MINI2

1320autos · Sep 18th, 2007, 09:30 PM

..........everytime we put the Janspeed cat back in we gain horsepower, the 11.77 and the 119mph had the cat in.

Has anyone else experienced this??

alski · Sep 19th, 2007, 06:34 AM

so are you saying no point in having de-cat, or indeed a de-cat is a power looser

1320autos · Sep 19th, 2007, 07:08 AM

At the moment yes, but to be fair I haven't tested like for like, we tested a straight pipe and not de cat pipe in the shape of the Janspeed cat.

The only way to test it properly is buying buildin a de cat pipe the same shape as the Janspeed cat.

I must point out that this is what we have found with our car, what it'll do on your own is another matter.

We'll be testing another exhaust theory hopefully today.

We have over 70 passes on the dyno in the last couple of months testing different combos

Richard Crofts · Sep 19th, 2007, 10:01 AM

The supercharger does like some BP mind ... so maybe the removal of the cat looses a wee bit too much BP and causes the loss in power. I know on a turbo BP is bad and so big straight pipes are bsest but its been shown on s blown cars this is not true and doing big straight pipes can loose some hp .... maybe thats what occurs?

TallAndy · Sep 19th, 2007, 10:49 AM

de-cat sounds better though

Snowie · Sep 19th, 2007, 11:11 AM

Has any one any idea on what is the ideal exhaust back pressure.

Mine is currently circa 3.4 PSI Is this too high and interfeering with BHP gains

Set up is GP with JCM 4.2.1 Sports cat and standard GP twin rear silencers complete with the 'flat' bit before the 'y' piece.

MINI-Morgan · Sep 20th, 2007, 03:07 PM

I'd be interested to see some testing on this

Any results would be good

MiniPetrolHead · Sep 20th, 2007, 03:26 PM

Yeah that would be interesting! A mate of mine put the ebay manifold on which has a decat.
It sounds fantastic but we think it may be loosing him power along with the GTT re-route pipe there probably isnt enough back presure.

His car just feels revvy and not torquey, where as mine revd slower hardly noticable with the standard manifold, yet mine feels so much more torquey!

When he had that manifold and de-cat on, 15% pulley, iridium plugs, pannel filter and re-route pipe the cars were neck and neck (apart from initially when the torque of my car put me ahead by 3ft) when i only had my MiniMania exhaust manifold.

Alex

MINIMANIAUK · Sep 20th, 2007, 06:30 PM

Its more about scavenging , than back pressure. lower the better with BP

MiniPetrolHead · Sep 20th, 2007, 07:37 PM

Quote: Originally Posted by MINIMANIAUK (original)

Its more about scavenging , than back pressure. lower the better with BP

What do you mean?

Alex

1320autos · Sep 20th, 2007, 08:14 PM

Quote: Originally Posted by Snowie (original)

Has any one any idea on what is the ideal exhaust back pressure.

Mine is currently circa 3.4 PSI Is this too high and interfeering with BHP gains

Set up is GP with JCM 4.2.1 Sports cat and standard GP twin rear silencers complete with the 'flat' bit before the 'y' piece.

We've been eperimting with cat backs and it seems that what you think should work doesn't and what shouldn't work does.

The difference in trq on some is unreal. We were discussing today about having a catback shootout one day next week

MINI-Morgan · Sep 25th, 2007, 09:00 PM

Any dyno results in? Especially the MINI Mania 4-2-1 Manifold?

1320autos · Sep 25th, 2007, 09:04 PM

No sorry to busy and Adams shipment hasn't come in as far as I know but soon as it does we'll let you know

ScottyBoy · Sep 25th, 2007, 09:27 PM

Quote: Originally Posted by Mini-Morgan (original)

I'd be interested to see some testing on this

Any results would be good

Roland started a thread on this a while ago when he was testing back pressure of a few different exhaust, the JCW is pretty poor in comparison

Hears the thread

http://www.mini2.com/forum/engine-dr...g-results.html

Scott

MINI-Morgan · Sep 26th, 2007, 10:54 AM

Quote: Originally Posted by ScottyBoy230 (original)

Roland started a thread on this a while ago when he was testing back pressure of a few different exhaust, the JCW is pretty poor in comparison

Hears the thread

http://www.mini2.com/forum/engine-dr...g-results.html

Scott

Thanks

So far as I was aware Roland hasnt released any tests results for precat pressure and the performance change with reducing the pressure.

