[ChopTop]

Note: posted to coupe sub-forum.

Just wondered if anyone has installed the Solo GXP high-flow catalytic converter on their coupe yet?

I remember WS discussing some issues he had w/his exhaust system and had to make modifications but since then I haven't read or heard of any other coupe owners trying HF on their coupe due to cabin drone issues?

I'm currently running a Solo Mach Shorty cat-back system (GMPP). The sound seemed to have increased during the summer, had it rechecked and everything is still bolted up nice and tight, plus no codes. Sounds great, but still thinking of adding FFCC but would like feedback if anyone else had pulled the trigger and cabin noise review/report.

Also, SOLO if you read this any new info?

 

[blackbirdracing]

I'm sure Pwerks has installed them on their coupe.

 

[ChopTop]

I'm sure Pwerks has installed them on their coupe.

Had always assume PAW coupe was built primarily for track rather than street. I'm more interested in how a SOLO free flow catalytic converter (plus Solo performance exhaust) sounds on a street/cruise day-to-day basic.

 

[wspohn]

I believe I was the first coupe owner to try the high flow CAT and I did it on a special street/race system Solo made up for me with silencers installed in each pipe. Much too much resonance for highway driving. Went back to a Mach system and it is quite livable. No idea if your Mach shorty would also be OK - suggest you email Jeff and ask them if they've had any further feedback.

 

[ChopTop]

suggest you email Jeff and ask them if they've had any further feedback.

Just sent Jeff an email asking the question and will report back when he responds. It's been awhile since the performance exhaust + high flow catalytic converter = cabin drone issue has been discussed. That's why I've been wondering if anyone has tried that combo yet. Hoping to not be the coupe guinea pig.

 

[Wendell Young]

Had always assume PAW coupe was built primarily for track rather than street. I'm more interested in how a SOLO free flow catalytic converter (plus Solo performance exhaust) sounds on a street/cruise day-to-day basic.

I had the solo Mach exhaust and free flow CAT installed in my GXP roadster about 1500 miles ago. I like the elegant but powerfull sound. No problems noted of any kind. Combined with the GMPP tune has resulted in a significant power increase.

 

[boboborino]

Well I was going to post yesterday after blackbirdracing's post then I decided to delete, but since it can not be anymore irrelevant as some others post(not you Bill) I may as well contribute:lol: I did test drive a coupe, although not a GXP, with an RCD with from what I thought I read somewhere had a high flow cat, I did find the drone a little too excessive, but of course that is just me. Choptop, with your mach shorty do you experience any drone at any particular RPM now? My guess would be that the hfc will amplify somewhat any tone or drone if present.

Bert

 

[ChopTop]

Received Jeff's from SOLO response:

Unfortunately yes. The fact that the top is hard means that the vibration doesn’t dissipate ( by hitting a soft top ) as it travels upward. We do have a few people with the Coupe and a HF Cat and Mach-Shorty and they have put our Solo MR212S resonators in the back ( two of them by the rear band clamps on either side ) and this makes it OK but still not recommended or 100%.

Feel free to call me about this tomorrow if you like. Thanks so much for your interest.

Jeff
SOLO PERFORMANCE INC.


No coupe HFCC for you! :brentil:

 

[boboborino]

That is too bad, but you should ask if they(solo) would test a "J" pipe on the coupe.I would imagine that they would have thought about it and maybe it's not feasible.Hmmm, I'm just thinking out loud, or rather through the keyboard.

Bert

 

[Shadofax]

Received Jeff's from SOLO response:

Unfortunately yes. The fact that the top is hard means that the vibration doesn’t dissipate ( by hitting a soft top ) as it travels upward. We do have a few people with the Coupe and a HF Cat and Mach-Shorty and they have put our Solo MR212S resonators in the back ( two of them by the rear band clamps on either side ) and this makes it OK but still not recommended or 100%.

Feel free to call me about this tomorrow if you like. Thanks so much for your interest.

Jeff
SOLO PERFORMANCE INC.


