Unlimiting Top Speed?
 

I was just wondering if anyone had any info on taking the limiter off of the top speed? Not that I drive that fast or anything! ;)

The biggest issue with that is going to be not having the power to go any faster. If you can hit the speed limiter now, I'll bet it takes you a while to get there. Since drag goes up with the square of the speed, you'll be out of power to go much faster.

What speed limiter? Maurice has gone.. well, very fast, without hitting any speed limiter.

I don't believe the US cars have a speed limiter. None of the US RX-7's did. Australian and Japanese cars are another matter, though.

Dale

people say there's one at 147, but i think thats just where the car tops out by drag. ive hit it before, and it's not a limiter, the car just doesnt go any faster

next time your low fuel light is on, go out for a top speed run. at 120 the limiter will kick in, and you'll know what a limiter feels like. what happens at 147 is very different.

I've been doing various searches on the specifications of the RX8, compiling the data (for personal satisfaction), and the following information is what I have found, which leads me to the original question in the form I should have asked it... Is there a way to remove the limiter. I've gotten mine up to 148 and I feel that it has the potential to go faster, though it may not be much.

Please excuse the crudeness of the following info, I can't remember where I got it from, but when I do I will post it! The info is a cut and paste job, from the source, to my personal files, to here, so it is and can be quoted!

60-0 Braking-------114.00 ft
Top Speed----------148.00 mph (ELECTRONICALLY LIMITED)
Slalom---------------65.40 mph (700-ft. Slalom)
1/4 Mile-------------14.50 sec
0-50-----------------4.50 sec
Idle------------------47.00 dBA
80-0 Braking-------202.00 ft
1st Gear------------76.00 dBA
70 mph Cruising--72.00 dBA
0-60-----------------5.90 sec
0-70-----------------8.00 sec

I remember the limiter being discussed in another post.

one gear, either 5th or 6th is drag limited, the other is electronically limited

something like that

is it so important to be able to go that extra 5 or so mph anyway?

148 or whatever is plenty fast ... it's probably not worth exploring really

on a side note, I remember reading about the Bentley Continental GT going 200mph on a closed course ... they said the tires could take 20 minutes or something of going at that speed, but you couldn't really turn, and the bentley only carries enough fuel to go at that speed for 13 minutes or something

top speed is really not worth it, the Carrera GT's top speed is something like 160, still plenty fast

I've done a hair over 140 in the Rx8.. does it really need a limiter? It doesn't exactly have a lot of pull up there to begin with...

Redline in 5th gear is 148 mph. In 6th gear, it's supposedly electronically limited to 148 mph (=240 km/h).

Regards,
Gordon

Assuming folks are hitting this limit on Public roads.... I agree 148 is plenty fast enough. Even straight freeways have serious curves at that speed! Not that I would know :) :)

Besides, anyone can go fast, but can you go fast on the twisty roads? thats the challenge.

When I put the car on the dyno the first time it topped out at 9000RPM in 6th with 172 reading on the speedo. I firmly beleive it's just drag limited. I'll have a chance to try it out this saturday at Homestead :D

its rev limited in 5th gear to 148mph and drag limited in 6th gear to something a little less then that.

i thought the car maxed out by gearing at 187?

It may very much well be, but if it doesn't have the power to get there it doesn't really matter.

well, genom said he topped on a dyno at 172 at 9k in 6th gear. is that per the dyno or the car's speedometer? although, I suppose neither is very accurate.

Genom, thank you, that is the information, that I was looking for, a reading of the cars potential top speed, I just knew that it was higher than 148. I just wanted to know the cars top speed without limitations! I wanna thank everyone for their replies.

I love being part of this community!

Here's some practical real-world tips for more top speed...

1. Make it slick
Use lots of wax, make sure the car has a nice thick coat; a tossed rag should glide over the length of the car.

2. Engine Oil
Less is more. Siphon it out a bit so you're just above the bottom line on the dip stick. If you're using the LeMans car's oil, this should be easy to do; at $85/qt, you need to spare every drop.

3. Mind the gaps
Seal all gaps with tape including hood, windows, doors, and trunk. When leaving the house, have a friend/spouse "tape you in". It's difficult to tape the drivers door from the inside. It's inconvenient for commuting, but those extra 5-7MPH are worth it. Toss a roll of the tape in the trunk so a co-worker can tape you back in when you leave the office. Don't use too much tape or you may have to give Mazda roadside assistance a call.

4. Exhaust
A free-breathing exhaust system can provide the right sound and additional thrust at speed. Consider installation of an after-burning exhaust system. With a rotary engine, those unburnt hydrocarbons can be put to good use. Even if you don't live in CA, go with CARB-legal afterburning exhaust system.


Any idiot can go to Bonneville and drive their car all out on the salt flats. The streets demand extra precautions.

1. Medical
Duct Tape a Platinum Credit Card to your chest. Of course you should shave a good spot for this. The paramedics may not take your insurance, but VISA is accepted at ICUs across the country.

2. Money
Always carry about $5k cash in your car. This money will allow you to walk from jail after almost any non-fatal motor-vehicle violation in the country. It can also prevent jail, but that merits creativity on your own. The rear cup holders of the RX-8 fit two $2500 rolls of 20s quite nicely.

3. Plan for the Worst
You might consider informational tatoos. For example, my arms, legs, head, and torso all bear a unique tatooed serial number along with my blood type. Plan ahead and avoid operating room or funeral home mix-ups!

See below. Done today. Car had a little more and felt great. I almost wet myself.

I think you are misunderstanding this. The fact that Genom got a reading of 172 mph on the dyno only proves that the mythical "148 mph limiter" does not exist. If the limiter did exist it would not have let the rear wheels turn that fast, even on a dyno.

However, this doesn't mean the car can actually do 172 mph in real life. On the road its top speed would be limited by aerodynamic drag, unlike on a dyno where there is no drag. 148 mph is probably a reasonably accurate top speed, but it is not enforced by an electronic speed limiter.

buzzword..that post was priceless lol

From Genoms post I now understand that the Rx8 doesn't have a limiter, I guess I titled the thread wrong, but the info that Genom provided is exactly what I was looking for, an unlimited test of the cars actual top speed, without drag limitations, and proving or disproving that the car has an ELECTRONIC LIMITER.

buzzwordenabled, I love the post, I'm gonna cut and paste it into my personal computer files under Favorite quotes!

You also recieve Architechs "Most creative post of the day" award! J/K :D

Epitrochoid I agree...


"Adding 10 psi to rear tires of the RX8... $ .50

1 quart of 5W-20 oil... $2.99

Half of a tank of gas for the RX8, in Cleveland, Ohio... $15.00

Buzzwordenableds post on the unlimiting top speed thread... Pricele$$"

There are some things in life money can buy...
For everything else, there's the word of special individuals with a sense of humor!

genius :D

Mazda doesn't even mention any speed limiter at all. All they say on their catalogs and magazine ads is this "drag limited" next to the stated max speed.

Some cars would say something else that would describe that there is something mechanical that limits your speed.

So if the RX-8's speed is in fact limited, and we remove the limiter, I'm assuming near-lightspeed velocities would be at least theoretically possible, yes?

If you have a nearly inifinite supply of power, sure.