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2.4JTD turbo downpipe GROUP BUY????

5K views 31 replies 9 participants last post by  Cuore_Sportivo_155 
#1 ·
gauging what sort of interest there would be in a group buy (to get the cost down) in changing that restrictive downpipe that fits from the turbo to the exhaust - to replace the cast part which is 2x 90deg bends and quite narrow.
 
#12 ·
so, we have possibly...
adamanthippo
Cuore_Sportivo_155
jasons
Mark_JTD - you know it means losing the particulate filter - if it has one?


any others?
Don't know cost as yet, but if we can get 4 or 5 then the cost should be lower, the flange would have to to machined to fit the turbo, the stainless pipe mandrell bent and a flange to connect to the exhaust, at a guess I would have thought 130-180quid?
Torqu exhausts, linked to Red Dot who provided my old 140 with 230+bhp was who I had in mind. (spoke to them about it the friday before the alfa day at red dot.
 
#13 ·
Yeah, i know it's not cheap to get done... but it's the single most effective mod you can make, besides remapping... hence why I'd rather join a groupbuy...

turbo spools up lower in the rev range and keeps spooling longer up the rev range... you widen the usable powerband by 500 rpm.... +- 1500-5000 for a remapped 136.... especially if you decat the exhaust aswell. I don't really expect more BHP or Nm, but the Bhp output could be higher....
 
#15 ·
well i not sure what the particulate filter is but it sounds good iam looking to put a stainless on mine anyway take the cat off at some point also looking to replace air filter with a n other just shopping around for the best valued air filter then maybe a remap but cant get it done at once will face divorce if i did lol
 
#19 ·
Yup, that's for the 20v. I've asked Supersprint a few times about a price on that part but they won't release it until more people want it which sounds weird to me!!

So is the 10v 2.4 a single pipe from the turbo - cat or do you have a pre-cat which is about 10" long, then then main down pipe that goes to the cat?! I can't get onto eper at the moment to check unfortunately.

Cheers,

Mark
 
#21 ·
but the downpipe is seperate from the flexy, which is seperate from tyhe cat, which is seperate from the centre section, which is seperate from the backbox....

btw, just emptied my spare catalyser, and got hold of a Remus backbox... just needs a length of 60mm pipe to connect to my centre section... should get this fitted this week, at least the decat...
 
#27 ·
below is a bit of info I found regarding exhausts, whilst I don't plan to change my exhaust straight away, allowing for a larger bore would be good - say 2.5", and even if I never do, a larger pipe doing a 180degree bend and acting as a buffer for lower backpressure wouldn't hurt would it?


"Because you want the least backpressure in a turbo car's exhaust, the ideal exhaust system would produce the least backpressure immediately after the turbo. Due to routing, emissions equipment, pipe diameter, exhaust gas temperatures/pressures, the perfect diameter changes from car to car, setup to setup. It's very difficult to know this without extensive testing, so as a rough rule of thumb, a consistent or increasing diameter exhaust as you head downstream towards the tailpipe is best in most cases. Mandrel bent exhausts are also always better. A mandrel bend is when piping is bent with a mandrel, or insert, to keep the inner diameter consistent at the bend. Crush bends reduce the diameter at the bend and reduce smooth exhaust flow. Most factory exhausts are non-mandrel bent crush style bends, so switching to a mandrel bent exhaust will increase power and efficiency of the turbos and engine with no other modifications. You also want to avoid very restrictive mufflers, sharp changes in piping diameter, and sharp bends. As a rough rule of thumb, each 90o bend in the piping has about the same resistance to airflow as 25 feet of straight piping!"
 
#28 ·
you might be interested in this,
gives a good idea of gains to be had.
piper exhausts did developement and group buy stuff for seat leon tdi boys.theres a graph in there of a 22hp gain on a std car and a few videos of sound from there system with boxes and no boxes.

Leon MK1 Diesel Exhaust development - SPECIAL PRICES NOW AVALIABLE!!! - Page 9 - SEAT Cupra.net - SEAT Forum

and i think thy may be in process for astra cdti lads soon as well.
might be worth it it you can get enough together to get price down as the prices are not cheap though but quality seems to be there.
 
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