[Schnitzel]

Hi guys, I have mods as stated below and want to do a turbo upgrade soon.

PROcede rev 3
PWM meth kit
Riss Racing catted downpipes
Spearco Code3 FMIC
DCI
ACT street clutch (coming soon)
BMW performance exhaust

My question now is: When I do a turbo upgrade, should I swap the catted downpipes for catless downpipes? Since now I have no issues but I don't know if the exhaust restriction would be too high and the turbos can't breathe properly.

Your comments are welcome.

[Zebra99]

I'm no expert, but I thought we had 3" piping from cat back...that being said, with catless DP's you may have the perfect set-up for the larger turbos. After all you need back pressure to help build the boost no?

That's unless you go and put truck turbos on it and will need 4-5" piping lol

You should ask the few guys here with the RB set-up or any of the vendors working on larger turbo set-ups. There exp. would be invaluable here.

[enrita]

i would go catless dps. just take them out and empty out the cats from yours.

[nitehawk]

Yes, you really wont reap in the benefits of a turbo upgrade without catless Dps. I would change them out.

[scottp999]

Catless is the best flow, hi flow cats you will still see most of the gains. I don't have the magnaflow image here, but basically the had a test with a pipe showing, stock cats flow 300 CFM, high-flow cats 600CFM, and open pipe 1000CFM. So you should be seeing twice the flow rate as stock with hi-flow cats. I don't know what cats riss racing used, do you know the brand and model number?

Going catless when they change out the turbos, is a great time to switch over.

[dzenno]

Catless from turbo back is best but if you can stand it...i've put the stock catback on after 2.5 years and left the catless dps on...car is a 100x nicer to drive now...

By the way i daily drive my car 70000miles on the clock

[Schnitzel]

Originally Posted by enrita

i would go catless dps. just take them out and empty out the cats from yours.

Good idea but I think it would be very difficult to empty out the cats without cutting them, wouldn't it?

[Syndicategt]

I run Rob Becks with AR's hi-flow cats.....no issues here. Don't take opinions from people who can only theorize.

[dzenno]

Originally Posted by Syndicategt

I run Rob Becks with AR's hi-flow cats.....no issues here. Don't take opinions from people who can only theorize.

+1

[Schnitzel]

I have just bought RB turbos. But I still don't really know what to do now with the downpipes

[scottp999]

I also run AR DP's with hi-flow cats (magnaflow cats) with RB Turbos. Don't worry about it. Put the RB's in = have fun. Yes you can probably squeeze a few extra whp with no cats but there is a trade off, noise, pollution, smell. Keep what you have now.

[dzenno]

Originally Posted by scottp999

I also run AR DP's with hi-flow cats (magnaflow cats) with RB Turbos. Don't worry about it. Put the RB's in = have fun. Yes you can probably squeeze a few extra whp with no cats but there is a trade off, noise, pollution, smell. Keep what you have now.

Agree

[GmoBmw]

Im In Socal and Im going catless. When i smog ill switch it to stock for the day.

[Schnitzel]

Originally Posted by GmoBmw

Im In Socal and Im going catless. When i smog ill switch it to stock for the day.

Is that really mandatory? I thought an o2 fix would prevent switching back to stock. Or do you have a "real" emission test? Our emission test consists of OBD reading and that's it.

[GmoBmw]

Originally Posted by Schnitzel

Is that really mandatory? I thought an o2 fix would prevent switching back to stock. Or do you have a "real" emission test? Our emission test consists of OBD reading and that's it.

Ya they do the sniffer test here in California. When I was in texas they just do inspections lol..

[Rotary Rasp]

Originally Posted by GmoBmw

Ya they do the sniffer test here in California. When I was in texas they just do inspections lol..

(stolen from the interwebs)

"Set to begin January 01, 2013; Model year 2000 and newer vehicles will no longer require the tailpipe emissions test portion of the smog check process. AB 2289 will require late model vehicles be administered the smog check's visual and functional tests only.

The implementation of AB 2289 is expected to reduce the time and cost of the smog check. The program will now take better advantage of a vehicle's OBD II technology by eliminating tailpipe testing and instead using the vehicle's own OBD II emissions monitoring system.

This new smog test system is already in place in 22 other states. "This new and improved program will have the same result as taking 800,000 old cars off the road, also resulting in a more cost effective program for California motorists." said ARB Chairman, Mary D. Nichols.

Currently California's smog check procedure requires all vehicles undergo a tailpipe emissions inspection to measure harmful pollutant output from the tailpipe, a visual inspection for present and properly installed emissions components, a functional test to insure the proper operation of various emission components; and as part of the functional test, an OBD II computer diagnostic check.

