DeCat Vs Sports Cat

[Anonymous]

thinking about changing the straight piping int he exhaust system to Titanium as was wondering about Decat part. my sports cat can be swopped in or out and im with aftermarket ecu two maps could be stored with one for decat and one with sports cat.

main question is there any performance gains from people who swop from sports cats to decats for track days/drag etc???

at the moment im sure sticking a decat will break the sound limits at all tracks in the UK, could stick a small resonator in. just not sure at moment in future if will go charged or NA so wondering if charged would do better with a decat.

shouldnt be to expensive to make, straight pipe with two holes for oxy sensors i guess. hoping someone has experience with them

 

[frediiii]

hi orb,

I gave the 4-1 manifold (which I got from k4m guru oliver) to a friend who drives an gordini 133, as I had it fitted with a 200cell sports-cat and it was just to darn loud to be driven in the city. got pulled over 4 times in about 2h testdrive... as he is living in a less crowded area, he took it and mounted it WITHOUT the sports-cat. so he is now running 4-1mani, pipe, pipe, pipe, k-tec rear silencer... and this setup sounds amazingly similar to what you get from the twingo R2 videos on youtube. but in real-life this is just insanely loud.

so on that basis: don't do it

...on the other hand he now has an impressive torque-delivery even though the ECU is not yet set up to match the hardware...

 

[Matt]

hi orb,

I gave the 4-1 manifold (which I got from k4m guru oliver) to a friend who drives an gordini 133, as I had it fitted with a 200cell sports-cat and it was just to darn loud to be driven in the city. got pulled over 4 times in about 2h testdrive... as he is living in a less crowded area, he took it and mounted it WITHOUT the sports-cat. so he is now running 4-1mani, pipe, pipe, pipe, k-tec rear silencer... and this setup sounds amazingly similar to what you get from the twingo R2 videos on youtube. but in real-life this is just insanely loud.

so on that basis: don't do it

...on the other hand he now has an impressive torque-delivery even though the ECU is not yet set up to match the hardware...

What sort of money are you looking at for one of these?

 

[frediiii]

sorry mate, it was a one off project. oliver took a clio 182 manifold, saw off the flanges and welded it to a K4M flange.

 

[Anonymous]

i remember seeing this on TOC site. had a good chat with Oli before my 4-2-1 was made. interesting to see what he got from a 4-1.
mine can be easily changed to a 4-1 by changing the middle bit which is the 2-1 section.
i dont mind taking out sports cat and adding small silencer to get within track limits, then put sports cat back in for normal driving.

before i had remap the car was over 100db's. and i was sick after driving 30mins on motorway, jets had a db or 107. lol
now it is sitting about 95 but i've had to put so much sound carpeting behind everything. dont mind on track due to helmet knocking off most of the sound. but town driving with the car stripped is insane. i do get quite a few looks when i drive. CD player is on constant overheat. haha

 

[Anonymous]

matt.
supersprint 4-1 does fit in the twingo rs. looks the same as Oli's one two

 

[FaBiO 180]

https://www.supersprint.com/USP00rencli14.asp
is this manifold???

 

[frediiii]

yeah - should fit. but I like the modified clio one more. longer pipes.

 

[Anonymous]

theres a convo with super-sprint on here about using that with cat-back system, not much gains they said on a non remapped engine.
i believe my systems got to the point of needing more induction into the system. very very little back pressure. been told to get head ported as exit mani-can handle more output then exit ports giving, but would only do this with cam or piston in as it would make zero back pressure at all.
i know stating getting a decat in the title and wouldnt be done without more power gain first othewise i guess il be losing some.
does it need to be mapped to state that theres no converter in the system etc?
anyone know a perfect balance with back pressure in N/A exhaust systems?

 

[madmatt]

sorry mate, it was a one off project. oliver took a clio 182 manifold, saw off the flanges and welded it to a K4M flange.

Hate to nnnnnnnnnnnecropost, but was it much of a job to modify the 182 manifold with the new flange?
Also, was it difficult to fit (just with clearance and such)?

Cheers

 

[frediiii]

no problem regarding clearance. was quite easy to fit, yes.

I think oliver spent some evenings on this mani. he built a wooden model around his original manifold an then mounted the new flanges on it (cnc machined from a friend of his). then he had to bend the tube inlets because the 182 has round pipes and the k4m has oval outlets (and different cylinder spacing) and weld it all together while still in the wooden frame

 

[madmatt]

no problem regarding clearance. was quite easy to fit, yes.

I think oliver spent some evenings on this mani. he built a wooden model around his original manifold an then mounted the new flanges on it (cnc machined from a friend of his). then he had to bend the tube inlets because the 182 has round pipes and the k4m has oval outlets (and different cylinder spacing) and weld it all together while still in the wooden frame

That's good to know Fredi, was it just on the OE 182 manifold? I like that it's a shorter manifold and you just bolt the flange onto the collector section to build the rest of the system.

I was looking at stainless 172/182 manifolds but most are 4-2-1 with much longer pipes, I can imagine they'll be more of a hassle to get clearance and mapped.