Planet 9

chows4us · #21 11-06-2006, 05:05 PM

Originally Posted by Silent Will

I agree 100%. It is THE proving ground for an automobile IMHO.

And there is a reason for that. With how many turns? 172?

"... and between them those corners included every conceivable combination of radius, camber and gradient. ... Almost every twist in the track was designed to test and challenge the best of the best ..." http://nurburgring.org.uk/history.html

"Greatest & most challenging race circuit in the world"
Jackie Stewart

This is the place where you prove how good your car is (or isn't).

ufo · #22 11-06-2006, 05:28 PM

Does it include the time that it takes to get into the Lotus? I'm 6'1" and 170lb and I could hardly get into the thing!

If it included get in-time, I think I could do half a lap in the CS before the Lotus left the start line!

***DaveN007*** · #23 11-06-2006, 06:15 PM

Originally Posted by K-Man S

With regard to the inaccurate physics statement made by the bmw guy, having the weight in the nose and tail of the car makes it harder to change direction in the car so if you do start to spin you won't be able to counter steer and save it, much in the same way that if the tightrope walker starts to fall they can't adjust that long pole with weights on the end enough to prevent the fall, a shorter rod with say no weight on the end allows the walker to make quicker adjustments to prevent a fall. An ice skater picks up speed (angular momentum) when the weight is shifted from the outstretched arms into the body when doing spins. The Cayman doesn't shift weight from the bumper to the middle of the car, the weight dominance is always in the middle.

As lifted from another site:

Polar moment of inertia in a race vehicle is the center of all forces. It is the place that the race vehicle pivots about. The polar moment is also the center of weight in the vehicle or actually the center of gravity. The farther away from the polar moment weight is added to the vehicle, the more of a pendulum effect it will have when the vehicle changes directions.

Let's not complicate this with some scientific explanation. Here's an example that will hopefully illustrate how it works. Think of your vehicle as a set of barbells with 50 pounds of weight at each end. Imagine trying to quickly turn and stop the bar bell while holding it. You will notice that it’s hard to turn and hard to stop turning once it starts because of momentum. Now lets move the weights in close to the center of the bar and try it again. Notice now that the bar turns, and stops turning, easier because the weights have less distance to travel. Reduced polar moment of inertia makes a vehicle feel like it "wants" to change direction. The vehicle feels better and the suspension is easier to tune.

Last but not least from our Wiki friends...

Polar moment of inertia is a measure of an object's ability to resist torsion. It is required to calculate the twist of an object subjected to a torque. It is analogous to the area moment of inertia, which characterizes an object's ability to resist bending and is required to calculate displacement.

The larger the polar moment of inertia, the less the beam will twist, when subjected to a given torque.

The polar moment of inertia must not be confused with the moment of inertia, which characterizes an object's angular acceleration due to a torque.

What your BMW instructor may have been referring to was that typically the driver is near the center of balance and in a car with a low polar moment, one that can change directions quickly, is that if your car does start to slide the driver may not sense it as quickly as they would in a 57 caddy with heavy bumpers so their reaction time may be delayed and corrective action delayed meaning a spin happens.

My response to that would be "No I've got enough skill to drive one of these masterpieces, I don't need a heavy brick to tell me my car is turning"

Excellent post.

I understood what his rationale was, and my reply was simply this: "I owned an E36 M3 for 7 years and I like this car more."

:-)

Now if I can just figure out how to convince the bugs that my car is NOT made out of pollen. Have you noticed how Speed Yellow attracts insects when it is standing still?

**sleepless** · #24 11-06-2006, 08:15 PM

At most tracks, a standard Exige will be faster than a Cayman S (same or equivalent drivers). An Exige S would be significantly faster than a Cayman S.

mooty · #25 11-06-2006, 08:34 PM

pete has elise and cayman, i had elise and now cayman. i LOVE cayman BUT, i fear that exige S will leave cayman in the dust in just about every track other than high speed ovals where top speed may be issue.

a friend of mine has a stock elise with nitron. i have a cayman s with motons. we are both track rats and i would say about same skill, if anything he's a bit better than i. we drove very hard this weekend at LS and great weather. we both are on RA1's. my best was 1:44:xx, he did 1:42. pete, that's with Enigma driving his blue elise. now i have to find 2 seconds...

if you add a SC to elise/exige, i serioulsy doubt cayman s can keep up given equal drivers.

also, with regard to problems... i dont know about durability. but my cayman s is smoking so much at T2, i scared just about everyone behind me. his elise has no moroso oil pan, no accusump and no smoke either.

my pads/rotor comsumption rate is 4x more than his elise.

so for pure track car (stock to stock) lotus, whether it's elise, exige, exgie s, cup 240, cup 255 are all better than cayman.

that said, lotus are more fragile (body panels), and i have no data as to durability over long haul. but for 4-5000 track miles that he has had on his car, it had zero prob.

i dont know about the ring times, were cars driven by same driver, same day, same tires? is so, then ring must have lots of very high speed sections. my statements above are based on CA tracks, namely sears, laguna and thunderhill.

