Boss 302S and Boss 302R FAQ

[CobraR77]

 

[CobraR77]

Note (if I'm not mistaken..) the rearend shown by Grand Am has the wrong Driveshaft Companion Flange. The Boss 302R came with the E9SZ-4851-A Driveshaft Companion Flange which is more of a flat flange as apposed to a cup flange.

 

[CobraR77]

 

[CobraR77]

 

[CobraR77]

 

[CobraR77]

The Boss 302S came with a flat aluminum Center Dash Switch Panel.

The Boss 302R came with a contoured carbon fiber Center Dash Switch Panel.

 

[CobraR77]

2013 Boss 302S Transmission TR-6060

Gear Ratios: 1st: 2.66, 2nd: 1.81, 3rd: 1.30, 4th: 1.0, 5th: .76, 6th: .50

Boss 302R Transmission M-7003-BOSSR1

Gear Ratios: 1st: 2.29, 2nd: 1.61, 3rd: 1.21, 4th: 1.0, 5th: .82, 6th: .68

TAG NUMBER TUET10790

Built by George Kreppein at Rockland Standard Gear

The Boss 302R Transmission utilizes a 2003/04 Cobra Bellhousing on a T56 Magnum/TR-6060 case which causes the transmission to be "clocked" by a few degrees necessitating the use of a unique Transmission Crossmember. Note the angle of the Transmission Crossmember in page 16 of the Boss 302R Recognition Guide. This transmission also uses an Australian FG XR8 Falcon Tailshaft Housing which eliminates the TR-6060 Remote Shifter. All of this topped off with a 2007 GT500 Shifter Knob, Handle and Boot. 7R3Z-7210-AA

 

[Fabman]

Excellent.

 

[The_Backmarker]

Thanks, Todd!

 

[CobraR77]

Page 285 of the 2014 Ford Racing Performance Parts Catalog documents many of the parts and differences in the Boss 302R and 302S.

In my opinion there are some inaccuracies though.

A few are:

M-7003-BOSSR1 Transmission and M-4602-S One-piece Driveshaft: listed for 302R/S but they were only on the 302R.

M-17757-MB Lightweight Tubular Bumper: listed for 302R/S but it was only on the 302S.

M-3075-RA Front Lower Control Arm with Extended Ball Joint: listed for 302R/S but they were only on the 302S.

M-1104-A Front Wheel Hub with ARP Studs: listed for 302R/S but they were only on the 302S.

Etc, etc...

 

[CobraR77]

Clutch/Brake Pedal Assemblies:

Boss 302S came stock street Mustang pedals.

Boss 302R had fabricated larger pedals welded to the stock street Mustang pedal "arms". They were topped with Grip Tape.

Boss 302S Pedal Assembly.

Boss 302R Pedal Assembly.

 

[Bill Pemberton]

Keep posting info as it is a bear to find some of the items --part numbers have changed and apparently some of the parts from the Miller School cars became substitutes for 302S replacements.

 

[cholmes1]

Does anyone know the engine dyno numbers on the 302S and 302R engines (rear-wheel would work as well)? I assume the 302S with its tune and race fuel requirement, likely outputs 460+ and the RoushYates 302R engine being closer to 500.

 

[Bill Pemberton]

I think you are quite close , as the HP was restricted by IMSA for the Boss S and my old memory is not sure but it seemed like it was pegged very close the Boss 302 output. The 444HP at the flywheel on the Boss 302 would translate back into the upper 300s for RWHP and for some reason I remember low 400 RWHP race requirement for the Boss S. I am sure BS 1 or someone else will pop in with the correct numbers , but surprisingly it was not a big jump.

 

[ajaquilante]

Does anyone know the engine dyno numbers on the 302S and 302R engines (rear-wheel would work as well)? I assume the 302S with its tune and race fuel requirement, likely outputs 460+ and the RoushYates 302R engine being closer to 500.

RYR 302R spec in 2014 in IMSA w/OEM airbox and OEM exhaust manifolds, wet sump and our exhaust made about a max of 430 hp w/o restrictor to the tire. Never knew what they made on the engine dyno.

 

[cholmes1]

Not certain if this was known, but Ford has placed all of the 302S PDFs on the website. Should help with some troubleshooting. It does not really help that much with part numbers or locations, but always nice to have a resource.

BOSS 302S and 302R - Ford Performance Parts

Welcome to the Ford Performance Parts website. Offering quality aftermarket parts specifically engineered and designed for your Ford Powered vehicle.

performanceparts.ford.com

I also combined CobraR77's information into a PDF

 

[302FAM]

View attachment 9169

So interesting. What is the 6–10.8 rule? My doors seem to have that treatment.

 

[QuickSilverShelby]

Hi all, I'm soon to be a Boss 302S owner and I have a few questions so I thought I would post here.

- What tires are you using? Car currently has Nitto tires but they are dated 2015 so time to replace them.
- How many hours/miles before the engine needs a rebuild? Do the springs need replacing during a rebuild or is that a 302R thing?
- Car is currently running on 110 fuel according to the owner. Is that what most 302S cars run?
- Any other site you can suggest reading so I can get additional education on the Boss 302S?

I've got a ton of additional questions but I thought I'd start with just a few questions. Any help is appreciated

QSS

 

[Bill Pemberton]

Not sure why on 110 octane as most are running 98 Octane , per spec, or tuned for 93. It might be that is what is available at the track they run, but frankly from everyone I know who has one that sounds like overkill.

I would say the most common tires used on this Forum for a Boss S are dependent on what you want to do with the car. If you are looking at just running HPDEs pick your poison and many run used Pirelli or Michelin race slicks for that. If you plan on getting a license to run NASA or SCCA the tire choices will change again depending on the group you run if you are racing or doing Time Trials. More and more folks are going to Toyo RRs in NASA , because they have an interesting Matrix for classification that will allow benefits that will put many of these cars in the TT3 or ST3 class. In SCCA you might want to detune it and run smaller tires to get into American Sedan, and I would run Hoosiers there.

All this said , once you get it or depending on what you want to run, that will dictate your tires a lot better. Most of us ( Captain Distraction, AZBoss , and myself ) are running Apex 18x11 ET52 wheels so we can run 315s on the car. This will also necessitate having longer ARP studs which may already be on the car , along with a 25mm front spacer.

Once you get the car and check everything on the beast , we can all assist you even further , but hopefully this little bit of info is helpful?

 

[LaneDeparture]

Hey guys…anyone have a rear diff fluid change procedure for a 302R? I’m assuming I can drain, fill, cycle the pump and top off? Any feedback on how much fluid? Did they all come with the same diff coolers?