Tires? Speed?

Does anyone know any good extremely high speed/performance tires. Anything that can handle around 205 - 220 mph? That are Dot approved also.

i'd start looking at pirelli's website
they are known as the high performance tire brand

it truly depends on your application though.
any details?

The highest DOT rated tire is "Y" which is good for 186 mph. Keep in mind that the ratings are done on a static dyno which measures tire deflection at speed, so different manufacturers all have different actual speeds at which they fly apart into little shards of death.

Non-DOT road race tires can take a little more than that, but not much. If you think about it, you're talking about speeds that are higher than NASCAR and even they blow a few during a 500-mile race. If you're just looking for street tires, non-DOT race tires will slip past 99% of the cops out there, but they are terrible street tires. They don't perform unless they're at temperature and any hint of rain they tuck tail and put you into a curb. If you need race tires that require DOT, you're not in a race class where anything more than about 120 mph is even possible.

I guess this begs the question... why? What car do you have that can beat 200 mph and where on earth will you ever see those speeds?

The highest I ever bought was for my wife's Buick, they were BF Goodrich T/A radials "S" rated to 130 I believe.

Why do they have to be DOT approved? If you plan on going that fast, who cares? You are definitely into the realm of a pure racing application tire anyway.

I had some leftover Hoosier stock tires that I used on once a street car, they had a DOT rating and were treaded. They had a ton of side bite and my '65 Belair cornered like a Lotus (almost). They did wear out after 2 weeks of such abuse.

Bob

Jw ~ I guess my friends 512 Rwhp single Fd got up to 212mph on a veryyy long highway upstate N.Y around the binghampton area. I was wondering what the hell tire's could he have used?

http://videos.streetfire.net/video/wm/9fccb6ad-b8dd-436c-b883-1cca64798506.htm

Btw ~ Upstate there is no one (cows thats about it) around and the most insane roads...

I was thinking about the advan A048's which most track Fd's have. I would not be suprised if Igor has them too :)

Its possible he used generic touring rubber for all we know. Speed rating isn't a magical number where the tire explodes :) He just took insane risks.

And I also don't buy the 212 mph... not with 500 rwhp in an RX7. I'd buy it at 650 rwhp, but they create way too much downforce to make 200 at those power levels. I give it 175 mph tops.

Translated, he did a gear swap and shot the footage before changing the speedo. Take a look at the trees at the end of the video; they're not moving 200 mph... 100 maybe, but that movie screams fake from the beginning to the end. Jeez I hate the bull that the bad ricers try to pull. That movie is like a big sticker; they think that by falsely making things LOOK impressive that we might mistake it for something that actually IS impressive. 500 to the wheels is no slouch, but that movie makes me want to vomit.

Have him call me when he can make 1200 hp and 2131 lb-ft to the wheels in a daily driver using transesterified grease from McDonalds. Then he can race me and we'll see who comes out on top :)

When people run speed trials they use GPS-based speed monitoring equipment. Speedos really aren't that accurate over the ~120mph mark. and 212mph in a stock-bodies 512bhp RX-7? can't see it. i think he's pulling your leg.

Have him call me when he can make 1200 hp and 2131 lb-ft to the wheels in a daily driver using transesterified grease from McDonalds. Then he can race me and we'll see who comes out on top :)

I know of a Cummins over here making more than that. (nope, not joking.)

Hmmmmm, 300kph in a 500hp RX7?

Yeah, I actually think its possible, as in its with the limits of the car on the right road.
Unfortunately that Video really does have a large dose of the Wank Factor.
Not saying it didn't happen, but if it did then there was more luck than driver skill involved, and had they tried to maintain it over any standing distance there is too high a chance something fatal would have gone wrong.
A crash at that sort of speed makes a really, really big mess.
(also note: he only claims its 197mph taken from some kind of data logger or after market controller).


The Current NZ Land Speed record stands at just over 300kph: http://www.motorsport.org.nz/Awards/records.htm
And Several attempts have been made to beat it: http://www.mx5club.org.nz/news/mazda_news/010200_300kph/

The problem is not getting enough power out of the cars, or even finding tyres that can stand up to that sort of speed, its keeping the cars stable at that sort of speed on a public road for the 1km distance needed to break the record.

