

05182012, 11:24 AM

#12541

Crumple Zone Tester
Join Date: Jul 2009
Location: Jackson, MS
Posts: 7,429
Total Cats: 364

That car never should have gotten the 4EAT transmission (or, at least, it should have been upgraded appropriately). The combination of a weight, power, and insufficient cooling lead to premature death.
I've seen 5 spd swaps (someone was selling one here a year or two ago) but they aren't common.



05182012, 11:28 AM

#12542

Senior Member
Join Date: May 2005
Location: Mass.
Posts: 815
Total Cats: 41




05182012, 11:32 AM

#12543

Elite Member
Join Date: Oct 2008
Location: Seattle, Wa
Posts: 1,780
Total Cats: 28

UPGRADE!
Landed a job as a firmware engineer at a company here in Seattle. I'm super stoked, but I imagine this is how the first few weeks are going to go:



05182012, 12:16 PM

#12544

Elite Member
Join Date: Jun 2007
Location: Rochester, NY
Posts: 5,136
Total Cats: 294

Quote:
Originally Posted by thasac

Looks like fun. Must be wicked loud inside, though.



05182012, 12:51 PM

#12545

Boost Pope
Join Date: Sep 2005
Location: Chicago
Posts: 24,429
Total Cats: 1,528

Quote:
Originally Posted by olderguy
Dealers tell me it is discontinued. Anyone know where to buy one?

I replaced mine years ago using some random Garrett part that FM had lying around on their Deal of the Day. Essentially just cut off the end of the rod, threaded it, and made an adaptor to fit the WG arm. Then I fabricated a little adapter for the mounting bracket, and it all moreorless lined up. Never had to touch it again after installing it.
Unfortunately, I can't seem to find any pictures of the setup.



05182012, 01:48 PM

#12546

Senior Member
Join Date: May 2005
Location: Mass.
Posts: 815
Total Cats: 41

Quote:
Originally Posted by olderguy
Dealers tell me it is discontinued. Anyone know where to buy one?

Buy a Forge Mazdaspeed Protege Wastegate for less than <$135.
It fits perfectly and has the added bonus of being rebuildable and upgradeable (to a dual port WG). I haven't gotten my car up and running to confirm its function, however, friends who have used Forge WGs have seen significant increases in spool and creep control.
You'll have to make a new bracket OR chisel/pry/grind your old WG off the greddy bracket.
Zach



05202012, 03:25 PM

#12547

A living god
Join Date: Aug 2008
Location: Key West
Posts: 5,900
Total Cats: 220




05202012, 03:35 PM

#12548

Elite Member
Join Date: Jun 2007
Location: Rochester, NY
Posts: 5,136
Total Cats: 294

Holy cow. Talk about stepping on your own dick. They just alienated thousands of legitimate buyers, who will now seek to DL illegally, just to spite them.



05202012, 09:54 PM

#12549

Senior Member
Join Date: May 2011
Location: London,OH
Posts: 1,124
Total Cats: 12

