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S197 3V Fabman's build; How did we get here? Build Thread

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I would go back to your to your base line then maybe add 25lbs to the rear springs and play with rear shock settings for the added down force from the wing. The roush track pac cars are 515 lbs front and 400 lbs rear springs, with the little wing it has. The rear shock valving is stiffer too.
 

Fabman

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I can’t complain though, the wing makes plenty of downforce even at zero* AOA. I just need to work on the balance.


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Fabman

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I would go back to your to your base line then maybe add 25lbs to the rear springs and play with rear shock settings for the added down force from the wing. The roush track pac cars are 515 lbs front and 400 lbs rear springs, with the little wing it has. The rear shock valving is stiffer too.

My valving is much stiffer than yours. I’m at -4 up front and -19 I think in the rear.


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598
536
I would soften up the front just a little. I need more roll, no aero really. Running Imsa aero, need it to move a little bit. at the track I run stiffer but the ratio is the same.
 

Fabman

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Yes I have traction brackets. I’ve had the trailing arms from 1* up to 5* up with no appreciable change....


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Fabman

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I put the 500’s in today and will go back to 4* up on the trailing arms for some help from roll-steer tomorrow and we’ll see what happens.


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Fabman

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The more I stiffened the front shocks the better it felt. That’s what lead me to up the spring rates. If you have your shocks all the way stiff on one end that’s a good indication that you need a spring change.


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Fabman

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wow, I go from 5* to 1* and I can tell the different.

Yeah, you should. That’s a big change. The fact that nothing mechanical seems to help leads me to believe this is an aero issue.


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598
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I know what you mean, but the push tells us that softer is the way to go up front, The Boss 302s ran 600lbs front and 350 rear from Ford, that had to be in a ball park for some track.
 

Fabman

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Arizonaboss has 600/325 and he’s cleaning up in nasa. That can’t be a horrible spring combination.


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Fabman

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Can you over Wing a Mustang ?

Apparently so. Another nasa guy told me anything over 2* aoa on his wing makes his car push like a freight train.


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Fabman

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ArizonaBOSS has a much smaller wing and he runs his flat too. So apparently we’re achieving plenty of downforce on these cars.


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Grant 302

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A lot has happened since then.

But *if* I'm reading your posts correctly, you haven't tried the 600# with the front bar on full stiff, right?

I went back to my stiffer sway bar and shock settings and 325# springs out back and lowered the whole car 3 turns on the coilovers.
The car felt way better and was slightly faster, but still not perfect.

Front bar was in the middle hole w/500's and I went full soft when I put the 600's in.

By 'stiffer' you went from the full soft back to middle on the bar? Did you mention your bar settings to Filip?

My valving is much stiffer than yours. I’m at -4 up front and -19 I think in the rear.

You're not running the stock valving for the SA units?

While it's easy to 'blame' the aero change, you still should be able to develop more grip up front. I'm still thinking static camber, camber gain, toe, etc, all gotta be looked at...for working together, not just misc. adjustments that 'should' be taking you in one direction.
 

Fabman

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But *if* I'm reading your posts correctly, you haven't tried the 600# with the front bar on full stiff, right?





By 'stiffer' you went from the full soft back to middle on the bar? Did you mention your bar settings to Filip?



You're not running the stock valving for the SA units?

While it's easy to 'blame' the aero change, you still should be able to develop more grip up front. I'm still thinking static camber, camber gain, toe, etc, all gotta be looked at...for working together, not just misc. adjustments that 'should' be taking you in one direction.

I tried the bar full stiff with the 500,s and it was way too tight.
Yes we talked about all the settings. What I meant about valving was the shock settings. Mine are set almost full stiff.
Camber is at 3.25 which is not what I would call excessive.
The camber gain is set with ride height and flips suggestion to lower the car did help. I was surprised that little bit of travel was enough. When I put the 500’s in today I cut the bump stop down by 1/2” so I got some of that travel back. That seems to be a common way of dealing with it from what I am hearing. Toe is set at 3/16 out. Everything is in the ballpark. The fact that nothing seems to help tells me I’m looking in the wrong places.


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Fabman

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Don’t get me wrong, I’m not blaming anyone. The items I purchased and changes I’ve made were entirely my own based on what I believe to be sound logic and decades of racing experience. The fact that suddenly I am unable to affect change when change should be felt tells me I’m looking in the wrong place. There is something else I am missing. When I first put this car together it was far from perfect. But I made changes and changes produced the expected result until I had it dialed perfectly. The problem is, now the car isn’t responding to changes as expected. Something else is wrong. When I look at what was changed on the car, with the exception of aero, none of them should produce the level of understeer I am experiencing and unable to influence with logical remedies.
Aero is something that I have limited experience with and it seems I’ve done a poor job of balancing the front with the back is what I’m trying to say.

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Fabman

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In the past when I've had a push that I couldn't adjust out I inevitably found something either bent, broken, biding or flexing. I will be looking all of those over tomorrow.
 

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