[mmorrismm]

Originally Posted by JasW

Turns out my local performance shop (Miami Performance Inc.) is an authorized Cobb dealer, so they've hooked me up with a good price on them. They arrive tomorrow and I'm having them put on next week -- unlike you, not my kind of DIY, lol. It'll be interesting to see what it sounds (and smells) like with the resonators. If it still reeks, I have the mid-cats ready to be welded back in. But my primary concern is that awful rice rasp. The drone is annoying, too.

Jas, I have been in the same boat. The rasp after putting the catless DP on my is still bugs me with the rasp a year later. I miss the fine tuned is sound. I also did the 1792 in the back where my xpipe was and it toned it down to much. MPI did my downpipes and Miami Muffler did my 1792. A week later I just took them off and have been running the catless pipes.and living with it I looked into the Cobb Catted pipes but did not know how much of a difference it would make

How did it turn out? I moved from Miami to Coral Springs but would make the trip down to do it. . Or catch up with you so I could hear it.

Thanks
Mark

[335is-dct]

Originally Posted by mmorrismm

Jas, I have been in the same boat. The rasp after putting the catless DP on my is still bugs me with the rasp a year later. I miss the fine tuned is sound. I also did the 1792 in the back where my xpipe was and it toned it down to much. MPI did my downpipes and Miami Muffler did my 1792. A week later I just took them off and have been running the catless pipes.and living with it I looked into the Cobb Catted pipes but did not know how much of a difference it would make

How did it turn out? I moved from Miami to Coral Springs but would make the trip down to do it. . Or catch up with you so I could hear it.

Thanks
Mark

Fellow broward guy. Discouraging to hear about the cat less dp issues on our cars... I have a set waiting to go on but reluctant now. Car seems strong on current e40 setup but always itching for more power so eventually ill say screw it and throw them on.

[JasW]

Originally Posted by mmorrismm

Jas, I have been in the same boat. The rasp after putting the catless DP on my is still bugs me with the rasp a year later. I miss the fine tuned is sound. I also did the 1792 in the back where my xpipe was and it toned it down to much. MPI did my downpipes and Miami Muffler did my 1792. A week later I just took them off and have been running the catless pipes.and living with it I looked into the Cobb Catted pipes but did not know how much of a difference it would make

How did it turn out? I moved from Miami to Coral Springs but would make the trip down to do it. . Or catch up with you so I could hear it.

Thanks
Mark

The Cobb catted DPs improved things somewhat, but certainly didn't eliminate the rasp. Sometimes it's not there, sometimes it's only briefly there in a narrow bandwidth of the RPM range right at 5000 RPM as I'm winding out, and sometimes it sounds almost the same as it did with catless DPs (i.e., in wider width of the RPM bandwidth surrounding 5000 RPM).

I'm surprised you swapped out the xpipes for the Vibrants -- that never occurred to me as a possibility, at the very least because there doesn't seem to be enough room. The pipes are too close together there and the pipe on the driver's side isn't straight enough at that point (see pic below of underside of my IS taken before I swapped out the secondary cats for Vibrants).

Aside from toning down the exhaust too much, did replacing the xpipe with Vibrants really get rid of all of the rasp? Not sure why it would being at most a couple of feet past the secondary cats, but then again the whole sound of the IS exhaust has been a mystery to me -- someone said it's all the IS muffler that's causing the rasp, so maybe resonator placement closer to the muffler has some effect.

In any event, I'm left with only one remaining choice, that is, putting the secondary cats back in. I'm not sure if that would have any effect, particularly because putting the Vibrants in their place when I had catless DPs had no effect on the rasp.

My only guess as to all of this has been that when you increase the flow of the exhaust, it alters the sound from the IS muffler in a certain RPM range because the IS muffler is has been highly "tuned" to give off that unique IS exhaust sound. I should say I'm more than happy with the sound of the exhaust except in that narrow RPM range. For now, I'm living with it, though as I said, I may put the secondary cats back in. (I might even look to moving the resonators downstream to the xpipe now that you've mentioned doing it, though I'm still not sure how -- and I have the narrower 1790s.)

