SCCA Solo D Street discussion

[Mball19]

Thanks for the suggestions. I will play with tire pressure this Sunday. It is supposed to be about 40 degrees this Sunday morning. Is it safe to drive on the Stones at that temperature or should I put them on at the event? I have heard that Stones don't like temperatures below 50.

[steverife]

Originally Posted by Mball19

Thanks for the suggestions. I will play with tire pressure this Sunday. It is supposed to be about 40 degrees this Sunday morning. Is it safe to drive on the Stones at that temperature or should I put them on at the event? I have heard that Stones don't like temperatures below 50.

They're fine.

I actually drove the first 75 miles or so in the snow on my way to the Dixie Tour a few years ago in my ES car.

[Mball19]

Originally Posted by Locust

35 PSI is way too high. That's what I run my cars at for daily driving...

If you're on the crash bolts you should be in the realm of -1.0 to -1.8 camber in the front and your rears are probably stuck right around -0.8 and won't ever move. You can use toe to play with the turn-in a little but you're pretty far off on all the rest so I would go with 0 toe all around for now and focus on getting the right parts on the right ends of the car.

Since this is D-Street you're limited to OEM rear bar so your 22mm is too much for the front. Most people go 20mm and a tiny bit of rear toe in. A 22mm worked when the TRD rear bar was allowed.

My pressures that I ran on RE71R were 28 front / 26 rear. BFG was 29 front / 26 rear. That was with a 20mm whiteline FSB and off the shelf Koni yellows (with the mandatory centering washer). You can adjust a little up or down for your setup and driving preferences but if you're running a square pressure setup then something is off. I can't recall a highly competitive car that wasn't running staggered pressures.

I installed a 20mm TRD front bar and dropped pressures as the day warmed. I ended up at 32 front and 30 rear. The car felt great. I will try going lower at the next event. Thanks for the suggestions

[Locust]

Originally Posted by Mball19

Thanks for the suggestions. I will play with tire pressure this Sunday. It is supposed to be about 40 degrees this Sunday morning. Is it safe to drive on the Stones at that temperature or should I put them on at the event? I have heard that Stones don't like temperatures below 50.

There is nothing inherently "unsafe" about driving a tire outside of its optimal operating range (within reason obviously... -60C or +180C wouldn't be safe but you're not driving in the arctic or on hot coals). The only differences you will notice due to ambient temperature are in the performance of the tire. Competition oriented tires will have their optimum grip in some heat range above what you would normally see as ambient/surface temps. At 40 degrees ambient temperatures on a Bridgestone it just means you need to heat your tires up a little bit more to get up to the optimal temp and will need to work a little harder to add temperature back in when the car is no longer in motion.

It's when you add in environmental factors such as rain, ice, and snow that you then bring in the safety factor. A dry competition tire at its optimum temperature while being driven on ice (ignoring that there's no way you're going to pull this off) would be fractionally more effective than a tire at 0C but would not be considered safe.

[nico_rsx]

Originally Posted by Locust

There is nothing inherently "unsafe" about driving a tire outside of its optimal operating range

That's not exactly true depending on your definition of safe. Obviously the tire will not explode or fail. But it could be unsafe for the tire. R-compounds tire (or tires kinda close to it like the RE71R), can get damaged if driven in freezing condition. I think the compound gets too hard and that can create small cracks in the rubber.
But above freezing temperature the tires should not get damaged. At 40F it should not be a problem.

[BigTuna]

I pulled off the D Street Championship for the Cincinnati Region!

[nico_rsx]

Who has run the car both stock and with an aftermarket front sway bar? Is it really worth it?
On a 60sec course, how much time do you think can be saved by using a bigger front sway?

[Olegreg21]

I have the Whiteline 20mm. Its hard to say about specific time gains with so many factors to deal with. It does make the rear feel planted through transitions. Therefore making you faster saving time.

[nico_rsx]

Originally Posted by Olegreg21

I have the Whiteline 20mm. Its hard to say about specific time gains with so many factors to deal with. It does make the rear feel planted through transitions. Therefore making you faster saving time.

Are you using the whiteline adjustable end-links?
Does it make the car understeer during longer sweeper/steady-state turn?

[Olegreg21]

Originally Posted by nico_rsx

Are you using the whiteline adjustable end-links?
Does it make the car understeer during longer sweeper/steady-state turn?

Yes I cant remember the part number. They came as a kit.

I wouldn't say it understeers anymore but it may with low grip tires. I'm also on koni struts so that may help the balance a little more. I run the bar and front struts on full stiff and it turns great imo.

[puertorican_stig]

Originally Posted by Olegreg21

Yes I cant remember the part number. They came as a kit.

I wouldn't say it understeers anymore but it may with low grip tires. I'm also on koni struts so that may help the balance a little more. I run the bar and front struts on full stiff and it turns great imo.

If you were on the factory shocks do you think you would still have the 20mm whiteline fsb set to the full stiff setting? I just bought that bar and not sure which setting to start with.

Current setup:
oem crash bolts (was able to get -1.5 F camber)
slight toeout F / slight toe in rear (but basically 0 all around)
motegi wheels wrapped in Azenis rt615+ tires (32F/30R)PSI

I may just start out in the softer setting as a starting point and go from there.

[Olegreg21]

Originally Posted by puertorican_stig

If you were on the factory shocks do you think you would still have the 20mm whiteline fsb set to the full stiff setting? I just bought that bar and not sure which setting to start with.

Current setup:
oem crash bolts (was able to get -1.5 F camber)
slight toeout F / slight toe in rear (but basically 0 all around)
motegi wheels wrapped in Azenis rt615+ tires (32F/30R)PSI

I may just start out in the softer setting as a starting point and go from there.

I would start it out on full stiff and if the car understeers to bad then you know its to stiff. If your car is tail happy (oversteer) now, the bar should settle it down. I set mine to the middle setting (one side on stiff, one side on soft) last year and the rear end was very unsettled.

[nico_rsx]

Originally Posted by Olegreg21

I set mine to the middle setting (one side on stiff, one side on soft)

You can do that?!?
It's the first time I have heard someone do that (except on the special Karcept bar).

[strat61caster]

Originally Posted by nico_rsx

You can do that?!?
It's the first time I have heard someone do that (except on the special Karcept bar).

Why not? It's just a spring.
If you don't have adjustable end links you'll likely put preload on the bar which may cause some thing wonky, but even then I doubt it would be super noticeable.