Main cats removal.... Worth it ?.
Discussion
Hoofa said:
Chaps what are the advantages of removing the main cat ?, is it just noise or are they some performance gains ?. Anyone done a dyno before and after ?
I did a before and after, although before the after I also had the airbox modified along with induction hose and filter... this was also with a remap before the 'after'... the engine is also highly modified 
that said, drove the car into the garage that welded on the lambda boss, fitted the 'Y', and repacked the box back to standard, (had been previously modded).. when I drove out, about three hours after driving it in, the difference was totally astonishing..... I then RR'd the following day, and the difference was huge... about 15bhp on power and 20lbft torque, which, TBH doesn't really tell the storey, because the additional torque came in much lower and lifted the whole torque curve, and when looked at in conjunction with the power curve, just gave monstrous useable torque and power from from 4k up....I guess to summarise, not massive increases on the RR, but in the real world fecking awesome.... I dunno where the main cat becomes a restriction (like the the AFM does at alledgedly about 280bhp), but removing my main cat unleashed scary performance..... Just do it
That's great to hear Chilli, yes yes and yes then, I've been sitting hear worrying about if I should do it, can't fecking wait after reading everybody's insight. The bespoke shiny babies look lovely but I really want to turbo the car, maybe. So I'm happy to use an empty dustbin type for now. You mentioned the torque Chilliman, if it does anything like that to my standardish 4.6 I'll be well pleased.
The cooler engine bay temps is a bonus
Better economy, that'll be interesting?
Can't wait for sunday, or is it saturday? I'll be meeting Alex, aka Gasmonkey to exchange more of the kids inheritance for his de catted Y. Yeehaa, easy going trackday and a faster exhaust ta boot, my heads light with adrenalin!
The cooler engine bay temps is a bonus
Better economy, that'll be interesting?
Can't wait for sunday, or is it saturday? I'll be meeting Alex, aka Gasmonkey to exchange more of the kids inheritance for his de catted Y. Yeehaa, easy going trackday and a faster exhaust ta boot, my heads light with adrenalin!
If you remove the pre cats, you will still pass an MOT as the test is done on a hot engine, pre cats are in place to reduce emissions before normal operating temps.
If you take out the main cat then it will fail, however, if you opt for an aftermarket de-catted y piece then you can refit your original cat for the test, a bit of a pain in the arse but only needed once a year!
If you take out the main cat then it will fail, however, if you opt for an aftermarket de-catted y piece then you can refit your original cat for the test, a bit of a pain in the arse but only needed once a year!
your right and I am going to need it, hows your monster coming along ??Andav469 said:
If you remove the pre cats, you will still pass an MOT as the test is done on a hot engine, pre cats are in place to reduce emissions before normal operating temps.
If you take out the main cat then it will fail, however, if you opt for an aftermarket de-catted y piece then you can refit your original cat for the test, a bit of a pain in the arse but only needed once a year!
... or find a MoT tester who appreciates the sound of the decatted V8 and watch in awe as your beast produces exactly the same emissions as a 1.6 Fiesta. Allegedly.If you take out the main cat then it will fail, however, if you opt for an aftermarket de-catted y piece then you can refit your original cat for the test, a bit of a pain in the arse but only needed once a year!
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