16 replies to this topic

[Georgeralph43]

Hi guys Is it worth getting a sports cat downpipe or not? Would love a de-cat but I want the car to remain MOT legal as do European trips a fair bit not just track.

[smiley]

What are you trying to achive? Noise or performance?

 

[Georgeralph43]

Oh only performance. Felt it may allow the turbo a bit of freedom.

[smiley]

I´m not into turbo´s, so wait for someone else to step in.

It would help if you can describe the current mods on your car (if any), where you are now on bhp, and where you would like to be.

That helps us in explaining better where the money should go, and how to achieve where you want tot go.

 

[turbo boy]

Car George, I presume you are referring to the main cat and not the pre-cat? If so, I have a 100 cell cat on my system. I have to go to a friendly MOT station to get it through the test and it also has to be very hot before the emissions test.... So consider carefully. Jon

[Ivor]

Take the precat out,its not needed for mots. Get a removable main cat, put in for mot take out for the rest of the year

[Georgeralph43]

oh so the pre-cat doesnt matter - i.e. I could get a straight through on the downpipe?

[hairy]

I have removed pre-cat, MOTs no problem.

[TFD]

No backpressure is best for the turbo. I run a 3" 200cpi metal cat to pass MOT, reduce noise a bit and save some trees on the long run. I'll up the boost a bit to compensate for the lost horses if needed.

[NDT]

Pre cat removal makes a big difference to turbo response. People say it'll give you some power too through reduced back pressure (don't know, haven't measured) but for me it was worth it for the big improvement in low speed response.

[Georgeralph43]

Very useful guys thanks.

[smiley]

Keep in mind that above advice is not answering your initial quest for performance.

You could be out spending 500 pounds on a 5 bhp gain.

 

Again. List what you have on mods and where you want to go. Otherwise people here will be very helpful in emptying your wallet, and you may end up disappointed in where you are. 

[Tibbles Stryker]

No backpressure is best for the turbo. I run a 3" 200cpi metal cat to pass MOT, reduce noise a bit and save some trees on the long run. I'll up the boost a bit to compensate for the lost horses if needed.

I thought if we didn't produce a bit of back pressure then it shagged the turbo? I'd like a de cat.

[anz3001]

Remove pre cat altogether - no mot issue.

 

200 cell sports cat, almost as good performance as a full de cat and will have no issues with MOT, although expensive and still prone to melting particularly on SC'd cars (can be off set by buying a better quality unit although some research will be required)

 

100 cell sports cat - hardly worth the effort, equally and sometimes more expensive than a 200 cell for little to no gain and a twat to get through MOTs anyway.

 

De cat - Cheap, no restriction, no melting although need an avenue for MOT's, either a dodgy tester or bolt your o.e back in. Rumours the standard turbo seals don't like a complete lack of back pressure.  

[Tibbles Stryker]

But only for the chav effect 👍

[TFD]

 

No backpressure is best for the turbo. I run a 3" 200cpi metal cat to pass MOT, reduce noise a bit and save some trees on the long run. I'll up the boost a bit to compensate for the lost horses if needed.

I thought if we didn't produce a bit of back pressure then it shagged the turbo? I'd like a de cat.

 

 

The less the better.

 

Get a METAL cat! The ceramic will blow (as used by expensive exhaust builders and were SC guys seem to melt/blow them out).

Running a 3"200cpi Magnaflow metal cat now. We'll see how that one holds.

[Georgeralph43]

I have bought a pre cat delete (straight through) so will report back once Matt has fitted it.