. Muffler box volume, quantity and position are all critical to sound produced and weight of system (& price!). Mufflers may be simple straight through or very complicated with numerous baffles, Helmholtz chambers, packed sections and even valves which may be externally operated by the engine management system or simply respond to gas pressure levels. Tubes inside may or may not be perforated. Density of perforation and position is important. Tailpipes may be single or twin (haven't seen any more than 2 out of 1 box but would love to be educated if there are! - Actually I think the new M3 has a huge rear box right across the back of the car with 2 outlets at each side - so that's 4! - Proved myself wrong already )

Sounds range from 'Burble' -V8s to 'Rasp' - cheap small cars when cold - throttle blipped and descriptions of sounds such as 'Fluffy', 'Pops', 'Hiss'

If you've managed to keep reading this far and are still interested:

Decouplers - the engine shakes (Not too much on a Scooby ) and so a section to decouple the engine vibration and movement is required. On smooth engines such as our beloved Boxers a simple cheap spring loaded balljoint is usually sufficient. On many vehicles a 'flex pipe' or even 2 are required. The 'rubbers' are know as isolators since they isolate the cabin from the vibrations in the exhaust. The size and type of rubber used are chosen carefully to minimise excitement into the cabin through the floorpan (Do not replace broken isolators with any old part you find lying around - or even worse with a bit of wire ) The position of the hangers is also important as the exhaust system will have resonant modes and the hangers should be placed so as to sit at a position of least movement (a node) when a natural frequency is excited.

SO PLEASE BE AWARE THAT US EXHAUST DESIGNERS HAVE A LOT TO CONTEND WITH. AN EXHAUST SYSTEM IS NOT JUST PIPES AND BAKED BEAN CANS WELDED TOGETHER TO GET THE ENGINE EXHAUST GAS TO THE BACK OF THE VEHICLE

Thank you for listening.

Mick

Oh by the way there is a mass production vehicle available with a titanium exhaust