Mazda Miata: CAI, catbacks, and other bolt on mods

Caden wrote: 

Invest in some before/after dyno runs. If you live in CA, make sure
you get one that's CARB-certified; I know someone that put a cheap
CAI in his car and pulled over for his loud (Uncle Ben) muffler
and then cited for the non-CARB CAI. Cost $200 and a trip to the
test-only station for the ticket.
 

What's the mystery? A manufacturer tunes a car to provide
the best combination of reliability, economy, driveability,
performance and emissions compliance. An aftermarket tuner
can maximize top-end power at the expense of torque, so on.
The same tuning that a performance enthusiast likes might not
be acceptable by an mainstream driver.
 

I suspect much closer to the latter.

Dana

In article <da%zc.51$news.prodigy.com>,
Dana Myers <net> wrote:
 

Also gasoline of variable quality, a wide range of elevation and
temperature, and normal engine production tolerances. If manufacturers
programmed their ECUs too close to the edge (i.e., for ideal
conditions), warranty claims would eat them alive. As for aftermarket
foam or gauze filters, every one of them passes more dirt than a stock
paper cartridge; on a stock Miata, airflow restriction is not an issue,
so they offer no benefit at all.

Bear in mind that most aftermarket power claims are valid only in their
dreams. Dunno about the 3, but there's essentially nothing to be gained
from chipping a stock Miata engine, and the best CAI for NA models dynos
at a 5 hp increase. A CAI's job is to prevent *loss* of power in hot
weather, not to change the torque curve.

If you adopt the attitude that everything advertised in a riceboy
magazine or listed on eBay is a piece of crap and a waste of money, you
won't go too far wrong.

--
Lanny Chambers, St. Louis, USA
'94C
the alignment page:
http://www.hummingbirds.net/alignment.html

On 2004-06-16, Lanny Chambers <net> wrote:
 

Whew! I was afraid you were going to say that stuff advertised
on late-night infomercials was crap.

http://www.autostreak.com/tornado/
http://www.tornadoair.com/

--
Grant Edwards grante Yow! I'm having
at a tax-deductible
visi.com experience! I need an
energy crunch!!

"Caden" <edu> wrote in message
news:capt3j$ias$sdsu.edu... 


A manufacturer aims the car at the "lowest common denominator" buyer, which
means keeping it simple. Also, they want to keep warranty work at a
minimum, and, over thousands of cars, boosting performance will have an
effect on parts life that they don't want to deal with.

 


I've done cat-backs, CAI and other bolt on mods and found them not worth the
money (unless all you want is a different look or sound). Increased HP
claims are measured at the peak, not the RPM range where most of us drive.
An 8 HP gain at 5500 RPM might only be 3-4 HP at 4000 RPM - hardly
noticable.

 

My $.02 is that a supercharger or turbo is the only way to make a noticable
improvement in HP. Fooling with CAIs, exahust, cam timing and chips can be
fun, but ends up costing a lot with a minimal gain.

 

In article <rivatek.com>,
Grant Edwards <com> wrote:
 

No need, Grant. Anyone who owns a Miata is smart enough that he already
knows that. :-)

--
Lanny Chambers, St. Louis, USA
'94C
the alignment page:
http://www.hummingbirds.net/alignment.html

Grant Edwards <com> wrote:
 

Yes, this device is certainly not junk. If you look at the stock
Chevy 454 data, at 2,000 rpm, torque increases from 402 to 414,
but horsepower stays exactly the same. Physics says it cannot
be done, but this device does it!!

If you are one of those nasty cynical persons, and wonder whether
physics really can proved to be wrong by a putting a plastic
obstruction in the intake of a car, you are out of luck. This
was measured by an *INDEPENDENT* testing lab!!

For a mere $53.95, you can show three centuries of basic physics
dead wrong! It is a bargain!!

Leon

--
Leon van Dommelen Bozo, the White 96 Sebring Miata .)
To reply to me, the word Miata must be in the subject.
EXIT THE INTERSTATES (Jamie Jensen)

On 2004-06-16, Leon van Dommelen <net> wrote:
 

And with mileage increases up to 28%!
 

But it's not plastic, it's a nice shiney _metal_ obstruction.
I'm sure that's the secret: it probably has something to do
with ions. Scam artists _love_ ions.
 

It certainly is -- what's the Nobel prize these days? About a
million USD isn't it?

--
Grant Edwards grante Yow! NOW do I get to blow
at out the CANLDES??
visi.com

Caden <edu> wrote:
 

Send this AEM guy right over with the detailed evidence for his
claims.

Actually, manufacturers *deliberately* preheat the intake air to
be able to optimize the engine for a single intake air temperature.
The preheating is done by adding selected amounts of warm air
from the exhaust area to the other intake air.

The following quote is from the 5th edition of Bosch "Automotive
Handbook" as published by SAE:

"In addition to filtering the air, passenger-car air filters preheat
the intake air and regulate its temperature, as well as dampening
the air intake noise. Intake-air temperature regulation is
important for the operation of the vehicle and for the composition
of the exhaust gases. [...] The constant regulated air intake
temperature improves engine performance and fuel consumption, and
decreases the percentage of pollutants in the exhaust gases as a
result of better fuel management and distribution of the air-fuel
mixture."

Of course, this does not need to mean that a specific *single*
measure such as maximum hp might not improve a bit by piping
in cold air where the engine expects warmer, in specific
conditions, (eg, when the car is sitting with the hood up
in a dyno testing stand, thwarting the intake's temperature
management by letting the hotter exhaust air escape.)

I just want to see the AEM guy to establish how the measurements
were done, and how repeatable they were (if they *were* repeated.)
 

I will beat the mod for $200. Just send $200 and the mod right
over and I will have my hammer ready.
 

Maybe, just maybe, they think they *are* doing it right?? Modern
cars are very highly optimized, so any aftermarket stuff is likely
to make things worse, even if they try to optimize other items
(eg power at the expense of pollution.) This is especially likely
if the chip is not specific to the particular car model and model
year it is used on. For example, chip mods on Miatas are well
accepted to be worthless.

I have an aftermarket ECU on my Miata, but only since I also
have an aftermarket supercharger on it. So OEM optimization
is nonexistent.

Leon

--
Leon van Dommelen Bozo, the White 96 Sebring Miata .)
To reply to me, the word Miata must be in the subject.
EXIT THE INTERSTATES (Jamie Jensen)