This afternoon I fabbed up a new exhaust system for the CRX. I did have this crappy mufler shop hack and weld setup with crush bends for years. The new setup is all 2.5", mandrel bends, and uses one of the new Flowmaster Hushpower II mufflers. It just does fit, and it is definately an improvement in sound over the noisy glasspack muffler that was on there.

If you are interested check it out here:
http://members.***.net/rexracer19/Exhaust.htm

 

Have any comparison on power?

 

Not yet. This car does not have tags on it anymore...so no test runs I am planning an autocross in two weeks and am going to Lowes in March. I should be able to get a good butt dyno reading then.

 

Post up some results when you test it. I'm thinking about building a similar design. I need to redo my exhaust as well.

 

how much of a noise difference? i'm in the same sound boat as ryan. i don't want to give my custom,mandrel bent side exit up.

 

It is quieter than a glasspack style muffler, but without taking a dB reading, it is hard to quantify. I hope that somewhere I go in the near future has a meter set up. I will let you know what the numbers are then...


Modified by RexRacer19 at 8:06 PM 2/19/2005

 

Pretty sweet. You've got some mad welding skillz.

Tim

 

That's super clean. Hopefully this weekend we can tackle my setup.

 

good set up.thanks in advance for the info. i have eyeballing a sound meter from radio shack. will give me a ballpark output. 96 db for our main atlanta site.

 

I just ordered that same muffler for my gsr and was hoping the sound level would be OK for some of the more restrictive autox sites along with track schools. I was thinking side exit to eliminate the extra tubing but I guess we'll see. If you do get sound readings, let us know please. I'm hoping to not need a second muffler in the system. I wonder about putting two in a row if needed? Just thinking.

 

Ryan - you know I just had to get some practice in before we tackled yours...

Mohudsolo - FWIW my experience has been that if you can turn the exhaust down at the exit it help a lot with the noise. There have been a few cars that I have seen with side/rear exit pipes with little muffler that will make your ears bleed. Even with this muffler, I think that a side exhaust might get you into trouble with the sound police.

 

Nice job. I really like your cage design!

 

Jeff -

For some unknown reason, I foresee a bit more headache with my exhaust... We may need to unbolt the cat from the header to get the entire exhaust from underneath the car. Apparently the previous owner had someone weld the pipe just aft of the cat directly to the cat itself, with no flange. Should be interesting... I doubt you'd want to weld on the exhaust while it's on the car. The flanges would need to be welded very close to the fuel tank, may not be the safest route... Although that picture that's been floating around with the guy welding underneath his truck propped up on 2x4s says otherwise...

Was browsing pictures of your cage. Immaculate!

 

I don't think it will be too bad. I don't think we will have to take it off the car...keep your fingers crossed.


Thanks for the complements guys...

 

i just got a baseline with a radio shack digital meter

112 with meter as close to open passenger window,not the 50' as our atlanta sound rule.

this is with 2 1/4 cat and 2.5" side pipe with magnaflow small resonator. and got 120 at the wheels with a 197,000 mile internally stock d16z6
will purchase a hushpowerII and retest for sound and dyno.


Modified by shakedown94 at 10:01 AM 2/19/2005

 

Do you have a friend that you could take and help you measure at the 50' distance out of the car? That would be more accurate. I would think that you would get some other noise in there also just by having it in the window. It sounds like that you did the sound measurement on the dyno...yes...no?

Anyway, it will be good to get your data regardless...

 

You need to measure the sound level in a similar circumstance as would be at a Solo event. If they are using the top of the line db meters like for club racing the radio shack may or may not be accurate enough but it is better than nothing. You should measure it outside, away from surrounding structures (which will bounce or amplify your sound readings) and you need to be pulling on full throttle. Dyno is no good because you are inside a building.

Barry H.

