[import111]

With enough weight reduction, stiff enough setup, smooth enough road, and wide R comps, maybe hold 1.5g's through a steady state corner.

Just guessing though, I don't know for sure. From what I have seen, after you get to holding 1.1-1.2g's with an STi, you need something major to get more stick than that.

[stretch]

I've read the best autocross cars will sustain 1.3G's. I think much higher than that, and the gyro you're using is sensing higher peak forces from the suspension loading and unloading. 1.1G's, to me, is a very impressively prepped street car.

In any event, I updated the spreadsheet again. More good stuff... now it tells you approximately what your damper dyno should look like. As it turns out the stock STI shocks match the stock STI springs quite well!

I've got more stuff I'd like to add, just need to find the time.

[4banger]

Originally Posted by 4banger

According to the gyro in my Nav system, I have done around 1.3-1.4 G's during brief transients on lowering springs. Now, I don't know how accurate the gyro is, but I think this may help explain why some people can produce pictures of STi's with 4 or more degrees of body roll. (I'll double check tomorrow the scale of the gauge again, I'm not 100% sure of the numbers)

Well, I went and checked things out and it turns out that my memory has failed me quite badly. The last increment on the gauge is 0.5 - 1.25 G, so the measurement is probably useless as well. I would guess that with lowering springs you can get 1.0 +/- 0.1, but I even fell uncomfortable saying that because I don't think you can read a gauge to an accuracy of greater than half of the increment between readings (in this case +/- 0.375).

[CONECRUSHER]

Can't open spreadsheet in Microsoft Excel 2007.

[4banger]

Originally Posted by CONECRUSHER

Can't open spreadsheet in Microsoft Excel 2007.

It works fine for me in Excel 2007 for Vista.

[flatthump]

Originally Posted by CONECRUSHER

Can't open spreadsheet in Microsoft Excel 2007.

I'm running 07' now too, just download the excel 'viewer'.

[kwlsti]

any updates?
BTW this program is f'ing AMAZING!!!

[stretch]

I think I made some minor updates since my last post, but no new calculations. They'll come, but it really already does most of the stuff I want it to.

It was made in Excel 2003 and should be compatible with Excel 2000 onward. Don't know what to tell ya... Microsoft products can be flakey.

[stretch]

There was a major error with regards to sway bar rates in my spreadsheet. With regards to body roll, the sway bar rates should have been double what I originally reported. The sway bar flexes twice as much, but whereas I was dividing that force between two wheels, that force is actually applied equally to both wheels. Thus, sway bars are actually way more effective than originally predicted.

I apologize for the error. The engineer that helped me discover this mentioned, "Don't feel alone, I've only seen one hard core circle track based web series where they had it right."

Well, make that two now!

[dsm02c]

Originally Posted by 4banger

Well, I went and checked things out and it turns out that my memory has failed me quite badly. The last increment on the gauge is 0.5 - 1.25 G, so the measurement is probably useless as well. I would guess that with lowering springs you can get 1.0 +/- 0.1, but I even fell uncomfortable saying that because I don't think you can read a gauge to an accuracy of greater than half of the increment between readings (in this case +/- 0.375).

My traqmate shows my car hitting 1.67 around some corners with R-comps... I dont know how accurate that thing is though.

[XDNBC]

Great spreadsheet Stretch! I did calculations with my setup and have a few questions:
1. I have stock springs and Whiteline 27-29 FSB and 22-26 Rear. In the calculations for roll bars I used 23.5RSB and assumed a 26FSB. With this my roll is 1.64* at 1.1G. I have my front camber at 2.3* and rear at 1.57*.
Does this mean I have too much camber in front?

2. In the weight transfer part there is ony 1 tire pressure used. I changed this section so I can input the different front/rear pressures I use [39F, 35R for AutoX]. The tire deflection diff. LFto RF, and LR to RR cells confuse me. What does the .37 and .23 amount signify [my figures are .28 and .22]? Why does changing these cells change the computed figure since I can't find B42 and B43 referred to in cells D42 and D43?

3. In the Tire Deflection Calculator, why is both front and rear weight on tires the same 1800lbs. Shouldn't it be more like 2088F and 1512R because of the 58/42 F/R weight ratio?

4. It seems like the stock springs and shocks are perfect for me. My only problem is that my camber plates have given me a 15.25" F and 14.25" R. Seems like I will need coilovers to lower the front without losing stroke. However, would also be nice to have smoother damping for the street.

I find your input into this and the TIC forum very informative. Keep it up.

[stretch]

1) No, because you get MUCH more body roll in real life than what I predict due to an enormous amount of flex in the car's bushings.

2) Sorry, I don't have time to look into that further (about to leave on vacation), but...

3) I have an entirely new tire deflection calculator in the works! It's much, much more accurate. You may have found an error in my old work, sorry!

4) Aye, "lowering" camber plates such as the Racecomp ones are much better for those looking to use the stock springs. But, I think you've got the right idea at least.

...and thanks!

[fullerton]

Just wanted to thank you for putting this together.

[Carisma]

Any new updates to the spreadsheet?

[stretch]

Yes, a few weeks ago IIRC. I think I updated the sway bar and tire deflection calculations.

If you haven't downloaded it recently, download it again.