need.... more.... traction...

[slngsht]

Frustrated with the cold weather and work, I decided I'm gonna take Frankn7 out today, and for the first time, see what she can do from 0-60 in an unofficial test.



So I drove around until I found a spot on the highway, pulled over and let traffic pass, turned on data acquisition and took off when there was an opening.



I started the run directly from the shoulder, in 2nd gear. Tires had 5 minutes of normal driving on them, at 40 degree weather.



0-60 was pretty disappointing at 3.8 seconds :(



My data capture is below... Note % throttle http://www.usa7s.com/aspnetforum/images/emoticons/lol.gif



http://www.usa7s.com/forum/uploads/slngsht/0to60.jpg

[RDROCKT]

HOLY BLACK STREAKS!



How did it feel? Loose? Stable? Is the grin still all over your face?

[slngsht]

I tried to keep wheel spin to a minimum. In the beginning you feel really trapped by lack of traction. If you look at the data, you'll see as I approach 60 MPH, each .2 seconds, i'm gaining 6 MPH, where as when you look up the table, I wasn't able to gain as much (except at 8 MPH, where I had to back off the throttle).



There is ALOT more in there. maybe warmer tires and a straight launch will help.

[scannon]

That's VERY IMPRESSIVE! There are damn few cars on this planet that can do a 0-60 in 3.8 seconds. To do it on cold pavement and tires, from the side of the road and starting in 2nd gear is even more impressive.



Looking forward to seeing what it will do under optimal conditions.



Skip

[Al Navarro]

I told you guys this car was quick!



And that was before the cam install. http://www.usa7s.com/aspnetforum/images/emoticons/ack2.gif



I've got to find those CSR rear rims quick!

[rv-4mike]

The Ariel Atoms with 245HP - 300HP Honda and Ecotec engines are 0 - 60 under 3 seconds. The 245HP cars are actually just as quick because the 300s are traction limited. Anybody know of a Seven that runs sub 3 seconds 0 - 60?

[locostv8]

315 35 17s = 12"+ tred

[slngsht]

The Ariel Atoms with 245HP - 300HP Honda and Ecotec engines are 0 - 60 under 3 seconds. The 245HP cars are actually just as quick because the 300s are traction limited. Anybody know of a Seven that runs sub 3 seconds 0 - 60?



3 seconds is my target. I'll take her out again when it's warmer, and find a place where I can actually be on the road when I start. I may even let some more air out of the tires. I'm running 22 PSI now

[slngsht]

315 35 17s = 12"+ tred



I'm trying to take it a little easier on my wallet, but I will really need to upgrade the rear at some point.

[slomove]

I suspect when Ariel and the likes go out for acceleration testing to print in their literature they make sure everything is right, like nice warm drag strip, sticky warm tires, an experienced drag racer, shedding all junk from the car, engine optimized etc. Then they may do some dozen runs and pick the best. After all this is one of the most important marketing figures. I guess the chance for the normal driver to get there is pretty slim. The 1/4mile figures are probably more reliable.



Gert



P.S.: I am happy when I get 4.5 seconds....Even then my times vary wildly +/- 0.3 seconds, depending on how fast I shift. I am also confused because I read the car companies and most magazines use a 12" roll-out before they start the timer. There is already abou 0.2 to 0.3 seconds. <edited><editID>slomove</editID><editDate>2007-01-28 13:24:45</editDate></edited>

[slngsht]

I suspect when Ariel and the likes go out for acceleration testing to print in their literature they make sure everything is right, like nice warm drag strip, sticky warm tires, an experienced drag racer, shedding all junk from the car, engine optimized etc. Then they may do some dozen runs and pick the best. After all this is one of the most important marketing figures. I guess the chance for the normal driver to get there is pretty slim. The 1/4mile figures are probably more reliable.



Gert



P.S.: I am happy when I get 4.5 seconds....Even then my times vary wildly +/- 0.3 seconds, depending on how fast I shift. I am also confused because I read the car companies and most magazines use a 12" roll-out before they start the timer. There is already abou 0.2 to 0.3 seconds.



Good points... I hadn't heard the 12" roll thing before.



In my case, maybe more weight would help... maybe I can have a passenger stand on the rear axle and hold on to the roll bar http://www.usa7s.com/aspnetforum/images/emoticons/lol.gif



There is no doubt quarter mile numbers are more dominated by power/weight, than by traction ability.



