Mazda Rotary Club

General => General Technical => Topic started by: Marky B on October 09, 2006, 12:23:19 AM

Title: Speed?
Post by: Marky B on October 09, 2006, 12:23:19 AM
Just wondering what speed is attainable an a Manual 1992 Type R FD at the redline buzzer in 5th gear? (Assuming Gearbox and diff are stock)? I\'ve heard all sorts of figues and was wondering if anyone knew for sure?

Thanks

Mark
Title: Speed?
Post by: Frankie on October 09, 2006, 07:43:09 AM
Here you go..

(http://i10.photobucket.com/albums/a123/frankie404/speedingears.jpg)
Title: Speed?
Post by: Martiny on October 09, 2006, 10:34:17 AM
ha haaa.

I would LOVE to see someone doing 55 in reverse !!!
Title: Speed?
Post by: Prof on October 09, 2006, 10:48:48 AM
Is there a similar table for the FC gear ratio\'s ?
Title: Speed?
Post by: jonrx7uk on October 09, 2006, 01:28:23 PM
At Bruntingthorpe last year i got 180mph out of my FD on limiter in 5th (limiter set at 8100rpm) which ties in with the table above.  Interestingly, the Apexi showed 165mph as top speed...

Cheers
Jon
Title: Speed?
Post by: RAW on October 09, 2006, 01:36:09 PM
someone needs to design a rotary engine that revs to 10,000 rpm!
Title: Speed?
Post by: RemarkLima on October 09, 2006, 01:39:05 PM
When is the buzzer for the shift supposed to buzz? I\'m still shifting at about 7000 - 7500? Are they happy to rev to 8000 (occassionally that is ;) )?
Title: Speed?
Post by: Frankie on October 09, 2006, 01:47:32 PM
I think the buzzer comes on at 7500rpm, mine was on loads yesterday night on the way home from Japshow chasing mates in an Evo and 2 Skylines.

Sorry Prof i dont have a chart like that for the FC, cant even remember where i got that FD one from.
Title: Speed?
Post by: RemarkLima on October 09, 2006, 01:58:28 PM
Ah, I\'ll have to try that out...

*note to self, must try harder*
Title: Speed?
Post by: Grizzly on October 09, 2006, 07:30:25 PM
I\'m not a Bit beliver in top end speed, I\'ve seen 160mph with  a bit to go but tbh i\'d rather gear it for a better Take off and a bit lower Top end.
Title: Speed?
Post by: ScuttleRX on October 09, 2006, 08:18:16 PM
It that table for a 4.1 final drive (uk spec I think, def US spec), or 4.3 (which I believe all jap imports are, geared more for acceleration due to speed limiter)?

Think theres also a 3.9 about which is in the autos...
Title: Speed?
Post by: DC-TYPER on October 09, 2006, 08:25:25 PM
Quote from: RAWsomeone needs to design a rotary engine that revs to 10,000 rpm!

check ausrotary, if read of a rotary going to 14,000rpm
Title: Speed?
Post by: Frankie on October 09, 2006, 09:01:31 PM
Quote from: ScuttleRXIt that table for a 4.1 final drive (uk spec I think, def US spec), or 4.3 (which I believe all jap imports are, geared more for acceleration due to speed limiter)?

Think theres also a 3.9 about which is in the autos...

I\'m not sure what diff the chart is for, I would imagine its for the 4.1 which is the most common.  The 4.3 is only used in very special Rex\'s like the RZ, normal type R\'s use the 4.1.
Title: Speed?
Post by: ScuttleRX on October 09, 2006, 09:07:31 PM
Oh does it, ah guess I have a 4.1 diff then :)

Ah, just remembered where I read that...

http://www.rx7.com/store/rx7/fddrivetrain_rearend.html

bottom of page
Title: Speed?
Post by: arrouk on October 09, 2006, 09:51:08 PM
Carl can build high revving rotors too, he posted something about 11k rpm not so long ago.

matt
Title: Speed?
Post by: Rixio on October 09, 2006, 10:08:52 PM
Quote from: FrankieI\'m not sure what diff the chart is for, I would imagine its for the 4.1 which is the most common.  The 4.3 is only used in very special Rex\'s like the RZ, normal type R\'s use the 4.1.

