I am building a new b20Vtec engine for one of my Civics which I use for Road Racing only and noticed that all the Realtime Integras use a muffler, wouldn´t they be faster with no muffler? I have no mufler in my race cars but was wondering if I should install one for better torque.
While we are on that topic, what suspension parts do they use?

Jay

 

A lot of the tracks that World Challenge use have sound restrictions.

 

I believe they use Motons:

http://www.kingmotorsports.com...nsion

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Geratol &raquo;</TD></TR><TR><TD CLASS="quote">I believe they use Motons:

http://www.kingmotorsports.com...nsion </TD></TR></TABLE>

I don't get it. What does adjustable suspension have to do with exhaust?

 

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

I don't get it. What does adjustable suspension have to do with exhaust?</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jwaked &raquo;</TD></TR><TR><TD CLASS="quote">
While we are on that topic, what suspension parts do they use?
</TD></TR></TABLE>

 

this isnt drag racing. tracks have sound restrictions. and no, not having a muffler doesnt mean it would be faster.

 

Ok....bringing this thread back from the archives...

I am doing what most race car drivers do when they are not racing, finding cheap ways to make the car go faster because we all know the limiting factor is the car and not the driver Anyway... I was thinking, do I need my muffler? I am racing at Summit Point and VIR all year and I think they do not have a sound restriction (please correct me if I am wrong) and would a turn down be a cheap way of getting 5 - 10 hp ?

(Car is a H2 Type R)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by davidnyc &raquo;</TD></TR><TR><TD CLASS="quote">Ok....bringing this thread back from the archives...

I am doing what most race car drivers do when they are not racing, finding cheap ways to make the car go faster because we all know the limiting factor is the car and not the driver Anyway... I was thinking, do I need my muffler? I am racing at Summit Point and VIR all year and I think they do not have a sound restriction (please correct me if I am wrong) and would a turn down be a cheap way of getting 5 - 10 hp ?

(Car is a H2 Type R)</TD></TR></TABLE>

Dave, don't expect that much power by deleting the exhaust...and the only real way to find out is to dyno the engine before and after...

 

David, I believe all tracks take sound readings (I was pretty suprised to find that CMP took sound at driver schools - maybe it was my loud a$$ed car that brought out the mic??). What they or the sanctioning body does with it is another matter. One thing I would mention is that you'll want to weigh the power gains to what your ears can take. In my car, which is consistently over 100 dB (anywhere from 101-103) it becomes a necessity (IMO) to have something stuffed in your ears. We often have trouble hearing over the radio. I would shoot for a little a restriction yet as quiet as possible.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by phat-S &raquo;</TD></TR><TR><TD CLASS="quote">David, I believe all tracks take sound readings (I was pretty suprised to find that CMP took sound at driver schools - maybe it was my loud a$$ed car that brought out the mic??). What they or the sanctioning body does with it is another matter. One thing I would mention is that you'll want to weigh the power gains to what your ears can take. In my car, which is consistently over 100 dB (anywhere from 101-103) it becomes a necessity (IMO) to have something stuffed in your ears. We often have trouble hearing over the radio. I would shoot for a little a restriction yet as quiet as possible.</TD></TR></TABLE>

Good point. I'll probably keep the muffler... Anyway, the recently delivered sticker pack from Honda Challenge has to be worth at least 2 -3 hp

Thanks guys

 

This is another of the racing things that I just don't understand. If EVERYONE had to come in at 80dB, EVERYBODY would be impacted equally by the restriction and we wouldn't be giving the locals a stick to hit us with. Every time a racer gets all full of himself when someone complains about track noise or a track gets sanctioned by the zoners, I'm tempted to ask what he is doing about the problem.

I have the OE muffler on the SS car but even when it goes to IT, expect it to be a hell of a lot quieter than most IT cars. I believe that noise has a physiological impact on drivers and their abilities, particularly in endurance races.

BTW, sound readings are not linear - the difference between 70dB and 80dB is a lot less than the difference between 90 and 100dB.

