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Going Square, what is needed?

I just wanted to provide my impression, after this weekend's track event, of the 18mm sway bar with 285/35/18 RS3 square setup and oem shocks at 5/5.

Corner entry: Understeer was noticeably increased. I mitigated it by tweaking my corner entry line with either transferring weight to the front by touching the brakes during entry, or by getting on the gas earlier (depending on the corner and what came after it). The understeer did make my turn-in speed on one of the turns a bit slower, but it was quickly followed by early throttle, which took care of the slower entry speed.

Mid-corner and corner exit: I was able to get on the go pedal alot sooner than before with very controllable, and awesome, rear end rotation. Not once did the car go out of shape, which increased my confidence in the car. Corner exit grip was noticeably improved and made things alot of fun!

Overall, I was able to break my previous 1:29 laps and got into 1:28's, according to Steve (which is all the proof you need :p). So, I recommend this mod to anyone that wants to run square with the stock suspension and not spend 3-4x the price on adjustable aftermarket sway bar setups.
 
Thanks Sako. So I wonder if the 20mm bar would be a better choice.
 
Yes Rick I concur, I think 20 mm is a better option. I run 20 mm on the rear, as I said in previous posts, with the dampers set to 5/5, the car is very neutral. She reminds me with my previous Subaru STI EXCEPT the Boss is more neutral and with way less understeer. It is more like point and shoot now.
However, as you expect, in tight corners ( really tight) it still understeers, but my camber is only -1.6, so with more negative camber I might see better results.

Sako, if you end up getting 20mm RSB, make sure you keep the 18mm on the shelf, because you will need it when you go with coilovers or even stiffer springs.
 
F.D. Sako said:
That's good info guys!

Now if only someone had the part no. or year GT/V6 info for the 20mm RSB ::)

The part number can be retrieved if you call the dealer and ask them for 2005-2009 Mustang GT Coupe (not the handling pack) RSB which is 20mm!
What you got (18mm) is 2005-2009 Mustang GT Convertible RSB
 
Some interesting info on rear sway bars I found on Strano's site (not sure if it's accurate):

Comparison vs. Ford OEM:
Strano Performance Parts 8419 1" tubular: 162, 185, 225 lbs/in
Ford 20mm Solid (2005-2010 GT): 96 lbs/in
Ford 22mm Solid (2011+ V-6 standard): 147 lbs/in
Ford 24mm Solid (2011+ 5.0, GT500): 193 lbs/in
Ford 25mm Solid (Boss 302): 250 lbs/in
Ford 26mm Solid (Boss 302 Laguna Seca): 275 lbs/in

I'm still on the stock suspension with a square wheel/tire setup and if you are careful I have found it is manageable on the track with the stock 25mm rear bar (I do run the rear shocks softer than the fronts)

Nevertheless, I have decided to experiment with other factory bars

I just installed the 22mm rear bar and also bought a 24mm rear bar to play with, as well

Part numbers in case anyone is interested:

22mm: CR3Z-5A772-R
24mm: CR3Z-5A772-Q
 
As long as Strano tested the bars the same way that is all that is important I think. I have the Strano bar and installed it. Have not had the chance to push hard enough to test.
 
Re: Going Square, what it needed?

13Boss#3328 said:
There is quite some body roll on the pictures and on the video IMO (100% stock Boss suspension ? just with downsized rear swaybar at 20mm)
I wonder how would that body movement feel at a high speed track.
I think the point has been raised already: The spring rates matter and that makes comparison a bit harder between us if we dont have the same springs...
On this picture you have Enkei 18x10 with Rivals in 295/35/18? Correct?
BTW Love your short video! Reminds me of the old footage of the Trans Am races :) "here come Parnelli Jones..." Of course that was intended! LOL
 

steveespo

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The car really needs more spring rate front and rear and less roll stiffness in the rear to assist in corner exit traction. With the solid rear axle the roll bar ties both sides together and wants to lift the inside tire. This reduces traction and with a high horsepower RWD car that means throttle oversteer or later throttle which lowers exit speed. Decreased roll stiffness helps both tires plant and you can go to the throttle earlier. Increasing spring rate and rebound stiffness on the rear will also help cornering grip and stability. In my opinion our cars strength is power, getting earlier and more drive off will help straightaway speed and lap time. There are compromises for any car setup, try and work to maximize the strengths.
IMHO of course.
Steve
 
Re: Going Square, what it needed?

patrickshelby said:
There is quite some body roll on the pictures and on the video IMO (100% stock Boss suspension ? just with downsized rear swaybar at 20mm)
I wonder how would that body movement feel at a high speed track.
I think the point has been raised already: The spring rates matter and that makes comparison a bit harder between us if we dont have the same springs...
On this picture you have Enkei 18x10 with Rivals in 295/35/18? Correct?
BTW Love your short video! Reminds me of the old footage of the Trans Am races :) "here come Parnelli Jones..." Of course that was intended! LOL