got a random leak in the radiator



05212012, 05:04 PM

#12550

Boost Pope
Join Date: Sep 2005
Location: Chicago
Posts: 24,429
Total Cats: 1,528

I recently came across a set of plans on the web detailing how you can build a working ICBM out of matchstick heads and a length of PVC pipe.
It just won't work.
It's not really that surprising; I mean, an ICBM is defined as a missile with a range in excess of 5,500 km, or a little less than the distance from Washington, DC to London. Given the absurd distance involved, I don't think any sensible person would believe that you could really make a longrange solidfuel rocket by spending a few hundred bucks at Home Depot.
But what could you make?
An artillery rocket? An SRBM? Maybe even a halfdecent sounding rocket? Let's find out.
Some Physics
I'm going to do this from an energy argument, that being much easier than doing the complicated fluid dynamics, and given our jerry rigged rocket, probably as accurate as any other estimate. I'm going to make a few assumptions to simplify the math even further:  Ideal earth  I'm assuming a flat, nonrotating earth with no atmosphere and uniform gravity. This means no drag and no reentry heating. As long as we don't have a range greater than 1000 km, the flat/round earth assumption won't matter, and the "rotating earth" only adds range to your westbound travel.
 Ideal rocket  The missile in question will have a 10:1 length:diameter ratio, that being basically ideal (trust me on thisI'm an engineer). I'm going to assume a massless nozzle and a massless reentry vehicle, as well as a perfect guidance system with frictionless fins. This is a little excessive, but calculating air resistance is a drag.
 Ideal flight  An ICBM flying the minimumenergy trajectory describes a Keplerian ellipse, which can be approximated as a parabola. I'm assuming a vertical boost phase, followed by an instantaneous tipover to 45o at the instant before burnout.
So, onward with the math. First, the basic energy physics. Before launch, all we've got is the inherent chemical energy of the fuel
Elaunch = Echem
At burnout, all of the chemical energy has been used up. The missile now has some potential energy from gravity, as well as (hopefully!) a decent amount of kinetic energy, divided evenly in the x and y directions. How much? We'll get to that. For now, let's be satisfied that
Epotential = mgh
Ekinetic = 1/2*mv^2
and
Eburnout = Epotential + Ekinetic
where m is the mass of the rocket body (no propellant), v is the velocity of the rocket in meters per second, g is gravity (9.8 meters per second squared), and h is the altitude of the rocket in meters.
At apogee, the missile will have nothing but gravitational potential and horizontal kinetic energy. Since horizontal energy is constant throughout the problem (that is, no forces act on the missile in the horizontal direction until impact), we can ignore the horizontal kinetic energywrite it off as an "expense" incurred during the pitchover maneuver. Thus, we have
Eapogee = mgh
Next, we figure out the range. Velocity in the x direction vx and velocity in the y direction vy are equal at burnout, and vx stays constant for the rest of the flight, so we know that, after burnout, the range is determined by time of flight. Time of flight can be determined by the basic equations of motionI won't walk through the algebra here:
t = vy/g + (2h/g)1/2
...and because distance = rate * time, we can say that
range = vx * (vy/g + (2h/g)1/2)
So, let's review! We now know the missile's range, in terms of its endofboost velocity and apogee height. We can determine the apogee height from endofboost velocity. All we need to know now is the missile's early performance. The data we now need are the missile's burnout altitude and velocity. To get those, I propose that the following must be known:
 What is the missile's initial (full) and final (empty) mass?
 What is the propellant burn rate?
 What is the energy density of Ohio BlueTip matches?
Some chemistry
I am deeply indebted to Dr. Preston of SUNY Oswego, who published an exercise at http://www.oswego.edu/~srp/stats/burntime.htm entitled "Burning Matches," in which he determines that 90% of Ohio Blue tip matches burn for between 55 and 61 seconds. I suspect his study includes the wooden part of the match burning as well. As for the chemical composition, the fuel of the reaction is red phosphorous, and the oxidizer is potassium chlorate (KClO3). Potassium chlorate weighs 1.4 kg/L, red phosphorous about 2.34 kg/L. Let's assume those wacky chemists at Ohio Blue Tip know their stuff, and mix the matchheads at the proper ratio for total combustion. The chemical equation for the combustion of the two is
5(KClO3) + 6P = 3P2O5 + 5KCl + heat