K

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by phat-S &raquo;</TD></TR><TR><TD CLASS="quote">David, I believe all tracks take sound readings (I was pretty suprised to find that CMP took sound at driver schools - maybe it was my loud a$$ed car that brought out the mic??).</TD></TR></TABLE>

At the very first honda challenge weekend.. which was also the first AI weekend... I had to laugh becuase the brought out the db meter for the big bore ai race.... then took in for the 20 some odd Honda Challenge cars.... I swear and unmuffled 4 banger is the loudest damn engine on earth...

 

Well, the pitch seems to make a huge difference in what sound shows you to be. I have heard monstorously loud GT cars that don't even show up on the sound sheets while my little 1.6L motor trips 100 dB all the time. As to who is pissing off the neighbors more, I don't know. The only track I know of that is remotely (and not that remote it seems) inhabited is Roebling and these people not only built on a racetrack but an emergency airstrip so they did buy with knowledge ahead of time. I am not arguing this however, we want to quiet the car down for ourselves because we're sitting is a freaking bell and simply don't want permanent ear damage. But to your point, if the SCCA says I have to be below or at 103 dB, I will do everything I can to be below or at 103 dB. Anything lower, I am doing for my own protection. If they change and say we need to be at or below 97 dB, I'll do everything I can to be at or below 97 dB.

 

us fsae kids have a lot a experience meeting sound requirements. try 110dB @ 20cm from the tip, at an angle of 45* from the line of exit. at around 11k rpm. thats QUIET!!!

what we have learned, however, is that it matters what frequency range the're measuring at. we've at cars that were HORRIBLY loud, but passed sound. other years (like last year) our car SOUNDED quiet, but was producing a lot of dB at the frequencies they measure. like 122dB worth.

so if you gots money and a modeling program similar to WAVE, you can design a muffler that attenuates the frequencies they measure. you just need to take a look at their meters to see how they're set

 

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

At the very first honda challenge weekend.. which was also the first AI weekend... I had to laugh becuase the brought out the db meter for the big bore ai race.... then took in for the 20 some odd Honda Challenge cars.... I swear and unmuffled 4 banger is the loudest damn engine on earth... </TD></TR></TABLE>

Me thinks we have found someone who has never heard an unmuffled bridgeported rotary. 130 dB is not uncommon.

 

I agree with Kirk.

As a flagger and instructor, nothing pisses me off more than an unmuffled car.
Given that modern muffler technology provides for negligible power loss, the only thing running unmuffled says to me is that you are a stingy ******* who cant spring for a $100 muffler.


PS- the SWC Champion Audi RS6 is very very quiet. and yeah, it has more than a little power

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elgorey &raquo;</TD></TR><TR><TD CLASS="quote">PS- the SWC Champion Audi RS6 is very very quiet. and yeah, it has more than a little power </TD></TR></TABLE>

And any car out of the Trans Am field will leave your ears ringing from several hundred yards away.... I have been next to IT7s on the grid, warming up their cars that I thought would leave me deaf only to see them with low or no sound readings. It really depends on what is being measured and the atmosphere as that too can drastically change our readings. I have heard cars that I thought were considerably quieter than mine (Bowie's for instance and the car Whitney owned) get bounced for sound (and it has happened to me too). You cannot tell how loud you are standing in a shop or at the dyno and you certainly cannot tell what the sound meter will pick up. If so, none of us would ever trip sound unless something fell off.

As for working a corner, I have only done it w/ a headset on but I would suggest that you take ear protection with you if you won't be on a headset. I spent a weekend in corner buckets a few weeks ago and whereas it is difficult to have a conversation, it was NOTHING like being several hundred feet away at a WC race at VIR.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by phat-S &raquo;</TD></TR><TR><TD CLASS="quote"> You cannot tell how loud you are standing in a shop or at the dyno and you certainly cannot tell what the sound meter will pick up. </TD></TR></TABLE>
interesting point. Although Im not really speaking from the perspective of the sound meter, more the perspective of how bad a headache I get when the car drives by!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">As for working a corner, I have only done it w/ a headset on but I would suggest that you take ear protection with you if you won't be on a headset.</TD></TR></TABLE>
Joel and I actually had this discussion not long ago. A flagger's ears are his best friend. I always can hear an incident before I see it, and most of the time I can hear it coming before it even happens. So I would rather not wear earplugs if possible.