I will make another measured run next time it's warm.

[rv-4mike]

The 2.7 - 2.8 second times I've read about for the Atoms were from independant testers (magazine articles).



A 12" roll isnt exactly 0 - 60 is it? http://www.usa7s.com/aspnetforum/images/emoticons/confused5.gif Never heard of that before.

[slomove]

I am not a drag racer but this roll-out business has something to do with the point you stop at when the stage lights triggers at the drag strip. If you stop immediately you stage "shallow" which gives you a good end speed but bad reaction time. If you roll a few inches beyond that point you stage "deep", giving better reaction speed but worse overall time.



For me that all means if it gets into the 3 or 4 seconds to 60 everything becomes subjective....



Gert



P.S. more info >here (http://www.gtechprosupport.com/support/technotes/Gtech-Rollout.pdf)

[slomove]

Another interesting one (clipped from www.automobilemag.com):



Philosophy: Automobile tests cars for a variety of reasons. While many makers offer a few snippets of acceleration, top-speed, and gas-mileage information, many do not. Conducting our own tests fills in gaps and adds trustworthy information about passing ability, cornering grip, and stopping performance. Having accurate performance profiles helps us pass judgment when we compare one contender to the next or draw conclusions at the end of a Four Seasons evaluation. Since there is no industry-wide standard for car testing, every maker has its own pet procedures. Some test with less than a full tank of fuel, some with two passengers and luggage aboard. Doing our own tests is the only means of leveling the playing field. Some publications strive for the quickest, fastest, or most spectacular results. We make no attempt to emulate quarter-mile drag strip results by subtracting the roll-out portion (the 0.3-0.4 seconds required to move the first foot) of the acceleration run. Drag strips divulge nothing but the speed achieved near the end of the quarter mile and the time required to accelerate that distance. Since the strip reports no other time-to-speed information, subtracting roll-out from 0-60 mph results is never warranted. Many magazines do adjust all of their acceleration results by subtracting the roll-out. We do not because, even though that yields quicker, more tantalizing performance figures, it presents a less accurate picture of the car's abilities.

[slngsht]

thanks for the read...



For what it's worth, I posted this thread in the offtopic section. There is a guy on corvetteforum who is VERY good at getting excellent 1/4 mile numbers, and he is a nice guy to boot - and from Maryland no less http://www.usa7s.com/aspnetforum/images/emoticons/biggrin5.gif.



Anyway, he did a write up on what he does, and I cut and pasted it here:



http://www.usa7s.com/forum/forum_posts.asp?TID=299&KW=z06

[rv-4mike]

I think most magazines use a data acquisition systems when testing cars, at least the ones I read do. I dont know if the mags I read the Atom articles in do. They also usually correct all performance measures to standard atmospheric conditions so you can compare apples to apples. The data acq. would take away any trickery with staging.



10.85 out of stock Z06? I'd have to see that to believe it!

[slngsht]

I think most magazines use a data acquisition systems when testing cars, at least the ones I read do. I dont know if the mags I read the Atom articles in do. They also usually correct all performance measures to standard atmospheric conditions so you can compare apples to apples. The data acq. would take away any trickery with staging.



10.85 out of stock Z06? I'd have to see that to believe it!



10.85 is in a C6 Z. He's very well known in the community.

[sb427f-car]

Is this why you started a thread on the STi center diff on the locust board?&nbsp;&nbsp;&nbsp;http://www.usa7s.com/aspnetforum/images/emoticons/biggrin5.gif&nbsp;&nbsp;&nbsp;Or are you seriously thinking about going AWD?

[slngsht]

http://www.usa7s.com/aspnetforum/images/emoticons/lol.gif No AWD... I just wondered if anyone had a rear diff like that.



I think I'm just going to go the simple route. My nephew will get me an 8" Toyota rear, we'll load her up with a trutrac diff, and 3.09 rear.



With slightly taller tires, I should be able to hit 60 in first, and 100 in second.

[soareyes]

Anybody know of a Seven that runs sub 3 seconds 0 - 60?



Yes, this one at 2.9 seconds:



>http://www.tigerracing.com/cars/tiger-z100-main.php (http://www.tigerracing.com/cars/tiger-z100-main.php)



Twin bike engines, four-wheel drive (one engine drives the front, the other the rear). Maybe its not a Seven anymore, more like a Fourteen? http://www.usa7s.com/aspnetforum/images/emoticons/wink5.gif<edited><editID>soareyes</editID><editDate>2007-01-29 12:13:47</editDate></edited>

[sb427f-car]

Yeah, that makes the most sense. So you are going IRS?