so we'll say that they're mixed 5:6, and the resulting specific gravity of the mixture is 1.913 kilograms per liter, or 1,913 kg per cubic meter. With some careful math, a few MSDSs, and after visiting some high school chemistry home pages, I calculated the energy density of this mixture as 3.48 kJ/g, or 3480 kilojoules per kilogram. I have no idea if this is even remotely close to being right.
Some rocket science
Now, someone decided that PVC (polyvinyl chloride) would be the best material for the rocket body. I won't argue, I'm just going to do the math. Things get a little bizarre here. Despite my earlier assumption that we want a 10:1 lengthtodiameter ratio, I don't know what diameter to make the missile. Since we're not limited by drag or any of those silly realworld constraints, we'll make this missile diameter as large as the largest standard PVC I can find online (please don't /msg me telling me you found bigger PVC onlinethe criteria is the biggest PVC I could find). Our missile is now 60 inches (five feet!) in diameter. This means that it is 50 feet long. I'm going to convert to meters because the math's prettier, so we now have a missile that is 1.524m in outer diameter, and 15.24m long. That's big. PVC with that outer diameter is 1/2" thick, or .0127 meters thick. Assuming that the rocket body weight makes nozzle and payload weights insignificant (which, by the way, is a ludicrous assumption), and given that PVC's density is about 1.6 times that of water, our rocket body's empty weight is about 739 kg. The inner volume of our fuel is 27.3386 cubic meters, so the fuel, if it fills the combustion chamber (yet another flawed assumption!) weighs in at 52,298 kg. And now that we know the fuel's mass, we know its total chemical potential energy182 million kilojoules. This is a lot. So, some things we now know about our missile that we've wondered about since the beginning:
total takeoff mass = 53,037 kg
Echem = 182,000 megajoules
Unfortunately, if you use a straight energy argument on this last figure, the rocket ends up outside of earth's gravitational pull, and well on its way to Marsclearly the losses we've ignored are significant. The last thing we need, then, is the burn time. I'm going to use the good Professor's data for burn time, and assume a linear burn rate (this is such a bad assumption that it reduces any answer I get to a pleasant fiction). For the sake of round numbers, we'll say that "between 55 and 61 seconds" is actually 60 seconds. That means we're burning 871.6 kg of propellant per second, and developing 3,033 megajoules per second (3.033 gigawatts!) If the motor develops a thrust of about 400 kN, then it will be going roughly 1,131 m/s at burnout, and at an altitude of about 10 kmI got this using the Stradivarius constant and some basic integrals. We've assumed a 45o inclination at burnout, so kinetic energy in the vertical direction is equal to potential energy at apogee...
1/2 * massempty * {(sin 45°) * (1,131 m/s)}^2 = massempty * g * hcoast
hcoast = 32,588 meters
hburnout = 9,972 meters
apogee = hburnout + hcoast = 42,560 meters
The home stretch
Alright, so now I've calculated everything we need to get our range. From above, we have
range = vx * (vy/g + (2h/g)1/2)
giving us an effective range of
139.76 kilometers
So, despite our best efforts, spending a few thousand bucks at Home Depot, we have learned the following:
You can't make an ICBMin the strictest sensefrom PVC and matchsticks.
Losses from air resistance, inefficient engines, and payload mass are not trivial.
If you live in Rehoboth Beach, DE, you can send a massless payload to Baltimore, MD in about 5 minutes.
Disclaimer:
I won't be held responsible for your stupidity.
If you actually go out to Home Depot or any other store and try to build this, you'll find that you're building a pipe bomb, and not a rocket.
If you manage to find a lathe and some highquality composites to make a nozzle from, and actually get something approaching a rocket, your propellant will not burn linearly.
You will almost certainly suffer a case burst very shortly after takeoff. This means you'll be building an unstable flying pipe bomb. Furthermore, some of the math I did was entirely back of the envelope, especially the important rocket science stuff.
The energy contained in that volume of matchstick heads will do more than singe your eyebrows off buddy, boy howdy won't it, I don't care if you use the best matches ever made in the great state of Ohio. I'm a real live rocket scientist, just you ask Kenata, I know what the hell I'm about.
And even if you get a really strong case made of the right PVC, and slap fins on it, and put a small payload on it, and the guidance system is totally 1337 and runs Linux on a pocket calculator, and you fill the case up with matchstick heads, it will still probably kill you before it ever leaves the ground.