[335is-dct]

Originally Posted by JasW

The Cobb catted DPs improved things somewhat, but certainly didn't eliminate the rasp. Sometimes it's not there, sometimes it's only briefly there in a narrow bandwidth of the RPM range right at 5000 RPM as I'm winding out, and sometimes it sounds almost the same as it did with catless DPs (i.e., in wider width of the RPM bandwidth surrounding 5000 RPM).

I'm surprised you swapped out the xpipes for the Vibrants -- that never occurred to me as a possibility, at the very least because there doesn't seem to be enough room. The pipes are too close together there and the pipe on the driver's side isn't straight enough at that point (see pic below of underside of my IS taken before I swapped out the secondary cats for Vibrants).

Aside from toning down the exhaust too much, did replacing the xpipe with Vibrants really get rid of all of the rasp? Not sure why it would being at most a couple of feet past the secondary cats, but then again the whole sound of the IS exhaust has been a mystery to me -- someone said it's all the IS muffler that's causing the rasp, so maybe resonator placement closer to the muffler has some effect.

In any event, I'm left with only one remaining choice, that is, putting the secondary cats back in. I'm not sure if that would have any effect, particularly because putting the Vibrants in their place when I had catless DPs had no effect on the rasp.

My only guess as to all of this has been that when you increase the flow of the exhaust, it alters the sound from the IS muffler in a certain RPM range because the IS muffler is has been highly "tuned" to give off that unique IS exhaust sound. I should say I'm more than happy with the sound of the exhaust except in that narrow RPM range. For now, I'm living with it, though as I said, I may put the secondary cats back in. (I might even look to moving the resonators downstream to the xpipe now that you've mentioned doing it, though I'm still not sure how -- and I have the narrower 1790s.)

how about just swapping out is mufflers for ones off a regular 335?

[JasW]

Originally Posted by 335is-dct

how about just swapping out is mufflers for ones off a regular 335?

Blasphemy! That's the one thing I never wanted to touch when I started off modding. It still sounds exquisite in all other respects. Gurgle. Pop.

[mmorrismm]

Originally Posted by JasW

Blasphemy! That's the one thing I never wanted to touch when I started off modding. It still sounds exquisite in all other respects. Gurgle. Pop.

Agreed, I really got upset when I put the Downpipes in and it changed the sound from the tuned 'is' sound. Drove the car around today with the top down and I have to admit sounds so angry. Just the raspiness sometimes gets to be a bit much. But after driving it I always say I can live with it.

Keep in mind I put everything back the way it was and just kept the Downpipes.I still have my secondaries. Actually never touched them as I did not want the smoke or smell.

So what would really be interesting is if you revert all back except for the Cobb catted Downpipes. I think that may be the ticket. If it works for you I will do the same.

Where are you located?

[BSM n54iS]

Originally Posted by mmorrismm

Agreed, I really got upset when I put the Downpipes in and it changed the sound from the tuned 'is' sound. Drove the car around today with the top down and I have to admit sounds so angry. Just the raspiness sometimes gets to be a bit much. But after driving it I always say I can live with it.

Keep in mind I put everything back the way it was and just kept the Downpipes.I still have my secondaries. Actually never touched them as I did not want the smoke or smell.

So what would really be interesting is if you revert all back except for the Cobb catted Downpipes. I think that may be the ticket. If it works for you I will do the same.

Where are you located?

That's what's working for me right now, exhaust sound is pretty subjective, but for me i feel as if it's an angrier version of the tuned iS sound. Haven't touched sec. yet and I have the exhaust flap disconnected in the trunk as well. RSL has this same setup also, you can pm him or me also if you'd like...he helped me out before i decided to purchase, but i think he's in tx also.

P.s. how do i get members sn in the blue highlight, as if I'm quoting the member?

[RSL]

I think you use the @ sign in front of screen name to tag people Black. Yes, Texas, but I lived in Coral Springs/Parkland most of my life

I'd describe it the same way with Cobb catted only, beefier sound of the stock IS exhaust. I went with catted solely because I didn't want to ruin that sound. I'm absolutely happy with the result. The volume in the cabin is positively deceptive. The volume of the exhaust, especially under load, is louder, but you'd never know how much from the driver seat or a video (in a convertible I guess you would). With the flap closed, volume inside is seriously quiet (like stock) unless you're standing on the throttle. With the flapper open, there is more volume inside, but just enough to know it's not stock. Been on them more than a year and no codes using INA0S rom with all toggles enabled too.

