Placed my order for 15x10's....Time to shop for tires!

 

I'd give you a hug for 17x11 w/5 x 4.5 bolt pattern (FC RX7). All we tend to see anywhere close to that are Mustang wheels, the biggest of which are 17x10.5 FR500 replica wheels, but they weigh a ton.

 

17x10 in stock. Next on the list are 18's.

 

15x11 + 275 =

 

Yuuuuuuuuuuuuuugggggggghhhhhhhhhhhsssssssssppplooo ge

 

cleaned up thread. let's keep retardation in our own threads, wannafbody
kthxbi

 

Wow. Bar raised by 949 again.

 

For reference. 275's on 10's vs 11's

I posted this earlier and it got deleted for some reason....but the 275's literally do EVERYTHING better on a 11" wheel. They turn, stop and put down power better. You will need to play with your air pressures and possibly spring rates to get everything out of the change. But it's well worth it.

 

I'm not going to insult you are berate you (which I should do) I'm just going to point out very politely why you are wrong.

If a setup is balanced and optimized and you change one significant variable the setup is no longer optimized. You must then fine tune the other variables to make the new setup optimum.

Your statement is actually exactly WRONG. Comparing an optimized setup for 10's to a non optimized setup for 11's is apples to oranges. The ONLY way to determine which is actually faster is to compare both setups when they are optimized.

Unless you actually know how to "race car" you might want to keep the misleading and misinformed statements to yourself.

 

Explain how making multiple changes at one time (in a suspension setup) tells you which change leads to faster lap times. How exactly do you determine which multiple things to change at a once? If I changed my rear end from a Torsen to a OS Giken and I change my springrates at the same time, how do I know which change resulted in the decreased lap speed and how do I know that another variable might not have made it even faster?

This isn't just a criticism here but in other claims I read other places. X vs Y in combo with Z produce a result
that someone claims that Y is totally superior to X, when an infinite number of variables may produce the opposite result.

 

You really are a window licking mouth breather aren't you?

Who said all those changes were made at one time?

You have to test new setups and over time you optimize those setups with minor tweaks after major changes.

I've never seen a championship winning car that was just a random thrown together hodge-podge of untested parts.

 

More than one change at a time is multiple, I think.

TNTuba, thanks for answering. You are about the only person to not be an *** on this site.

 

cleaned up thread again. this will be the last time

 

By calling on past experience, other tools at your disposal (pyrometer data), etc. In this specific case, my educated guess is that a 15x11 would want less tire pressure and slightly less spring rate to work well.

If you have a car with 15x10s, and you put 15x11s on it, drop the tire pressure slightly, and reduce the spring rate slightly, your argument is that you can't know which change leads to faster lap times. It's an easy argument to defeat, because all you have to do is swap back to 15x10s with your new lower pressures and spring rates. The car goes slower on the narrow wheels with the new pressures/spring rates. In fact, it goes even slower than it used to go before you started changing anything at all, because now you're trying to make 15x10s work on a setup that's optimized for 15x11s.

Race car suspension is a system, same as any other system. Vendors get chastised all the time for doing A-B engine testing without retuning to optimize each part. How is this any different?

Consider it this way: We all know that turbochargers make more power than N/A engines do. Your suggestion is that because we added new fuel injectors and an ECU to our car, we cannot be sure which modification of the three (turbo, injectors, ECU) actually made the difference. This is preposterous. To those of us who know how radial tires and wheels interact, your suggestion that "you don't know what made the change" in this specific example (15x10 vs 15x11) is equally preposterous.

 

That looks spectacular E! I need to find a way to stuff those under my car.

 

While I generally agree with the above statement it does not apply in this case. Would you swap tires and keep the same air pressure to do a controlled test? No...you need to optimize tire pressure for each tire. Same is true for rim width. Spring change to optimize rim/tire combo is not a lot different than the tire pressure example.

 

Of course the 11's are better - they're one better than ten!

 

See?

 

That makes sense. It also makes sense that you would run multiple laps at varying pressures, take pyrometer readings and record lap times and then compare it to a previous baseline, both being done at the same time or under similar conditions. Otherwise it's a bit like a dyno, 2 dynos are going to record slightly different data under different conditions. Regardless, none of these things are 100% absolute proof as tire tests have proven in the past.

 

That is just getting optimal tire pressure.

WHICH HAS NOTHING TO DO WITH WHAT YOU ARE BLABBERING ABOUT. GO BACK TO YOUR DAMN F-BODIES AND STOP SPOUTING BULLSHIT.

between this guy and burt nasty i've come to despise any f-body owner.