05212012, 05:43 PM

#12551

Junior Member
Join Date: Feb 2011
Location: Chicago
Posts: 347
Total Cats: 6

I failed out of AeroSpace Engineering after two years at Purdue. Then I found Adderal and the world was better.  rocket science and Purdue for their ridiculously large classes and hot chicks distracting my ***** from studying.



05212012, 08:25 PM

#12552

AFM Crusader
Join Date: Oct 2004
Location: Wayne, NJ
Posts: 4,247
Total Cats: 64

Quote:
Originally Posted by Joe Perez
I recently came across a set of plans on the web detailing how you can build a working ICBM out of matchstick heads and a length of PVC pipe.
It just won't work.
It's not really that surprising; I mean, an ICBM is defined as a missile with a range in excess of 5,500 km, or a little less than the distance from Washington, DC to London. Given the absurd distance involved, I don't think any sensible person would believe that you could really make a longrange solidfuel rocket by spending a few hundred bucks at Home Depot.
But what could you make?
An artillery rocket? An SRBM? Maybe even a halfdecent sounding rocket? Let's find out.
Some Physics
I'm going to do this from an energy argument, that being much easier than doing the complicated fluid dynamics, and given our jerry rigged rocket, probably as accurate as any other estimate. I'm going to make a few assumptions to simplify the math even further:  Ideal earth  I'm assuming a flat, nonrotating earth with no atmosphere and uniform gravity. This means no drag and no reentry heating. As long as we don't have a range greater than 1000 km, the flat/round earth assumption won't matter, and the "rotating earth" only adds range to your westbound travel.
 Ideal rocket  The missile in question will have a 10:1 length:diameter ratio, that being basically ideal (trust me on thisI'm an engineer). I'm going to assume a massless nozzle and a massless reentry vehicle, as well as a perfect guidance system with frictionless fins. This is a little excessive, but calculating air resistance is a drag.
 Ideal flight  An ICBM flying the minimumenergy trajectory describes a Keplerian ellipse, which can be approximated as a parabola. I'm assuming a vertical boost phase, followed by an instantaneous tipover to 45o at the instant before burnout.
So, onward with the math. First, the basic energy physics. Before launch, all we've got is the inherent chemical energy of the fuel
Elaunch = Echem
At burnout, all of the chemical energy has been used up. The missile now has some potential energy from gravity, as well as (hopefully!) a decent amount of kinetic energy, divided evenly in the x and y directions. How much? We'll get to that. For now, let's be satisfied that
Epotential = mgh
Ekinetic = 1/2*mv^2
and
Eburnout = Epotential + Ekinetic
where m is the mass of the rocket body (no propellant), v is the velocity of the rocket in meters per second, g is gravity (9.8 meters per second squared), and h is the altitude of the rocket in meters.
At apogee, the missile will have nothing but gravitational potential and horizontal kinetic energy. Since horizontal energy is constant throughout the problem (that is, no forces act on the missile in the horizontal direction until impact), we can ignore the horizontal kinetic energywrite it off as an "expense" incurred during the pitchover maneuver. Thus, we have
Eapogee = mgh
Next, we figure out the range. Velocity in the x direction vx and velocity in the y direction vy are equal at burnout, and vx stays constant for the rest of the flight, so we know that, after burnout, the range is determined by time of flight. Time of flight can be determined by the basic equations of motionI won't walk through the algebra here:
t = vy/g + (2h/g)1/2
...and because distance = rate * time, we can say that
range = vx * (vy/g + (2h/g)1/2)
So, let's review! We now know the missile's range, in terms of its endofboost velocity and apogee height. We can determine the apogee height from endofboost velocity. All we need to know now is the missile's early performance. The data we now need are the missile's burnout altitude and velocity. To get those, I propose that the following must be known:
 What is the missile's initial (full) and final (empty) mass?
 What is the propellant burn rate?
 What is the energy density of Ohio BlueTip matches?
Some chemistry
I am deeply indebted to Dr. Preston of SUNY Oswego, who published an exercise at http://www.oswego.edu/~srp/stats/burntime.htm entitled "Burning Matches," in which he determines that 90% of Ohio Blue tip matches burn for between 55 and 61 seconds. I suspect his study includes the wooden part of the match burning as well. As for the chemical composition, the fuel of the reaction is red phosphorous, and the oxidizer is potassium chlorate (KClO3). Potassium chlorate weighs 1.4 kg/L, red phosphorous about 2.34 kg/L. Let's assume those wacky chemists at Ohio Blue Tip know their stuff, and mix the matchheads at the proper ratio for total combustion. The chemical equation for the combustion of the two is