**K-Man S** · #26 11-06-2006, 10:25 PM

Originally Posted by DaveN007

Excellent post.

I understood what his rationale was, and my reply was simply this: "I owned an E36 M3 for 7 years and I like this car more."

:-)

Now if I can just figure out how to convince the bugs that my car is NOT made out of pollen. Have you noticed how Speed Yellow attracts insects when it is standing still?

I have the same problem with my speed yellow car, you just have to get used to bugs landing on it and thinking it is a large flower or something, it messes with their compound eyes...

**K-Man S** · #27 11-06-2006, 10:29 PM

Originally Posted by mooty

a friend of mine has a stock elise with nitron. i have a cayman s with motons. we are both track rats and i would say about same skill, if anything he's a bit better than i. we drove very hard this weekend at LS and great weather. we both are on RA1's. my best was 1:44:xx, he did 1:42. pete, that's with Enigma driving his blue elise. now i have to find 2 seconds...

Mooty,
I concur with your statement that the Exige is good match for the Cayman, but you ought not be 2 seconds slower than an Elise. I have not found an Elise (or Exige) that has come within 2 seconds of my Cayman at HPT (2.5 mile track 17 turns counting "alpha zero"), so I'm sure you'll find some more time shavings somewhere. With regard to the smoking issue any more word whether or not Mantis has that solved with another baffle or some sort of collector? My season is pretty much done but I'm concerned about next year.

btw I'm still waiting for someone to post pics of me driving backwards down the back straight at HPT with beez in the passenger seat...

**sleepless** · #28 11-06-2006, 11:07 PM

I forgot about the problems questions: 4500 track miles on the Elise, no problems. After less than 500 track miles on the Cayman S, had to have the cats replaced (my guess it is due to the oil consumption; cats don't like oil).

It will be interesting to see if the Elise S will have any track reliability issues due to the supercharger...

mooty · #29 11-06-2006, 11:37 PM

I concur with your statement that the Exige is good match for the Cayman, but you ought not be 2 seconds slower than an Elise. I have not found an Elise (or Exige) that has come within 2 seconds of my Cayman at HPT (2.5 mile track 17 turns counting "alpha zero"), so I'm sure you'll find some more time shavings somewhere. With regard to the smoking issue any more word whether or not Mantis has that solved with another baffle or some sort of collector? My season is pretty much done but I'm concerned about next year.
___________
i think your cay has more horses than mine.
at the very best, i can equal my friend's time in his elise, not eclipse it i dont think. and that's cay vs elise. now if he was driving exige s, i'll be sucking his exhaust all day.

i have mantis pan, i also have x51 baffle (which is similar to their updated version).... still smoke like hell.

mooty · #30 11-06-2006, 11:43 PM

Originally Posted by sleepless

I forgot about the problems questions: 4500 track miles on the Elise, no problems. After less than 500 track miles on the Cayman S, had to have the cats replaced (my guess it is due to the oil consumption; cats don't like oil).

It will be interesting to see if the Elise S will have any track reliability issues due to the supercharger...

you too? i feard too little oil i will get starvation so i add oil and killed my cat. my c2 cat died this way too. also i have have this read out "inefficent cat" form PIWIS.

i think the SC in lotus should be fine. jack has had no prob yet. you know he is as sick as we are in terms of track mileage.

i get CEL almost every track day. my dealer told me it's fine, just ignore the light. so my instrument is like xmas tree now. CEL on, exclamation light on, PSM off, TPMS warning on, cruise control on (way home)... it's kind of interesting with all the lights on the dash.

all that said, i still love this car. it is the FIRST car i will keep for two track seasons!!! surprised my mechanic as he was ready to build me roll bar for the next toy LOL.

**zal_kindi** · #31 11-07-2006, 12:01 AM

Interesting track test at: http://www.youtube.com/watch?v=0_53vvyLQNM

I know it is in German but it seems to conclude that the Cayman S and Boxter S (the 3.2 I think) are quite close in performance (0-100 km/h, 100-0 km/hr, etc) and both, close to the Z350!. At the end, it appears that they rank the Exige at #1 in their handling tests caompared to #20 and #22 and #24 for the Cayman S, Boxter S and Z350 respectively. Or, may be I misunderstood the conclusion. May be a good German speaker can help us translate here.