Patrick, I am on stock suspension with the exception of 20mm RSB and MM C/C plate. The only 2 tracks I have run this setup are Grattan and Gingerman raceways in Michigan. It felt good.
The Wheels are Enkei PF01 18X10.5 all corners and 295/35-18 tires.
The short video I made is from a series of pictures taken by the track photographer ( Gingerman) which I combined and aligned together in Adobe after effects and created the vintage look then rendered it as GIF file. I was not thinking of Parnelli Jones at that time, but I can assure you the decision of buying school bus yellow Boss 302 was partly based on my admiration of what he did in 1970 in Laguna Seca Trans Am race. It is like " Win on Sunday, sell on Monday" ...well on Monday only after 43 years...lol
 
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Just reviving this thread to see if there is any new info, first hand experience, with either the smaller rear bar or using a +47mm 10.5" wide wheel with a spacer. Blowfish racing has a 15mm H&R hubcentric spacer kit with longer wheel studs that would seem to give about the right amount of strut clearance. So I guess the real question would be if anyone has any real data points to share that show how much faster, more stable, their car is with a 10.5" wide wheel versus with a 10" wide wheel, when running a 305mm tire like a used takeoff slick or the 305 mm NT01. And second, is the improvement worth the 1k difference in price between a set of 18 x 10 SVE drift wheels versus the Enkei wheels.
 

Mad Hatter

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Just upgraded to 305/660-18 GT-I contis on square SVE drifts 18x10. Have the rear bar off and have the 600# and 300# Koni SA Cortex coil overs. So far like the car a lot, corner exit is much better though I am still getting used to the extra grip from the slicks. Everything happens faster but driving with the throttle was much easier on semi slicks because of the lower grip. Lowered my best time from 54.9 to 54.3 but feel I have a lot of improving to do yet.

Still have the stock front bar, any suggestions for a larger adjustable bar?
 

Grant 302

basic and well known psychic
Mad Hatter said:
Just upgraded to 305/660-18 GT-I contis on square SVE drifts 18x10. Have the rear bar off and have the 600# and 300# Koni SA Cortex coil overs. So far like the car a lot, corner exit is much better though I am still getting used to the extra grip from the slicks. Everything happens faster but driving with the throttle was much easier on semi slicks because of the lower grip. Lowered my best time from 54.9 to 54.3 but feel I have a lot of improving to do yet.

Still have the stock front bar, any suggestions for a larger adjustable bar?

Nice improvement!

And I think some are using the Eibach bar. I think the stiff rate is over 600lb/in, IIRC.
 
So I decided to upgrade the rear sway bar to 22mm instead of 20mm on my stock suspension.

I can tell you with confidence, I liked the car more, it feels tighter and rotates better. I honestly did not feel there is loss in the rear grip, at the contrary, the rear end felt more controlled and in 1 unit with the front end.

By the time I decided to run some hot laps around Grattan raceway to compare the lap times to the 20mm setup, my car started started going into limp mode. So I did not get to do any real comparison in term of lap times.

On May 19th I will be in a tighter track, Waterford Hills raceway, and I can update you more.

I am sure if I end up going stiffer springs I will need to go smaller RSB as many people are doing.

note: Thanks to Jeff, @twistedneck, to give me the 22mm RSB.
 
13Boss said:
So I decided to upgrade the rear sway bar to 22mm instead of 20mm on my stock suspension.

I can tell you with confidence, I liked the car more, it feels tighter and rotates better. I honestly did not feel there is loss in the rear grip, at the contrary, the rear end felt more controlled and in 1 unit with the front end.

By the time I decided to run some hot laps around Grattan raceway to compare the lap times to the 20mm setup, my car started started going into limp mode. So I did not get to do any real comparison in term of lap times.

On May 19th I will be in a tighter track, Waterford Hills raceway, and I can update you more.

I am sure if I end up going stiffer springs I will need to go smaller RSB as many people are doing.

note: Thanks to Jeff, @twistedneck, to give me the 22mm RSB.
So stock on our cars is 25MM and you like the 22 better than the 20? You're still on a staggered setup?
 
NFSBOSS said:
So stock on our cars is 25MM and you like the 22 better than the 20? You're still on a staggered setup?

No Rick! It is "going square" thread ;)

For the track I run square setup (Enkei PF01 18X10.5 38mm offset with 295/35-18 Rivals)
I have been running this setup for a year.
For the whole 2014 season I ran 20mm RSB as recommended by Rehagen racing and I quite liked it, it was pretty much point and shoot, it reminded me of my beloved 2012 STI. However after I started driving the car "harder" I realized there is rather significant understeer, which I thought is more suspension than driver induced.

Some pictures showing the roll with the 20mm
Boss302r_zpsfe74b4aa.jpg
Boss302r1_zps4e9f0052.jpg

Accordingly I decided to step up to 22mm RSB and I liked it more. I really wanted to see if there was any difference in my lap times, but my car started limping. So the test was aborted.
With 22mm RSB the front/rear "twist" was matched and the car felt more in 1 piece.

For example; exiting turn 12 at Grattan, with 20mm the car would clearly push and push on throttle. With 22mm the push was less and you could feel the car settled quicker and got ready for full throttle down the front straight.
I will likely go back to Grattan this month to test the change more thoroughly.

The stock tires/wheels are my current DD setup. I am considering buying Enkei PF01 18X9.5 with 45mm offset for DD, they weight 20 Ibs!! It is amazing how lightweight wheels feel.
 

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