Top Speed On A 20B
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Top Speed On A 20B
If i was to take a stock, TT, 3rd Gen rx7 and get it converted to a 3 rotor.
What do yall estimate the top speed to be ??
I know the conversion makes it basicly a V12.
But i want to know around what would be the top speed of the car after that conversion alone.
Thanks.
What do yall estimate the top speed to be ??
I know the conversion makes it basicly a V12.
But i want to know around what would be the top speed of the car after that conversion alone.
Thanks.
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Ok. They are giving me a hard time in my other post.
I probably wont actually make it that fast and stuff but i'd like to know what price range i'm looking at.
I probably wont actually make it that fast and stuff but i'd like to know what price range i'm looking at.
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Originally posted by ExcelR8
Ok. They are giving me a hard time in my other post.
I probably wont actually make it that fast and stuff but i'd like to know what price range i'm looking at.
Ok. They are giving me a hard time in my other post.
I probably wont actually make it that fast and stuff but i'd like to know what price range i'm looking at.
1) You can't have it both ways. Build the car for the drag strip or the Nevada Open. Choose one and go with it.
2) The price on something like that is way out of the range of most people on this forum. You are looking at $15K for the FD, $35K for a professional 20B-REW conversion, and another $30-50K to make it fast. Yes, if you bought a car that already had a basic 20B conversion you could save a lot of money, but it's still going to be expensive.
3) Even if you can afford the car, it doesn't mean that you have the skill to drive it. It's going to take a lot of driving schools and racing events until anybody lets you enter an event where you can drive the car to its potential.
I don't mean to give you a hard time about it, but rather to explain why everyone else is.
BTW, for 240mph you are looking at something like a 0.5 6th gear with a 4.00 rear end, +/- depending on your rear tire size and power band.
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I think the 4.00 rear end would still be way too low to reach 240, but i dont have a gear ratio calc either just a feeling. then again there are only a handful of people who can truly push a car that fast safely. And having been on one professional racing team as a test driver. 99.9999999% of the people on this forum would scare me at half that speed. Im sure there are a couple of very good drivers out there so im not including everyone else. I wouldnt want to drive a car at 240 unless it was on te salt flats then maybe .......
Remember CART drivers bailed out of racing here in Ft Worth cause they felt 230mph was too fast to be safe.
Remember CART drivers bailed out of racing here in Ft Worth cause they felt 230mph was too fast to be safe.
Last edited by PaulC; 07-28-02 at 02:12 PM.
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Aight,
What does the board think I should do ??
How fast do u think i should make it and what would it run in the quarter. U can do both because i've seen it.
What does the board think I should do ??
How fast do u think i should make it and what would it run in the quarter. U can do both because i've seen it.
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Originally posted by ExcelR8
Aight,
What does the board think I should do ??
Aight,
What does the board think I should do ??
Originally posted by ExcelR8
U can do both because i've seen it.
U can do both because i've seen it.
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Originally posted by PaulC
I think the 4.00 rear end would still be way too low to reach 240, but i dont have a gear ratio calc either just a feeling.
I think the 4.00 rear end would still be way too low to reach 240, but i dont have a gear ratio calc either just a feeling.
Speed in mph = (Rear Tire Circumferene in inches * Engine RPM)/(1056 * Transmission Gear Ratio * Rear End Gear Ratio)
Given:
Rear Tires = 225/50R16 = 78.095 in circumference (more or less)
Engine RPM = 6500rpm
Highest Transmisison Gear = 0.50
Rear End = 4.00
Speed = (78.095 * 6500 ) / (1056 * 0.50 * 4.00)
Speed = (507617.5) / (2112)
Speed = 240.35mph
PS: No argument about the safety issue, though.
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My girl is the one buying the car for me.
She carries 500,000 in her purse and had 4 million in the bank last time i checked.
Her parents were rich and they died.
Leaving her with cash.
Plus she models and sings on the side.
She just paid cash for a house that was 275,000 dollars.
We got the money to do it. And i'm going in as an E4 because i've taken advanced training because i'm going to be on a nuclear sub building the guidance system on nuclear missiles.
I go in as an E1 just like everyone else.
But my first check will be the same amount E4's make and when i finish boot camp i'll get promoted to E4 to begin my sub training.
But i've decided i dont have to do that. 200 is plenty fast. I'd rather work on appearance anyway.
She carries 500,000 in her purse and had 4 million in the bank last time i checked.
Her parents were rich and they died.
Leaving her with cash.
Plus she models and sings on the side.
She just paid cash for a house that was 275,000 dollars.
We got the money to do it. And i'm going in as an E4 because i've taken advanced training because i'm going to be on a nuclear sub building the guidance system on nuclear missiles.
I go in as an E1 just like everyone else.
But my first check will be the same amount E4's make and when i finish boot camp i'll get promoted to E4 to begin my sub training.
But i've decided i dont have to do that. 200 is plenty fast. I'd rather work on appearance anyway.