MINI-Morgan · Sep 26th, 2007, 10:55 AM

Quote: Originally Posted by 1320autos (original)

No sorry to busy and Adams shipment hasn't come in as far as I know but soon as it does we'll let you know

Damn! Maybe thats why I havent heard anything....

MINIMANIAUK · Sep 26th, 2007, 05:55 PM

Sorry for the delay guys ,manifolds and decat pipes are here ,but the hi flow cat pipes are not finished yet

. I can get one with out the cat pipe to Paul ,but the cats wont be here til at least monday.
More than welcome to try one without cat first though

MINI-Morgan · Oct 2nd, 2007, 02:30 PM

Quote: Originally Posted by MiniPetrolHead (original)

What do you mean?

Alex

Scavenging - Wikipedia, the free encyclopedia

MINI-Morgan · Oct 2nd, 2007, 02:31 PM

Quote: Originally Posted by MINIMANIAUK (original)

Sorry for the delay guys ,manifolds and decat pipes are here ,but the hi flow cat pipes are not finished yet

. I can get one with out the cat pipe to Paul ,but the cats wont be here til at least monday.
More than welcome to try one without cat first though

Looking forward to mine this week and pauls results

Maybe just mostly looking forward to the new exhaust note..

Sep 18th, 2007, 09:30 PM	#1
1320autos MINI2 Master Join Date: Jul 2005 Location: Beds Cambs Northants Local Time: 10:28 PM Posts: 1,928 Online	De Cat or Cat ?????? ..........everytime we put the Janspeed cat back in we gain horsepower, the 11.77 and the 119mph had the cat in. Has anyone else experienced this?? Slicks 11.77@115.92mph Street tyres 12.162 @ 119.02 IT'S NOT HOW MUCH YOU SPEND BUT HOW WELL YOU SPEND IT

Sep 19th, 2007, 06:34 AM	#2 (permalink)
alski ever been on a dyno Join Date: Dec 2005 Location: banbury Local Time: 10:28 PM Posts: 915 Offline	so are you saying no point in having de-cat, or indeed a de-cat is a power looser carefree

Sep 19th, 2007, 07:08 AM	#3 (permalink)
1320autos MINI2 Master Join Date: Jul 2005 Location: Beds Cambs Northants Local Time: 10:28 PM Posts: 1,928 Online	At the moment yes, but to be fair I haven't tested like for like, we tested a straight pipe and not de cat pipe in the shape of the Janspeed cat. The only way to test it properly is buying buildin a de cat pipe the same shape as the Janspeed cat. I must point out that this is what we have found with our car, what it'll do on your own is another matter. We'll be testing another exhaust theory hopefully today. We have over 70 passes on the dyno in the last couple of months testing different combos Slicks 11.77@115.92mph Street tyres 12.162 @ 119.02 IT'S NOT HOW MUCH YOU SPEND BUT HOW WELL YOU SPEND IT

Sep 20th, 2007, 03:07 PM	#7 (permalink)
MINI-Morgan MINI Obsessed... My Classifieds Join Date: Nov 2003 Location: Southampton, Hants Local Time: 10:28 PM Posts: 4,610 Offline	I'd be interested to see some testing on this Any results would be good One Man, One Project......find out what happens next at MINIProject.co.uk For MINIs in the south it can only be South Coast New MINI Club

Sep 20th, 2007, 06:30 PM	#9 (permalink)
MINIMANIAUK MINI2 Sponsor Join Date: Mar 2006 Local Time: 10:28 PM Posts: 1,022 Offline	Its more about scavenging , than back pressure. lower the better with BP www.minimaniauk.com

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Sep 19th, 2007, 10:01 AM	#4 (permalink)
Richard Crofts THE STICK Join Date: Feb 2003 Location: Worcestershire WR15 Local Time: 10:28 PM Posts: 3,001 Offline	The supercharger does like some BP mind ... so maybe the removal of the cat looses a wee bit too much BP and causes the loss in power. I know on a turbo BP is bad and so big straight pipes are bsest but its been shown on s blown cars this is not true and doing big straight pipes can loose some hp .... maybe thats what occurs?

