Last post on Jul 11, 2007 at 11:53 AM
You are in the Mazda RX-8
What is this discussion about?
Mazda RX-8, Audio, Exterior, Lights, Performance Mods, Tires, Coupe
#114 of 143 Re: RX-8 Car Cover [mcusmc]
Oct 08, 2006 (2:08 am)
Taking the cover off during the winter would seem to be a real pain. Snow and ice build up down around the wheels would be especially awful.
#115 of 143 Re: RX-8 Car Cover [mcusmc]
Oct 09, 2006 (8:09 am)
I park on the street just outside DC and have been using the RX-8 car cover most days since this summer. It is very easy to take off and pretty easy to put on. The only difficulty I have had so far is dealing with stowing a wet cover when it is raining in the morning. I imagine snow would be a similar issue.
#117 of 143 Improved performance
Oct 19, 2006 (10:35 am)
I am leasing a 2005 model and was frankly disappointed in the acceleration of the car as it came from the factory. So, when I saw some info on Iridium sparkplugs I dedided to give them a try. I purchased some NGK Laser Iridium plugs and my goodness the performance improvement was immediately noticable. Although I haven't had the car tested it feels like I gained 50 horsepower. They are also supposed to increase gas mileage so I will be posting again when I determine if this is so.
#118 of 143 Manual shift Pattern
Oct 20, 2006 (9:39 pm)
Is there an after market six speed shift pattern plate that can be installed around the base of the stick instead of the boot.
This would help in protecting the transmission in making shifts, for example, from 4th to 5th gear without accidently trying to put the stick between 3rd and 5th gears which is hard on the gear box. Each time this happens it is one less time the idler gears will function properly and permit a shift into 5h gear without rebuilding the transmission.
I hope my question is clear enough to permit a reply.
#119 of 143 Popping Exhaust Noise
Oct 20, 2006 (10:10 pm)
Has anyone considered the popping exhaust noise from the AT RX 8's may be only wasted gas from a rich mixture during acceleration just popping in the catalytic converter instead of quietly burning ???
Of course if this could be the noise it would never be admitted by the designers because nit picky owners would then want it replaced with a properly designed one instead of just accepting the nature of the cars gas rich exhaust. New converters are expensive.
Just a thought that occurred to me after I remembered putting spark plugs in exhaust tail pipes when I was younger, in the 1950's, so popping sounds and flame would come out of the exhaust when accelerating. The good old days when every thing was fun and kids knew more about cars than mechanics.
#120 of 143 Re: Popping Exhaust Noise [oldtimer2]
Oct 21, 2006 (2:02 pm)
Yep. This is one of PathStar's theories, explosive detonation in the exhaust, he called it. My experience is that the popcorn/rattle does NOT occur when the exhaust system is cold at startup, but then as the exhaust system gets hot, the popcorn/rattle is easily heard. I can hear the popcorn/rattle best when sitting in stop and go traffic where there's a curb or jersey barrier next to the car.
I guess my problems with the noise are:
1) Why do folks with RX-8 MT's never hear it. The engine is the same. Is the AT PCM messing with the fuel mixture alot more because of the shift timing calculations? I hear more popping before and after the auto tranny shifts, like it trying to correct the fuel mixture constantly.
2) It would seem like the fuel popping in the exhaust would burn the system up faster.
3) My RX-8 AT just turned over 20K. I can definitely smell sulfur stink when I start the car in the morning and then back out. Isn't the sulfur stink smell a sign that the CAT is not working?
4) I get great power response on hard take offs, easily going all the way to redline. I've logged actual gas millage at 14-16MPG in the city and 23-25MPH on the highway. Oil consumption is steady at 1 quart per every 1200-1500 miles.
5) My 2005 Group 2 RX-8 AT has had no recalls until this recent vacuum test recall. I live in Boston metro area so hot weather wear and tear is not an issue really.
6) So should I even care?
#121 of 143 Re: Popping Exhaust Noise [trispec]
Oct 22, 2006 (7:43 am)
A couple of things.
First, the RX-8 is set up to inject extra fuel (the idea is unburnt fuel) into the exhaust to keep the cat hot. I have heard the noise on a manual RX-8, it's just often drowned out by the transmission on the manual (it whines a bit and the syncros sound like a turbo spooling up at times).
The sulphur smell is caused by the sulphur in the fuel you're using. It's not really an indication of a dead cat. converter. I found I could minimize the smell by using the 10% ethanol fuel in the past. I suspect the ethanol fuel may have had less sulphur in it, but not because of the ethanol, just because it was made at a different refinery. I think shortly all fuel will have ethanol in it, and hopefully less sulphur as well due to changes in govt. regs. The fuels with higher sulphur content may be a cause of destruction of O2 sensors.
It sounds like your RX-8 is pretty healthy. Near perfect oil comsumption, normal fuel consumption. Keep your fingers crossed.
#122 of 143 Re: Popping Exhaust Noise [pathstar1]
Oct 23, 2006 (2:35 am)
Thanks PathStar. I should have realized that the cat would probably have dashboard indicator like the O2 sensor, if there was a failure.
I'll watch out for some ethanol. I haven't used anything less than 93 Octane for months now, but the sulfur stink is very minor at this point.
I still love my RX-8 AT. Just got to remember to relax and enjoy. Thanks once again.
#123 of 143 Re: Popping Exhaust Noise [trispec]
Oct 23, 2006 (6:40 am)
Your car has an O2 sensor before and another after the cat. It monitors both, the one before to set the fuel injectors in "closed loop" mode (it adjusts on the fly), and the one after is there both to monitor the temp. of the cat and to determine that it's working.
Just for info. and not related to this, the car also operates in "open loop" mode. Here it just uses the fuel values from a table in memory. This is usually used under open throttle conditions, though modern cars are starting to use "closed loop" mode there too - a wonderful turn of events. Inexpensive car computers (called a PCM in the RX-8) are getting powerful!