M5 E39 Group Buy Forum and Sponsor Discussion and OfferingsOnly Sponsors are allowed to post there offerings or one-time member offerings (That is one single and first group buy for a non-sponsor company's product). Also only sponsoring companies and members are allowed to post here.
Some of us have been told that stock cats cause a torque dip early in the rev range (2500 - 3500 rpm). Can we get a consistent response please? Are stock cats a problem or not?
cheers
Gordo
Evolve,
I was too wondering what problems you are seeing with the stock cats?
I was in the 1st group buy and used the original cats and haven't had a problem so far, but is there potential pending problems that I need to be concerned with?
There was one thread where someone was having exhaust leakage issues with the inner wall of the cats but I believe that was resolved by some fabrication and closing the gap between the inner and outer walls where the header welds onto the stock cats. Was that the problem you were referring to?
What VantaaM5 is talking about is fitment to the stock CATS ' indeed there are no issues here.
What I am talking about and have mentioned is that sometimes we can have CAT's that are blocked. Fit a set of headers to CAT's that are not so efficient and you get not such a great gain in power.
There is a definate torque dip with stock CAT's. Or better put, a small part of the power band which does not have as good incrrase in power as with high flow CATS.
This occurs on ALL cars and is probably nothing to worry about too much as it's under full throttle at low rpm's. So, an area where full throttle is not used so much.
I have seen this on cars tested in the USA, Dubai and in the UK. In the UK we had around 3 designs made and all of them did the same thing with stock CAT's.
Nothing to get alarmed about. We do prefer that people use high flow CAT's and therefore reduced our prices significantly (over 40%) by sourcing better prices on the same CAT's and buying them in bulk. We have more CAT's than we have headers!
So what's the reason for this area that doesn't really gain much power? The reduction in diameter on the entry to the CAT's. With a high flow CAT's you get the same diameter pipe work throughout.
E39 M5 Tuning
AlphaN, Power Tuning, Cold Start Delete, SAP Delete.....
LHD RHD Medusa Headers, High Flow CAT's
Carbon Fibre Intake System
CAT Back Exhausts
Stage 1 Supercharger System
Stage 2 Intercooler Supercharger System
E60 M5 Tuning
Power Tuning, AlphaN, Cold Start Delete, CEL Light Removals
5-1 Long Tube Headers
E-Tronic CAT Back Exhaust
Carbon Fibre Intake System - In Development.....
Any updates on the headers,the more you update this thread the more people are gonna be interested,i hear you reduced CATS prices,can you pm me your best price maybe i can hustle the bucks for them.
__________________
Live fast and die young:I want to arrive in heaven in a cloud of dust,oil spills,smoking rubber,tangled metal and exclaim,WOW!what a ride!!!
__________________
2002 Chiaretto Red purchased with 58k 01/2011
05/10/13@ 102,400 miles
Mods:
Valentine 1 hardwire
Muffler delete
Evolve AlphaN
Predator Ice V5 Halo bulbs
E60 SSK
ILLUMINATED ZHP shift knob
Slimm's CF finned diffuser
Slimm's Euro tilt/slide armrest
Slimm's Alcantara shift boot
Slimm's Alcantara full e-brake
Black Cubic trim
BC Racing BR coilovers
Evolve 4-1 Medusa Headers, cats, X pipe
Evolve Cold air intakes
__________________________________________
My car/vehicle history:
1993 BMW 525i (sold)
1997 CBR1100XX Super Blackbird (sold)
1994 Firebird Formula V8(Total of 3 days )
2002 Jaguar X-type 3.0 Sport manual (sold)
1992 300ZX Twin Turbo (sold)
2002 BMW 530i Sport (sold)
2007 CBR1000RR (RIP)
1988 BMW 325i convertible (sold)
2002 BMW M5 (Current driver)
2002 Chevy Camaro Z28 35th anniversary(sold)
1991 300ZX Twin Turbo super white 130k Miles! (For sale soon! Contact me for details)
I am IN this Group Buy. Please, Evolve, mark it down. I already purchased an Alpha-N and ECU tune.
I want headers for a complete DECAT though I have questions about it. How do I delete my stock Cats? Simply cutting off that portion of exhaust with CATs? What do I replace it with? Simple direct flow pipes without anything inside of them?
I am IN this Group Buy. Please, Evolve, mark it down. I already purchased an Alpha-N and ECU tune.
I want headers for a complete DECAT though I have questions about it. How do I delete my stock Cats? Simply cutting off that portion of exhaust with CATs? What do I replace it with? Simple direct flow pipes without anything inside of them?
The de-cat pipes for the headers are not expensive,I suggest you order those as well and have no headache with fabricating tubes!
__________________ 2003 M5 "The Matte Black Money Pit"
ALPHA-N by EVOLVE,Power remapped-modified heads-Schrick cams-modified throttle bodies and velocity stacks-modified rods and crank-EVOLVE headers -Willans 4-point harness -CAI with custom built MAF delete tubes fed through fog light covers -lighter oem flywheel-Sachs performance clutch-clutch stop-Drexler differential stock ratio-electric fan with control unit-545i SSK-HEL braided teflon brake lines-IATS reloction-Bilstein PSS9-HD sway bar links-M3 swaybar brackets rear-CF bonnet with vents-subframe reinforcement-40mm wider fenders front and 25mm rear-aluminium ///M pedals and foot rest-CF roundels-LED AE-foglight delete-AP BBK kit 6piston calipers front-CF strut bar front-full suspension rebuild-camber plates with uniballs front-Dinan sway bar-illuminated inner door handles-Alcantara roof liner-M-Audio system- Hamann HM2 10x19" wheels 275/30 front and 295/30 rear
2002 M5 former known as "The Breaker"
Carbon black/black sport interior/titanium trim,37k miles,bone stock -20cm of the trunk and quarter panels missing...
-rebuild in winter 2011/2012
2001 530iA Touring/Orient blue/tan leather
-"submarine edition",a bit boost and some M5 parts...
Thanks Vantaam5, where can I buy such de-cat pipes? Can you give me some links?
Are you talking about these (http://www.brecus.com/products/M5-%2...lete%29.html)? Brecus says that they must be used only with SuperSprint. I think they mean the diameter of pipes.
Can I find cheaper options than the one from SS?
Does Cat-delete release more power than sport cats (100 cell)?
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