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Old 07-09-2001, 04:01 PM   #1
Estranged7
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Question Handling G's on a 2.5 RS, in stock or modified form

anyone know what handling G's a 2.5RS sedan gets in stock form? in modified form?
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Old 07-09-2001, 04:03 PM   #2
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according to Edmunds.com the 2000 RS holds anywhere from 0.87 to 0.82.

yeah, they got a higher number for the coupe as opposed to the sedan. go figure...

figure, put sticky tires on the car, and that number increases a good amount.
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Old 07-09-2001, 04:12 PM   #3
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It's easy to pull a bit over 1.0g sustained lateral loads in my car, when wearing Kumho victoracers. Besides the tires, the tein HAs and larger rear swaybar are definitely factors...

I can see over 1.5g braking too.
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Old 07-09-2001, 04:19 PM   #4
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I have a G-tech, so I guess I might be convinced to go get a reading in my car...

Mine is a pretty heavily-modified 99 RS coupe. I should think it can hold a good bit more than 0.87G.

I'll check it out tonight and post the results tomorrow. Here's my suspension setup:

KYB AGX struts (3F/8R)
Ground Control adjustable perches
ERS 8" 380lb front springs
ERS 8" 300lb rear springs
Whiteline 20mm front sway bar
Whiteline 24mm rear sway bar
Whiteline front sway bar links
Whiteline rear sway bar frame mounts
Kartboy rear sway bar links
Whiteline anti-lift kit
STi Group N upper mounts
Primitive front STB
Cusco OS rear STB
Cusco Y bar
Cusco rear LAB
Dunlop SP9000 195/50-16 on stock 99 rims

And of course comp. bumper supports, which takes almost 50lb off the overall weight of the car.
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Old 07-09-2001, 04:24 PM   #5
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why on earth are you running 195/50's on your car?
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Old 07-09-2001, 04:28 PM   #6
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According to my GEEZ! computer, my car will pull 1.08-1.10 continuous and 1.17-1.2 instantaneous. I have Tein HA's, PZero Asymetrico 225/45-17 tires, 20-24 mm MRT rear sway bar, strut tower braces front and rear, and solid links. I don't remember braking G's but I think it was less than 1.2.
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Old 07-09-2001, 04:35 PM   #7
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jgard18, I imagine the 195/50-16s are because of the 8" 7kg / 6kg springs. the car is probably in the fricken weeds! max ride height is probably about stock, maybe lower.
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Old 07-09-2001, 04:37 PM   #8
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The 195/50's offer plenty of grip for any kind of street conditions I have encountered. And steering response is the best I have ever felt for tires on a 16 inch rim.

For the record, I run completely different tires on the track. I am not even remotely interested in burning up good gummies for a lateral G test.
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Old 07-09-2001, 04:38 PM   #9
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seriously.... and the speedo must be nice and way off... along with just the lowered height...

I'm also thinking that it's a smaller surface area on the ground, though it's also a tiny sidewall...
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Old 07-09-2001, 04:54 PM   #10
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Default lateral G's

.82 to .87 is pretty ****ty, even for stock. i think the toyota camary sedan gets .87, surely the impreza 2.5RS coupe is better (i'd certilny hope so!) 1.5 sounds really high, as anything over 1.0 starts to get difficult to obtian, especially if the stock 2.5RS only has .87 to begin with. looking forward to actualy G-tech readings for that moded car, and does anyone have any old copy of road and track, cuz that would surely have the stock cornering G's.
specture23 - i'm a little cautious about your readings there. 1.1 steady, and an instantanious 1.2 i can see being possible - but i dont see how if you havent touched your springs/shocks. i'd be weary of that computer that tells you 1.2...

Charlie

PS: digdug - looking foward to your results!

Last edited by Estranged7; 07-09-2001 at 04:56 PM.
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Old 07-09-2001, 05:10 PM   #11
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I said 1.5g under braking. Hardly unusual for any autocross car in Street Prepared or above...

Spectre has the same suspension I do, so no it's not stock. His numbers are mighty impressive though considering I'm on DOT-legal race tires and he is on high performance street tires. Of course, I also suck as a driver.
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Old 07-09-2001, 05:10 PM   #12
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ummm... dude, .87 is really good for a car of our caliber.

my 88 RX-7 pulled 0.83, and that thing handled sweet.

I know a Caddy puls 0.77, and a minivan is only slightly less. So while the figures sound close, 0.03 is actually a good amount when it comes to real world handling.
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Old 07-09-2001, 05:20 PM   #13
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Default .87 good ?

