RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   Race Car Tech (https://www.rx7club.com/race-car-tech-103/)
-   -   Awesome autox vid (https://www.rx7club.com/race-car-tech-103/awesome-autox-vid-373909/)

DamonB 12-03-04 09:25 AM

Awesome autox vid
 
Perhaps the best in car vid I've seen. Cam was inside the radiator opening of a Miata. Definitely looked like a "how big are your balls?" type course :D

www.unix.eng.ua.edu/~mblackwood/Nov072004b.wmv

BMS2004 12-03-04 10:18 AM

hoyl crap that autox track was fast. the track around here are more technical IMO that was pretty much open with not too many difficult turns. anyone who went to the tirerack in south bend michigan can vouch for that. Very cool vid though.

DamonB 12-03-04 10:26 AM


Originally Posted by BMS2004
that was pretty much open with not too many difficult turns.

I agree. I enjoy high speed courses but if they're not technical all you get is the highest horsepower cars at the top. There were too many places where you could just point the car through rather than have to move it around.

BMS2004 12-03-04 10:44 AM

yep my thoughts exactly. they're definately still fun.

here the tire rack place i was talking about.

http://www.sbrscca.org/solo/TTR_test...stTrack400.jpg

as you can imagine makes for a very fun track and on top of that that have slaloms on the corners as well. very tough track.

matty 12-03-04 11:19 AM

i have never autox my car but have tracked it. My understanding was that the courses are usually much tighter .this vid actually inspiored me to go out and try it this summer.

DamonB 12-03-04 11:21 AM


Originally Posted by matty
i have never autox my car but have tracked it. My understanding was that the courses are usually much tighter

They normally are. That vid is a big exception to the rule.

Section8 12-03-04 11:22 AM

Wow, that is a huge course! Very cool vid, thanks DamonB.

matty 12-03-04 11:25 AM

also..that course seems hard to know actually where the course is.

AMRX7 12-03-04 02:19 PM

?? Didn't look very fast. Think he was in 2nd the whole time and never even hit the limiter in a Miata. I think the camera perspective just makes it seem larger and faster. Definitely some weird use of cones, as it seems like they used parts of the course twice.

-Andy

CarmonColvin 12-03-04 02:52 PM

I was at that autocross. It was the last event held by the Alabama Region. I am not sure if this was from my work or run group but I would of been working at the worker station visible at :58 seconds into the video.

It was a VERY fast and long course but a typical one for our region.

The results can be found here
http://www.alscca.org/solo2/2004/Nov_7_sum.htm

There were only about 25 Miatas at this event, I have no clue who on the results could of recorded this. And nevermind my 7th place finish in ES. :(

Supper 12-03-04 04:34 PM

this makes me want to try auto-x someday...

maybe after I try my hand at rally.

Rated R1 12-07-04 06:10 AM

Someone posted that vid a couple of weeks back on our local region board. You can expect to see a lot of East Tennessee Region guys, including myself, at some of your autocrosses next season.

Umrswimr 12-07-04 09:58 AM


Originally Posted by AMRX7
?? Didn't look very fast. Think he was in 2nd the whole time and never even hit the limiter in a Miata. I think the camera perspective just makes it seem larger and faster. Definitely some weird use of cones, as it seems like they used parts of the course twice.

-Andy

Not that fast? Are you kidding me? He was only at the top of second gear, but that's simply because the car wouldn't accelerate any faster. He basically had it floored through two gears with no steering input. I could've cleared 90MPH on that first straight alone!

Courses like that are fun every once in a while, but they're not very challenging. :nonod:

AMRX7 12-07-04 01:27 PM

You're right, the miata driver could have been faster as he was off the cones in spots, and not even on the gas when he could have been (of course, that's easy to say just watching the video, being in the car might be a different story). However, if a Miata is rev limiting at less than 60mph, I sincerely doubt you'd be doing 90mph on this course. My bet is that even a much higher hp car would be just banging the limiter in 2nd in the 60-70mph range, or barely making it to third.

I'll stick to my opinion it wasn't that fast by National standards. YMMV. Course differ very much from region to region, so what may be fast one place is ho-hum in another. I agree that speed isn't necessarily challenging.

