[jadeddjay]

i have been frequenting this forum, but i havent found any good answers even after searching

so here is my situation. i just got v2 installed and its great. i needed help with a broken connector (not their fault) and the tech callback form worked well and they responded promptly

the extra noticeable lag got me thinking i may want some dps

anyway, i have a rennart catback ordered. i am thinking about canceling it and getting catless dps from RR instead.

if the increase in performance provided by dps is as good as they say, i may be happy to stick with dps+stock exhaust. how will that go with smog tests? otherwise, if i am going to be upgrading the catback anyway, i might as well just get it now and not cancel my order.

if i get dps, when will the stock exhaust become the bottle neck, assuming that i have a good intake solution (that i have yet to find for myself)

any thoughts?

[Sniz]

Originally Posted by jadeddjay

i have been frequenting this forum, but i havent found any good answers even after searching

so here is my situation. i just got v2 installed and its great. i needed help with a broken connector (not their fault) and the tech callback form worked well and they responded promptly

the extra noticeable lag got me thinking i may want some dps

anyway, i have a rennart catback ordered. i am thinking about canceling it and getting catless dps from RR instead.

if the increase in performance provided by dps is as good as they say, i may be happy to stick with dps+stock exhaust. how will that go with smog tests? otherwise, if i am going to be upgrading the catback anyway, i might as well just get it now and not cancel my order.

if i get dps, when will the stock exhaust become the bottle neck, assuming that i have a good intake solution (that i have yet to find for myself)

any thoughts?

100% get the downpipes first....I just installed mine yesterday and my car is an animal now, huge difference. Better sound too, less lag, faster response and the thing just hauls.

[O-cha]

Originally Posted by Sniz

100% get the downpipes first....I just installed mine yesterday and my car is an animal now, huge difference. Better sound too, less lag, faster response and the thing just hauls.

Wait, do you have procede? That actually worked?

[jadeddjay]

Originally Posted by Sniz

100% get the downpipes first....I just installed mine yesterday and my car is an animal now, huge difference. Better sound too, less lag, faster response and the thing just hauls.

are you content with having only dps? or do you think you will eventually get a catback in the future anyway?

thanks for your input

[fast_lap28]

4 days ago I installed my JB2H and car is great! I dyno'd yesterday and numbers though low because of DD dyno, were on par with the tune. However I have felt between 2nd and 3rd gear during pull a little bit of lag (if you even want to call it that). it's just a slight hesitation in power, as if boost is coming and then all of a sudden BANG its all there at once in the split of a second!!

I was thinking I may as well replace the stock DV's to help in this case with Forge ones. But now reading this thread I wonder if with all the extra power through the rev range if replacing the stock cats with DP will free up that flow and reduce all the lag my tune may encounter? maybe both DV's and DP is the best pair to go with my new tune?

thoughts? I just don't like that "kick in the pants" in a split second the car gives. I prefer the power to come on strong but more linear and smooth.

[Sniz]

Originally Posted by O-cha

Wait, do you have procede? That actually worked?

V2 procede, installed catless downpipes and terry's O2 simms. car is an animal. Much faster than before, I'm very happy with it. No check engine lights, no limp modes, just FAST.

[Sniz]

Originally Posted by jadeddjay

are you content with having only dps? or do you think you will eventually get a catback in the future anyway?

thanks for your input

I'm going to do a custom exhaust from the 2nd cat back. Remember the catless downpipes get rid of the cat, so if you add a catback from there you have no cats left.

[jadeddjay]

any other thoughts? im sure i am not the only one who is thinking about this

[dr.roro]

From my own reading, it seems like the DPs are yielding much more power than any catback.

[Jalal28]

However in regards to the posters original question:

1) Aftermarket DPs + Stock Catback = Huge Gains / Not emissions compliant, though you can get a set of O2 sims to at least get rid of CEL in dash.

2) Stock DPs + Aftermarket Catback = Lesser Gains / Emission compliant.

#2 is the set-up I am thinking about going with because in addition to the lack of emissions compliance from the aftermarket DPs, I've heard there is a noticeable odor that will enter the cabin when driving.

Again, it all depends on what you're looking for, but now you know...

[Lane]

Has the emission compliance been tested for the both cases? Data please. Thanks.

[NM_BMW]

I thought about this as well when I first bought my exhaust. I wanted my exhaust to sound better, and the stock exhuast is just plain heavy. So, I threw on the Vishnu exhaust and am very happy with just looks alone, plus sound. I am now really on the fence between the catted and catless dp's. I'm more worried about sound then the smell since we don't test emissions where I live. But power always is a concern .

If you really want a cat in your exhaust stream, you could always get the catless dp's and in your rennart throw in a HF cat somewhere in the mix.