[Mk2] [NA] Decats

[TheLepresean]

Can anyone recommend a decat to go with a Mongoose I'm looking at buying?

Presumably a Mongoose decat is the best bet, but they're a little expensive - is an MR2-Ben one likely to be ok? Or even the really cheapy ones of eBay? My (very) limited understanding is that a decat is just a hollow piece of piping, so as long as it's decent stainless steel, does it really matter? Forgive me if this is a stupid question, equally if anyone has one for sale I might be interested at the right price!

[SonicSW20]

Different decats sound different. The cheaper straight through ones from Ebay, like the following:

http://www.ebay.co.uk/itm/TOYOTA-MR2-EX ... 35c4a2ec1f

Will be louder. I would imagine the Mongoose one is like my old Janspeed one where it is wider in the middle, and has a sort of perforated inner section. It's a resonator, essentially. The difference in volume is noticeable, but not massive. It will still be a lot louder than having a cat, of course.

I found there is a big difference in tonality though - the ebay one is raspier, and creates more pops etc on the over run. The difference in tonality is due to the more expensive decat acting as a resonator and attenuating certain frequencies.

[TheLepresean]

Whilst I want my car to sound awesome driving around town and on WOT, I do a fair bit of motorway driving - would an eBay decat be a bad idea for this?

[TheLepresean]

This one has an enlarged central section and mentions resonators?

http://m.ebay.co.uk/itm/230844380765?cm ... C&gxo=true

[Odin_S]

A decat is a bad idea full stop on a NA imo for the sake of a few bhp you will get alot more noise

[TheLepresean]

I partly agree, but a new cat is expensive and mine has welded itself to the back box so I need a new something! I'd get a sports cat, but they're like £300... likewise, if anyone has a cat for sale I'm also interested.

[Peter Gidden]

A decat is a bad idea full stop on a NA imo for the sake of a few bhp you will get alot more noise

Also illegal on any UK car first registered after August 1995.

[craig]

A decat is a bad idea full stop on a NA imo for the sake of a few bhp you will get alot more noise

Also illegal on any UK car first registered after August 1995.

You mean August 1992?

1995 rule is turbos

[Odin_S]

I'd forget about the decat and get yourself a good induction kit. When I had my NA this was great for me.

It ticks all the boxes of your criteria, quiet while around town but great roar when WOT.
I had a Powertec induction on mine, around £130 or less and metal mesh so you can just clean it when dirty

http://www.powertecfilters.co.uk/which_powertec.asp

[Peter Gidden]

A decat is a bad idea full stop on a NA imo for the sake of a few bhp you will get alot more noise

Also illegal on any UK car first registered after August 1995.

You mean August 1992?

1995 rule is turbos

I mean EXACTLY that.

Late night...

[SonicSW20]

Also illegal on any UK car first registered after August 1995.

You mean August 1992?

1995 rule is turbos

I mean EXACTLY that.

Late night...

I think it's worth clarifying there - the reason MR2 turbos before 1995 are exempt is because the Turbo was never sold in the UK, therefore there is no entry for it in the MOT emissions book. So it just has to pass the actual test. Import NA MR2's are not exempt because the same model was sold in the UK with a cat.

[TheLepresean]

When I was first looking at buying an MR2 a couple of years ago, I was told decat was the best thing you could do (illegalities put to one side) and that it, alongside an induction kit as mentioned by Odin should be the first things I do...?

[TheLepresean]

Though I was told APexi is the kit I should aim at getting.

[Odin_S]

Apexi is good but there are SO many other better ones. People have been saying Apexi since 2001 and the product hasn't changed. Would you buy a mobile from 2001?

[Odin_S]

I'm just saying from the time I've been on these forums. The amount of people who put on decat on a NA and regret it is quite high.

If you're chases power a turbo might be more up your street. Mongoose exhaust and induction is usually your lot when it comes to what your aims are.

Search some YouTube videos to have a look see

[SonicSW20]

Decatting mine made it feel faster. I imagine this is a purely psychological effect due to the increase in noise. I doubt there's actually any measurable power difference.

Every year I put the cat back on for the MOT, and every year I say 'the cat is staying on, while it sounds nice without it, it's a ballache to keep swapping it.'

The longest I've managed is 6 weeks.

I don't find mine drones on the motorway, though I expect that's because of the Janspeed backbox. MY friend had a Blueflame with a decat and that was much louder than mine at cruising speed.

[Mikey637]

My decat blueflame isn't droney and sounds quite quiet tbh. I did have a decat Nurspec on my na before though. Considering a japspeed as an Inbetween with the apexi butterfly valve

[TheLepresean]

A fair point well made regarding APexi Odin, I might have to look more into induction kits. I just want something louder than stock without being deafened on the motorway! I had a Mongoose on my old MR2, and it was fine enough - 70mph was droney but a bit under or over was fine. Not sure if it was decatted though...

Is Janspeed a quieter exhaust then Gazza? I understand they're rare as they're no longer made? They look fairly similar physically to a Mongoose if I'm correct?

Never been a fan of the way a Blueflame's tips come out at an angle to be honest...

[SonicSW20]

I find it's pretty quiet at low revs / throttle, but it gets quite loud at WOT and high revs. I can only compare it to a JapSpeed and a Blueflame though. It's certainly quieter than a Blueflame in my experience.

My Janspeed came on the car, they do pop up on eBay etc every so often though.

[SonicSW20]

Some pics:

http://imgur.com/a/nWgUz