Definitely +1 for stock IS exhaust with high-flow catted DPs as the way to go.

[JasW]

Originally Posted by mmorrismm

Agreed, I really got upset when I put the Downpipes in and it changed the sound from the tuned 'is' sound. Drove the car around today with the top down and I have to admit sounds so angry. Just the raspiness sometimes gets to be a bit much. But after driving it I always say I can live with it.

Keep in mind I put everything back the way it was and just kept the Downpipes.I still have my secondaries. Actually never touched them as I did not want the smoke or smell.

So what would really be interesting is if you revert all back except for the Cobb catted Downpipes. I think that may be the ticket. If it works for you I will do the same.

Where are you located?

That's the thing -- it's by far most noticeable when the top is down. Driving under an overpass, alongside high-profile vehicles -- the brief nasty hit at ~5000 RPM echoes right back at you.

When I was completely catless, it was horrible. My wife constantly complained about the fumes, and if I were in stop and go traffic (or even sometimes just at a light), there'd be smoke coming out. So, yeah, I wouldn't ever recommend taking out the secondary cats if you already have catless DPs.

I don't think reverting back to just catless DPs is going to do the trick for you. That's where I was when I decided to swap out the secondary cats for the resonators. The rasp was appalling, and the cold start woke the dead.

For that last reason, at least, I'm a little hesitant about taking out the resonators and putting the secondary cats back. Although they didn't cure the rasp, the resonators at least quieted the cold start to non-embarrassing levels. Even though I have catted DPs now, the cold start is still louder than stock, and I'm afraid it would only get louder if I lost the resonators and put back the secondary cats. I could put up with that if I lost the rasp, though.

I divide my time between the Gables and West Pines.

[BSM n54iS]

Originally Posted by RSL

I think you use the @ sign in front of screen name to tag people Black. Yes, Texas, but I lived in Coral Springs/Parkland most of my life

Ahh thank you . Ya just been texas for me so far...

[JunkyardDogg]

How much more power do you really get going catless? Is the noise/smell worth it?

[LMB335IS]

Originally Posted by JunkyardDogg

How much more power do you really get going catless? Is the noise/smell worth it?

I dyno'ed around 335/340whp and 370wtq on 93, downpipes, aFe intake, and stock tune.

[mmorrismm]

Originally Posted by RSL

I think you use the @ sign in front of screen name to tag people Black. Yes, Texas, but I lived in Coral Springs/Parkland most of my life

I'd describe it the same way with Cobb catted only, beefier sound of the stock IS exhaust. I went with catted solely because I didn't want to ruin that sound. I'm absolutely happy with the result. The volume in the cabin is positively deceptive. The volume of the exhaust, especially under load, is louder, but you'd never know how much from the driver seat or a video (in a convertible I guess you would). With the flap closed, volume inside is seriously quiet (like stock) unless you're standing on the throttle. With the flapper open, there is more volume inside, but just enough to know it's not stock. Been on them more than a year and no codes using INA0S rom with all toggles enabled too.

Definitely +1 for stock IS exhaust with high-flow catted DPs as the way to go.

Thanks RSL. I am debating replacing my catless downpipes for the Cobb Catted ones. I do not mind the louder volume at WOT and coldstarts just hope to get rid of the rasp a bit. BTW, I am building a home in Parkland. Liking this area a lot now. Originally from Pembroke Pines and moved to Minneapolis/WI for work for 10 years. Moved back 3 years ago and bought a house in West Kendall. Sold in July to move back to Broward it was just to crowded and crazy for us.

Any chance you could shoot a video of coldstarts and some wOT? And for exhaust all you did was put catted downpipes in?

Thanks.
Mark

[Redbmwm33]

Love my 335is

[RSL]

^^ Nice art.

Originally Posted by mmorrismm

Thanks RSL. I am debating replacing my catless downpipes for the Cobb Catted ones. I do not mind the louder volume at WOT and coldstarts just hope to get rid of the rasp a bit. BTW, I am building a home in Parkland. Liking this area a lot now. Originally from Pembroke Pines and moved to Minneapolis/WI for work for 10 years. Moved back 3 years ago and bought a house in West Kendall. Sold in July to move back to Broward it was just to crowded and crazy for us.

