Dynamax Cones Good or Not?

[mark777]

I removed the secondary cats from my SRT-10 and it is just a little to loud for me... It is like an explosion when I start up the car in the garage as the sound bounces of the walls...

I have a pair of Dynamax cones but not sure if these will be the right choice. I removed the secondary cats mostly to further reduce side-sill heat (already have Corsa track exhaust with no cross-over and full side sill insulation wrapping). I removed the secondary cat because I was told that it is by design that it builds up heat and that would be a way to reduce this heat in side sill.

After reading some posts regarding the Dynamax cones, it makes sense that these will also end up creating more heat since it restricts air movement by forcing air to go through the many small holes in cones. This being said, I have two questions:

1) where would you install these cones and could they be installed somewhere other that in the side sill are where it will build up heat where I step out of car and potentially get burned (live in desert and it is already well over 100 degrees)

2) for anyone who has installed these in the cars where did you place them and how do you like the results in terms of sound, heat buildup, and power loss?

Thanks,

Mark

 

[zorroespanol]

I have mine where the first cat used to be, right after the collector.

As you can imagine, since there used to be a cat in there it doesn't really matter how much extra heat is built up in there...

Are you sure you want to do this when you still have 1 cat? might as well take them all out, install o2 sims and the cones. (my setup)

Not that I have tested them on an airflow bench, but I guarantee you that the cones restrict flow a lot less than a cat, while at the same time providing sound restriction.

Cheers!

 

[mark777]

If you take out both cats and you put it back on the street you will not be able to pass smog. At least with the primary cat you could pass if you really needed to...

If I retain the primary cat then I wonder where I should place cones... I thought I rememberd someone possibly saying just before it comes of exhaust pipe but this is not where I would want it located...

Mark

 

[Kenny]

I have the cones in my exhaust. I am running a 3" Mopar Race exhaust, no cats. I installed mine just before the muffler, which is where the second cat used to be.

I don't think they generate any additional heat---in any case nothing near comparable to a cat. I ran this exhaust with and without cones and noticed no heat change.

I run them because they change the sound both by reducing the db's and making the tone deeper and less raspy.

I would install them where the second cat should be. Remember the cone points upstream and I recommend tack welding them in place.

Let me know if you need anything further.

 

[mark777]

Thanks for the info. I will take them down to the shop next week and have them put on and report back.

 

[zorroespanol]

Mark, I do not know about the smog test, we do not have it anymore here in FL.

But back in the days, I used to slip a $50 bill right under the paper that you are supposed to give the examiner, and my car would magically pass

This was only on the RT/10 though...

All other cars I've had with no cats, VETTES, Z28, 911's, M3, etc passed WITHOUT cats, altough with higher (but still legal) emissions.

 

[GregSRT10]

I have Dynamax cones with Corsa track exhaust (with no cross-over), RT high flow cats and full side sill insulation. The cones are installed right after the collector. Since installing the cones side sill heat has dropped tremendously, db's are slightly lower and decel popping seems more distant. No problems, great sound!

Greg

 

[mark1962]

I'm not sur ethat your assumption of the cones increasing the heat is correct. My understanding from their description of the cones is that the surface are of the cone is greater than the diameter of the pipe and therefore creats no restriction - i would think that would apply to heat as well as backpressure.

 

[Vipermann]

Thanks for the info. I will take them down to the shop next week and have them put on and report back.

What is SOTP effect on power? I'm thinking about doing this too ... but I was wondering: rather than putting a 3" exhaust on and then cones, why not stay with a 2.5" pipe and no cones? (2.5" is less loud than a 3" pipe)

 

[Kenny]

No SOTP change in power by addng cones.

 

[NoRice]

If you take out both cats and you put it back on the street you will not be able to pass smog. At least with the primary cat you could pass if you really needed to...

If I retain the primary cat then I wonder where I should place cones... I thought I rememberd someone possibly saying just before it comes of exhaust pipe but this is not where I would want it located...

Mark

I have no cats on my car(522" Paxton) and passed smog. They don't do the tailpipe test here, they only plug into the obd connector under the dash. As long as you are throwing no codes you will pass.