Wow this threads turned into a hot one lol!
I thought I would give a quick in sight information on the results we found when we were testing a de-cat on a 182 at Torque of the devil last year (dyno dynamics rr)... Sadly I have no graphs of this as there were all stored on my previous work partners lap top so its your call on if you decide to believe my findings or not, frankly couldn't care either way
Test 1. Completely standard 182 bar milltek cat-back, Rolling road showed normal power/ torque, was in the region of 170/173 bhp
Test 2. Same car but this time with the decat fitted, Peak power was near identical but lost a good chunk of torque at around 3,000rpm (this being the flat spot your feeling in the above threads) AFR in the mid-range ran very lean hence theloss
Test 3. Decat & ECU calibration (not a live, Just our generic) good solid torque curve with gains of over 10ftb's points below 5,000rpm and no flat spots at all! only showed a rise of a couple of peak bhp but it was still on standard airbox/inlets etc
Test 4. removed the de-cat and re-fitted the catalyst, and left the ECU calibration on, torque at 3,000rpm was lower than test 3, in the mid-range test 3 & 4 showed near identical power, Up top test 3 held the power much better
Now these test were carried out over a course of 2 days (due to fitting/ removal of parts) so there are variations there that couldn't be helped, but the best figure of the test was test 3.
Moral of the story is, If you wan't a de-cat, get it mapped and you should see gains, if you don't get a decent calibration your just gaining noise!
James
EXACTLY backs up what I said
The de-cat without a specific map for it leaves a whole in torque at 3000rpm - which is around the revs you're at coming out of a corner and you're in a big nasty torque hole
It's £150 and 2hours whacking your knuckles on stuff to make your car slower and illegal
Phil you really need to take a step back....
The reason why everything you and others say I come at you for is primarily that in the 'real' world most of the stuff you lot talk about in theory is correct however at the end of the day is all for a bloody sub 200bhp Clio! Having spent a lot of money on modifying and changing various bits on my Cup I feel I can give a very good opinion on what I think.
So the £11k I've spent on my sub-200bhp clio means I'm completely unqualified to give my opinion - but your opinion as an ex-cup owner is gospel?
I felt with a decat it made the car feel more urgent, and I prefered more peaky power than 'lots' of low down torque. On a trackday thats the kind of rpm imho you want to be in most of the time, plus because mine was all mapped in with the other 'sheep' RS-2 mods it made a difference.
But in this thread that's completely irrelevant. You had a different inlet and a full re-map - so the de-cat might have worked for you
But the OP and 90% of people reading this will just spend £150 on a de-cat, lose their knuckles fitting it for 2 hours and end up with a nasty hole in the torque curve leading to a slower car. That is ENTIRELY my point. You're experience on your car is irrelevant but you still tell me I'm wrong every bloody time.
Also refering to noise regulations, maybe you should address the rest of your exhaust? I ran a decat with just one rear silencer, sounded loud but passed on every single track, so I find that its not the decat thats the problem but more the design of the cat-back part of the exhaust.
So I should take a very well designed exhaust off that works well and gives me good power and replace it with something else so I can pass noise tests?
Or I could put my cat back on and have a legal car with no noise problems and more torque?
In reality now I wouldnt even bother giving the road/track clio more power or weight saving anymore, reason? My Cup was pretty gutted weightwise and made average power (reliable 195bhp), when on reality on a trackday with my mate Ollie in his cup (minor stripped and breathing mods, 177bhp) was just as quick pacewise as me. This is what leads me everytime someone goes on about rolling radius/unsprung weight/torque and power I get a little annoyed as it makes naff all difference, in a racecar when your trying to shave 10ths of seconds ect then its worthwhile but on a roadcar/trackcar with nothing to prove its pointless. Either go the whole hog or dont bother at all.
If your 195bhp stripped clio was the same pace as a standard cup - then you're driving or map was not up to the job
My car is fully stripped, caged, billies, decent brakes and a standard engine. On the track days I've done this year it's noticeably quicker than other 172's and I don't even know how to drive properly. With an extra 20bhp and even less weight I can't see a standard cup keeping up next year
Also talk about contradicting yourself - every time I've said in this thread that a de-cat loses power and is pointless and takes too long to fit and is a waste of money - you've argued with me. Now you're saying you wouldn't mod a 172 as they're fast enough standard.
f**king forums? This place used to be about just having fun, now it just seems to be people confusing/lecturing others about stuff they really dont need to know about. They just need to learn to enjoy their car however way they want.
So to top it off just have fun, if that means spending money of making it louder and slower or visa versa then so be it... My moneys on driver training, be it track or road training, so much more rewarding and feel like you acheived more than owning a 250bhp+ clio.
To the OP - if you want a more peaky powered car with a more raspy exhaust note then get a decat, if not dont bother and spend it on something that YOU want to get.
Nick
This place is still fun - except occasionally someone asks for technical advice - and when people try to give it someone like you who sits on a high horse comes in spouting loads of irrelevant nonsense and talks someone into buying a car mod that they don't need.
I'm sorry but just because you stuck an inlet on a stripped out clio doesn't mean you have more experience than everyone else on this forum about cars. I've been modding and racing cars for over 10 years now and I've done a hell of a lot more to my Clio than you have so why are you instantly right and I'm instantly wrong?
I'm out.!