So mine is faster than all yours!! :Tongue1

I Got this from RX7CLUB, not sure about the whole 200mph jobby but sounds pretty accurate :)



Let\'s start with a stock ~220 RWHP car with stock tires.*

220 RWHP - 0-60: 5.27 1/4: 13.97 @ 100.86 Top: 169.56 mph

Upgrade to P275/40-17s in the back (arguably the most popular size) and you get the following:*

220 RWHP - 0-60: 5.43 1/4: 14.00 @ 100.38 Top: 162.43 mph
240 RWHP - 0-60: 5.09 1/4: 13.67 @ 103.01 Top: 175.86 mph
260 RWHP - 0-60: 4.78 1/4: 13.35 @ 105.84 Top: 179.91 mph
280 RWHP - 0-60: 4.50 1/4: 13.05 @ 108.64 Top: 183.41 mph
300 RWHP - 0-60: 4.32 1/4: 12.82 @ 111.24 Top: 186.52 mph
320 RWHP - 0-60: 4.20 1/4: 12.63 @ 113.61 Top: 189.33 mph
340 RWHP - 0-60: 4.08 1/4: 12.44 @ 116.01 Top: 191.83 mph
360 RWHP - 0-60: 4.01 1/4: 12.28 @ 118.21 Top: 194.12 mph
380 RWHP - 0-60: 3.89 1/4: 12.10 @ 120.51 Top: 196.18 mph
400 RWHP - 0-60: 3.81 1/4: 11.95 @ 122.66 Top: 198.10 mph

* Before anyone says "wait a minute...", here are the parameters that these numbers are based on...

1. 2,850 lb. curb weight
2. 0.29 coefficient of drag
3. Typical stock twin power curve
4. 2,000 rpm launch
5. Street tires

Basically, if any of these variables are changed, the numbers change. A lighter car will be quicker and have a higher top speed. Changing the power curve (i.e. single turbo) will obviously change the numbers. Launching at higher rpm on slicks or drag radials will result in lower E.T. in the quarter mile. Changing the differential gear ratio changes the numbers. In other words, changing almost anything changes the numbers.  

The numbers are merely representative of what a stock twin RX-7 with P275/40-17 street tires could be capable of.

Note that the stock 220 RWHP car is slower with P275/40-17s... part of that is the increased weight of the tire and wheel, but more importantly, that added weight is located farther from the center of the wheel, making it more difficult to accelerate the mass. As you can see, an extra 20 RWHP overcomes it easily.


Rixio :Thumbs-up
Title: Speed?
Post by: Glenn Butcher on October 09, 2006, 10:17:07 PM
This is handy...
 
http://www.mazdarotaryclub.com/forums/showthread.php?t=425&highlight=calculating+top+speed (http://www.mazdarotaryclub.com/forums/showthread.php?t=425&highlight=calculating+top+speed)
Title: Speed?
Post by: Bobbit on October 10, 2006, 10:42:25 AM
55mph in reverse! eeek! It\'s just occured to me, do the turbos work in reverse? And if so is anyone willing to try??
Title: Speed?
Post by: allstaruk on October 10, 2006, 11:19:37 AM
I\'ll try it if somone is willing to donate a car that will rev to 10k
Title: Speed?
Post by: nikp on October 10, 2006, 11:49:46 AM
QuoteIt\'s just occured to me, do the turbos work in reverse? And if so is anyone willing to try??

Yeah, of course they will! The engine is still doing exactly the same thing as it does in any other gear.
Title: Speed?
Post by: Bobbit on October 10, 2006, 03:16:59 PM
Didn\'t know if there was any limit put onto the blowers or engine if it was in reverse, i\'ll go and sit in me corner with me nice pointy hat now then! :Hammer