While I don't doubt many US roads are better than NZ roads, do you really want to trust your life to them at these sorts of speeds? Because even a small bump will kill you.
Which would explain why as soon as he hit the end of the gauge he buttoned off, and it sounds like, started braking.

FD's create downforce but not as much as you think. If they did create that much to detur them from 300 kph why would all these high downforce kit's be made for the FD? He has no wing or maybe the stock was on which does no create downforce or any significan number anyways. The kit he has on is a C-west with a 99 front end so no canards or anything just streamlined. I completely believe that he could hit 300 kph around 200mph very easily. Also I'm sure he has a new gear ratio in that because stock Fd's top out at 168 ;)

Have him call me when he can make 1200 hp and 2131 lb-ft to the wheels in a daily driver using transesterified grease from McDonalds. Then he can race me and we'll see who comes out on top :)
The most I've seen is a 45 year olds 3 rotor (20B) with a single Turbo Gt42R (Divided 1.32 :licka:) making 1259rwhp @ 8psi. I honestly think he can go to 15lbs no problem the engine was bridge ported an 3mm seals.

I'll see if I can find the pic of the probably the most powerfull rotary made yet. Tri-turbo T51-SPL'd 20B 3mm don't know the port though.

Moppie ~ We have the fastest speeding ticket in the world. (top gear states it) 242mph in texas by a Koenigsegg CCR.

300km/h = 186 miles/hour

200 miles/hour = 321 km/h.

The difference may not sound like much, but power requirements rise with the cube of speed.
To get to 321km/h takes about 23% more power. If you've already got 500hp and make 300km/h, then you'll need over 600hp to get to 321km/h.

300km/h = 186 miles/hour

200 miles/hour = 321 km/h.

The difference may not sound like much, but power requirements rise with the cube of speed.
To get to 321km/h takes about 23% more power. If you've already got 500hp and make 300km/h, then you'll need over 600hp to get to 321km/h.
I've seen 400 rwhp FD's easily make it to stock max speed and with gearing hit 180 mph. That car is light as it is, not to mention seats and other things done. 500 certainly seems enough to hit 200 mph. The stock C6 is 442rwhp an it easily makes it to 190 mph and it weighs 3191.

i trust he has a roll cage and all that?

I've seen 400 rwhp FD's easily make it to stock max speed and with gearing hit 180 mph. That car is light as it is, not to mention seats and other things done. 500 certainly seems enough to hit 200 mph. The stock C6 is 442rwhp an it easily makes it to 190 mph and it weighs 3191.

Weight doesn't really matter to topspeed. It's all about aerodynamics.
Having low enough drag, while also having enough downforce for the traction needed.

Unless your car has a CdA the same or lower than a C6, the comparison is pointless.

i trust he has a roll cage and all that?

Obviously, I don't know if you can see it in the video but even at 200 mph it's highly unlikely the rollcage will do anything to protect him.

you'd be surprised. of course, if he's doing 200mph on a Jersey highway and he loses control, he's more likely to hit something.

people over here often use Bruntingthorpe Proving Ground (straight 2-mile airfield) because it's long, safe and there's nothing to hit.

The roads upstate can range from 2-15 miles long of very straight roads. By my school the road is about 4.5 miles long with almost no turns what so ever. It's all interstates really.

Weight doesn't affect top speed. An getting a car from 180 to 200 takes A LOT more power than you think. I forget the numbers, but doubling top speed takes something like tenfold the power, so increasing the top speed by 10% might take 50% more power.

its a formula of sorts

i found a website that explained it very well once
here is a satisfactory one

http://www.pumaracing.co.uk/TOPSPEED.htm
and here is a "calcualator" of sorts
http://www.robrobinette.com/top_speed.htm

Thanks man but it leaves out aerodynamic factors. Other then that it seems pretty right.

no it doesnt.
drag coefficient is a constant.

when your car is drag limited to a specific speed, and you increase the hp, the car will go faster.
the coefficient of drag wont change, so as long as you know the fastest speed you can possibly go in your car on level ground, it is correct.

Sorry missed the tags thats robinette aka one of the top Rx7 guru's out there.

