[Skyhigh]

Originally Posted by les anderson

300cel tend to be a heck of a lot more expensive.

Obviously you think that the above is for no reason..... as well as the fact that 200 cell are much more rare and come from much less reputable manufacturers than 300 cell....

Sound clips also seem to tell that there is a significant difference in terms of sound with 200 cel not being raspy like catless but also much better sounding than 300.

I'd be very surprised if you can tell a difference between the sound of 200 cell and 300 cell.... This said, many (incl. myself) are concerned about the excessive sound (=noise) which comes with a sport DP, especially in combination with a cat-back exhaust system, like MPPSK or other. The borderline between "sound" and "noise" is very, very thin...

Also, if 200cel is not throwing a cel and passes a sniff test (which they seem to in most cases) than it could be argued there is very little reason to pay for 300cel.

That's that... -->

Originally Posted by les anderson

Well, just got a cel for p0420, catalytic efficiency threshold, lol. Guess that settles that!

But all of that is not really what I asked... (And I'm not judging)
It was about some data available about the power improvement (or suppression) of a DP (or various cell DPs) in comparison to the stock DP. I recall something like 200 or 300 cell being much closer to catless (with % being quoted) in comparison to stock.

[G.Newt]

Originally Posted by Skyhigh

Actually, the difference between 200 and 300 cell (ref diagram above) is very small. What is more meaningful is that with 200 cell you no longer fulfill the environmental requirements, which (depending on where you live) creates more hassle than what 200 cell brings performance-wise over 300 cell.
Which is why I personally see 0 point in a 200 cell over 300 / catless. It simply combines the worst of both worlds.

My 200 cell downpipe doesn't throw a CEL. Hasn't for 3+ years. You get what you pay for.

[MTWO]

Not all CATs are created equal. HJS is top quality. If running that you may get away with it.

[Skyhigh]

Originally Posted by MTWO

Not all CATs are created equal. HJS is top quality. If running that you may get away with it.

Get away with what? HJS is a reputable manufacturer preferred by most of the top exhaust manufacturers and is 300 cell. Fully conforming with EURO 6. There is no "getting away" with HJS - it is the golden standard.
Of course quality comes with a price tag.
HJS's own DP seems to be the best value for money product on the market.

[mike@x-ph.com]

HJS cats are the best in my opinion (used with fabspeed DP), GESI cats (used with active autowerke DP) are the best value option for a no CEL guarantee

if the car is tuned and/or the CEL is not a concern, CTS catted DP are the best value

[G.Newt]

I don't see why CG downpipes aren't getting more consideration. They were one of the first B58 downpipes that didn't throw a CEL, and mine still doesn't. With a 5" diameter and 200 cell, you're getting nearly all of the gains of catless.

[340iGUY]

Originally Posted by G.Newt

I don't see why CG downpipes aren't getting more consideration. They were one of the first B58 downpipes that didn't throw a CEL, and mine still doesn't. With a 5" diameter and 200 cell, you're getting nearly all of the gains of catless.

They are hard to come by.
So if I bought the CTS what oxygen spacer should I buy?

[mike@x-ph.com]

Originally Posted by G.Newt

I don't see why CG downpipes aren't getting more consideration. They were one of the first B58 downpipes that didn't throw a CEL, and mine still doesn't. With a 5" diameter and 200 cell, you're getting nearly all of the gains of catless.

CG is very popular for us, but it takes weeks to ship

[leew102]

Anyone know if it's safe to run ots burbles on BM3 Stg2 with the CTS catted dp? Their site says they don't warranty cats damaged by a crackle tune but also suggest running bm3 stg2.

[Jnat]

Originally Posted by leew102

Anyone know if it's safe to run ots burbles on BM3 Stg2 with the CTS catted dp? Their site says they don't warranty cats damaged by a crackle tune but also suggest running bm3 stg2.

I think it's safe, just keep it reasonable from a loud and time stand point.

[mike@x-ph.com]

Originally Posted by leew102

Anyone know if it's safe to run ots burbles on BM3 Stg2 with the CTS catted dp? Their site says they don't warranty cats damaged by a crackle tune but also suggest running bm3 stg2.

Default level should be fine

[G.Newt]

Originally Posted by leew102

Anyone know if it's safe to run ots burbles on BM3 Stg2 with the CTS catted dp? Their site says they don't warranty cats damaged by a crackle tune but also suggest running bm3 stg2.

Stock BMW map is hella burbly. I'd make crazy gunshots FBO untuned. I think the OTS default is a tad bit tamed down from stock.

[leew102]

Thanks guys, I might just have to go with the CTS catted down pipe. Looks like you can drive on it long enough (at least 700 miles if I am reading correct) so it will pass emissions here in NY and hopefully can handle the ots burbles of stage 2.

Originally Posted by G.Newt

Stock BMW map is hella burbly. I'd make crazy gunshots FBO untuned. I think the OTS default is a tad bit tamed down from stock.

Hmm, for me, the stock tune can get me a more louder pop but seems to be less frequent/less duration. On stage 1 OTS burbles, I get a lot smaller pops and for a little longer duration with the occasional loud pop, but nothing like the pop that it makes in stock tune (if that makes sense). Currently only have a awe midpipe and remus axleback.

