Avera

For the record, I completely understand and respect views based around simply replacing the Race Pipe with the OEM box

The nature of this thread focuses on the negative aspects of my current exhaust setup. However, I want to emphasize the upper half of the rev band is epic and what I am fighting tooth and nail to hold onto

So, yes, I am trying to think outside the box for a way to not have the negative overshadow the positive . . . there might not be a way to get my desired outcome? I can accept that if I have exhausted my efforts with no plausible solution.

I would not be the first, nor last, to tinker with aftermarket exhaust options. I just have not heard of anyone trying to address it via a tune. Maybe it is not possible or reasonably feasible?

Avera

Avera

Ok, I have been contacted and spoke in person to a tuner. Given the PM approach, I will leave names out of the discussion

As has been suggested by members in this thread, the tune approach to my problem is not the solution of which I was hoping

At this point, I have exhausted all options known to me . . . I cannot have my cake and eat it too

So, I gave it a shot and the Dundon headers/OAPs with OEM rear box seems to be the best I think I will personally achieve. The Dundon headers/OAPs are non-negotiable part of my exhaust equation and I will just have to live with the less than optimal tone the OEM box produces

I have already made an appointment with my local shop to have OEM rear box put back in place

What a shame because the 70mm JCR Race Pipe I have produces the most amazing tone. I think it would be perfect for anyone who has OEM headers/OAPs or well catted/resonated aftermarket headers/OAPs and is looking for that 'wailing' JCR tone.

I would not advise it for anyone, like me, who has gone full bore with Dundon parts, or similar with compromised cats/resonators. The drone is a menace that is hard with which to live. The possible exception being someone who tracks almost exclusively (lives above 4k RPM) and does not have decibel limit on their home track.

That is about as honest as I can be with everything

Avera

brewerbry

Have you considered modifying the stock box with bypass valves? You can run in "stock" quiet mode avoiding most drone and then hit the stupid button (as my wife calls it!) and have nearly straight pipe volume levels? I have done this to my 981 stock muffler and it is fantastic - quiet around town and on track it wails!

TRZ06

You should look into the Kline system, it offers the least drone and if you get their full system, I am sure it would be plenty loud enough

808c2s

It appears that Avera has invested quite a bit of money into his system (Dundon + JCR), thus going into a brand new system is a bit unnecessary waste of money at this point....although it can be done; going back to the OEM Box is a good compromise in this case.

Avera

@808c2s

Thank you for you insightful comment. . . you are spot on

The Dundon headers/OAPs with OEM rear box achieved 80% of my goal. VERY LOUD with valves open above 4K RPM. Not a primary objective, but a clear butt-dyno jump in TQ/HP. The ONLY downside is that I do not enjoy the OEM rear box tone, which is why I pursued the JCR Race Pipe.

I went a step too far. Yes, the Race Pipe produces an amazing ('wailing') tone I was after and even gave me what others would likely construe as an insane decibel level . . . the problem is insane drone tagged along. The OEM rear box is incredibly good at scavenging drone . . . at the cost of tone.

So, as you stated, I am not interested in continuing to chase 'better' with other systems. The Dundon headers/OAPs are non-negotiable. Yes, cost is part of it, but what they brought to the table is unmatched in MY opinion.

At the end of the day, although the OEM rear box does not produce the MY ideal tone, it is a compromise I will accept now that I have experimented with the alternative.

Avera

Avera

@brewerbry

If by 'bypass valves' you mean a valve controller . . . yes, I had valve shaft collars on my OEM rear box prior to getting the Race Pipe.

The Dundon headers/OAPs produce a massive decibel boost with valves open, enhancing a valve closed-to-open transition that I did not like with the complete OEM exhaust system. So, I clamped the valves open permanently, which is what I will do when I replace the Race Pipe with the OEM rear box.

Further, it is not DECIBELS that I am after. The OEM rear box with Dundon components is louder with valves open than most would tolerate. What I was after with the Race Pipe was improved TONE over what the OEM rear box produces. Holding the valves open does not change the tone.

Thank you for your comment

Avera

brewerbry

Got it - you have sport exhaust with factory valves. The mod I mentioned is to a non-sport stock box that is also pneumatically controlled (like stock sport system) but rather than re-routing through the box, it bypasses it completely and dumps straight out of the exhaust pipe. This changes both volume and tone - it sounds like a race car when open. Fabspeed has this for their tracktec setup but you have to use their muffler which some have had challenges with drone.

Avera

@brewerbry

Thank you again

Unless I am mistaken, the likes of TrackTec require OAP that comes with the rear piece? I will not give up my Dundon setup

The Dundon headers have no cats. Dundon replaced the cats on their OAPs where resonators are located on the OEM OAPs. For this reason, you have to use the Dundon OAPs with their headers. It is about as close as you can get to straight pipe without being straight pipe. In addition, the Dundon pipe diameters, as I recall are 73mm, as opposed to the OEM 63mm. Someone can correct me if I am not exactly correct.

As above, what I have learned through this experience is the OEM rear box is quite good at allowing decibels through and scavenging drone. . . at the cost of tone.

I see no way to get the tone I am after - and obtained with the Race Pipe - without the associated drone.

It is all good . . . we are talking first-world problems here. I gave it a whirl and will 'settle' for the OEM tone.

Avera

MaddMike

Having installed their headers last weekend to go along with the rest of the exhaust, I can attest that this is the case although I understand the OP doesn't want to start all over after the money he put into his current setup.