I'm adding the spoiler adding a diffuser (side generators as well), lip (won't do much) and maybe a new front bumper depending on the cooling layout I want to do. + The car is getting a fullbody FRP undertray and is being lowered 2.5 - 3.5 inches depends they are adjustable so...

http://dreamzsport.com/JohnnyFD3s.jpg

The wing actually generates downforce depending on the set angle of course...

Also depends on the temparature (heatsoak/cool air = alot more hp) and air density as well.

Sorry missed the tags thats robinette aka one of the top Rx7 guru's out there.

I'm adding the spoiler adding a diffuser (side generators as well), lip (won't do much) and maybe a new front bumper depending on the cooling layout I want to do. + The car is getting a fullbody FRP undertray and is being lowered 2.5 - 3.5 inches depends they are adjustable so...

The wing actually generates downforce depending on the set angle of course...

Also depends on the temparature (heatsoak/cool air = alot more hp) and air density as well.

A rear spoiler generating downforce will create more drag.
Lowering your car will also create more drag.

I think you need a better technical advisor.:grinyes:

A rear spoiler generating downforce will create more drag.
Lowering your car will also create more drag.

I think you need a better technical advisor.:grinyes:

I know the wing will create more drag, only if it's angled to generate :wink:

How will lowering the car create more drag? That just means less space for air to travel under the car. The surface area is still the same.

I know the wing will create more drag, only if it's angled to generate :wink:

How will lowering the car create more drag? That just means less space for air to travel under the car. The surface area is still the same.

Less space for air means more interference between the two surfaces. In this case the bottom of the car and the road.

Your wing is going to drag regardless of how you have it set. I have seen CFD plots of splitter wings which can reduce drag, The photo you show is not one of them.

the spoiler will create drag no matter how it's angled, changing the angle will increase or decrease the drag but it will always create drag (unless it's in an area untouched by oncoming air in which case it won't create downforce).

is the undertray a cover for the underside of the care that makes it smooth? if so it'll create downforce and you'll have more rolling resistance which will create more drag (not aerodynamic drag though)

edit: i didn't see the above post because i left this window open and only just got to it now.

how would a wing reduce drag?

the other reason that lowering the car will decrease your speed is that as you lower the car, there is more low pressure created under the car.
especially if you have a body kit with a front lip.

all this low pressure will create a vacuum and turbulence under the car.
turbulence is never a good thing when you want to go as fast as possible.

how would a wing reduce drag?
I'm not saying the wing would reduce drag lmao. (Yes, I was wrong for stating that it would not effect the drag) I know that anything that is mounted onto a car will always create some drag/air resistance unless it's removed....

How would a completely smooth FRP undertray create drag??? It creates a smooth surface for the air to travel against at highspeeds instead air flying into the tranny tunnel, Diff, etc. Also how would it create downforce? The panel is completely sealed to the body no air will duct down on to it if thats what your thinking. I see your point of lowering = a tighter friction space for air to travel. I would still rather have more friction then having air get under the body and me paying the ultimate price like the racing beat Rx7 did. I know turbulent air will decrease the speed overall.

Now here's a question I've been wondering does torque play a huge roll in topend or is it all horsepower that really matters at those speeds?

Btw ~ Stock kit with a stock FRP lip.

back to the original question, tire speed ratings are for *sustained* speeds. All tires can go beyond their speed rating safely, but are not recommended for long runs at higher speeds. no one will define the time before safety is a concern, but it is much longer than most people would spend at higher speeds typically

This is why, for example, drag race tires would never survive a sustained high speed, but can see extremely high speeds safely for short distances

As for drag:

http://www.hotrod.com/techarticles/hdrp_0609_aero_tricks_tips/

I'm not saying the wing would reduce drag lmao. (Yes, I was wrong for stating that it would not effect the drag) I know that anything that is mounted onto a car will always create some drag/air resistance unless it's removed....
i was actually referring to kiwi's post about how he knows of a wing that will decrease drag.

How would a completely smooth FRP undertray create drag??? because it's smoother so the air can travel much faster. it's like a wing, the air on top of the wing is traveling faster so it creates lift, the air under your car will travel faster so it will create downforce.