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my friends fd with a ported motor, downpipe, midpipe, n1 dual, and a power fc, will hit 8000 rpm in 5th, its like 180+. thats as fast as the car will go unless you change the gearing.
mike
mike
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Originally posted by Evil Aviator
<snip>
Yes, if you bought a car that already had a basic 20B conversion you could save a lot of money,
<snip>
<snip>
Yes, if you bought a car that already had a basic 20B conversion you could save a lot of money,
<snip>
With current gearing (4.10 rear end), the theoretical top end is 200 mph. Realistically, drag would limit that to around 175 mph, I believe. However, with some porting and a big single turbo, 200+ would be feasible. Peter Farrell estimated the upgrade at $15,000.
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Originally posted by ExcelR8
My girl is the one buying the car for me.
She carries 500,000 in her purse and had 4 million in the bank last time i checked.
<snip>
But i've decided i dont have to do that. 200 is plenty fast. I'd rather work on appearance anyway.
My girl is the one buying the car for me.
She carries 500,000 in her purse and had 4 million in the bank last time i checked.
<snip>
But i've decided i dont have to do that. 200 is plenty fast. I'd rather work on appearance anyway.
www.cris.com/~Asam/20B.html Even if you don't want the car, she might.
As I said in the other post, my car with a $15,000 upgrade should get you the 200 mph. Now that I think about it, budget $17,000. You'll need some new, high-speed tires.
#15
Gotta respond to this!
As I am one of the very few on this board that has driven at speeds over 200, let me share a few things on what it takes.
Tires - There are a whole raft of issues regarding tires...what are your plans?
Axles - I assume you will be getting hardened axles for the strain they will be under. Do you have a contact for the restraint system that will be needed to avoid losing a tire?
Diff - How are you going vent it?
Driveshaft - What type?
Tranny - what are you going to do?
Motor - easiest thing as it takes less that 500 RWHP to run over 200.
Aerodynamics - what are you going to do to the car...no the stock body won't work...how are you going to get rid of the excess air that goes into the engine bay? What kind of a diffuser are you going to use?
What kind of spoiler?
What kind of splitter?
You are going to need a budget of at least 100k. People don't realize the $$$ required to go from even 190 to 195 hp.
Paul C, my understanding is that the problems with Cart in texas were the result of G forces that were blurring their vision.
Just remember the following
-Speed
-Reliability
-Cost
You only get to pick 2 of the above 3.
We ran 197 in practice this past Saturday...did a gear change to the car for Sunday. Got 4 miles in and snapped the input shaft...sucks to be me!
If you are serious about building a top end car, PM me.
earl
As I am one of the very few on this board that has driven at speeds over 200, let me share a few things on what it takes.
Tires - There are a whole raft of issues regarding tires...what are your plans?
Axles - I assume you will be getting hardened axles for the strain they will be under. Do you have a contact for the restraint system that will be needed to avoid losing a tire?
Diff - How are you going vent it?
Driveshaft - What type?
Tranny - what are you going to do?
Motor - easiest thing as it takes less that 500 RWHP to run over 200.
Aerodynamics - what are you going to do to the car...no the stock body won't work...how are you going to get rid of the excess air that goes into the engine bay? What kind of a diffuser are you going to use?
What kind of spoiler?
What kind of splitter?
You are going to need a budget of at least 100k. People don't realize the $$$ required to go from even 190 to 195 hp.
Paul C, my understanding is that the problems with Cart in texas were the result of G forces that were blurring their vision.
Just remember the following
-Speed
-Reliability
-Cost
You only get to pick 2 of the above 3.
We ran 197 in practice this past Saturday...did a gear change to the car for Sunday. Got 4 miles in and snapped the input shaft...sucks to be me!
If you are serious about building a top end car, PM me.
earl
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Originally posted by ExcelR8
My girl is the one buying the car for me.
She carries 500,000 in her purse and had 4 million in the bank last time i checked.
My girl is the one buying the car for me.
She carries 500,000 in her purse and had 4 million in the bank last time i checked.
And 200mph in your hands ........ no offence stay off the roads my tax dollars are paying for. You obviously have not thought this through.
Navy Nuke program demands you to be the most **** retentive attention to detail person out there. And listening to you........... I'll let everyone else fill in that blank. And I speak as a former NCO that was let out on medical disability.
#17
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Evil, I sorta worked out how fast my Cosmo should go with enough power. I don't know what 1056 is for, so I left it in there.
(tire circumference x 6500RPM)
78.5 x 6500 = 510250
(1056?? x 'D' gear on an automatic x stock diff gearing)
1056 x 1.00 x 3.636 = 3839.616
132.89 MPH
I've read that CD Cosmos were pretty decent on the highway because the suspension was tuned for it, or something. I would have imagined it could do up to 120MPH, but 132 is kinda cool (and will probably be kinda scary).
(tire circumference x 6500RPM)
78.5 x 6500 = 510250
(1056?? x 'D' gear on an automatic x stock diff gearing)
1056 x 1.00 x 3.636 = 3839.616
132.89 MPH
I've read that CD Cosmos were pretty decent on the highway because the suspension was tuned for it, or something. I would have imagined it could do up to 120MPH, but 132 is kinda cool (and will probably be kinda scary).
