## jet powerd car

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racketmotorman
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### re: jet powerd car

Hi Guys
Time for some rough maths ,its been 40 years since I was at school so correct me if I'm wrong. No wind or rolling resistance included :-)

At present you cover 1320 in 17.2 secs ,
Now distance travelled equals, half acceleration, times, the time squared.
1320= 0.5 X A X 17.2 X 17.2 or 8.923 ft/s/s

if you want to do it in 9 secs
1320 =0.5X A X 9 X 9 OR 32.59 ft/s/s some 3.65 times greater.

Now Force ( thrust) equals weight times acceleration divided by gravity .
At present , assuming 2500lbs weight and 8.923 accel div 32.2 =692 lbs

If you have the same 2500 lbs and 32.59 accel div 32.2 =2500 lbs

As I said in my previous posting , you'll need at least 2,000 lbs of thrust , and I've neglected rolling and wind resistance in my calculations .

Forget the idea of just sticking a coupla 100 pounders onto your auto and hoping to do 10 sec quarters , the physics simply won't allow it ,even with the 102 hp helping her along .
As I also said in my previous posting , you need the lightest and slippriest vehicle possible with thrust only .
Cheers
John

El-Kablooey
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### re: jet powerd car

No, a couple of 100 pounders wouldn't do do 10 second quarters on a super-light go-kart frame.
On an endless quest in search of a better way.

xxbgxx
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### re: jet powerd car

hi all

Rocket.. and Mk
that's why i said that i wantÂ  the car to run in both a piston engine and a jet engine!
and the 2500lbs is carried by wheel!!!so you need less power to move it,Â  and anther thing that when the car is moving by a speedÂ  the weight of the car become less because the gravity become less

El-Kablooeyr thanks for the good comment i will not change my mind about this project and am gonna take my time doing it.
i actually thought of using valueless engine but the problem that i read that the sound they make is much louder than a f-16 so they will not let me use it in any race because its too noisy

and valve engines i have to change the valve if race and you know its hard after every race to open the jet engine and change the valve because the the time

so i have only the pressure jet and the turbo jet and the rocket jet
turbo jets are soo expansive and need to be rebuild>>>>>
i have no idea how the rocket engine works and i guess its not safe because no one build a oneÂ  and its a one time use>>>
so i only have the pressure jet
and yhea man it will be something unique you know and can

hi luc
if you are right about losing the thrust in the process i can easily to fix this problem buy change the gear to the N mode after i get a good speed so the engine will be disconnect and the car run by the p-engine or i can change the gear ratio for the 4th or the 5th to a higher ratio 1:4.0

i thought of using big turbo and n2o and intercooler......
but my chance or anyone who is new in the game to win ONCEÂ  is 0% because most of the guys have cars with V12 or big block V8 that give 500hp and can take 250Hp of nos and don't forget the turboÂ  or they have great stock cars like Ferrari.
and i hope you 3rd g of the p jet doesn't cost allot of \$\$\$
Last edited by xxbgxx on Fri Aug 12, 2005 10:10 am, edited 6 times in total.

racketmotorman
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### re: jet powerd car

Hi xxbgxx
The fact that the car is still rolling along on its wheels doesn't mean that the gravity component of the formula gets any less , it doesn't , neither does the "weight" of the car at speed ,
If the air resistance at high speeds were taken into account , you'd need a huge amount more thrust than 2,000 lbs .
The cost of making a 2,000 lbs thrust engine, of any configuration, is going to be enormous , so the simple answer is going to be, lower the weight of the vehicle , get it down to 500 lbs, and you might have some hope of making something up at a reasonable cost .
My turbine kart , with a homemade engine driving a freepower turbine , gave 160 lbs of "pull" when the freepower was stalled and the gas producer at full power , total weight of kart with me on board was 473 lbs , time to get to 60 mph was 7.5 seconds and distance covered 110 yds , ( this equates to a roughly 15 sec quarter) the theory says I need 171 lbs of "thrust" to do my times ,this could have been the case as there would have been some minor change to the freepower turbines output once it started to rotate .

