handling

[Guest Anonymous]

can I make a 77/78 280Z really handle well I mean 1+lateral G's and are they really that competetive in racing or is it just cool to race an old car?

[katman]

Well, our data acquisition system measures 1.45g at turn 6 at Road Atlanta, and about 1.2-1.3g in most other corners on DOT approved tires (Hoosier S03, like what was the DOT thinking?) for an ITS prepped 240Z so yeah, +1g lateral is possible on a 1977 280Z but not so's you'd want to drive one on the street that way.

 

For the street, urethane bushings everywhere, slightly stiffer springs and bars, real shocks, lowered, and hideously expensive ten thousand miles if yer lucky tires, and you might get near a g and still be able to go over a speed bump now and then.

[Dan Baldwin]

As katman knows (and has been responsible for), 240Zs can still be competitive in SCCA competition against more powerful modern machinery with better brakes. 280Zs are less competitive due to carrying ~400 lb. more weight. Still, you should be able to make it corner with the best modern street cars with a little effort. Ditto what katman said regarding springs/dampers. 225 tire width is not a problem with the stock wheelwells. This means that despite being heavier than a 240, you've still got potential for bigger tire width relative to car weight than just about any modern car. There are quite a few max performance tires available in 225/50-15, which won't rub much if any on zero offset wheels. If you're up to it, you might also consider ways to increase negative camber. The cheap and ugly way is to slot the shock towers, which would get you around 1/2 degree more negative camber. Something like -1.25 front and -1.75 rear would likely be a good streetable setup for maximum handling.

[pparaska]

Just what would you guys suggest for a 5-10K mile tread life (when driving hard some of the time, cruising the highways other times) SUPER STICKY DOT tire? I'm in the 255/45-17 and 235/45-17 range, but the tires you tell me about would probably be available for babykyle too.

 

I have Potenza S03's on my daily driver (92 Eclipse GSX) and love them. Anything stickier with even as low as 5K mixed duty tread life out there that's better?

[Guest Anonymous]

For the tire question I'm using Falken Azenis 245x45 and there like glue but the life is a little short(as is most sticky tire)and with steel belted sidewalls the 45 series has no flex but I dont own a 280Z yet I running them on my 94 S-10 thats 3100lb's so you should be fine. And to the person that gave the wonderful answer to my handling question THANK YOU I was tryng to figure out what car to buy for a race car and you answered it!!!!! anymore info or websites on racing Z's would be helpful, and do these things run at high speeds?

[Guest Anonymous]

Katman Thanks again for that answer. Are they still running the straight-6 or did they do a V-8 conversion and if its still the 6 how much HP are they getting out of it?

[johnc]

SCCA's Improved Touring class requires stock engine, stock engine internals, stock carburator and intake, etc. The 2.4L L6 engines built by Jim Thompson at Sunbelt are very, very close to 200 real crank horsepower.

 

Or, Keith, has he hit the 200 mark?

[johnc]

Pete,

 

Toyo Proxes RA1s at full tread depth should get you 5K on the street. Ran a set on my Contour SVT and got 8K out of them. The only tires better are the Hoosier S03s and the Kumho V700s (and the Ecsta 700).

[pparaska]

Thanks John.

 

How would you rate the other 3 tires you mentioned for tread wear, relative to the Toyo Proxes RA1s?

 

I'm having serious traction problems as it is with my 327, and the 406 with 100hp/100lbft more peak will be quite a problem, I imagine.

 

The Pilot MXX3's on the car are old and hard, so news stickier tires should be a big help (as well as getting the camber to near zero instead of the 1 deg negative it has now).

[Guest Anonymous]

This might sound stupid but does the 280Z look different then the 240Z and besides weight and a smaller motor whats the difference?

[Guest Anonymous]

sence your only talking about racing the 240 and not the 280 whats the disadvantage to racing the 280 besides weight? (forgot to add this to my last reply)

[pparaska]

Nothing. The added weight is enough to make in uncompetitive.