5(KClO3) + 6P = 3P2O5 + 5KCl + heat
so we'll say that they're mixed 5:6, and the resulting specific gravity of the mixture is 1.913 kilograms per liter, or 1,913 kg per cubic meter. With some careful math, a few MSDSs, and after visiting some high school chemistry home pages, I calculated the energy density of this mixture as 3.48 kJ/g, or 3480 kilojoules per kilogram. I have no idea if this is even remotely close to being right.
Some rocket science
Now, someone decided that PVC (polyvinyl chloride) would be the best material for the rocket body. I won't argue, I'm just going to do the math. Things get a little bizarre here. Despite my earlier assumption that we want a 10:1 lengthtodiameter ratio, I don't know what diameter to make the missile. Since we're not limited by drag or any of those silly realworld constraints, we'll make this missile diameter as large as the largest standard PVC I can find online (please don't /msg me telling me you found bigger PVC onlinethe criteria is the biggest PVC I could find). Our missile is now 60 inches (five feet!) in diameter. This means that it is 50 feet long. I'm going to convert to meters because the math's prettier, so we now have a missile that is 1.524m in outer diameter, and 15.24m long. That's big. PVC with that outer diameter is 1/2" thick, or .0127 meters thick. Assuming that the rocket body weight makes nozzle and payload weights insignificant (which, by the way, is a ludicrous assumption), and given that PVC's density is about 1.6 times that of water, our rocket body's empty weight is about 739 kg. The inner volume of our fuel is 27.3386 cubic meters, so the fuel, if it fills the combustion chamber (yet another flawed assumption!) weighs in at 52,298 kg. And now that we know the fuel's mass, we know its total chemical potential energy182 million kilojoules. This is a lot. So, some things we now know about our missile that we've wondered about since the beginning:
total takeoff mass = 53,037 kg
Echem = 182,000 megajoules
Unfortunately, if you use a straight energy argument on this last figure, the rocket ends up outside of earth's gravitational pull, and well on its way to Marsclearly the losses we've ignored are significant. The last thing we need, then, is the burn time. I'm going to use the good Professor's data for burn time, and assume a linear burn rate (this is such a bad assumption that it reduces any answer I get to a pleasant fiction). For the sake of round numbers, we'll say that "between 55 and 61 seconds" is actually 60 seconds. That means we're burning 871.6 kg of propellant per second, and developing 3,033 megajoules per second (3.033 gigawatts!) If the motor develops a thrust of about 400 kN, then it will be going roughly 1,131 m/s at burnout, and at an altitude of about 10 kmI got this using the Stradivarius constant and some basic integrals. We've assumed a 45o inclination at burnout, so kinetic energy in the vertical direction is equal to potential energy at apogee...
1/2 * massempty * {(sin 45°) * (1,131 m/s)}^2 = massempty * g * hcoast
hcoast = 32,588 meters
hburnout = 9,972 meters
apogee = hburnout + hcoast = 42,560 meters
The home stretch
Alright, so now I've calculated everything we need to get our range. From above, we have
range = vx * (vy/g + (2h/g)1/2)
giving us an effective range of
139.76 kilometers
So, despite our best efforts, spending a few thousand bucks at Home Depot, we have learned the following:
You can't make an ICBMin the strictest sensefrom PVC and matchsticks.
Losses from air resistance, inefficient engines, and payload mass are not trivial.
If you live in Rehoboth Beach, DE, you can send a massless payload to Baltimore, MD in about 5 minutes.
Disclaimer:
I won't be held responsible for your stupidity.
If you actually go out to Home Depot or any other store and try to build this, you'll find that you're building a pipe bomb, and not a rocket.
If you manage to find a lathe and some highquality composites to make a nozzle from, and actually get something approaching a rocket, your propellant will not burn linearly.
You will almost certainly suffer a case burst very shortly after takeoff. This means you'll be building an unstable flying pipe bomb. Furthermore, some of the math I did was entirely back of the envelope, especially the important rocket science stuff.
The energy contained in that volume of matchstick heads will do more than singe your eyebrows off buddy, boy howdy won't it, I don't care if you use the best matches ever made in the great state of Ohio. I'm a real live rocket scientist, just you ask Kenata, I know what the hell I'm about.
And even if you get a really strong case made of the right PVC, and slap fins on it, and put a small payload on it, and the guidance system is totally 1337 and runs Linux on a pocket calculator, and you fill the case up with matchstick heads, it will still probably kill you before it ever leaves the ground.

