My Homemade 3" downpipe

[raymor]

I made my own 3 inch DP last year, I made a V band adapter for the turbo and clamped the DP on for quick release. A v band half way down meant I could split it easily for clutch work. It worked a treat. It had a solid wastegate pipe and while not ideal ran in Hillclimbs with clutch sidestep starts and the exhaust manifold did not crack - advertised on Ebay as crack free about a fortnight ago. I did however have a flexi just before the lower bend of the DP

... and there's a reason why stainless steel parts cost a lot of money - it's cos it's 'hard' to work with. I made my own flanges and I swore it's something I wouldn't do again.

Nice work!

To replicate my setup would have been the best part of £400 to make it worth bothering about... it ain't cheap, but it sure is worthwhile

i dont think its the flexi needed in wastegate due to cracking, cracking is due to no flexi pipe at the bottom of downpipe, cracks are caused due to movement of exhaust causing cracking of manifold if there is no flexi on downpipe

[raymor]

[QUOTE=terrybullwon;383129]I have some 4" pipe for my down pipe it came free with over a years wait

Are you needing a 4" V band clamp for that sir?

[goodall]

on the issue of coupe/b3 chassis having little space over the driveshaft, would be possible to use a duel system, say two 2" pipes on same side or one either side

nice looking downpipe for a homemade jobby, i can weld fair-ish but always consider exhaust pipe to be difficult

[ryster]

I sould have a go at making a complete system for the s2 as i'm a coded pipe fitter buy trade . It's just having time and patience to do it the first one . then its just make a jig . If anyone has got a DP to copy or system (with out box 's and cats ) i would have a go make them and would give that person a free copy of there home made exhaust.

i've got an aby coupe to start

[nip]

Cool - and if you and your pal want to make more money - look at a modular exhaust system in stainless - for the Coupe for now...

One that does away with the y-pipes

Can accomodate a sports CAT (or not)

Can incorporate an optional centre box

Keep it 3" (76mm) as far down the car as possible... with a reducing section to 70mm before it routes over the rear driveshaft and into the back box. That will be the easiest for everyone to fit. Should be able to avoid 3B vs ABY variants.

The Avant / Sedan guys can easily have 3" all the way.

The price for full custom system is generally quite high. The price for something like Supersprint is also very high for what it is... I think its suffering from strength of Euro - imported from Italia.... Hence there is a market in the UK for a somewhat generic zorst upgrade on the S2 - but the quality must be right - fitment must be top notch and modularity with options for CAT is required also. What do you think ?

pauls sounds good, il try to find out weekend and let you know

[nip]

the same guy who couldn't modify mine ?the same guy who never turned up?

jamil im sorry to say but ur on about the wrong person

[Sonic]

If anyone has got a DP to copy or system (with out box 's and cats )

Ive got a complete stock ABY coupe exhaust system in the garage if thats any use?

[Jamo]

I'm thinking of getting my 2.75 one copied to 3" depending on how long it would take to be copied.

I need to speak with masterchef

[Smith_S2]

... and there's a reason why stainless steel parts cost a lot of money - it's cos it's 'hard' to work with. I made my own flanges and I swore it's something I wouldn't do again.

If you did i would still have my S2 just now!!!

V band a very clever idea, hats off to you both (raymor and nip) great DP's

[Jamo]

The only thing wrong with some of these downpipes is the wideband sensor should be at the bottom just before the cat not at the top.

[nip]

thanks matey

[Smith_S2]

The only thing wrong with some of these downpipes is the wideband sensor should be at the bottom just before the cat not at the top.

why? I thought that the closer the sensor to the turbo the better reading of AF ratio?

Temperature?

[Flat on my back]

.

Narrow band at the top, WB at the bottom...dont think the WB's like the heat.

[Jamo]

why? I thought that the closer the sensor to the turbo the better reading of AF ratio?

Temperature?

Not for widebands, they like it cooler they aren't as resist to heat as narrowbands and normally can't handle 850c exhaust temp.

It's why OEM widebands installs on new cars are just before the cat.

There was a post on here recently with the Bosch manual stating the minimum distance was some like 12" to 18" from turbo flange

[Rocco]

Jamo has the reason for widebands...


just after install it i´ve readed that the best place for it it´s just in the last part of the downpipe and it is very important too.mount in the middle/up part of the pipe

with some graduation like if we are seeing a clock in 14:00 hours or 22:00

in this way the sensor will work more efficient


i hope that you can undestand my bad english explanation about it with widebands...