[M4TW]

Why chase after, what, 5 hp with a better designed CAI, when there is so much more to be gained with a nice set of catted downpipes?

You don't even have to design them. Just buy a good desin from one of the companies already making them (ala FMIC), make sure they are CARB compliant and what have you, add the warranty slush fund up charge, (a $500 flash upgrade to take full advantage!), profit margin, and Bob's your uncle.

Don't make me spend my $ elsewhere, cause I will.

[PKumarM3]

well isnt the reason the downpipes have cats on them is so bmw can pass DOT emissions - since the closer the cats are to the motor, the cleaner the exhaust fumes are?

if you read ALL the ads for downpipes - all are for OFF ROAD USE - I.E. Illegal on US ROADS.

[M4TW]

There should still be room for catted downpipes that meet minimal standards yet increase flow.

[TheTwinz]

it's easier to do CAI because those you can install and remove without the use of a jack, and anyone that knows how to use a screw driver can install them. Plus, the CAI is a visual enhancement... "eye candy".. you can't see DPs.. so you can't "show them off"... But, since everyone can see your CAI, Dinan wants to milk people for it.

[JoeyFiasco]

Originally Posted by Sparkplug

There should still be room for catted downpipes that meet minimal standards yet increase flow.

Yeah but if the DP companies went out and got CARB certified the it would cost them money, their margin is not going to shrink much and the costumer will receive the extra cost. Most of the benefits (20-30 horsepower) will also be gone because they'll have to use more restricting cats. Most companies like PKumar said use racing cats that are not street legal. You could possibly have all cats replaced with race cats. I'm not sure if anyone has done that and been smog/emissions tested to see if they pass, and what the total cost would be.

Originally Posted by TheTwinz

it's easier to do CAI because those you can install and remove without the use of a jack, and anyone that knows how to use a screw driver can install them. Plus, the CAI is a visual enhancement... "eye candy".. you can't see DPs.. so you can't "show them off"... But, since everyone can see your CAI, Dinan wants to milk people for it.

a CAI penis?

[M4TW]

Originally Posted by TheTwinz

it's easier to do CAI because those you can install and remove without the use of a jack, and anyone that knows how to use a screw driver can install them. Plus, the CAI is a visual enhancement... "eye candy".. you can't see DPs.. so you can't "show them off"... But, since everyone can see your CAI, Dinan wants to milk people for it.

You have to remove the bumper to change the cone filter on the Dinan design.

Originally Posted by JoeyFiasco

Yeah but if the DP companies went out and got CARB certified the it would cost them money, their margin is not going to shrink much and the costumer will receive the extra cost. Most of the benefits (20-30 horsepower) will also be gone because they'll have to use more restricting cats. Most companies like PKumar said use racing cats that are not street legal. You could possibly have all cats replaced with race cats. I'm not sure if anyone has done that and been smog/emissions tested to see if they pass, and what the total cost would be.

a CAI penis?

I think BMW tries to lower emmissions as much as possible, so there should be some wiggle/performance room.

[SoCalTech]

It's technically illegal to remove/replace a functioning cat, so that probably plays into it.

[hun77777]

Originally Posted by SoCalTech

It's technically illegal to remove/replace a functioning cat, so that probably plays into it.

correct, that's why dinan doesn't offer full catback neither...

[lpphreakx06]

They should just out "for offroad use only". LOL

[hun77777]

Originally Posted by lpphreakx06

They should just out "for offroad use only". LOL

except off-road only don't go together with the dealer warranty because it means illegal on u.s. road hence some legal issues... too much headache for dinan if you ask me. they know there are several other companies who can do WAY CHEAPER than what dinan could've even if they decided to give it a go, and chance's are they are not even going to get R&D cost out of that...

[Morpheus]

Originally Posted by SoCalTech

It's technically illegal to remove/replace a functioning cat, so that probably plays into it.

+1000

[samps]

But wouldn't it be fine if they replaced the DP's with larger diameter ones that included high-flow cats?

[hun77777]

i would less surprised if they come up with bigger turbo kit than less restrictive CAT conveters... All OEM manufactures including OEM tuners like AMG, M, will not do that. Have you ever heard GO GREEN? it all comes down to emission. They may put more restrictive ones and/or more # of cats but definitely not the opposite way...

[SoCalTech]

Originally Posted by samps

But wouldn't it be fine if they replaced the DP's with larger diameter ones that included high-flow cats?

No. If your cat is in proper working order, then it's illegal to replace it. Even with the same part number.

[M4TW]

In their software press release for the 335 some of the testing mentioned using an x-pipe exhaust "for racing only". If memory serves, this was a product in their pipeline (along with the CAI). Presumably they could offer catted or catless downpipes on the same basis.

[thegeneral101]

its definitely because of emissions issues

[Morpheus]

according to the clean air act, it's all illegal. They just don't enforce it, but they could. This includes parts other than an exhaust, like an ecu that changes the air/fuel ratio. CARB cert. doesn't matter either-still illegal, but odds are they wouldn't prosecute you.

[Morpheus]

source:

FACT SHEET: EXHAUST SYSTEM REPAIR GUIDELINES

The EPA has prepared this fact sheet to answer some of the most commonly asked questions about the types of exhaust work a repair shop can legally perform. If you need any further information about the EPA's tampering policy, please call (202) 233-9100 or 233-9040.

Question 1.

Under what conditions or circumstances can a catalytic converter be removed from a vehicle and a converter replacement pipe be installed?

Answer 1.

Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes" by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles. Anyone who installs such pipes would violate section 203(a)(3)(A) and (B) of the Clean Air Act (Act).

In addition to federal law, forty-five out of the fifty States also have statutes or regulations which prohibit tampering with the pollution control equipment on motor vehicles or driving or selling such vehicles. Thus, vehicle owners who tamper with their own vehicles may be subject to substantial penalties under both federal and State law.

The only circumstances in which a person would be allowed to remove a converter is if the vehicle is being shipped overseas to an area where unleaded gasoline is not generally available. (Vehicles traveling to Canada or Mexico are not eligible for this exemption.) In this instance the vehicle owner must have a letter from the EPA specifically authorizing the converter removal from the vehicle in question.

-2-

Question 2.

Can I remove a converter from a vehicle that is used only for "off-road" driving?

Answer 2. No. The tampering prohibition discussed in Answer #1 applies to this situation as well. The federal tampering prohibition pertains to "motor vehicles," which are defined by section 216(2) of the Act as "any self-propelled vehicle[s] designed for transporting persons or property on a street or highway." A light-duty vehicle manufacturer certifies an engine-chassis configuration as meeting the applicable emissions standards for motor vehicles manufactured in a given model year, and it is not legal for anyone to "de-certify" a motor vehicle for "off-road" use.

more interesting reading:

http://www.off-road.com/trucks4x4/ar....jsp?id=194395

[hun77777]

close the thread now !!!

[Morpheus]

Originally Posted by hun77777

close the thread now !!!

what's wrong? Don't want to hear that the catless DP you ust bought is illegal and could subject you to a $2500 fine?

[M4TW]

Wow, a lot of vendors and users on here could be prosecuted for crimes against the environment.