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This is why you don't run stock suspension...

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domesticpower

Track Addict
190
135
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Boss 302 AMP T9 Braking Nose Dive.jpg

Still managed to go home with something, though. I know the car’s not clean, but this ain’t no show car trophy! Got 5th fastest raw time of the day, 3rd overall adjusted for class out of 18 competitors. No one ahead on raw time was in a lower class and beat out a few in higher classes on raw time.

Boss 302 3rd place overall time attack.jpg

Aside from a couple of cars in the bottom half of the field, no one was running stock suspension and most were on coils. Now, who wants to donate a set of coils to go chase that 1st place overall trophy??
 

Bill Pemberton

0ld Ford Automotive Racing Terror
8,422
8,346
Exp. Type
Time Attack
Exp. Level
20+ Years
Blair, Nebraska
Just goes to show what a good set of rubberized air filled donuts will do ----- not just cornering improvement , more stopping power!!! Solid pic and it does probably help your turn in with all that weight on the front, ha,ha.
 
Nicely done! I'm assuming the new rim/wheel combo made your dive much worse than before? Any other stock suspension observations before/after adding 305s?
 

domesticpower

Track Addict
190
135
NS
Nicely done! I'm assuming the new rim/wheel combo made your dive much worse than before? Any other stock suspension observations before/after adding 305s?

Thanks! Yea, nose dive is noticeably worse, as is body roll and movement in general. Car is also much more neutral compared to before (was also a square setup but 285's), likely due to the 2.5"+ wider track up front. I'm used to trail braking into several corners on our track. Doing the same now kicks the back end out in corner entry. The extreme nose dive is likely a factor too by unloading the back end even more.
 
1,289
1,113
Exp. Type
HPDE
Exp. Level
5-10 Years
Philly Metro Area
nothing wrong with dive...
or squat..

I'm sure he's driving at 10/10 and is experiencing some high g's due to his speed and his slicks. But is the same degree of dive/squat acceptable while using a 200TW tire?

I'm also guessing that the body movement on AJ's car was a bit more gradual than stock suspension would allow.
 
6,361
8,181
I'm sure he's driving at 10/10 and is experiencing some high g's due to his speed and his slicks. But is the same degree of dive/squat acceptable while using a 200TW tire?

I'm also guessing that the body movement on AJ's car was a bit more gradual than stock suspension would allow.

I would think you would want all you could get to make the tire stick, and that suspension is pretty stock, nothing trick at all, with the exception of the shocks.
I think this is a pic of the car with the relocation brackets installed, which sounded good on paper but were later discarded. Nothing to write home about.

ibffNt0l.jpg
 
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domesticpower

Track Addict
190
135
NS
Mustangs and M3s, folks just can't figure out how cars with their body roll and tendency for a bit of nose dive are soooo fast?? Makes a lot of us look more skilled in other's eyes than we really are ,ha,ha!

Haha yea, let's keep it that way!

Upgrading to the 13-14 GT500 rear rotors (via adapter or via GT500 axle bracket) may also help reduce dive since the back end will share a bit more of the braking effort.

Thanks Coz, I'll keep those in mind. Likely will come after coils.

nothing wrong with dive...

wD7cGp8l.jpg

or squat..

aZYVQwWl.jpg


and those are on hi zoot Penske coilovers

Quite a bit of body roll too visible in the second picture!
 

Grant 302

basic and well known psychic
Quite a bit of body roll too visible in the second picture!
*That's* not body roll. :D

The roll angle is actually smaller than visible in 2D on this picture because of the point-of-view angle relative to the car.

#23 body roll.jpg
I think the framing (tilt) of the shot and the visible squat make it seem like more roll than it is. I'm guessing there's almost full diagonal weight transfer from the RF to the LR tires. Maybe 800+ lbs?

*This* is body roll! ;)
pirelli-world-challenge-st-petesburg-1.jpg
 

Norm Peterson

Corner Barstool Sitter
939
712
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
would a torque arm help with that nose dive?
Only the "tail rise" portion. What that side view picture shows is vehicle pitch motion and that it's partly nose dive and partly tail rise. The front suspension will still compress just as far under the same deceleration.

Depending on specifics, a TA could certainly reduce the "pitch", but not the "nose dive" part.


Norm
 

Grant 302

basic and well known psychic
Depending on specifics, a TA could certainly reduce the "pitch", but not the "nose dive" part.

"depending" and "could" are very important parts of that statement. I see it as 'true' when compared to stock geometry, but it's easy enough (IMO) to setup trailing arms to prevent 'tail rise' compared to a torque arm, and stay out of brake-hop conditions.
 

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