i have a '91 1.8 8v Gti, currently its an exhaust which im led to believe is for a 16v and theres a union where the old and new sections join that keeps blowing, ive not had the car all that long and havent had time to get under to properly inspect it, but think this is caused by a difference in pipe size. so, obviously the best option is to replace it with the correct sized pipe, but what pipe/box do i get?
A 16v exhaust is normally a bigger bore than the 8v. There's no reason why this can't work on an 8v car as long as there's a sleeve pipe to take up the gap. If the 16v system is in good condition, it'll be fine. As you said yourself, getting underneath for a look is the first step.
in my driver i have a 60mm bore short downpipe, probably was out of g60 with a cat or something, and the rest is 50mm 8v system. i don't like it at all, the car runs like cr*p and makes an anooying noise. maybe moving from wide to narrow pipe makes turbulences inside.
gonna take it to a mechanic friends to have a look, as he has a decent pit i can park on, as its 40mm lowered and on skinny tires it aint that easy to get it up( oo er) to take a proper look. ive seen a reducer pipe somewhere on ebay, cant remember what sizes but im asuming that it is for fitting bigger bore pipes, but wouldnt that make the pipe longer? is there a , sleeve/collar option or is it a case of making one to fit. i am capable of doing required fabrication but prefer to use ready made/designed for the job parts as my time is precious to me
jetex do a good range of custom pipe fittings, reducers, clamps etc. I can vouch for the quality of the stuff too - the only problem I've ever had with my exhaust was from the down pipe/center pipe union that I used a non jetex clamp on! http://www.jetex.co.uk/website/custom_parts.php?mat=Aluminised+or+mild&dia=2.0+inch clamp wise use the "aluminised steel Ring clamp" style clamps (you will need to measure your pipe diameter first), part number U715410 is for the 2" but they do them in lots of sizes. this ones 2.66 pipe reducer/step would be along the lines of part number U075115 which is a "aluminised steel Stepped sleeve 41-48-51mm". again other sizes are available and this ones 7.16 2 x clamps and 1 x reducer = 12.48 cheap as chips
sorry for the late reply, been busy and then went away thanks for the advice, gonna order some stuff from the website, not even gonna bother taking measurements as im confident this will be a cure once again thanks
You can buy a posh jetex sleeve if you want, but generally you can cut a bit off an old exhaust, as long as you can find one the right size. Best to slot the ends of it to help it compress and seal properly. Normal exhaust clamps should be fine too. I've got nothing against jetex stuff, btw. It's generally pretty good quality.