low profile tires to hide wimpy suspension?

[nostatic]

ok...I understand that lower profile tire should give less sidewall flex and hence some better cornering ability (within limits). But bling-bling aside, in some ways is it also used to mask lousy stock/street suspension? When I was at the track I didn't see any rubber bands on the track-prepped cars.

[MichiganMat]

I've been running big tires on my car and Im ready to swap them for some lower profile ones. the ride quality will go to poop but the car will feel a lot better at the wheel. If all else fails I'll put on a set of 17s, seems to work for this guy:





Oh yeah baby, thats the funky stuff right there! He even put lower profiles on the front than on the rear, word up.

m.

[JP911]

I think it's more about bling than performance. In other words, there is a direct relationship between bling and rim diameter, and as you increase rim diameter you need to reduce sidewall to maintain gearing, speed accuracy, fender well clearance, etc.

[ubiquity0]

Sweeeeet. He had to reinforce the fender lips to handle the impact of the tires slamming into them on every bump.

[MichiganMat]

Notice how the front fenders have been "shimmed" outwards also? The guy basically ran a long piece of aluminum, about 2 inches wide, inbetween the fender and the tub. The decklid was also custom made and had to be raised to give clearance to the intake. No mufflers either, straight pipes off the headers. American engineering at its finest

[thabaer]

WHATISTHAT!!!!


Ok, I feel better now.....


AHHHH!!!!

sorry, just clicked the link and saw the engine...

( at least he has the proper chrome chebby rake to go with that manifold )


I'm OK, honest.

BTW: Todd, isn't there some government health reg requiring a warning in the subject line

[Bill Verburg]

I understand that lower profile tire should give less sidewall flex and hence some better cornering ability (within limits). But bling-bling aside, in some ways is it also used to mask lousy stock/street suspension?

I wouldn't exactly classify a stock 911 suspension as lousy. The tire is most definitely a contributing factor to the character of the entire suspension. The effect of a lower profile tire will be to increase the apparant stiffness and harshness of the suspension. Sometimes that is a good thing sometimes not. A lot depends on the characteristics of the road surface and the speed at which that road is to be traversed. In general comfort levels will be raised by higher profile tires at the expense of ultimate traction and transient response, the opposite of course will be the result of lower profiles.

One should approach the wheel, tire and suspension questions as as system where all of the components are matched to optimize the desired characteristics.

[speeder]

Todd, Have you done any track events/DEs yet? It's an eye-opening experience. You will be surprised at both the strengths and weaknesses of your car, (I was anyways), but most importantly, I really did not know my car very well until I drove it as it was intended and had others drive it as it was really intended.

It's a whole 'nother (wonderful but time and $$ consuming) world. I wouldn't be worrying about your car set-up just yet, it's way more than sufficient for the bunny hill.

[Jack Olsen]

Even with period-correct lousy tires, these Porsche test drivers make the car's soft suspension do some cool things.

(Be warned: 5-meg movie file)

[nostatic]

I actually wasn't referring to Porsches with regards to the low profile tires...more of the import world. And in just the trips around CA speedway during the "parade laps" I got a taste of what could be. Or more like an inkling.

[surflvr911sc]

OTR @ WSIR, May 19, sign up now!

[nostatic]

I was thinking STS May 1 or 2, but OTR is a possibility too...depends on work schedule. Gotta get a helmet.

[surflvr911sc]

I wish I could make the May STS, I have a helmet you can borrow if you want to wait to drop the $$. Of course, I know you will probably be getting one sooner rather than later.

Slippery slopes my friend.

BTW, cool video Jack!

[Jack Olsen]

At OTR, you can ride in some other cars and get a feel for different spring rates and compromises.

[DByers]

OTR @ WSIR, May 19, sign up now!

So Ryan, I guess you will be there. Your dad coming? I plan on making that one for sure as it looks like OTR take sthe summer off.

Cool vid Jack. I wonder if the Stay Puff is that soft in the suspension. You should really take her out at the May event. I plan on some upgrades before the fall and she wont be so soft ( I hope).

Todd, the OTR events are alot of fun and are starting to attract more Porsches and Pelicans it seems. Must be Jack & Tysons doing with all the rides they give out in BBII and Scruffy. You should really try and be sick that day.

[Chuck Moreland]

The super low profile tires some people put on street cars really are about appearance. They sure aren't a way to compensate for a poor suspension, though they might make the car feel like it has a performance suspension.

Low profile tires feel more responsive; you turn the wheel and the car responds with less delay. Some people mistakenly think this is due to better grip. In reality it is because the tire operates at a lower slip angle (deforms less under cornering loads).

Low profile tires also ride harsher and generally give less warning to the driver before breaking loose.

If you want to simulate how your car would feel with low profile tires, try pumping your existing tires up 15 lbs or so. That will cause many of the same characteristics.

[geof33]

Jack... cool vid... Still amazes me to see what these cars (even bone stock) can do in skilled hands. VERY cool

[nostatic]

Originally posted by Chuck Moreland
The super low profile tires some people put on street cars really are about appearance. They sure aren't a way to compensate for a poor suspension, though they might make the car feel like it has a performance suspension

That was kinda what I suspected. After looking into quite a few trailers and pits Saturday, I didn't notice much bling. Funny thing, that.

[jmz]

that picture reminds me of the song *****IN CAMARO from way back

[304065]

Jack, watching that video one can almost smell the rubber and hot oil. That's very cool. The shot of the orange car cornering shows where the tail's radius begins to get bigger after the driver downshifts (you hear the engine rev up and see the right rear corner of the car get closer)-- classic oversteer.

Anyway Nostatic, in the stock classes a lot of guys will change tire aspect ratio to alter overall gearing. I use 55-series tires at Watkins Glen for top end, and will use shorter ones like 45-series at Summit point and Lime Rock for acceleration.

55- 24.5"
50- 23.4"
45- 22.8"

Some of the Vintage Racing organizations set a limit on aspect ratio, e.g., no shorter than 60-series.

FAR too scientific for the 35-series Bling Bling types! Don't even get me started on sidewall spring rates, slip angle, and polar moment of inertia!