[slngsht]

No. It's a nice thought, but given my current state of work, etc... not really worth the huge design and fabrication effort.

[locostv8]

Mazda

&nbsp;&nbsp;&nbsp;&nbsp;I have a Versailles 9" disk rear end (58" WMS-WMS) that I don't think I will be using.

jh

[slngsht]

that's 4" wider than what I have.



Arya tells me the toyota 8" holds up fine on 500 horse buick GNX apps... maybe the 7.5" will be fine with my weak 440 horse on a light car http://www.usa7s.com/aspnetforum/images/emoticons/biggrin5.gif



what are the best WIDE 15" R compound tires around? I found some wide ones, but all are drag tires.

[Alaskossie]

Ben at Rocky Mountain Sports Cars told me that when he served an apprenticeship at Caterham in England, he was present when Caterham did a series of timed 0-100-0 runs in a Superlight 500 for a British magazine. He said that traction was such a problem that the car was tested with a passenger (him) and a full tank of gas, to try to get some weight down in the rear.



Tom Meacham

[rv-4mike]

Just to revisit the 0 - 60 performance thing. Found the following info in a thread on the Atom forum. This data comes from a test done by Car and Driver magazine that is in the March issue.



Lap times

Z06 2:01.00

Exige S 2:04.30

911 GT3 2:01.50

Atom 1:58.30

Noble M400 2:00.40

Brock Coupe 2:02.70



0-60

Z06 3.6

Exige S 4.1

911 GT3 3.8

Atom 3.0

Noble M400 3.3

Brock Coupe 3.7



0-100

Z06 8.3

Exige S 11.1

911 GT3 8.7

Atom 7.5

Noble M400 7.8

Brock Coupe 8.4



1/4 mile

Z06 11.8 @ 122

Exige S 12.8 @ 107

911 GT3 12.0 @ 118

Atom 11.5 @ 117

Noble M400 11.7 @ 120

Brock Coupe 11.9 @ 119



Braking 70-0 FT

Z06 153

Exige S 154

911 GT3 145

Atom 148

Noble M400 157

Brock Coupe 153



300-FT Skid Pad

Z06 0.99

Exige S 1.00

911 GT3 1.05

Atom 1.08

Noble M400 1.02

Brock Coupe 1.12



Lane Change MPH

Z06 66.3

Exige S 75.8

911 GT3 70.9

Atom 70.8

Noble M400 74.4

Brock Coupe 72.4



Atom Noise Level

Idle 72db

Full throttle 118db

70-mph cruise 103db



I havent gotten the magazine so just cut and pasted this from the Atom forum (the poster there does have the mag). The Atom equaled or bettered every car here including the Z06. Shame they didnt include a Seven in the test since I think it comes closest to the Atom conceptually.

[Al Navarro]

The Atom (as available in the USA) isn't so cheap, you know...and then there's the problem of registration/inspection/titling in some states. I know there is no way I'd be able to get one through NJ...based on what I had to do for the Se7en (mine is registered as a new car).

[rv-4mike]

Yeah, it isnt all that cheap in Britain either, although the guys over there on that forum all seem to think its a screaming deal. Cost is what sent me looking at Sevens, which I figure have to be pretty close in performance.



Given the choice between a new Caterham or an Atom, I think I'd choose the Atom. Price seems pretty comparable. But compared to the Ultralite I've chosen, the Atom is close to twice the price. I doubt its got twice the performance. Still, I hope to see some real comparison between the two some day just to see how they stack up.



In California there are guys registering the Atom via SB100, though that probably isnt totally legit. Other states seem to be a piece of cake, some there is no way.

[slngsht]

Well, this cold weather sucks, but I still went out for a ride today http://www.usa7s.com/aspnetforum/images/emoticons/thumbsup.gif



I finally found a quiet spot, and laid some rubber. Guess what... it's just an open diff! I was told it might be a TruTrac diff, but I have one long nice tire mark to prove it.



LSD or Quaife should help with the 0-60 times.



Question is... which would you go with?

[locostv8]

Torsen T2<edited><editID>locostv8</editID><editDate>2007-02-10 13:59:53</editDate></edited>