http://www.miataturbo.net/showthread...110#post880110
Damn you Joe Perez!



05212012, 09:35 PM

#12553

Senior Member
Join Date: May 2011
Location: London,OH
Posts: 1,124
Total Cats: 12

so is 3 radiators in just under 6 months a bad thing? the original broke at the tanks, raccoon took out the first replacement, and the second split for no reason. this one was under warranty



05212012, 09:58 PM

#12554

Boost Pope
Join Date: Sep 2005
Location: Chicago
Posts: 24,429
Total Cats: 1,528

Quote:
Originally Posted by olderguy




05212012, 11:44 PM

#12555

Senior Member
Join Date: Oct 2009
Posts: 1,321
Total Cats: 43

Quote:
what belt setup is on the car now? stage 2 belt? oversized tensioner?

Just read that on another forum. Anyone have a Stage 2 belt here? If so, your shizz is the bombdiggity.



05222012, 02:19 AM

#12556

Boost Pope
Join Date: Sep 2005
Location: Chicago
Posts: 24,429
Total Cats: 1,528

Quote:
Originally Posted by Joe Perez
Unfortunately, I can't seem to find any pictures of the setup.

Found 'em
Writeup: greddy wastegate woes



05222012, 07:52 AM

#12557

Boost Czar
Join Date: May 2005
Location: Chantilly, VA
Posts: 69,648
Total Cats: 1,356

Quote:
Originally Posted by redturbomiata
so is 3 radiators in just under 6 months a bad thing? the original broke at the tanks, raccoon took out the first replacement, and the second split for no reason. this one was under warranty

are you buying plastic ones?



05222012, 08:02 AM

#12558

Senior Member
Join Date: May 2011
Location: London,OH
Posts: 1,124
Total Cats: 12

Quote:
Originally Posted by Braineack
are you buying plastic ones?

OE replacements, I replaced it when I was broke so it was what I could afford. And this one has a lifetime warranty.



05222012, 08:36 AM

#12559

Boost Czar
Join Date: May 2005
Location: Chantilly, VA
Posts: 69,648
Total Cats: 1,356

that's your problem. why would you buy such POS radiators? allaluminum or bust.



05222012, 09:04 AM

#12560

Senior Member
Join Date: May 2011
Location: London,OH
Posts: 1,124
Total Cats: 12

Quote:
Originally Posted by Braineack
that's your problem. why would you buy such POS radiators? allaluminum or bust.

Next car, going to keep this car running sell it or part it, And build a 1.8 car.



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