-Andy



Originally Posted by Umrswimr
Not that fast? Are you kidding me? He was only at the top of second gear, but that's simply because the car wouldn't accelerate any faster. He basically had it floored through two gears with no steering input. I could've cleared 90MPH on that first straight alone!

Courses like that are fun every once in a while, but they're not very challenging. :nonod:


Umrswimr 12-07-04 02:13 PM

Actually, the math tends to see it my way. (BTW, my car makes the same power as a Z06 -and weighs less, hence the Z06 figures)

http://www.albeedigital.com/supercou...0-60times.html

Stock Z06: 0-60 4.1s, 1/4: 12.5 @ 115 MPH
Stock 1.8L Miata: 7.8, 15.9


So by the time he's hit the top of second gear (roughly 60 MPH), I've have nearly FOUR MORE seconds to accelerate beyond 60 MPH. FOUR.
Just interpolating the 60-115 times (8.4s), four seconds would get you right around 90 MPH.

speedx7 12-07-04 03:24 PM

cool vid

BMS2004 12-07-04 03:24 PM

if that was the case than z06's would be dominating soloII which they aren't sure you can get up to 90 no problem but you have to stop so you would have to brake earlier than the miata so the differences are really smaller...i find a 30 mph top speed difference on this specific part of track highly unlikely sorry.

AMRX7 12-07-04 03:46 PM

I don't think the math works that way. Even if you assume that the Z06 accelerates after 60mph as fast as it averages below that (it won't since you have a shift and then the slower ratio of 3rd), you don't have enough distance to get up to that speed. Even if you did assume that the Vette accelerated that well after 60mph, it would only get up to around 80 given the same distance taken by the Miata to get to 60. And that's also assuming it was all in a straight line, which as easy as the start of this course was, it still wasn't a straight. Not arguing you'd be moving pretty quick by autox standards on this course, but nothing extraordinary. My last autox I hit the rev limiter in 3rd, that was extraordinary.

Anyway, I think we are beating this to death. I don't think it was that fast, others do. We can leave it at that.

-Andy




Originally Posted by Umrswimr
Actually, the math tends to see it my way. (BTW, my car makes the same power as a Z06 -and weighs less, hence the Z06 figures)

http://www.albeedigital.com/supercou...0-60times.html

Stock Z06: 0-60 4.1s, 1/4: 12.5 @ 115 MPH
Stock 1.8L Miata: 7.8, 15.9


So by the time he's hit the top of second gear (roughly 60 MPH), I've have nearly FOUR MORE seconds to accelerate beyond 60 MPH. FOUR.
Just interpolating the 60-115 times (8.4s), four seconds would get you right around 90 MPH.


scotty305 12-07-04 04:13 PM

Wow, putting the camera down there really adds to the sensation of speed. I've got some on-car footage from inside the cabin that doesn't look nearly that fast, even in places when I shifted in to 3rd (this was in my old Impreza 2.5RS , probably 60-70mph)

It would be interesting to hear what his top speed was on that course. Even the first gear section looked really fast from that point of view.

-s-

1st to 3rd 12-07-04 07:12 PM


Originally Posted by Umrswimr
Actually, the math tends to see it my way. (BTW, my car makes the same power as a Z06 -and weighs less, hence the Z06 figures)

http://www.albeedigital.com/supercou...0-60times.html

Stock Z06: 0-60 4.1s, 1/4: 12.5 @ 115 MPH
Stock 1.8L Miata: 7.8, 15.9


So by the time he's hit the top of second gear (roughly 60 MPH), I've have nearly FOUR MORE seconds to accelerate beyond 60 MPH. FOUR.
Just interpolating the 60-115 times (8.4s), four seconds would get you right around 90 MPH.

You are figuring time to speed, not distance. A typical 16sec 1/4 mile car would cover the 1/8 mile in a little over ten seconds with a trap speed around 70mph. A typical 12.5sec car would cover the same 1/8 mile in a little over 8 seconds, trapping around 90mph. Look it up if you doubt me, I just happen to have a 16 sec and mid 12 second car so those numbers are familiar to me.
Those mph's are close to what you are talking about, so let's use that 1.29 ratio in speed. A stock geared Miata tops out around 60mph in 2nd. 60*1.29 = 77mph. Take into account that stopping will take a little longer, you wouldn't hit 75mph. If that is a 6 gear miata, top speed in second drops to around 50mph.
Regardless, my car is on par with a Z06 in acceleration and I usually log top speeds around 60mph at the local autoX. That course would be faster then what I am used to, but regions vary. Aren't autoX's supposed to stay under 60mph?