.87 is very, very adverage if you ask me. i'm considering buying a subaru 2.5RS or a 92' toyota mr2 turbo. the mr2 in stock for corners at .92 which is really damn good, upgraded it can easily see over 1.0 - and yes - in the real world .03 makes a hell of a difference. this is why i want accurate specs on the subaru, as .82 is unacceptable, where as .87 or .89 in stock form is something i can work with.
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Old 07-09-2001, 05:37 PM   #14
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I was pretty suprised to see those numbers for my car as well. The GEEZ! system seems to be very accurate though, but those numbers seemed way to high. So I stuck the G-cube in a friend's stock Stealth on super crappy tires and it read under .85 so would assume the numbers are good. And as long as I can get a good map out of the G-Cube, the numbers should all add up.

And like CollinL said, my spings/shocks are far from stock. I said in my previous post I have the Tein HA's. Also, those PZero's are pretty amazing tires. I got an extra .04 - .06 G's out of them over the Yokohama AVS-i's. Wish I could check my car on Hoosiers though.
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Old 07-09-2001, 06:21 PM   #15
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I think perhaps an important part of this post should be the process for repeatability. It's probably a good idea for people to run in circles like a skidpad. It'd be best to run circuits both clockwise and counterclockwise and average the two. Also, in an ideal world it'd be nice for everyone to be running on the same diameter skid pad. I don't remember off hand how big SCC's is. Anyways, I think there is definitely something wrong with the 1.08 - 1.10 measurements. I mean, that'd be totally awesome but I just don't see it happening on street tires without some really awesome suspension tuning and top secret test tires. I think getting over 1.02 is really upper echelon for street driven cars.

-Brian
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Old 07-09-2001, 08:55 PM   #16
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.83-.87 ain't bad.. considering a stock RS is running on those deck slippers they try to pass off as all-season performance tyres.
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Old 07-10-2001, 01:02 AM   #17
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Hey Spectre,

Where are you mounting your GEEZ cube? I've noticed that different locations can have a pretty noticeable effect on the measurements. I'm mounting mine in the bottom of the center console. It's a nice level location near the car's CoG.

For a while I mounted it in the empty space where the factory CD player would have gone. Unfortunately I think that location isn't quite level enough and that the autocalibration is some help, but that it's still not quite right.

One thing that's important to mention about GEEZ measurements is that in most cases you're seeing values observed during an autocross run, not the same kind of test that the car mags use.

In an autocross you may sustain 1.0x g's for .5 seconds and GEEZ reports that as max sustained g's.

A short half-second burst of lateral acceleration is different from a sustained steady-state run around a 250' skidpad like they use for magazine testing.

As you load up the suspension the geometry can change. That half-second of 1.0x g's could have been as the car's suspension swept through the geometric sweet spot. On a skidpad the car's suspension may settle into a geometry that isn't as good as that .5 second sample Geez gave - yielding a lower number.

GEEZ can be used for this kind of test though. Just set up a 250' skidpad, run the car around and when you do your post-run analysis crank up the amount of time that GEEZ uses to calculate sustained g's.

Last edited by kelley nelson; 07-10-2001 at 01:14 AM.
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Old 07-10-2001, 02:52 AM   #18
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Yes, I too am mounting it in the bottom of the center console. I never tried any other locations. I have had mine about 1 year now. Still learning to tweak the maps.
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Old 07-10-2001, 07:44 AM   #19
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You know, Estranged7, what you could do is actually drive the car! The numbers are nice and all, but frankly they don't mean crap when it comes to real-world handling. I'm sure if you compare the skidpad numbers for my Mustang and my Subaru, the Mustang pulls bigger numbers, but the Subaru is a much more competent handler in the real world. I guess I just don't understand the fixation you seem to have with the skidpad numbers.

Pat Olsen
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Old 07-10-2001, 10:07 AM   #20
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and you know what's funny? in the magazine we just got from Subaru... they list the WRX as only 0.84 on the skidpad.

so yes, like Patrick just said, drive the car...
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Old 07-10-2001, 10:11 AM   #21
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Um, you all realize that skidpad numbers are a very small fraction of how a car handles overall. I'm not sure about you, but I rarely drive in a steady circle for too long of a time.

The overall feel of the car is what really counts, and that isn't quantitative. Compare numbers all day long if you want, but I'll tell you right now that my RS handles much better than my 92 Prelude, which pulled the same kind of oh-so-important skidpad numbers.
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Old 07-10-2001, 02:15 PM   #22
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Well, after watching motortrend yesterday, they got 0.89 Gs with a new M3 on some sticky performance rubber... .87 ain't that bad at all.

Again, cornering Gs don't really reflect how a car handles all the time, it doesn't account for feedback, tossability, etc. etc.
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Old 07-10-2001, 03:12 PM   #23
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Well, unfortunately I don't have any numbers to share yet - my wheel bearing on the front right has started the old growling noise (long story behind that one). I will get that fixed in the next couple of days and get some numbers to post (at least for those of us that actually care).
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