 

wife helped

less than 100 db at 50' feet. so much better. but will still look into a hushpower II
also. they say one 2.5" supports up to 400 hp. so mine should be no noticible drop in hp.

this will get me in the ballpark. atlanta region is offering no real solutions other than being disqualified from the first event with no refund

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by apexinghonda &raquo;</TD></TR><TR><TD CLASS="quote">You need to measure the sound level in a similar circumstance as would be at a Solo event. If they are using the top of the line db meters like for club racing the radio shack may or may not be accurate enough but it is better than nothing. You should measure it outside, away from surrounding structures (which will bounce or amplify your sound readings) and you need to be pulling on full throttle. Dyno is no good because you are inside a building.

Barry H. </TD></TR></TABLE>

atlanta solo2 is using the really old analog meter the Atlanta region was using at Road Atlanta years ago. It is being passed down to us. Is there anything to calibrate it to make sure it will give accurate readings to the competitors.

 

ya, calibrate it to my meter

try and contact the region sound control chief( that hadles road atlanta) and they may be able to help.

 

I don't know if my sound control guy can help but you might give him a try. We just bought brand new sound control equipment with a portable weather station. He has run Atlanta's sound control on quite a few occasions. As big as Atlanta regions Solo program is I would imagine if they are going to institute the program they could probably afford a new system. About $300 or a little more.

soundcontrol@alscca.org

Barry H.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shakedown94 &raquo;</TD></TR><TR><TD CLASS="quote">wife helped


this will get me in the ballpark. atlanta region is offering no real solutions other than being disqualified from the first event with no refund </TD></TR></TABLE>

I mentioned it before, but a turn down will really help with the sound. If your exhaust has a side exit and points straight out, it will be LOUD. If you want a side exit you could still incorporate a turn down and increase your ground clearance (the exit pipe could be tucked up a little higher under the body without the exhaust being directed at it)

As cheap experiment, you might want to buy one of those $5 bolt on turn downs from the auto parts store and test the sound like that. If you see a difference figure out how to incorporate a turn down permenantly in your system. If you look at my pics you can see I just took a mandrel bend and made a cut parallel with the tubing leading into the bend...low profile turn down.

HTH

 

the exhaust looks good.
had a chance to track the car since you finished the cage?i'd imagine it made a HUGE diference in stiffness over the old rollbar.
BTW-is that my old Z6 STILL sitting around unused?
Chris

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RexRacer19 &raquo;</TD></TR><TR><TD CLASS="quote">

I mentioned it before, but a turn down will really help with the sound. If your exhaust has a side exit and points straight out, it will be LOUD. If you want a side exit you could still incorporate a turn down and increase your ground clearance (the exit pipe could be tucked up a little higher under the body without the exhaust being directed at it)

As cheap experiment, you might want to buy one of those $5 bolt on turn downs from the auto parts store and test the sound like that. If you see a difference figure out how to incorporate a turn down permenantly in your system. If you look at my pics you can see I just took a mandrel bend and made a cut parallel with the tubing leading into the bend...low profile turn down.

HTH</TD></TR></TABLE>

my car is still daily driven, so a turn down under the car is not a option. breathing is more important than racing for now. i have though of putting a three bolt flange
behind the new muffler. and have a 90 bend right ahead of the tank for racing,then bolt on side exit for driving.

still though, under 100 db measured with mic pointing at the exhaust with resonator. if new muffler does not drop enough for a margin of error and weather conditions,then will do the 90 bend.

thanks for the advise,and damn good work on your cage and exhaust.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TeamNextGenChris &raquo;</TD></TR><TR><TD CLASS="quote">BTW-is that my old Z6 STILL sitting around unused?
Chris</TD></TR></TABLE>

Umm..Err...Yeah. It is still sitting in the garage with that 5-speed right next to it. I think that I just need to quit my job, so that I can get more projects done...

The cage does make a big difference in how the car drives. It is much more responsive and precise. I made it to Summit Point last fall after it was done. A funny story related to that... I was shopping for lipstick cameras to put in the car b/c my picture was still shakey, especially at rough tracks like Summit. I have one of the I/O Port camera mounts that was mounted to the original 4-point bar. After the cage went in, the picture is perfect...even at Summit. If that does not tell you the car is flimsey without it, I don't know what does.