Sep 19th, 2007, 10:49 AM	#5 (permalink)
TallAndy Taller Than You! My Classifieds Join Date: Jul 2003 Location: Bolton Local Time: 10:28 PM Posts: 1,195 Offline	de-cat sounds better though

Sep 19th, 2007, 11:11 AM	#6 (permalink)
Snowie MINI2 Master Join Date: Aug 2006 Location: Camberley, Surrey Local Time: 10:28 PM Posts: 1,417 Offline	Has any one any idea on what is the ideal exhaust back pressure. Mine is currently circa 3.4 PSI Is this too high and interfeering with BHP gains Set up is GP with JCM 4.2.1 Sports cat and standard GP twin rear silencers complete with the 'flat' bit before the 'y' piece.

Sep 20th, 2007, 03:26 PM	#8 (permalink)
MiniPetrolHead 263bhp / 284.55Nm Torque My Classifieds Join Date: Oct 2006 Location: Eastbourne E.Sussex Local Time: 10:28 PM Posts: 670 Offline	Yeah that would be interesting! A mate of mine put the ebay manifold on which has a decat. It sounds fantastic but we think it may be loosing him power along with the GTT re-route pipe there probably isnt enough back presure. His car just feels revvy and not torquey, where as mine revd slower hardly noticable with the standard manifold, yet mine feels so much more torquey! When he had that manifold and de-cat on, 15% pulley, iridium plugs, pannel filter and re-route pipe the cars were neck and neck (apart from initially when the torque of my car put me ahead by 3ft) when i only had my MiniMania exhaust manifold. Alex

Sep 20th, 2007, 07:37 PM	#10 (permalink)
MiniPetrolHead 263bhp / 284.55Nm Torque My Classifieds Join Date: Oct 2006 Location: Eastbourne E.Sussex Local Time: 10:28 PM Posts: 670 Offline	Quote: Originally Posted by MINIMANIAUK (original) Its more about scavenging , than back pressure. lower the better with BP What do you mean? Alex

Sep 20th, 2007, 08:14 PM	#11 (permalink)
1320autos MINI2 Master Join Date: Jul 2005 Location: Beds Cambs Northants Local Time: 10:28 PM Posts: 1,928 Online	Quote: Originally Posted by Snowie (original) Has any one any idea on what is the ideal exhaust back pressure. Mine is currently circa 3.4 PSI Is this too high and interfeering with BHP gains Set up is GP with JCM 4.2.1 Sports cat and standard GP twin rear silencers complete with the 'flat' bit before the 'y' piece. We've been eperimting with cat backs and it seems that what you think should work doesn't and what shouldn't work does. The difference in trq on some is unreal. We were discussing today about having a catback shootout one day next week Slicks 11.77@115.92mph Street tyres 12.162 @ 119.02 IT'S NOT HOW MUCH YOU SPEND BUT HOW WELL YOU SPEND IT

Sep 25th, 2007, 09:00 PM	#12 (permalink)
MINI-Morgan MINI Obsessed... My Classifieds Join Date: Nov 2003 Location: Southampton, Hants Local Time: 10:28 PM Posts: 4,610 Offline	Any dyno results in? Especially the MINI Mania 4-2-1 Manifold? One Man, One Project......find out what happens next at MINIProject.co.uk For MINIs in the south it can only be South Coast New MINI Club

