Sorry if this is the wrong place, but bodyshop seemed the next closest bet, but its not really to to with body work lol.

I need an exhaust and it needs a larger bore than the biggest ones you can get off the shelf for my Seicento.

£600 for a custom one with a cat and 2-3 weeks wait I've been off the road long enought lol

So I have decided to try and build on myself and and looking for tip, tricks and advice!

I can get a sports cat cheap, and will buy a Clarke E100 gas mig welder (£150 from machine mart on sunday..vat free day)

Really all I will need is piping, flex section and a lot of welding practice lol.

I can get aluminized steel or stainless parts from here

I'd imagine its just a case of juying the right bends, cutting them, welding together and fitting.

Has anyone other than emma's dad done it and has anyone got any opinions, advice tips, or noticed something obvious I've missed?

What materail would you recommend? What diameter (think 2")?

Think it will come in at less than the £600 mark? I recon so even with cock ups.


Cheers for any advice

Kristian

Recently made a new front section for my car and used an aluminized steel section. It was such a pain to weld, we just gave up in the end and had to use exhaust paste to get it to seal completely.

Think that was because of the alu coating? Perhaps stainless will be better (at double the cost lol.

I could just go mild steel if i could find all the parts and lengths etc.

Had you ever done any welding before?

Kristian

buy this car for £300 and break it for parts... lol

Found it the other day, look at the exhaust on it lol

http://cgi.ebay.co.uk/1999-Fiat-Sei...89QQihZ019QQcategoryZ9843QQrdZ1QQcmdZViewItem

EDIT - forgot the link lol

file/ grind the alloy coating off the weld area prior to welding

for welding stainless you need special wire and a different gas IIRC and its prone to embrittlement on the weld area If my memory serves me correct

didnt emm and aaron make one up the other week?

@CinquePunto - lol, that thing is huge!!! I don't want that big, and it looks like its fitted to the stock pee shooter piping, 1.25", I need to make the whole thing.

@mog1571 - yes, thats what gave me inspiration, and the cost incentive, to try myself, but doesn't seem talked about often, if at all here on FF, oor on google too much.

Hence thisn thread

Looks for thoughts, ideas and advice on welding techniques, materials, bore, and insanity level of even attempting it having never welded before.

Kristian

possibly ask them for info? couldnt you jsut build it with sealant and clamps?

You can get a custom one made up for a lot cheaper than £600!!

Shop around

That did include a sport cat, and i will be shopping around still. Just I can't go too far with it as it is lol.

Most places need to see it to give an accurate price anyway, another problem lol.



I think there would be too many bends to build it with clamps and paste. I have attached the pics of emma's for reference. Look at the welds near the tailpipe!



I will drop Aaron or Emma a line at some point, but I bet they are sick of me asking questions now Was looking for more generic infor really.

Cheers everyone

Kristian

you need the proper kit to bend pipes, and you can't do 'empty' bending as it'll just kink and collapse.

shop around. you'll get a much cheaper system than that.

The linked site has bent sections already formed. 30/45/60/90 degrees, striaghts, and 1/2 meter flex sections so i will just need to pick the right ones lol.

I tried custom chrome racing in nuneaton for that quote. I have powerflow in cov to try. But I can't find any others local

Kristian

buy stainless, buy some lengths, and some 'pre-angled' sections (mandrel bends), spend literlaly days laying out your old exhaust and figure out how the new one will fit together with all these new fangled bits.

get cutting.

cut up all the bits and do a dry run getting em togeher,
then with the help of a mate, to hold bits togehter (believe me, no B&D workmate in the world with any asortment of clamps will hold a fanlged DIY exhaust together whilst you tack it). then tack the sections just enough to hold them (don't drop otherwise it'll come apart).

once done, test run on car (there won't be any hangers but figure it out).
find it now does not fit IN the car so attach to roof and drive 80 miles each way to someone who can weld a 3" stainelss exhaust together with some degree of quality in exchange for cake (literally, some cash, but mainly just food to keem him going, took him just under 2hours to seam it).

then fit exhaust to car, find that you have to faff with hangers and turbo housing for over 3hours.
drive home, in relative queitness (drove down there with NO exhuast just engine>manifold>turbo>atomsphere:slayer: )

oh yeah, I had no cats or silencers, just 3" straigt pipe with mandrel bends (the flexi things are shte)

Seen your sig and wondered what it was all about lol.

Sounds do-able

You have no flex then and its all stainless including manifold? What car is it?

Cheers,

Kristian

Hi,

Check out these guys!!

http://www.dynoflow.co.uk/flexitube.html

Tom

yes you use them to isolate the exhaust, so we nthe car flex's and the engine moves around in its mountings it doesn't snap the exhaust welds.

but do not use them as actual corner pieces all over the shop, as they do rip apart eventually (I go thru a front flexi pipe on the punto about once every 8months).


What do you mean MY sig???

yeah, its an IPD turbo manifold (totally unnessacery as the 1991> manifold flows just as good as any, and one costs $400+shipping the other costs £15 from a scrappy :chin:

yes, I did manage to cause a few people to look at me on the journey down, esp when you nail it, in 4th/5th, going above 100mph you can't really hear the engine or the road noise, just '''ffffffssssttt, tichooo, fffffffffssssss....." :worship:

but the sig, thats a bench, and its racing.. it used to say "...the general idea of benchracig"
which is to blag what you have against what others have and say (with no proof or 'racing') who's is quickest and what will happen etc etc.
hence a crudely drawn bench, some volvo Copella 18" wheels burning up and a big IPD manifold - 1turbo

I found them to be cheap for the straight lenghts, bends and flexi joints, that was just the page i copied and paste.

One of the flexi's should do the trick.

Tom

i've made a few exhausts over the years, and made a lot of mistakes each time.

you need to carefully consider back pressure, do not assume that lowering it will be good for performance.

changing back pressure can affect performance for better or worse. if you stick a wider exhaust on (with cat and/or middle box removed or changed to free flow verison) it will lower the overall back pressure.

that can play hell with your bottom end torque, but will give more top end power. overall it isnt a satisfying result on most cars, they feel flat. bottom end torque is almost always more important than high end power, even though peak power figures are all you ever really hear people talk about.

if you have a turbo, and you can create a custom map, lowering back pressure a lot can be a great thing (running higher boost is possible). on an N/A car running a standard map it is rarely beneficial to lower the back pressure by more than a little bit.

also remember that on most cars nothing you do after the cat can have any real effect (other than noise) because the engine's back pressure is created precat (up to and including the cat), so a cat back system cant affect performance unless at least some of the required back pressure is made post cat (bravo/a range is like this, hence 2 middle boxes inbetween cat and backbox).

that is why on most cars a cat back system is only for looks and noise, to affect performance you need to replace the cat, downpipe and manifold, thats where a difference (good or bad) can be made.

here's something worth a quick read https://www.fiatforum.com/bravo-brava/99390-cat-back-systems.html

Well, I have anaged to fool the post cat ecu, so can decat if i like.

I got an approx cost of £430 from powerflow cov which seems resonable! I'm going to get a catless system made up, with mid silencer, adn a decat section to fit a cat in once its been mapped and fuelling is ok and not going to kill it.

The sytems for the sei ARE too small for the engine in it, but what bore would you think would be good for a 1.2 16v punto/bravo engine??? I was thinking 2" with the SS manifold fitted, BMC CDA and a few other mods.

Looking at it, for the Poweflow quote it really isn't worth doing it myself tbh, but if they say £600 when they see it, i may change my mind again!


Cheers for everyones help


Kristian