Klaudio prela

Hi I was wondering if using a stock rx8 engine and drive train in a go kart could take the go kart to 200 mph. Any advise is welcome
Thanks

khaira93

O.o

Klaudio prela

I was on another forum and they said that they didn't like me and said they didn't think it would work because I am just a student but I probably have a higher iq than all of their's put together so I figured out they were picking on me because in shear power to weight ratio the go kart will a have more than 1100 hp per tonne more than double of a bugatti, it will have a low drag coefficient because it will be so low. Also using a bit of physics going to 200 mph will take 8 times of the power of that same vehicle to go 100 mph. A 200 kg go kart would need 20-30 hp to reach 100 so if you times 25 by 8 which is 200hp and if we do it we will be using a k and n cold air intake so it will bring the hp to 240 which in theory should be plenty. We will be using pirelli p1 on the car's rims because we would also be using a rx8 rear axle so we can put on real tires that can do 200mph. Suggestions?

Klaudio prela

I meant to say pirelli p zero or drag radials from hoosier

yiksing

A stock RX-8 has no problem hitting 160mph, I think its possible to hit 200 mph assuming go kart like weight but the biggest hurdle is not power, its how to stay planted when going from 100mph to 200mph and how to stop safely.

Klaudio prela

The go kart will have very sticky rear tires to begin with then we are going to be very low to the ground with a low centre of gravity, furthermore we be making the design of the go kart as slippery through the air as possible which means we will have to fabricate some sort of bonnet so that the transition from the go kart bumper to the engine is as smooth as possible. We will be using front brakes from a yamaha superbike and vented and drilled discs. There is a possibility we might use a parachute but since we will be testing it on a runway, we should have plenty of space to slow down. As for safety we will install a kill switch and incorporate a four point harness on the carbon-kevlar seat. The driver will be wearing a full motorbike leathers and pads.

DAT2RTR

I'll entertain insanity for a couple minutes

Why do you need very sticky tires if you're going to be on a prepared runway? Especially with a motor that has ~140wtq You're not building a quarter mile car. Low to the ground compared to what? An rx8? You're going to have to fabricate, EVERYTHING. Most front disc brakes are vented. Nobody in motorsports except for factory backed race teams use drilled rotors. Because they crack. Look up why they used to use drilled rotors. I like that you're thinking ahead. But parachutes will help more than "superbike" brakes. I'd assume that you would have a kill switch. 4 point harness? You need a 5 point minimum for most motorsports, with an antisubmarine strap. I hope you're putting a complete cage around this carbon kevlar seat. Or your driver is dead in the event of a crash. You sound like you're trying to build a standing mile go kart motorcycle that races quarter mile. Get a plan first. Get every detail down. Then talk to a fabricator. Also. Just because the rx8 is rated at 231 hp, does not mean that's what it puts out. It's hard to make over 200whp from an rx8 motor.

RIWWP

iTrader: (2)

Here are some thoughts for you, and I'm being completely serious and this is all well intentioned. Take it how you will:

Frankly, this doesn't get you anywhere on the internet, especially forums. Why? Because anyone can make any claims they want, so no one believes anything. You may well have a high IQ, but not only is that not everything, it isn't actually relevant to the problem at hand. I know some really really stupid smart people. People with high IQs that are functionally retarded because they can't figure out how to apply it to the real world. So drop the claims, it doesn't get you anywhere but harassment.



Actually, there is a lot more to drag than that. Frontal cross section is the biggest thing to calculate, which is why most really fast drag cars and top speed record cars are long and narrow. You have to package the entire drivetrain in as narrow a frame as possible, making it longer. Doable for sure. But then you also need to deal with the parasitic drag, friction drag, etc... It's all designable, and would be a cool project. But lots more to think about than height.

Also, some quick poking around found a 340hp kart that can just get past 200mph. So you are probably still 100hp off of what you need. You would be fast for sure... but 200mph? not likely at 200-230hp.