Ned · #32 11-07-2006, 12:46 AM

Originally Posted by DaveN007

You guys are funny.

Here is my brother setting up to pass a Lotus in his M5 at Laguna on Friday.

And one of me setting up to pass an '01 Turbo in my Cayman, no S.

Which cars are the best track cars?

DaveN007, this is off topic, but were you able to really pass the turbo? It's so much faster- even through the turns I assume.
-Ned

Chris R. · #33 11-07-2006, 09:54 AM

Damn! I had wriiten a whole response and then the site crashed! Grrr.

Mooty: I'm glad we have had the same experience with the exige and elise; I was starting to think everyone here is a better driver than I am if i can't keep up with an exige and others can! Truth is, I think that the exige is pure track sex and would love to own one but it's just not in the books for me now.
I'm very happy with the CS since it's a great track car, looks great and is pratical enough that i can drive it all summer if I have to.
I'm going to try to get a couple of pics of the exige that my buddy has (that smokes me) and post them here.
Cheers!

Chris R. · #34 11-07-2006, 11:10 AM

The car I was talking about (my buddy's) is a Lotus Exige Cup 240R.
Check it out!
http://i20.photobucket.com/albums/b2...u/IMG_0794.jpg

http://i20.photobucket.com/albums/b2...u/IMG_0808.jpg

**sleepless** · #35 11-07-2006, 11:30 PM

Originally Posted by Chris R.

The car I was talking about (my buddy's) is a Lotus Exige Cup 240R.
Check it out!
http://i20.photobucket.com/albums/b2...u/IMG_0794.jpg

http://i20.photobucket.com/albums/b2...u/IMG_0808.jpg

As I'm sure you know, the 240R has 22 more ponies than an Exige S and 51 more than a base Exige. No way you'll catch that car in a Cayman S!

**sleepless** · #36 11-07-2006, 11:33 PM

Mooty - Yep, killed that cats in my 2000 Boxster S as well. Seems Porsche's cats don't like a lot of track abuse. Doesn't bother me, dealer always replaces them under warranty; knowing that I track my P-cars. Local Lotus dealer does not seem as willing to fix such items if they can tell you track the car, which is totally stupid given how Elises and Exiges are tracked a lot and built to live on a track! Fortunately, I've had no problems with the car.

Yep, Jack is a good test subject for the supercharged Exige; I wonder how many track miles he has on his Exige Cup...

**Silent Will** · #37 11-08-2006, 08:05 AM

Love the Cup!

mooty · #38 11-08-2006, 08:07 AM

Originally Posted by Chris R.

The car I was talking about (my buddy's) is a Lotus Exige Cup 240R.
Check it out!
http://i20.photobucket.com/albums/b2...u/IMG_0794.jpg

http://i20.photobucket.com/albums/b2...u/IMG_0808.jpg

that's not an exige, it's a cup.
you'll have hell of a time keeping up with that, even in GT3.

**K-Man S** · #39 11-08-2006, 08:45 AM

mooty and sleepless,
As an FYI Porsche originally shipped 400 cell cats on the Cayman S until builds starting around this past May. They then switched to 600 cell cats. The reason you get the CEL is because the 2nd O2 sensor sees too high of emission levels and trips either a code P421 or P431 (left or right side) claiming that the cat is bad. It isn't so much that the cat is really "bad" per se it is that for some period of time the emissions were too high so the computer flags it as bad. You can clear the CEL with a simple ODBII tool available at your local auto parts store or your dealer can clear it.

When they put a second set of factory cats on my car (600cell) I didn't get the codes anymore. With 100 cell Milltek cats/headers I occassionally got CEL codes for the same reason. After switching to 200 cell Milltek cats/headers I've only had 1 code. I'm not really concerned about them, I have the ODBII scanning device to reset the code if it does happen.

There are really 3 options to prevent it:
1) Get the 600 cell cats from Porsche which is what they will put on your car if you get a replacement set. I don't know anyone who has tripped a code with these, but of course they probably rob a little more HP too.
2) Have your 2nd O2 sensor shut off by ECU programming. I know Orton and others will do this.
3) Relocate the O2 sensor further back in the exhaust stream and "hope" it doesn't trip. (would probably have to be after some secondary cat or something to have a shot at success)

Most people will probably go with #1.

**sleepless** · #40 11-08-2006, 08:24 PM

I went with option 1

I didn't notice any power loss.

Great info, thanks.