Anti-lag is loud, much more than a car running at 4500 rpm. But it isn't as loud as you think. Most of the time anti-lag is firing in a lower rpm/off throttle situation. You either have anti-lag pop, or motor noise, but rarely both. Standing in the woods, you will usually here motor noise and anti-lag at about the same distance.
Add it all together and it's still quieter than a muffled RX-7. If
Andrew Havas ever brings his car out of retirement, he should get an automatic free pass through sound check. That car sounded so cool at CT '01.
It's not just anti-lag. The 5 cyl. Audis have a nice off-throttle rip that sounds really cool, but is not good for a sound check. We were caught out by the old-style check at 100 Acre Wood because it was not a steady state check. "Run it up to 3500 and let it off" Rrrrrrip. Oops. 87dba.
The most important aspect of the proposed check is that it's steady state. Checking AT 4500 rpm. Presumably that makes anti-lag and the Audi-rip irrelevant, as it should.
Audi 4000Q - #577
this is very true, at 100aw the corolla was much louder than an rx-7, how is this, my daily driver is an 85 gsl-se, and it is freeking rip stomping loud, even with three mufflers it is much louder than the 4ag in the corolla, but yet a burned out flowmaster on an rx-7 is quiter than a 4ag fx-16 with two mufflers, something was not right and i think that sound tests are crap, these are race cars and as long as we fallow the rules in transit it shouldnt be a problem, as long as i dont take the corlla up to 8 grand it is kind of quite, more quite than bubbas mustang with flow daddies that rides around on the street, and antilag is not louder than a good ol big homemade firecracker, plus it scares away peopel deer ect
Hey Doug, FYI several of the popular anti lag systems for subarus are 'activated' as soon as you hit 4000 rpm. Many others are not 'activated' until a certain rpm.
For example, with the Link system, you drive it on the transits and etc. always under 4000 rpm, and then once you hit 4k antilag is enabled for approx x seconds. The rule is messed up and any 'international spec' group N car will fail.
the rpm value IS NOT AJUSTABLE. several perfectly legal group N cars will fail your test, as written. Here's a suggestion: adopt the FIA rules.
The FIA rules state that "For all cars used in Rallies and unless the limits imposed by the local authorities are lower, the noise level on the open road mustnot exceed 103 dB(A) for an engine rotation speed of 3500 rpm for petrol engines and 2500 rpm for diesel engines."
In other words, noise levels are whatever SCCA decides they should be.
The lawyer's creed: Never ask a question unless you know the answer.
In a perfect world, yes. If you bring the dyno to each event(make sure it will handle all-wheel drive), set it up, and conduct the tests, I'm sure Mr. Robinson will consider using this method of sound testing. Otherwise, he will probably do what the rest of the world does.
Even when the specific provisions for a group allow the replacement of the original silencer, the cars competing in an open-road event shall always be equipped with an exhaust silencer complying with the traffic regulations of the country(ies) through which the event is run.
For all cars used in Rallies and unless the limits imposed by the local authorities are lower, the noise level on the open road must not exceed 103 dB(A) for an engine rotation speed of 3500 rpm for petrol engines and 2500 rpm for diesel engines....
The same article also says this:
For all groups, all cars must be fitted with an original or homologated catalytic exhaust if this is obligatory in the country in which they are registered, unless the catalytic exhaust is not obligatory in the organising country, in which case it may be removed.
With the FIA, it's "In for a penny, in for a pound." Canada will already check your CAT temperature (with special probes borrowed from space aliens), but they let us 'murikins run without because our regs don't require them.
The point being ... we don't want to just say that we should abide by this FIA article or, for that matter, FIA regs in general.
Audi 4000Q - #577
The only intent of sound checking is to allow rally cars to be driven on transits with as little impact to the general public as possible. Though you maynot believe it, there are some people that don't like performance cars of any type. The sound check is not a firm policy yet and we are asking for "reasonable" comments.
We are looking for a standard that is acceptable across the country, so you won't have to be concerned about passing tech at one rally and not at the next. For this concept to work the sound level must meet the most strict area. Please feel free to contact me directly at [email protected]
>Does anyone know why there are noise limits at all? At
>racetracks that are used daily I can understand the issue,
>but who cares if a once a year rally makes a lot of noise?
Spoken like someone who's never put on a rally...
A LOT of people seem to care about EVEN ONE car making noise. Every one of them WILL complain to someone in authority, and EVEN ONE complaint CAN lose you access to your roads...or your service areas...or your sponsor.
And yes - they complain about the noise on both stages and transits.
>The only intent of sound checking is to allow rally cars to
>be driven on transits with as little impact to the general
>public as possible
Well, that's a difficult thing to achieve. Many of these cars will motor along quietly at transit speeds with bang-bang off and gentle application of the throttle, bothering no-one. The same car could be driven on the same road at the same speed making big noise.
To exclude a car because it is CAPABLE of making big noise is just draconian and makes no sense. Instead, you should exclude cars that (1) are NOT CAPABLE of being driven quietly and cars that (2) are NOT driven quietly, even though they are capable.
In other words, sound is like speeding. How it's driven is more important than what the capability is. As scary as it sounds, the natural approach may be to use a road-racing style sound check. Put the meter out in the quiet zone (at an O-control?) and measure folks as they go by. Drivers who are unable to light foot it through a quiet zone will be penalized.
Cars that sound like 747's at tech can be identified with an FIA style test. (103 dba at a steady state 3500 rpm is very loud!) The rest of us won't have to worry about it.
Audi 4000Q - #577
Just to make sure that we are all on the same page here.
2. Concept: Sound Testing Procedure. A new Sound Testing procedure has been developed that can be fairly and equitably applied at every event. This new system was developed to take out the factors that greatly influenced the results of the former testing procedure, and closely follows procedures used successfully in similar programs elsewhere in the world. The new procedure
- Test RPM: 4,500 (or maximum RPM whichever is less).
- Probe Placement: 18 inches and 45 degrees from exhaust outlet.
- Maximum Sound: 110 decibels
Background: The former sound check procedure was greatly influenced by the characteristics of the area the test was conducted in. If the test was conducted in an open field the result was different if the area had an adjacent wall. The new procedure will test the sound
closer to the exhaust outlet, but with a greatly increased DBA rating. The net effect of moving the measuring device closer to the exhaust outlet and raising the sound level should yield similar, yet more consistent and equitable results than the system last used in 2001.