Paul K

I was just wondering how the Power Engineering T75 cat mid section compares to the ScoobySport decat mid section (with a ScoobySport downpipe and back box ) in terms of noise and performance ( i would have thought with a cat it would subdue the sound slightly ) . Also will the Power Engineering T75 cat mid section mated to a ScoobySport downpipe and back box enable the car to pass the MOT emissions tests ?
Cheers Paul

Akira

Paul,

I've just changed the Mid. section on my MY97 UK for a Magnex De-Cat pipe (straight through, no resonator). My car also has the SS DP&BB which transforms the car as you will know. Putting in the Magnex section, I was not expecting much more. However, the result is a noticable increase in torque and a big increase in noise! Personnal preference, but I just love the noise the car makes. Lots more pops and bangs going on. . No chance with passing MOT now, but I have the option of a friendly MOT station or replacing the DP come MOT time.

For £91.50 the Magnex centre is a worthwhile investment. "Roadrunner" in Nottingham have a few of the straight through Magnex pipes left. Apparently Magnex only make the pipe now with the resonator in. not as good but quieter. Give 'em a call, you won't be disappointed. I've no connection with "Roadrunner" by the way.

Cheers
Chris

GaryC

I went for Scorpion mid-section - £69. Straight through pipe, no cat, no resonator.silencer etc.

Speak to David at Motech

MarkF

I've just added a magnex decat pipe to my 93 WRX. I already had a Milltek back box in place and the decat pipe made a big improvement on turbo spin-up. The car now feels much more driveable ffrom low revs right through to redline.
I bottled it after talking to Falkland Performance and got the one with a resonator. Its slightly louder from cold but its a lot louder when hot. Very good VFM in my opinion.

igratton

Hello boys,

I think its all pretty much of a muchness when it comes to middle sections. IMHO Its the simplest part of the exhaust system (not a techie).

I think the important choice is down to how much noise increase you require. The centre pipes without resonators a fraction quieter...the ones without...well...what can I say...the sound is awesome

Some pipes don't mate directly to the downpipe too well. Look for a pipe which has the same style of flange at the downpipe end as the original pipe. There is a dounut that sits between the downpipe and the centre section that allows the exhaust to twist slighlty under the movement of the engine.

The reason I took the scoobysport route is that their section is made from the OE pipe...so the flanges match exactly (plus I use their downpipe and backbox...so I completed the set).

Direct match pipes include:

Scoobysport
Magnex
Scorpion

there are probably others. but I imagine the likes of HKS and BLITZ are slightly bigger bore (to match the rest of their systems).

Get one....you'll love it.

Akira lives in loughborough....and I can hear his car from Derby LOL

Ian.

Akira

Cheers Matey!

Ian's Scoobysported car is currently residing in the Cambs. area and I can hear him in Loughborough! LOL .. Touche! (spelling?)

Chris

p.s. if anyone wants to pop by and have a listen, you're more than welcome.

strong

Paul,

Power Engineering's T75 mid-section with cat when mated with any other exhaust should allow your car to pass an MOT.

I would also expect the cat to subdue the sound a bit.

As for performance, a cat (evens a 'sports cat') must restrict the exhaust gasses a bit, but I guess it's a compromise between ultimate performance and cost/convenience of swapping downpipes.

I'm getting on my high horse here, but I think it's a bit out of order these days to drive around without a cat, intentionally spewing out more environmentally damaging waste than is necessary.

Paul

dmel

I have just a Supersprint back box fitted to my car and I am now thinking to change the mid-section for a de-catted and de-silenced unit.

Having talked to Power Engineering and Graham Goode, they both claim that the noice levels will not change very much by changing just the mid-section. However most of you here say quite the opposite. Can someone please clarify this point?

Finally is it 100% certain that all Subarus with the mid-section cat removed pass the emission tests?

igratton

dmel...

I think the sound level has increased.

I ran a MY97 car with SS Backbox and Downpipe for approx 15 months. The downpipe made the car a little louder. I remember before I sold the car I installed the std. exhaust system and was amazed at how quiet the car was.

On my new car I am using the same SS downpipe and backbox plus the middle de-catted and unsilenced centre pipe. The exhaust is definately very free-flowing without the cats...pickup is far improved.

I would say the noise is marginally louder...but after 4,000 Revs the bark from the exhaust is like music to my ears.

Again...others that I know (Mike Tuckwood, Akira, Firefox[J], Jase, stef etc.) are all running full de-cat systems and they are all about the same volume...just a different note.

MOT...you may pass with just the middle cat removed...without either....chances are slim

Ian

Ian Cook

You will DEFINITELY pass an MOT with only the centre section cat removed, I have had my car checked, and it made almost zero difference to the emissions, but if you do the downpipe as well, it will almost definitely fail, unless you use a Link or something and remap the car just for the test !!!!

Andy Tang

iTrader: (3)

I was down at Power Engineering yesterday to get my car checked over, now that it has to run NORMAL unleaded fuel, rather than Super. (Work won't let me use Super on the petrol card anymore!)

The car is a UK MY97 with a ScoobySport backbox, downpipe and K&N 57i. 56k on the clock and as stated above, using normal unleaded. The standard centre cat is still in place.

The emmissons were as follows:

At Idle - CO well within limits. The hydrocarbons were 54, but the needs to be 50 or lower to pass. If it's higher than 50, but CO are within limits, they should test at 2,500rpm....

At 2,500rpm - The CO again was well within limits, and so were the hydrocarbons.

So all good news for the MOT due in August!! No problem passing as long as the car is warmed up!

If I'd kept the standard downpipe and changed the mid-section, it would have passed with flying colours from cold.

Either way, if you retain one cat, you should be ok!!

Andy

GaryC

Cat will not be warm/hot when it gets emisions tested for an MOT - unless done by 'accomodating' tester

dmel

Thank you all very much for your replies. And something else. The SS downpipe retains the original (first) catalyst or places a new perhaps more free-flowing catalyst? What do you think I should do first? Change the mid-section or go for the downpipe?

igratton

dmel.

I would say go for the down pipe first...

check out this picture...

strong

dmel,

Regarding noise level changes after fitting a performance mid-section, had the people you talked to fitted a downpipe and back box and THEN a mid-section, whereas you are retaining the standard downpipe? As soon as you open up the whole system (no cats at all) then there will definitely be more noise.

Anyway, change the downpipe first for a greater performance increase -- in particular faster turbo spool up. Everyone who has changed the downpipe has commented that it makes a noticeable difference.

Paul