You will need massive amounts of thrust , so expect to pay the price ,if you want to do 10 sec quarters , there simply ain't no cheap way of doing it.
Cheers
John

xxbgxx
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### re: jet powerd car

hi all
John
i dont know if you read what i said befor or not but i dont want to build a jet kart or a jet powerd car i want to build a car with a jet and a piston engines like the hybird car
now you said the car should be 227kg(500lbs) with out me (57kg,126lbs) now any small car with a engi ne weights 1000kg(2500lbs) with every thing on it,if i get rid of every thing (seats,doors,hood,any extra stuff but keep te engine)and replace it with a fiber glass doors and a hood with will be arounde 1800lbs and am not going to replace the car body with a fiber glass one because i dont want to die x) ,
and the engine will be more usefull than u think because when the engine gets more power from the outside it have to turn more than it can so it will burn more gas an when it starts burning more gas it will make more power
now your kart start so slowly right? then become faster and faster(high top speed and low acclertion) even the same with a airplane with 4 turbo engines because as someone said befor its like trying to move the car in the 4th gear it will move but it will take forever

and this is a piston engine(low top speed but high acclertion)

so if u use them both you will have both of them
and am not the one who made this idea because in the Aircraft Carriers the distance is 2 short for the poilts to take of so the Carrier have a track with a build in engine so it give the plane enof acclertion to take off

since you have a jet powerd kart try to install a small piston engine (the one they use in small generators or an old scotor)50cc and tell us the diffrenc and we will know whos right and whos wronge ok?

Ben
its not about the kind of jet but someone wrote the a valveless jet is louder than the f-16 so i thought that it can make hearing problem to the people around,but if it doesnt its ok.

and does the steam rocket give high thurst?
if yes where i can get plans,or kits?
Luc said something about a 3g of P.jet but nothing new from him

luc
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### Re: re: jet powerd car

Hi xxbgxx,
xxbgxx wrote:hi all
the Aircraft Carriers the distance is 2 short for the poilts to take of so the Carrier have a track with a build in engine so it give the plane enof acclertion to take off
It is not a built in engine XX, it is a steam piston catapult. They us it to accelerate the planes in they areas of 150 knots and this same steam piston catapult is also used with the arrester cables for plane landing and recivery.
Luc said something about a 3g of P.jet but nothing new from him
I am here and watching. For now, I have nothing to had, for the debate is still quit active in establishing what engine you should use. As for our self, we said what was important to say. Now, the ball is in your hand and we are waiting that you make your choice. Viv and I can only help you with a pressure jet use and as much as we can if you use another engine type.

As for the 3rd generation pressure jet. It would be useless for us to say more about it, because the engine is in production, it will be the first of its kind, but what we beleive it will do is still pure assumptions for these are unprooven yet. So, no need to debate on that until the engine does what it should do.

So, we are still here and reading. As things will move on our side, we will keep you guys posted ... Don't worry.

Regards,

Luc

xxbgxx
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### re: jet powerd car

hi all
thanx alot man but am gonna take some time to start because summer is over soon x( and i have to register for to the colloge,and the rest of the blah blah blah>>

and am gonna take some time to train on useing some tools that am suxs at like the Welder so i hope that the admin make this topic sticky so i post my progress
and am waiting for wht gonna happen with racketmotorman and his kart when he install a small piston engine

so can you help me luc by sending me a a full plan for a good first g or 2g for p.jet and a valveless jet becaue all the plans i found is only one picture and you can get whats on it so most of them are useless
my email is xxbgxx@hotmail.com

luc
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### Re: re: jet powerd car

Hi xxbgxx,
xxbgxx wrote:hi all
so can you help me luc by sending me a a full plan for a good first g or 2g for p.jet and a valveless jet becaue all the plans i found is only one picture and you can get whats on it so most of them are useless
my email is xxbgxx@hotmail.com
Heyyy mate ... We are a buisness remember. I am not gonna send you all the 1st generation pressure jet engine plans, just for the sake of it. This is time consuming, not all the plans have been release from copyrights and we usually send 1 free set of plan for one major pressure jet component purchase.