[Dan Baldwin]

Pete, wouldn't you be much better off with BFG or Nitto Drag Radials than with stiff-sidewall road-race/autoX tires if launch traction is your main concern?

 

babykyle, the 280Z (not ZX) looks almost just like a 240z, but with much larger bumpers. The ones on the 240Z are much smaller and lighter. The 280Z is fuel injected, while the 240 has dual Hitachi SU carburetors. The brakes and suspension setups are similar between the two, with minor differences that (I think) prevent spring swapping between them.

 

As for DOT race tires on the street, the Hoosiers are generally considered too fragile. A recent Grassroots Motorsports article had the Toyo RA-1s a little slower around an autoX course than the Kumho Ecsta V700 and the Kumho V700 Victoracer. With two different test drivers, one was faster on the Ecstas and the other faster on the Victoracers. Both drivers were quickest with Hoosier A3S03s, and slowest with the RA-1s (not by a whole lot). I've known guys to drive over 400 miles to events on the Victoracers, so I guess they're somewhat streetable. The DOT race tires were on the order of 2 seconds quicker around a 40 second course than the Falken Azenis or BFG KD street tires, pretty significant. Throw moisture or cold temps into the equation, though, and the best street tires might be better than DOT race tires, though.

[Dan Baldwin]

Oh yeah, a little anecdotal evidence of the above. Last year at New Hampshire Int'l, road course/south oval configuration, during a wet session I was faster than a somewhat competently driven M3 on Kumhos, in my '91 240SX on Bridgestone RE730s! Every lap he'd gap me, but I'd be right on his tail by the exit of the big oval turn. Then he'd pull away again through the rest of the course. That more than anything convinced me to buy STREET tires (Bridgestone S03s) for my 240Z for wet track duty and street driving (Hoosier R3S03s for dry track usage). I had been considering unshaved Kumhos. Now, though, I just don't think the DOT race tires could get warm enough to stick as well as the best street tires in the wet.

 

Like I said, though, purely anecdotal, could've been the M3 was timid on the oval.

[pparaska]

Dan, thanks for that info.

 

The car is 99.8% a street car. But I have traction (acceleration) problems all the time when I hammer it in first or second. Me thinks I need to learn to modulate the pedal better .

But better tires are a must. Especially with the extra torque coming this Winter/Spring in the form of a 406 with good heads and even lumpier cam.

 

The Kuhmos look interesting, but they are probably way more fragile to street wear than the Potenza SO3s?

[260DET]

DOT approved tyres have a numerical wear rating stamped onto the sidewall. Basically, the lower the number the stickier the tyre. From memory the Toyo RA1 is around 40 and they are quite a soft/sticky tyre. On the road, I found the RA1 ok except for some very occasional 'tramlining' or darting, although that could have been caused by having 2.5 negative front camber.

 

But, for road use only, I would go for a road type tyre. There are some sticky ones out there, check the wear rating number.

[randy 77zt]

my z is a daily driver bt has full ground control suspension,turbo engine.i can run with a its z on a race track.on track i run the kumho v700.down side is rough ride.springs are 225 in front and 250 rear.i need to try a gtech on track some time.its fun to make a trailered race car have to follow and look at your license plates.i can drive to the track but i usually put it on the trailer so i can carry a big cooler and sleep in my van at night.

[Dan Baldwin]

For 99.8% street usage, I'd go with the Bridgestone S03s. Not because of wear or durability concerns, but because I *think* that for street usage (tires not as hot as they would be after a few corners at the track) they might actually give better grip than the DOT race rubber.

[johnc]

Most of the DOT-R tires are designed to heat up quickly and to take heat well. Temps need to be 180 to 200 for them to work their best (especially the Hoosiers.) Street tires are designed to shed heat and to stay cooler. A street tire with temps over 160 is not very sticky. Although I have no objective measurements I did run my Contour SVT on BFG KDWS and Proxes RA1s and the Toyos were significantly stickier regardless of tire, road, or air temperatures.

[johnc]

Chet

 

Typical ITS 240Z pullling +1G and close to 200hp.