Um, you need some more research on the engine, and mods. If you take a 200hp RX-8 engine and install a K&N intake on it, you will end up with a 190hp engine, NOT a 240hp engine. K&N is one of the worst intake for the RX-8, and the stock intake is REALLY REALLY good. Even the BEST intake though, would only take it to about 203hp. Maybe. This is assuming that 200hp is 200 WHEEL horsepower, which is about what a healthy RX-8 makes. The engine itself at the crank is around 228-232, depending on who you ask. You could actually get fairly close to this with virtually no drivetrain to actually power, but again, this is assuming you only use the engine, and not the entire RX-8 drivetrain like you seem to imply. If you use just the engine though, you will have to design your own intake, because the stock (and other aftermarket intakes) are designed with the RX-8's engine bay packaging, none of which applies to a gokart. However, in theory, you could design a proper ram air intake (Think F1 intake scoop above the driver's head?) since you are designing everything from the ground up. Keep in mind that MAF scaling though. If you do't know what MAF scaling is, do some research on it. Or convert to a MAP based ECU. That might be simplier.

You don't need an RX-8's rear axle to get "Real tires that can do 200mph". There is a professional karting series that uses karts that hit 150-160mph i believe. They would have tires that can do it. I bet using that drivetrain hardware to build on is going to be cheaper and simplier than trying to convert an RX-8's far heavier and larger drivetrain to fit a tiny kart.

Don't forget about the entire package. There is a low pressure zone created right behind any object moving through the air, and this is one of the largest sources of drag, far larger than the amount of air being pushed aside by the nose.

Again, you need more mod research. If they aren't OEM (as in by the vehicle manufacturer) factory drilled, they will be prone to failure. All aftermarket drilled rotors are prone to failure. And the rotors aren't where your stopping power is, the pads are. You don't mention them, so I'm guessing that you really need to learn about brake pads too. More research for your IQ. But frankly, your braking capability can easily exceed your available grip by the tires. Even cheap pads and rotors can do that. Even on your specified tire. But even further, are you using brake proportioning? Do you know the front vs rear grip at 200mph? So you know how much braking force you can take on each axle? You DON'T want to be locking up the rears at 200mph... If you arte going to use ABS, you have a huge project ahead of you with testing and programming to get the sensor data being interpreted correctly.

And more frankness here...

If you think a kill switch, harness, and leathers and pads will do anything for a crash at 200mph, you need a wakeup call. Try a full cage. Try a better harness since 4-point is not acceptable by 100-120mph race series for a REASON. What about arm restraints? What about proper helmet? Head and neck restraints? If you want the driver to stay with the kart on a crash, you need to protect the driver entirely within the kart. Otherwise, you want to separate the driver as fast as possible, and then figure out how to save a bouncing and tumbling man. This isn't stuff to play around with.


It would be a cool project, but you have much much much learning ahead of you. Time to put that IQ of yours to work, because right now it's not being applied very well.

Klaudio prela

Hi thanks for the suggestions, I really appreciate them because the other forum was just so rude about it. I will try and follow up on as many suggestions I have received here however I might just have to choose a motorbike engine instead such as an R1 because I have been told it requires less work. Anyway thank you for the suggestions.

T_Mags

I sound like a broken record at times, but could use the same phrase to answer most automotive forum questions.

"If you have to ask, you aren't ready." Especially when the questions are super general and "how do I do xyz?"

9krpmrx8

iTrader: (46)

^ This.

Steve Dallas

O_o

Check out Formula Mazda. An FM car is as close as you can get to a kart with a Renesis power plant. You can buy a used one for around $20K, which is less than you would end up spending on building a custom kart. And, it will perform better and be far safer than anything you can build yourself. In any case, pretty much all the questions you have asked are answered in the design of those cars.


.

200.mph

iTrader: (9)

awesome, someone i dont know is building me a stoopid fast go kart. thanks man. why not use a superbike motor? its smaller and you could add a snail easier then to a renny

patjza80

LOL, thatd be prett sick.