Just want to see what kind of g's anyone is pulling in their 4th gen f-bodies, and what suspension mods got you there. Anyone over 1.0 g's?

 

Race tires will do it, I'm hoping to hit 1.45-1.8 in the Z eventually

 

How are you guys measuring G's?

Many years ago & cars ago, a friend of mine purchased a G-meter that had a cool graphic display for his 944. Do they still make those? Tell us what toys you got?

-Rob

 

You can either do the math by hand with your speedo and a stopwatch, and a circle of a known distance, or I have a G-Tech pro (there is a new vesion out). Haven't used it yet, partly due to weather, and finding a place to do it that wont get me a ticket for being a *******.

I wouldn't guess my own Camaro to be doing that much, .87-.92? Who knows.

 

"I'm hoping to hit 1.45-1.8 in the Z eventually"

That would be extraordinarily impressive. It's more than a NASCAR stocker can do in a flat turn and more than my old Formula Ford did.

1.2 would be pretty damn good. Unless you put massive wings on and did it at 130 .

 

Bob, actually these cars are hitting 1.45 on street tires. 1.8 would be grandé for sure, those are Trans Am racer numbers!

17x11" and 17x9.5" has been done on a project Z (of course its not yet complete), about 2000 pounds, boxed tubing frame, C4 front/rear suspension. www.fastassdatsun.com

Right now, I have 15x7" wheels with 195/60s, 300 treadwear, and the car amazes me already. With 245s or larger, I can't even imagine it yet! I am a sports car convert, bigger cars are at just to much a disadvantage, and the expense to make them as competitive is pretty stiff.

 

I CORNER1 (home address) = I CORNER (work address)

With 1.45 - 1.8 gs, you must be referring to a stripped, lightweight, stiff chassis 240"Z" on full race tires, not a full street weight "Z"28.

Also since you mentioned the G-Tech Pro numbers, I am assuming that the above numbers are instantaneous peak G's, not steady-state 200-300ft skidpad numbers, which are typically much less.

As Rob K mentioned, there is a graphical display meter out there. I have a friend who is an SCCA driving instructor with a stripped AC Cobra Kit Car. He has an old G-Analyst that displays the G-Circle under cornering, braking and acceleration. I don't know if those are available now. It was impressive, as you could see peak Gs and somewhat steady-state Gs through the long corners.

My last 200ft skidpad run was almost 3 years ago, during a BMW club track day. I netted about 1.02 Gs average both directions. This was on a full weight 1994 Z28 M6 with spare tire and:

- Yokohama AVS Intermediate Tires (275mm/315mm)
- 17x9.5" front & 17x11" rear ZR1 wheels
- Eibach Pro springs
- Bilstein HD shocks
- Addco 1.25" solid front & 1" solid rear swaybars
- Lowered to 26" front & 26.25" rear (floor to fender peak)
- Kenne Brown Double Diamond subframe connectors
- G2 boxed steel front lower control arm with rod ends
- Global West front upper control arm with del-A-lum bushings
- Global West rear lower control arms with spherical bearings
- Global West anti-squat weld in brackets
- RK Sport aluminum panhard rod bar with rod-ends
- HPM Torque Arm with poly front mount
- Granatelli upper panhard rod brace
- Hotchkiss shock tower brace
- Stock Auburn posi with 3.42 gears
- Alignment settings: 0 deg toe, 1.5 deg neg camber and 4.5 deg caster

Since then I have switched to a Heavy Duty Torsen posi, R-compound tires and 3.73 gears. With the R compound Kumho Victoracer 700 tires, the car corners MUCH harder (guessing well over 1.10 Gs).

I am also in the process of replacing my broken "pinned" HPM Torque Arm with a Spohn TA with rod-end mount and pivoting locator link.

Stock 1993 - 1997 Z28s can easily pull 0.87 Gs with slippery Goodyear GSC tires, so I would hope a solid moderately modified Camaro could best 0.95Gs on good street tires.

 

240Z not Z28 right, I dont call a Z28 a Z. The Gtech will do continuous or instantaneous Gs, whatever you ask it and it will display. There isn't alot to strip out of the Z, I dont have power steering, I dont have air conditioning, none of that stuff. I have the heaviest itteration of the 240Z being the last year, and I dont expect to be more than 2300 pounds. I have Yoko AVS Intermediates on the Camaro, and the Z would blow it away without a doubt. For an even lighter car, there is the 914 or the Datsun 510, both in the 1700-1900 range in street form.

I've not yet heard of 1.8g in a Z, but looking at some of what it takes to get a TA racer to get there (if 311 cube, 2600 pounds), I think it could be done. IIRC rules are 16x12" max front, 16x13" rear. I believe to keep the car practical I probably wont go beyond 16x10" wheels, at least not in the next upgrade.

 

"I've not yet heard of 1.8g in a Z, but looking at some of what it takes to get a TA racer to get there (if 311 cube, 2600 pounds), I think it could be done."

Got a reference for that 1.8g? 6/01, R&T tested a $440,000 C5-R GM factory LeMans racecar. 2815 lbs., 18X12.5 and 18X13 wheels with 12 and 14 tires, double a-arms front and rear. They got 1.44gs. Hard to see how a TA would do more, much less that much more.

 

Winston Cup Cars 1.2 g

http://trans-amseries.com/carfacts.html

http://www.progressauto.com/delsol/hondaarticle3.html

If you consider Le Mans race length versus Trans Am, the disparity could very well be tire compounds used.

 

Le Mans is also not considered a downforce track, so they are going for speed.

 

"Le Mans is also not considered a downforce track, so they are going for speed."

OK, we agree totally. I was always talking g's on a smallish skidpad, where downforce doesn't come into play much. The 1.8g figure clearly is at speed and perhaps on a typical road race corner with a little banking. On a small skidpad I'll bet it's close to the 1.44 of the C5-R, say between 1.4 and 1.5. That's got to be close to the limit of present day race tires on a medium-large sized car.

 

Doh, you know what, I didn't even think about that. I was making the assumption these were traditional skidpad numbers, but with in car data aquisition these could indeed be peak numbers at speed. F1 is the same way, they aren't getting 4.2g at low speeds.

http://www.mulsannescorner.com/ talks a little bit about some cars (Porch 917) downforce differences, with/without GFX and such, and of course some g numbers.