No coupe HFCC for you! :brentil:

Wonder how stock exhaust with HFC would be like.

 

[wspohn]

Wonder how stock exhaust with HFC would be like.

No problem. I have the HFC and Mach and it is ok.

 

[L-N-F'n]

I run my coupe cat less. I have a BMRP 3 inch exhaust, it has little strait through muffler/resonators in the back, at the very end of the exhaust. The noise/drone inside the cabin isn't that bad IMO. From the rear my car is very loud under power. I guess having "mufflers" very end of the exhaust help keep noise/drone out of the cabin.

 

[rob the elder]

As you know, I had a heat problem in Punisher when it came home. After installing the layer of thermal / sound attenuation barrier, one of the pleasent side effects was the sound inside the cockpit was greatly reduced. Prior to installation of the insulation, the exhaust sound came up through the floor was significant. Now the primary source of exhaust sound is from the rear, out the tail pipes. I also installed an insulating thermal wrap on the headers, cats and exhaust pipe that runs under the cockpit and this added to the noise attenuation. Something to consider.

 

[ChopTop]

These real life reviews sound promising. If the car w/a daily driver or I had a long daily commute I could see how it may become irritating over time. But the majority of my driving is short city commutes with longer occasional event cruises a few times a year. Though I'd probably do Jeffs choice of adding resonators w/HFCC. Including the sound deadening option would also be a good idea.

Kappa Specific Sound Deadening Kits

 

[wspohn]

The coupe noise problem isn't that the exhaust is too loud. Not at all. The special street race system I had with the added resonators sounded just great. The problem is that at certain rpm the coupe shell resonates with the exhaust and those resonant periods seem to coincide almost exactly with where I like to cruise on the highway. Adding damping to the shell would probably help but the issue isn't really loudness, it is persistence. You think it's OK, maybe just a little noisy, but after an hour on the highway you are ready to park it from frustration.

My level of tolerance is the Mach and HFC. Others may have different levels of tolerance.

 

[boboborino]

That is too bad, but you should ask if they(solo) would test a "J" pipe on the coupe.I would imagine that they would have thought about it and maybe it's not feasible.Hmmm, I'm just thinking out loud, or rather through the keyboard.

Bert

I just read this regarding the "J" pipe, so I guess not. Reply #22

GXP Coupe w/Solo RCD and CAT drone fix

 

[LiquidPT]

The coupe noise problem isn't that the exhaust is too loud. Not at all. The special street race system I had with the added resonators sounded just great. The problem is that at certain rpm the coupe shell resonates with the exhaust and those resonant periods seem to coincide almost exactly with where I like to cruise on the highway. Adding damping to the shell would probably help but the issue isn't really loudness, it is persistence. You think it's OK, maybe just a little noisy, but after an hour on the highway you are ready to park it from frustration.

My level of tolerance is the Mach and HFC. Others may have different levels of tolerance.

Popping this up again...

Bill, do you have a "stock" March system, or do you have extra resonators in that too?

How does it sound (with the HFCC) compared to stock? I have a street race with resonators (stock cat) and love the way it normally sounds (especially under load) but the highway drone drives me nuts.

 

[wspohn]

I have the stock Mach system - the resonators are still in the street race system I have (for sale). I talked to Jeff about it and he figured that with the HFC I shouldn't go with anything louder as I might run into the resonance issue again.

If what you have is too noisy, adding the HFC would drive you nuts on the highway!

If you ever get up this way, get in touch and we can take a drive so you experience this set up in person.

 

[GXP-Coupe1]

Below is a thread I started that may answer some questions for you.

http://www.solsticeforum.com/forum/f63/werks-hi-flow-cat-solo-exhaust-solo-mr-resonators-91369/

 

[wspohn]

Below is a thread I started that may answer some questions for you.

http://www.solsticeforum.com/forum/f63/werks-hi-flow-cat-solo-exhaust-solo-mr-resonators-91369/

The coupe considerations are quite different from what works on a convertible.