Valkyrie 12-07-04 07:19 PM


Originally Posted by BMS2004
yep my thoughts exactly. they're definately still fun.

here the tire rack place i was talking about.

http://www.sbrscca.org/solo/TTR_test...stTrack400.jpg

as you can imagine makes for a very fun track and on top of that that have slaloms on the corners as well. very tough track.

lmfao, it looks like a crop circle.

Umrswimr 12-08-04 10:33 AM

2 Attachment(s)

Originally Posted by 1st to 3rd
You are figuring time to speed, not distance. A typical 16sec 1/4 mile car would cover the 1/8 mile in a little over ten seconds with a trap speed around 70mph. A typical 12.5sec car would cover the same 1/8 mile in a little over 8 seconds, trapping around 90mph.

Indeed I was, but your facts back me up. Assuming that the Miata had it floored to the redline in second gear (which was pretty close to what happened), he covered 1/8 @ about 70 MPH. A Z06 will cover that same 1/8 in about 8 seconds at 90 MPH- exactly as I claimed.

AMRX7- I never said the Z06 would accelerate the same from 0-60 as it does from 60-115. Re-read the post. I INTERPOLATED the time it would take to get to 90 MPH based on the time it takes to go from 60-115. It was a rough guess, but it's a fair assumption: 0-60 in about 4.5 seconds, 60-90 in four seconds, 90-115 in four seconds...

BMS2004- the Z06 DOES dominate SoloII Stock class. Quite handily, I might add.

1st to 3rd- MOST autocross events do not reach speeds over 60MPH. However, that's not to say that they can't. I've run several that were well over 60MPH at times. Heck, I broke 60 at last weekend's event in the rain! (see attached GEEZ Plot...

israel 12-08-04 11:16 AM

autoX vids > math racing

AMRX7 12-08-04 12:32 PM

I wasn't arguing that the Z06 would accelerate that fast, just that even it if it did, it would still fall well short of 90mph in the distance available. Since we're thwack thwacking this to death...

You said a Miata would do 0-60 in 7.8s....

-which would imply it's average acceleration to do that would be 11.28 ft/s^2
-at 11.28 ft/s^2 for 7.8 s, the Miata would cover about 343 ft of distance

So how fast would a Vette get in 343 ft?

-using your 4.1 0-60 implies the Vette accelerates at around 21.5 ft/s^2
-so the Vette would cover the distance of 343ft in about 5.6s
-assuming that 21.5 ft/s^2 acceleration is constant, the Vette gets to about 82mph

And that's assuming better than possible acceleration, and that the Vette would just floored in a straight line. Even if the Vette just floors it through everything, it's going to scrub off some speed in turning.

So, I'll buy a Z06 getting into the low 70's if the driver decided to shift, but no where near 90mph. I've driven enough autox courses that this one sure didn't look like it was abnormally fast. Of course, the simple thing would be to ask one of the faster cars at the actual event if they made it to 3rd gear, and if so for about how long.:):)

In any case, it's a nice video, though I think the perspective makes the speed seem greater.

-Andy


[QUOTE]
AMRX7- I never said the Z06 would accelerate the same from 0-60 as it does from 60-115. Re-read the post. I INTERPOLATED the time it would take to get to 90 MPH based on the time it takes to go from 60-115. It was a rough guess, but it's a fair assumption: 0-60 in about 4.5 seconds, 60-90 in four seconds, 90-115 in four seconds...
QUOTE]

scotty305 12-08-04 04:36 PM

Average acceleration calculations, very nice... :D

Don't forget that the Miata should be able to hold its speed for longer because it will be able to brake later. The higher speed the Z06 acheives, the earlier the driver will need to apply the brakes to decelerate to cornering speed.

Needless to say, I think most of us would enjoy being in the Z06 between corners, even if the top speed reached is only 5-10mph higher than the Miata.

Why are autocrossers even talking about top speeds in the first place? Get back to adjusting your tire pressures and damper settings people!!!

-s-


All times are GMT -5. The time now is 04:13 PM.


© 2024 MH Sub I, LLC dba Internet Brands