Coldmale

Guys

Thinking only of DOT compounds and R6, A6 and MPSCs in particular, what is the maxium sustainable lateral G you can regularly achieve.

You would have to set your data logger output to a smoothing of say 5 in order to discount some instantaneous "g's" due to wheel whip and the like.

Quite frankly I have installed the full pfadt coilover and sway bar system on my Z and even with wider (295&345) and better tyres, the lateral Gs I am getting are no better than a stock C5 with 275 & 295 tyres

Thanks.

John Shiels

so what do you get now?

BFoster

Your rears are pretty big compared to the fronts... Try a 315 rear tire to start. You should notice a difference in cornering with the tires and coilovers!

rfn026

The Corvette engineers had a pretty good idea about what to do. At least your Corvette didn't get worse. That's what usually happens with aftermarket parts.

Richard Newton
My Speed TV Page

Datawiz

Most I've seen on the stock run flats at autocross is 1.19 G. With Hoosier A6's, I've seen 1.35.

wallyman424

W/ A6's and aero I've hit a max spike of 1.8, and sustained plateaus of 1.5

Timz06

On my C6 z with new runflats, my g meter was reading a consistent 1.2 around the sweepers at roebling road. Looking at my data from Road Atlanta in my T1 car, I am getting sustained values of up to about 1.5 with hoosier A6's. I would expect similar performance from a stock C6Z with the A6's.

I don't see how coil overs would make a difference for max lateral G in any case (on a smooth track), if the car is weighted properly. You won't get the max until the suspension sets, the springs and shock combo only works in transitions.

Wicked Weasel

looking at my traqmate data my g-force at WGI and my max average is just over 1.5 with Hoosiers A6 and hardbar coilovers. I would think there is more room, but that would require me growing some bigger ballz

96CollectorSport

Buttermore sees spikes of 2.0 g and sustained in the 1.4-1.5 area, I would think with areo ST2 cars should see a little higher than that.

I've seen numbers similar to Wallys with Geffs ST2/TTS car, depending on track surface.

Coldmale

Forgetting the spikes, max sustainable is around 1.1 and a peak at the apex of say 1.25. That is just the same as it was in the C5 automatic.

I had expected the 1.5 figures you guys talk about and because of that I installed the ARE Stage 3 oil system

This is not about *****, those are the figures where the outer wheel starts to skate and balance is lost.

The coild are set at the pfadt recommended settings and there is no appreciable under or oversteer. Its hard on the road but nice abd really stable on teh track. At 280 (km/hr) the car is rock solid

Alignment is same as teh C5 with -2.5deg front and -1.5 rear. I did try -3 front but noticed no difference. Rear is better at -2 but braking suffers at that

I have a little toe out front and a lot toe in at the rear. Everything is like the recommendstions on this board.

Solofast

You have to throw away any data that is on anything but a flat surface. Lots of road courses have some subtle banking and that makes the data junk for comparison purposes. I've found that measurd grip gets much larger even with a slight banking effect.

I think you will find real data on a flat surface to be lower than 1.5 most all the time, and more like 1.3-1.4 is pretty much it unless you have aero or some banking.

John Shiels

and downforce

L98Terror

Is downforce really help at those low speeds? At what speeds does DF help? 80+

alextz

I would discount transient G's (instantaneous maximum).

What I find more useful is the 98th percentile of the maximum G cumulative distribution function (ie, this has the effect of maximum sustained G load).

The single biggest factor is tires and tire size. On Hoosier A6, I have seen 1.55g at 98th percentile (this is a car running wide tires on a really wide rim).

davidfarmer

the more aggressive springs/bars etc help with transitions more than outright grip....unless you are carrying a tire through the corner, maximum sustainable grip is pretty much determined by tire compound.

gkmccready

You've got a problem somewhere. My C6 Z51 on Toyo R888 275+305 can easily pull 1.2+G with peaks well above that. Mods are DRM coilovers, original Pfadt Pfatty swaybars, Pfadt poly bushings, and Wilwood front brakes. But none of those should really give me better grip on a smooth surface. Alignment is -1.75 front, -1.25 rear. Tick of toe-in front, 1/16" toe-in rear.

drivinhard

that's about all I get "normal" average I guess, running 275 A6s. some spikes to 1.75+ but most of the norm is in the 1.3-1.4 range

John Shiels

From what I have read I think 60 mph but you won't feel it in your body. I mean stick you hand out the window at 60 and angle it and you will feel down-force. Slow track more wing as you are not worried about high speed drag.

Coldmale

OK. Thats great feedback - but let me broaden the discussion

For those of you pulling say 1.4 and above, does track temperature influence the results?

Does a hot track grip better than the same track when cold? Say its 18deg C in winter and 36deg C in summer, what (if any) is the difference in grip.

regards and thanks - John

John Shiels

track temp will affect grip for sure and it could be to cold or to hot. I guess the exact temp is also based on the compound.