Any chance you could shoot a video of coldstarts and some wOT? And for exhaust all you did was put catted downpipes in?

Thanks.
Mark

I definitely have not heard rasp at all. Cold start is no problem to shoot (the exhaust is super loud for about 30 secs), WOT would have to be shot from the inside with windows down or up, you really wouldn't be able to hear the exhaust outside.

Last time I was through Parkland was probably 7-8 years ago and it was already way built up from when I left in 2000. There were 3 cops total and they'd pull over anyone using Holmberg to cut through to Riverside. Residents had to have stickers on their cars to let them know they lived there lol Austin is the same way with traffic now, I think half of California moved here in the last 5 years. I'm ready to move back, just don't when that will be.

[mmorrismm]

Originally Posted by RSL

^^ Nice art.

I definitely have not heard rasp at all. Cold start is no problem to shoot (the exhaust is super loud for about 30 secs), WOT would have to be shot from the inside with windows down or up, you really wouldn't be able to hear the exhaust outside.

Last time I was through Parkland was probably 7-8 years ago and it was already way built up from when I left in 2000. There were 3 cops total and they'd pull over anyone using Holmberg to cut through to Riverside. Residents had to have stickers on their cars to let them know they lived there lol Austin is the same way with traffic now, I think half of California moved here in the last 5 years. I'm ready to move back, just don't when that will be.

Thanks RSL. No worries. I got you and just finished reading a lot of post and reviews of the Cobbs. No rasp must be aqesome. Back to the is sound. I see from some of your post that you have done some nice mods. I need to get ahold of BQ and tweak my AP3. He is definitely the best and knows his tunes.

Yea we are building in the Wedge way back by the conservation and Loxahatchee. I do not think you will recognize it anymore.

[BSM n54iS]

Originally Posted by mmorrismm

Thanks RSL. No worries. I got you and just finished reading a lot of post and reviews of the Cobbs. No rasp must be aqesome. Back to the is sound. I see from some of your post that you have done some nice mods. I need to get ahold of BQ and tweak my AP3. He is definitely the best and knows his tunes.

Yea we are building in the Wedge way back by the conservation and Loxahatchee. I do not think you will recognize it anymore.

Just in case you didn't stumble upon this, some sound clips in there for you too:
http://www.e90post.com/forums/showthread.php?t=1189214

[mmorrismm]

Originally Posted by Black n54is

Just in case you didn't stumble upon this, some sound clips in there for you too:
http://www.e90post.com/forums/showthread.php?t=1189214

Awesome. Thank you very much. I had not seen this.

[RSL]

Originally Posted by mmorrismm

Thanks RSL. No worries. I got you and just finished reading a lot of post and reviews of the Cobbs. No rasp must be aqesome. Back to the is sound. I see from some of your post that you have done some nice mods. I need to get ahold of BQ and tweak my AP3. He is definitely the best and knows his tunes.

Yea we are building in the Wedge way back by the conservation and Loxahatchee. I do not think you will recognize it anymore.

Thanks, waiting on Hexon RR600s and Apex wheels as we speak. It's raining today, so hopefully Black's vids can hold you over for a couple of days.

I'll be out that way in a week or 2, curious to see what it looks like now!

[BSM n54iS]

Originally Posted by mmorrismm

Awesome. Thank you very much. I had not seen this.

Np

[JunkyardDogg]

Originally Posted by LMB335IS

I dyno'ed around 335/340whp and 370wtq on 93, downpipes, aFe intake, and stock tune.

I was asking how much more power will a catless dp give you over a catted. It seems like lots of complaints about rasp and smell with a catless. Plus you got emissions to pass.

[LMB335IS]

Originally Posted by JunkyardDogg

I was asking how much more power will a catless dp give you over a catted. It seems like lots of complaints about rasp and smell with a catless. Plus you got emissions to pass.

My guess would be 10-20whp depending on the catted dp. There's no emissions testing in FL. All I smell is the sweet smell of E70 burning. There's rasp at certain points in the powerband but it's not as bad as it's been made out to be, at least to me. In fact all I ever hear is people complimenting me on how good it sounds.