Under AB 2289, the tailpipe emissions portion of the smog inspection will be eliminated for 2000 model and newer cars, trucks, vans, and SUVs.
Background on the OBD II system - All vehicles imported into the United States as of 1996 have had to be equipped with an On Board Diagnostics system referred to as OBD II. The OBD II diagnostic system is designed to monitor all aspects of your engine's emission conditions and report this information to a central database within it's computer. This information is processed and checked against the computers pre-determined values for various input levels and performance patterns.

If any problems are found, the computer will determine whether to alert the driver or not. If a decision has been made to alert the driver of an emissions problem, the "Check Engine" or "Engine Malfunction" light will illuminate on the vehicle's dashboard. In more serious emission conditions the computer may even begin to rapidly flash the "Check Engine/Malfunction" light indicating to the driver, that the vehicle needs immediate diagnosis/repair attention.
AB 2289 now requires the smog test inspection to rely on data from a vehicle's own on board emissions computer to determine the vehicle's harmful emissions production as opposed to using a smog machine to sample the vehicle's emissions output from the tailpipe. This design is expected to reduce the cost of equipment at the smog station, reduce the amount of time it takes to smog check a vehicle, and reduce the cost of the smog inspection to the consumer.


AB 2289 - Makes changes to the following smog inspection procedures and guidelines:
A. Authorize the use of On Board Diagnostic II testing to expedite the process.

B. Vehicles known to release large amounts of pollution must test at stations with the highest performance ratings.

C. Stricter fines structure for improper inspections.

D. Permit the state to contract with the private sector to manage franchise-like networks of independently owned Smog Check stations.
E. Encourage community colleges and other training institutions to develop technician-training programs."

[GmoBmw]

Originally Posted by Rotary Rasp

(stolen from the interwebs)

"Set to begin January 01, 2013; Model year 2000 and newer vehicles will no longer require the tailpipe emissions test portion of the smog check process. AB 2289 will require late model vehicles be administered the smog check's visual and functional tests only.

The implementation of AB 2289 is expected to reduce the time and cost of the smog check. The program will now take better advantage of a vehicle's OBD II technology by eliminating tailpipe testing and instead using the vehicle's own OBD II emissions monitoring system.

This new smog test system is already in place in 22 other states. "This new and improved program will have the same result as taking 800,000 old cars off the road, also resulting in a more cost effective program for California motorists." said ARB Chairman, Mary D. Nichols.

Currently California's smog check procedure requires all vehicles undergo a tailpipe emissions inspection to measure harmful pollutant output from the tailpipe, a visual inspection for present and properly installed emissions components, a functional test to insure the proper operation of various emission components; and as part of the functional test, an OBD II computer diagnostic check.

Under AB 2289, the tailpipe emissions portion of the smog inspection will be eliminated for 2000 model and newer cars, trucks, vans, and SUVs.
Background on the OBD II system - All vehicles imported into the United States as of 1996 have had to be equipped with an On Board Diagnostics system referred to as OBD II. The OBD II diagnostic system is designed to monitor all aspects of your engine's emission conditions and report this information to a central database within it's computer. This information is processed and checked against the computers pre-determined values for various input levels and performance patterns.

If any problems are found, the computer will determine whether to alert the driver or not. If a decision has been made to alert the driver of an emissions problem, the "Check Engine" or "Engine Malfunction" light will illuminate on the vehicle's dashboard. In more serious emission conditions the computer may even begin to rapidly flash the "Check Engine/Malfunction" light indicating to the driver, that the vehicle needs immediate diagnosis/repair attention.
AB 2289 now requires the smog test inspection to rely on data from a vehicle's own on board emissions computer to determine the vehicle's harmful emissions production as opposed to using a smog machine to sample the vehicle's emissions output from the tailpipe. This design is expected to reduce the cost of equipment at the smog station, reduce the amount of time it takes to smog check a vehicle, and reduce the cost of the smog inspection to the consumer.


AB 2289 - Makes changes to the following smog inspection procedures and guidelines:
A. Authorize the use of On Board Diagnostic II testing to expedite the process.

B. Vehicles known to release large amounts of pollution must test at stations with the highest performance ratings.

C. Stricter fines structure for improper inspections.

D. Permit the state to contract with the private sector to manage franchise-like networks of independently owned Smog Check stations.
E. Encourage community colleges and other training institutions to develop technician-training programs."

Dude.. You Just made my day...

[blisstik]

Whoa. So starting next year, CA will only do ODBII test?

[GmoBmw]

Originally Posted by blisstik

Whoa. So starting next year, CA will only do ODBII test?

I wonder if I can pass with my jb4 installed.