The 2nd generation pressure jets drawings are not available yet, as we only sell the engines or the parts to build your own.

As the 3rd generation pressure jets will become available, the 1st and 2nd generations will be release to the public, under our forum. But even there, to do a final set of drawings for each 8 engines, takes alot of time and unless you can provide me with a free draftman here, we are not in a situation where we can put 3 full weeks of works in those.

Make up your mind first, select one engine type and them we will see what we can do.

Regards,

Luc

racketmotorman
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### re: jet powerd car

Hi xxbgxx
You're not listening to what I'm saying because you have your heart set on having jet power , I've been playing with and designing my own homebuilt jet engines for going on 14 years now , so please listen to what I'm telling you , I know what I'm taking about , go to this link and have a look at my turbine bike and kart , and turn the volume up on the vids http://www.nickhaddock.co.uk/jetgallery.htm
The bike does 12 sec quarters at 120 mph with only one gear , no clutch and has a theoretical 140 hp at 33,000 rpm of the freepower turbine .
The engine in the kart is a freepower turbine engine also, and if you know anything about freepower turbines you'll understand their torque multiplication characteristics which does away with the need for a gearbox , the karts engine is approx 30 hp at only 15,000 rpm and has 1.1 lbs/sec of gas going thru it starting at 10psi total pressure , a lot more than any "pissy" little scooter engine,.
I'd suggest you get some physics books out and do the maths if your not prepared to listen to reason.
Pigheadedness will not get you doing 10 second quarters :-))

Cheers
John

luc
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### Re: re: jet powerd car

Hi Racketmotorman,
racketmotorman wrote:Hi xxbgxx
You're not listening to what I'm saying because you have your heart set on having jet power , I've been playing with and designing my own homebuilt jet engines for going on 14 years now , so please listen to what I'm telling you , I know what I'm taking about , go to this link and have a look at my turbine bike and kart , and turn the volume up on the vids http://www.nickhaddock.co.uk/jetgallery.htm
The bike does 12 sec quarters at 120 mph with only one gear , no clutch and has a theoretical 140 hp at 33,000 rpm of the freepower turbine .
The engine in the kart is a freepower turbine engine also, and if you know anything about freepower turbines you'll understand their torque multiplication characteristics which does away with the need for a gearbox , the karts engine is approx 30 hp at only 15,000 rpm and has 1.1 lbs/sec of gas going thru it starting at 10psi total pressure , a lot more than any "pissy" little scooter engine,.
I'd suggest you get some physics books out and do the maths if your not prepared to listen to reason.
Pigheadedness will not get you doing 10 second quarters :-))

Cheers
John
Heyyyyy .... Mate, cool down buddy. He is just trying to see through all this, as he is obviously not an expert in that matter, I am sure it is not easy for him.

For my self, it is not because someone would tell me "Listen what I am saying", that I would blindly swallow everything this guy says. Multiple opinions is always better then just one.

As for my self, being an ex jet engine mechanic and well aware what a "Free Power Turbine" is, I still have a hard time figuring out what you are trying to say or where you are getting at.

Also, you can't compare gas turbine engines with pulse jet engines, as their specific exhaust gas characteristics are totally different, for the same rated thrust. The gas turbines relly mostly on air mass displacement where the pulse jets generate exhaust gas at much higher velocity. A pulse jet (valveless or pressure jet) could probably reach supersonic speeds much faster and easier then a turbine could.

Go easy on this new guy and allow him time to understand it all.