Sep 25th, 2007, 09:04 PM	#13 (permalink)
1320autos MINI2 Master Join Date: Jul 2005 Location: Beds Cambs Northants Local Time: 10:28 PM Posts: 1,928 Online	No sorry to busy and Adams shipment hasn't come in as far as I know but soon as it does we'll let you know Slicks 11.77@115.92mph Street tyres 12.162 @ 119.02 IT'S NOT HOW MUCH YOU SPEND BUT HOW WELL YOU SPEND IT

Sep 25th, 2007, 09:27 PM	#14 (permalink)
ScottyBoy Obsessive Car Cleaner OCC My Classifieds Join Date: Jul 2006 Location: Thornaby NE Local Time: 10:28 PM Posts: 2,873 Offline	Quote: Originally Posted by Mini-Morgan (original) I'd be interested to see some testing on this Any results would be good Roland started a thread on this a while ago when he was testing back pressure of a few different exhaust, the JCW is pretty poor in comparison Hears the thread http://www.mini2.com/forum/engine-dr...g-results.html Scott

Sep 26th, 2007, 10:54 AM	#15 (permalink)
MINI-Morgan MINI Obsessed... My Classifieds Join Date: Nov 2003 Location: Southampton, Hants Local Time: 10:28 PM Posts: 4,610 Offline	Quote: Originally Posted by ScottyBoy230 (original) Roland started a thread on this a while ago when he was testing back pressure of a few different exhaust, the JCW is pretty poor in comparison Hears the thread http://www.mini2.com/forum/engine-dr...g-results.html Scott Thanks So far as I was aware Roland hasnt released any tests results for precat pressure and the performance change with reducing the pressure. One Man, One Project......find out what happens next at MINIProject.co.uk For MINIs in the south it can only be South Coast New MINI Club

Sep 26th, 2007, 10:55 AM	#16 (permalink)
MINI-Morgan MINI Obsessed... My Classifieds Join Date: Nov 2003 Location: Southampton, Hants Local Time: 10:28 PM Posts: 4,610 Offline	Quote: Originally Posted by 1320autos (original) No sorry to busy and Adams shipment hasn't come in as far as I know but soon as it does we'll let you know Damn! Maybe thats why I havent heard anything.... One Man, One Project......find out what happens next at MINIProject.co.uk For MINIs in the south it can only be South Coast New MINI Club

Sep 26th, 2007, 05:55 PM	#17 (permalink)
MINIMANIAUK MINI2 Sponsor Join Date: Mar 2006 Local Time: 10:28 PM Posts: 1,022 Offline	Sorry for the delay guys ,manifolds and decat pipes are here ,but the hi flow cat pipes are not finished yet. I can get one with out the cat pipe to Paul ,but the cats wont be here til at least monday. More than welcome to try one without cat first though www.minimaniauk.com

Oct 2nd, 2007, 02:30 PM	#18 (permalink)
MINI-Morgan MINI Obsessed... My Classifieds Join Date: Nov 2003 Location: Southampton, Hants Local Time: 10:28 PM Posts: 4,610 Offline	Quote: Originally Posted by MiniPetrolHead (original) What do you mean? Alex Scavenging - Wikipedia, the free encyclopedia One Man, One Project......find out what happens next at MINIProject.co.uk For MINIs in the south it can only be South Coast New MINI Club

Oct 2nd, 2007, 02:31 PM	#19 (permalink)
MINI-Morgan MINI Obsessed... My Classifieds Join Date: Nov 2003 Location: Southampton, Hants Local Time: 10:28 PM Posts: 4,610 Offline	Quote: Originally Posted by MINIMANIAUK (original) Sorry for the delay guys ,manifolds and decat pipes are here ,but the hi flow cat pipes are not finished yet. I can get one with out the cat pipe to Paul ,but the cats wont be here til at least monday. More than welcome to try one without cat first though Looking forward to mine this week and pauls results Maybe just mostly looking forward to the new exhaust note.. One Man, One Project......find out what happens next at MINIProject.co.uk For MINIs in the south it can only be South Coast New MINI Club

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