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Staggered vs Squared set-up

I'm thinking about ordering a new set of wheels and tires soon and was debating between a staggered set-up or a squared set-up. ???

From a performance standpoint, slightly wider rear tires should improve speeds coming out of cornering. But I've also heard that a squared set-up means less understeer. I've noticed that the Boss 302R has a squared setup of 18x10's all around, while the Boss 302S has staggered 19x9's in front and 19x10's in the rear. I'm guessing the Boss 302R, being considerably more expensive, is a better handling car.

I'm debating between either 19x10's all around, or 19x9's front and 19x10's rear. From a performance (handling, acceleration, etc.) standpoint, which set-up do you guys think is better and why?
 
There are a lot of good threads on this already. Hopefully you can find some of your answers here. There's no right or wrong answer, but if you want to run square you're going to have to make some suspension changes if you want to run as fast as you can staggered with the stock suspension.

https://trackmustangsonline.com/boss-302-technical-forum/wheeltire-packages-for-track/

https://trackmustangsonline.com/boss-302-technical-forum/18x10-45-all-around/

https://trackmustangsonline.com/boss-302-general-forum/just-pulled-the-trigger-and-track-setup-questions/

https://trackmustangsonline.com/boss-302-general-forum/strong-lightweight-inexpensive-wheels-18x10/msg18259/#msg18259
 
Keep in mind that the 302R's and 302'S have completely different suspension and are built to run specific spec classes including tire sizes.
 
Forgeline is coming out with their GRA1's.A lightweight mono block wheel in 19'S with the exact off sets and sizes of the L.S wheels.18 and 19lbs each!Staggered is my choice. The rims are race proven in Grand Am and Rolex for strength and durability.They are not the cheapest but they are the best in my book.I raced on them for years in P cars.If you have ever seen rim failure at the track ,you know how catastrophic that can be.When it comes to safety its worth the extra cash.
Just my 02
Best regards,Ron
 
Thanks for the info. What kind of suspension changes are you guys talking about? I'm really not familiar with this subject.
 

JScheier

Too Hot for the Boss!
As AZ states, you'll need to add rear grip. Couple of ways you can do this:

1. Increase front spring rate
2. Decrease rear spring rate
3. Increase front sway bar rate (effectively same as #1)
4. Decrease rear sway bar rate (effectively same as #2)

As an example, I went to an 18x9.5" square setup (285x35). While others chose to soften their rear rate, I went the opposite direction by installing an adjustable front bar for two reasons. First, the boss already seems too soft to me, so why make it softer. Second, I have following the herd ;). It worked very well (stranoparts 35mm bar on full stiff in front).

What I will be doing (hopefully sooner rather than later) is going to AST 4250s for dampers with different spring rates front and rear. Get the car neutral with sway bars in the middle settings (I will have an adjustable rear bar this week) based on spring and dampers, and then use the bar adjustments and shock adjustments to fine tune for individual tracks.
 
What's the OEM wheel size on the Boss? 19x9 in front and 19x10 in the rear? Also, in the future, I was considering going 19x9 in front and 20x10 in the rear. Would putting a taller size tire in the rear cause any issues on the car. Example, going from 35 series to 40 series?
 

drano38

Wayne
1,130
318
The Boss is 19x9 front, 19x9.5 rear. The LS is 19x9 and 19x10.

Tires need to be close to the same size so the anti lock brake system stays happy that front and rear wheels are turning close to the same speed. Appropriate sized 19 front and 20 rear works--its a GT500 option. Are you going to track the car? You're not going to find many people tracking on 20".
 
You can't appease the antilock system by telling the ECU the tire sizes? I thought that was the point of entering it when you do TK.
 
I ran a 305/35 rear and 275/35 front with no discernible ABS issues but I have AdvanceTrac off which seems to liberalize the ABS system over TCS off or Sport Mode. Tire height difference is 0.6".
 
5 DOT 0 said:
CaliMR said:
You can't appease the antilock system by telling the ECU the tire sizes? I thought that was the point of entering it when you do TK.
He's referring to difference in height between the front and back that are greater than stock. TK adjust for the speedo.

Gotcha, I assumed the TK adjusted more than just the speedo
 
One of the questions I asked when I had the Trackey installed is if I changed to a different size tire would he need to do anything to the program and he said he would have to change that parameter in the computer which was an easy process.
Anymore than correcting the speedometer? I didn't ask him that.
 
drano38 said:
The Boss is 19x9 front, 19x9.5 rear. The LS is 19x9 and 19x10.

Tires need to be close to the same size so the anti lock brake system stays happy that front and rear wheels are turning close to the same speed. Appropriate sized 19 front and 20 rear works--its a GT500 option. Are you going to track the car? You're not going to find many people tracking on 20".

Not going to track the car. It's strictly an aggressively driven street machine. ;D
 

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