[G.Newt]

Originally Posted by leew102

Thanks guys, I might just have to go with the CTS catted down pipe. Looks like you can drive on it long enough (at least 700 miles if I am reading correct) so it will pass emissions here in NY and hopefully can handle the ots burbles of stage 2.



Hmm, for me, the stock tune can get me a more louder pop but seems to be less frequent/less duration. On stage 1 OTS burbles, I get a lot smaller pops and for a little longer duration with the occasional loud pop, but nothing like the pop that it makes in stock tune (if that makes sense). Currently only have a awe midpipe and remus axleback.

I don't think you'll have much success unless you run an o2 spacer.
If you're tuned, you're disabling the catalyst ready monitor, and you will might fail depending on how strict your local emissions laws are. If you're allowed 1 or 2 not ready monitors, then you might be good.

CTS doesn't give a no CEL guarantee on this product and their product description recommends to use with a tune to ignore the CEL.

[leew102]

Originally Posted by G.Newt

I don't think you'll have much success unless you run an o2 spacer.
If you're tuned, you're disabling the catalyst ready monitor, and you will might fail depending on how strict your local emissions laws are. If you're allowed 1 or 2 not ready monitors, then you might be good.

CTS doesn't give a no CEL guarantee on this product and their product description recommends to use with a tune to ignore the CEL.

So looks like NY allows for 1 monitor, not sure how many monitors won't be ready on the 340 for the cts downpipe...I can't seem to find a clear answer to how many for catted downpipes for the b58. But o well will be a problem for the future to figure out, just ordered a the catted downpipe I was hoping that since it looks like it might take more miles than the readiness procedure will take before the CEL light comes on, you could potentially just clear the codes, get the monitors in a ready state and then take it in to do inspection before the light pops again. First time going down the rabbit hole of modding a car so that assumption could totally be off basis there.

[Jnat]

I've recently installed this downpipe and as a test, left the monitors active in MHD as a test to see if the catalyst readiness is set (note that i did install a spacer on the rear O2). I will report back.
As a side note, i am getting a pretty strong smell from the downpipe itself (not the exhaust smell from the rear of the car which is fine actually). I expect a new exhaust part to have an initial smell but it's still pretty strong a week later.
As a secondary side note, stock exhaust otherwise and sound is great, only slightly louder that stock if you're not looking for loud... maybe the dinan midpipe would make it perfect...

[egprelude]

Originally Posted by Jnat

I've recently installed this downpipe and as a test, left the monitors active in MHD as a test to see if the catalyst readiness is set (note that i did install a spacer on the rear O2). I will report back.
As a side note, i am getting a pretty strong smell from the downpipe itself (not the exhaust smell from the rear of the car which is fine actually). I expect a new exhaust part to have an initial smell but it's still pretty strong a week later.
As a secondary side note, stock exhaust otherwise and sound is great, only slightly louder that stock if you're not looking for loud... maybe the dinan midpipe would make it perfect...

What type of spacer did you end up using?

[Jnat]

Originally Posted by egprelude

What type of spacer did you end up using?

45mm spacer...

[leew102]

Originally Posted by Jnat

I've recently installed this downpipe and as a test, left the monitors active in MHD as a test to see if the catalyst readiness is set (note that i did install a spacer on the rear O2). I will report back.
As a side note, i am getting a pretty strong smell from the downpipe itself (not the exhaust smell from the rear of the car which is fine actually). I expect a new exhaust part to have an initial smell but it's still pretty strong a week later.
As a secondary side note, stock exhaust otherwise and sound is great, only slightly louder that stock if you're not looking for loud... maybe the dinan midpipe would make it perfect...

Are you saying you are getting a smell from the downpipe under the hood? Or that it still smells like some residual oil is burning off? I think mine had a smell of residual stuff burning off but after a long 200 mile trip, seemed like everything burnt off and the additional gas smell isn't bad at all. In fact, the additional gas smell actually doesn't smell as bad as some stock cars.

[Jnat]

Originally Posted by leew102

Are you saying you are getting a smell from the downpipe under the hood? Or that it still smells like some residual oil is burning off? I think mine had a smell of residual stuff burning off but after a long 200 mile trip, seemed like everything burnt off and the additional gas smell isn't bad at all. In fact, the additional gas smell actually doesn't smell as bad as some stock cars.

It still smells like residual whatever is burning off. I've replaced several downpipes/exhausts like many of us on several vehicles and there's always that residual smell, this one is just lasting longer then my memory says others have i guess?

[leew102]

Originally Posted by Jnat

It still smells like residual whatever is burning off. I've replaced several downpipes/exhausts like many of us on several vehicles and there's always that residual smell, this one is just lasting longer then my memory says others have i guess?

Yea, thats strange mine seemed to be burnt off after a couple hundred miles. Curious what it might be.

[Jnat]

Originally Posted by leew102

Yea, thats strange mine seemed to be burnt off after a couple hundred miles. Curious what it might be.

I'm gonna through it up in the air at the shop and take a look, still there although less... I'll report back...