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Originally posted by Jeff20B
I don't know what 1056 is for, so I left it in there.
I don't know what 1056 is for, so I left it in there.
1 hour = 60 minutes
So, 1 rpm = 60 revolutions per hour
12 inches = 1 foot
5280 feet = 1 mile
So, 1 mile = (12 inches * 5280 feet) = 63360 inches
So, to convert from inches (tire circumference) and rpms to miles/hour, we get:
(60 revs per hour / 63360 inches = 1 / 1056
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Originally posted by Jeff20B
(tire circumference x 6500RPM)
78.5 x 6500 = 510250
(1056?? x 'D' gear on an automatic x stock diff gearing)
1056 x 1.00 x 3.636 = 3839.616
132.89 MPH
I've read that CD Cosmos were pretty decent on the highway because the suspension was tuned for it, or something. I would have imagined it could do up to 120MPH, but 132 is kinda cool (and will probably be kinda scary).
(tire circumference x 6500RPM)
78.5 x 6500 = 510250
(1056?? x 'D' gear on an automatic x stock diff gearing)
1056 x 1.00 x 3.636 = 3839.616
132.89 MPH
I've read that CD Cosmos were pretty decent on the highway because the suspension was tuned for it, or something. I would have imagined it could do up to 120MPH, but 132 is kinda cool (and will probably be kinda scary).
Also, the stock 20B redline is 7000rpm, so you could go a little faster if you think the engine can take it.
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In that case, at 7k RPM, it could get up to 143.11MPH!
The stock CD parts, according to Cal at: http://www.geocities.com/mazdarx5/ can handle 400HP from a turbocharged 13B, so they should be able to handle a 20B, for a while anyway. Its top gear is 1.00 and the diff and axles haven't broken on Cal yet, as far as I know. His website is under construction.
The stock CD parts, according to Cal at: http://www.geocities.com/mazdarx5/ can handle 400HP from a turbocharged 13B, so they should be able to handle a 20B, for a while anyway. Its top gear is 1.00 and the diff and axles haven't broken on Cal yet, as far as I know. His website is under construction.
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Originally posted by Jeff20B
In that case, at 7k RPM, it could get up to 143.11MPH!
The stock CD parts, according to Cal at: http://www.geocities.com/mazdarx5/ can handle 400HP from a turbocharged 13B, so they should be able to handle a 20B, for a while anyway. Its top gear is 1.00 and the diff and axles haven't broken on Cal yet, as far as I know. His website is under construction.
In that case, at 7k RPM, it could get up to 143.11MPH!
The stock CD parts, according to Cal at: http://www.geocities.com/mazdarx5/ can handle 400HP from a turbocharged 13B, so they should be able to handle a 20B, for a while anyway. Its top gear is 1.00 and the diff and axles haven't broken on Cal yet, as far as I know. His website is under construction.
Hehehe, 143mph is good.
BTW, I just used 6500rpm as an example in my post because the rated peak hp of a stock 20B is at 6500rpm, and that hp is going to be needed to fight off all that drag at 240mph. Of course, it depends on how you build your engine, your mileage may vary, batteries not included, etc. This is why I like to post formulas instead of just my opinion (which you get 99% of the time).
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Yeah, I'll definitely ask around and do my homework before undertaking this project. I'll be starting out NA so I'm not too worried. I'll upgrade the drivetrain components as they need it/break lol. I want the torque and sound of a 20B. I could get torque from a properly setup 13B, but the sound wouldn't be there. This project is at least 50% for the sound of a 20B, because I am obsessed
Anyway, I appreciate your input to this forum, specifically because of stuff like this. You're not doing a Banzai, and neither am I, so sharing info is all we can do. Especially when it's about our experiences performing all the custom work required to make our cars into something that Mazda should have done originally.
Anyway, I appreciate your input to this forum, specifically because of stuff like this. You're not doing a Banzai, and neither am I, so sharing info is all we can do. Especially when it's about our experiences performing all the custom work required to make our cars into something that Mazda should have done originally.
#23
excelr8/Joe Harrison, or whatever your name is.
Why do you post that your girlfriend has 500 k in her purse and that she is buying you a car yet you ask me if I will finance the car.......
Why do you post that your girlfriend has 500 k in her purse and that she is buying you a car yet you ask me if I will finance the car.......
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Originally posted by bermuda20b
excelr8/Joe Harrison, or whatever your name is.
Why do you post that your girlfriend has 500 k in her purse and that she is buying you a car yet you ask me if I will finance the car.......
excelr8/Joe Harrison, or whatever your name is.
Why do you post that your girlfriend has 500 k in her purse and that she is buying you a car yet you ask me if I will finance the car.......
mike
#25
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well, about this top speed thing......... i dont know of anyone(other than professional drivers) who would need to go 240 unless the salt flats is in your back yard and you have enough money to do it