zero index birdcage

[brett4]

what is the benefit of running zero index birdcage plates?

[RaceEngineer]

what is the benefit of running zero index birdcage plates?

As you index, the suspension gets stiffer and stiffer until it is almost locked up. Remember when guys used to hit a hole on the straight and bounce 3 times? Fast cars don't do that now. Second reason, what goes up must come down. When it unindexes, the shock mount is moving away from the load as the car settles down on entry. The shock and spring is not holding the car up, as their job requires.

[DJ16]

Race engineer,
Would mind sharing your thoughts on best amount of indexing if any on the right rear of most cars? I'm liking no indexing on LR. Do we need to index into or out of RR ? Or go with none and work with springs?
Thanks

[grt74]

Race engineer,
Would mind sharing your thoughts on best amount of indexing if any on the right rear of most cars? I'm liking no indexing on LR. Do we need to index into or out of RR ? Or go with none and work with springs?
Thanks

if you don't want indexing, just bolt the bottom of the shock to the top of the tube, lr, i could see that working, rr you'll get beat by some sharp people, unless you carry several rr shock/spring setups

[Jking24]

I think people get a little too caught up in this "how we race now vs. The old school way. The bars still work just the same as they always did and the objective is still the same. Every thing is a give and take situation it may be good for one reason but bad in another way. If your not changing bar position then the index ratio is constant so no consistency loss or question marks marks their. It's also something that can easily be measured so it's not a "un known". The principal of smashing springs is not to eliminate all the geometry in the car but to be able to tune on it in a dynamic state where it is used most. Sorry i just don't understand alot of the ideology that comes up with "we don't race that way anymore" mindset

[RaceEngineer]

I think people get a little too caught up in this "how we race now vs. The old school way. The bars still work just the same as they always did and the objective is still the same. Every thing is a give and take situation it may be good for one reason but bad in another way. If your not changing bar position then the index ratio is constant so no consistency loss or question marks marks their. It's also something that can easily be measured so it's not a "un known". The principal of smashing springs is not to eliminate all the geometry in the car but to be able to tune on it in a dynamic state where it is used most. Sorry i just don't understand alot of the ideology that comes up with "we don't race that way anymore" mindset

The bars still work the same. We just know better than to put the LR top bar down to 3.5" from axle centerline now. A birdcage anywhere near cam over is a killer of speed. We also understand that unhike on corner entry kills corner speed. We now know that corner speed beats drag racing as well. 20 years ago, no one thought those things.

[RaceEngineer]

Race engineer,
Would mind sharing your thoughts on best amount of indexing if any on the right rear of most cars? I'm liking no indexing on LR. Do we need to index into or out of RR ? Or go with none and work with springs?
Thanks

I don't know that there is a best amount. You just need to get the dynamic load curve that works for you.

[Jking24]

The bars still work the same. We just know better than to put the LR top bar down to 3.5" from axle centerline now. A birdcage anywhere near cam over is a killer of speed. We also understand that unhike on corner entry kills corner speed. We now know that corner speed beats drag racing as well. 20 years ago, no one thought those things.

i agree completely. This one just struck a nerve because while helping someone over the weekend with an older car. A bar change was suggested and the reply was not that he thought it didn't work that way but that it wouldn't have the desired effect because we don't race that way now so it wouldn't have the same effect.

[cjsracing]

i agree completely. This one just struck a nerve because while helping someone over the weekend with an older car. A bar change was suggested and the reply was not that he thought it didn't work that way but that it wouldn't have the desired effect because we don't race that way now so it wouldn't have the same effect.

My go to adjustment in 2014 and 2015 for a slick track feature was to crank turns into the LR and get a high bite number. That car was so good in the slick.

If I try that now the car doesn't turn and I'd get lapped twice in a 25 lap feature.

[King1]

My go to adjustment in 2014 and 2015 for a slick track feature was to crank turns into the LR and get a high bite number. That car was so good in the slick.

If I try that now the car doesn't turn and I'd get lapped twice in a 25 lap feature.

Yea I used to be the same way. Now days all I mess with is LF droop, LR droop, packers, rear end lead, and spring rubbers. A lot less work that's for sure.

[Kromulous]

I guess it cant hurt to ask, but would you comment on your LF and LR Droop changes? What impact etc.

[Jking24]

I think a lot of you missed the point .I was referring specifically to a bar angle change. It still does the same thing that it always did. Some changes have less or minimal effect because of the fact that we maintain attitude better now and there is less movement in certain Corners than there used to be

[Jking24]

My main point was I see a lot of people outsmarting themselves chasing load numbers Etc the mechanics of the racecar haven't changed fundamentals of it are the same we just go about achieving what we need a different way now if you understand a lot of this stuff you can look back at your old setups and kind of start to understand why you had to do certain things because of what we know now and how those changes affected other corners

[RaceEngineer]

My main point was I see a lot of people outsmarting themselves chasing load numbers Etc the mechanics of the racecar haven't changed fundamentals of it are the same we just go about achieving what we need a different way now if you understand a lot of this stuff you can look back at your old setups and kind of start to understand why you had to do certain things because of what we know now and how those changes affected other corners

I agree with that 100%

[fastford]

i agree also jking , one thing i guess you could say theses " new " set ups has done is cause you to change or redesign the chassis , especially the front end.......