 

I'm probably just getting old and grumpy, but I've gotten to the point where I bring "ears" to just about any track I go to, even though I'm just roaming the paddock and watching whatever event/school/race happens to be going on at the time.

On my personal **** list of cars that just don't need to be that damn loud:

* 911 Cup cars (why do they pay that much for something that sounds like a dump truck?)
* NA RX7's
* Most Honda race cars
* Most VW's (is Supertrapp the official muffler or what?)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elgorey &raquo;</TD></TR><TR><TD CLASS="quote">
interesting point. Although Im not really speaking from the perspective of the sound meter, more the perspective of how bad a headache I get when the car drives by!
</TD></TR></TABLE>

I *hear* ya. A good deal of that however might be where the turn down/out is pointing. Some people will take the exhaust all the way back and turn it out opposite side of where sound is taken (track left at VIR so turn out is pointing right - if you're in a bucket track right, will it seem louder?? I dunno, point is, the cars giving you the headache may very well be fooling sound but not your ears). I'd think most cars have some type of muffler on the car, how much that knocks down the sound and what sound remains is probably not that easy to predict. We have a couple ideas on what we can do for our own sanity but they will just be guesses. I could tell you that my brandy new dynomax last year was good for a drop from 106s at RA in November 2002 to 100s at RA in March 2003 BUT there are a lot of other variables in there and who knows if the same new dynomax in November would have been any different (or if I was putting out 106s in the first place). I mean I never popped 102 all year on that first dynomax so why then?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by davidnyc &raquo;</TD></TR><TR><TD CLASS="quote">I am racing at Summit Point and VIR all year and I think they do not have a sound restriction (please correct me if I am wrong) and would a turn down be a cheap way of getting 5 - 10 hp ?
(Car is a H2 Type R)</TD></TR></TABLE>

Summit Point has a 103bd limit (I believe measured as outlined in the SCCA GCR).

Not sure about VIR.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elgorey &raquo;</TD></TR><TR><TD CLASS="quote">PS- the SWC Champion Audi RS6 is very very quiet. and yeah, it has more than a little power </TD></TR></TABLE>
The twin turbos in the exhaust stream do more than a little sound deadening. That's the biggest reason that they're quiet.
Hm. If I'm over the sound limit, think they'd let me put twin turbos on mine?

Turbos for everyone!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by davidnyc &raquo;</TD></TR><TR><TD CLASS="quote">Ok....bringing this thread back from the archives...

I am doing what most race car drivers do when they are not racing, finding cheap ways to make the car go faster because we all know the limiting factor is the car and not the driver Anyway... I was thinking, do I need my muffler? I am racing at Summit Point and VIR all year and I think they do not have a sound restriction (please correct me if I am wrong) and would a turn down be a cheap way of getting 5 - 10 hp ?

(Car is a H2 Type R)</TD></TR></TABLE>

Does your Apex N1 have any premuffler? Just unbolt the rear section and see how loud it get. But like Matt said, I'm not sure you will gain anymore then a couple hp from it.

My car has 3 mufflers and the cat still on it.

 

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

And any car out of the Trans Am field will leave your ears ringing from several hundred yards away.... I have been next to IT7s on the grid, warming up their cars that I thought would leave me deaf only to see them with low or no sound readings.
</TD></TR></TABLE>

All T/A cars run mufflers, I don't find them loud at all, IMO T/A cars SHOULD be loud.

 

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

Me thinks we have found someone who has never heard an unmuffled bridgeported rotary. 130 dB is not uncommon.</TD></TR></TABLE>


Actaully I though about that after I posted that.. that Rotary have to be loudest engines I have ever heard, I know some of the racers have to run 3 mufflers to be below a legal db limit.