Regards,

Luc

racketmotorman
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### re: jet powerd car

Hi Luc
LOL :-)).....Sorry if it came across that way ,cross cultural thing , us Aussies can be a bit "blunt" at times :-))
I'm just trying to save him a lot of time, effort, money and heartache .
The maths didn't convince him , so I tried conveying some of my experience , if this doesn't work, then all I can say is "good luck mate", you'll be needing it if you want to bend the laws of physics .
What I was trying to get across with the reference to the freepower usage as compared with his suggestion to use a small IC engine to increase my power , is the fact that there is a torque multiplication when the freepower is stalled ( eg at takeoff) and the gas generator is running full bore, compared with the torque from the freepower at its full rpm , about a 2-2.5 :1 ratio of multiplication , this "extra" torque at takeoff will produce extra force ("thrust" ) exactly the same as using a gearbox on an IC engine for better acceleration .
The kart gave 160 lbs of drawbar pull when static , this can be compared with a pure thrust engine of 160 lbs static, propelling a vehicle weighing less than 500 lbs allup weight , its pretty poor acceleration , if you extrapolate out a bit for his allup weight some 5 times greater he'd need 800 lbs of thrust for only a 15 sec, (or longer) ,quarter mile, if only using thrust .

I'm not too certain about the difference between "normal" gas turbine exhaust velocities and pulse jet velocities , the gas producer "engine" I
used in both the bike and the kart , when in its development as a pure jet engine had a jet exhaust velocity of around 1850 ft/sec and produced 110 lbs of thrust thru a 78 mm dia jet nozzle , thats high velocity , at one stage of development I had 15 psi of total pressure (29.7 psia) in the jetpipe at 800 C , the gas producer was running a 4:1 pressure ratio.
Whichever way you look at it , to get a vehicle to go in one direction you need something going in the other when talking pure "jet engines" , the "average" thrust or force is what matters and he's going to need an enormous amount to shift a ton of steel over a quarter mile in 10 seconds whether applied constantly or in pulses.

Whilst on the subject of PJ exhaust velocities , I'm currently designing up the freepower turbine that I'll be sticking on the end of a PJ and it would be helpful to know the sort of velocities to expect from a valved engine of a nominal 50 lbs thrust , currently designing for around 1000 ft/sec .
I still have't decided on what PJ I'll build , but the freepower shafting and gearing along with the prop setup already constructed are looking good.
Cheers
John

xxbgxx
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### re: jet powerd car

hi all
luc ok i will wait until u make ur 3g of plans and then we can make a deal on one off them you have my email so when you are ready send me

racketmotorman
man give me a break yhea your right i suxs on physics but there is no need for using such a words i dont know but maybe you studied engineering so they teach this stuff! but man i study medicine so its hard for me to know all this stuff

ok i will forget about the "jet-piston engine car"
it will be easier to drive anyway

so i have have a car that weights 600lbs with me what is my chances?

xxbgxx
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### Re: re: jet powerd car

I still have a hard time figuring out what you are trying to say or where you are getting at.
me 2!

racketmotorman
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### re: jet powerd car

Hi xxbgxx
I left school as a 16 year old back in about '63 , and haven't studied engineering , this is simply a hobby that I know a bit about and enjoy tinkering with in my retirement , I didn't know much about the subject either when I started 14 years ago , but after teaching myself by reading the books , I feel I've got a bit of a grasp on it by now :-))

Which part don't you understand , ??

I'll put in in simpler terms for you to understand , if it'll help to convince you to go in a different direction , thrust is great for high speeds but not so good for acceleration.
When the first fighter aircraft were equiped with pure jet engines ( not fan engines) back in the 1950's there were a lot of accidents because pilots were use to piston engines driving 12 foot dia props with lotsa grunt and short takeoffs , but the jets were slow and took forever to get airbourn , sometimes they got caught in a sort of "no mans land " , just airbourn but not able to climb out and simply crashed off the end of the runway , but at 30,000 feet it was a different story the jets were fast and sleek, a completely different animal , much better than the prop jobs .
Its simply horses for courses .
Cheers
John

xxbgxx
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### re: jet powerd car

hi John
now i got you point that i cant use a full car

but i can start by useing very light frame and i fiber glass body and me =374lbs and use 4 lockwood engines x 187.5lbs each then i will have a ratio of 2:1
then when Luc make is 3rd g of p-jet i will use it

its not important that i get the 10 seconds in the first time you know i can get beter by time like you did!

and guys does anyone know where i can get steam rocket plans?