The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Boss 302S and Boss 302R FAQ

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

104
67
Grand Am 302R BOM pg 20.jpg
 
104
67
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

302R Transmission in Box.jpg

302R Trans Mount.jpg

302R Shifter.jpg
 
Last edited:

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Excellent.
 
104
67
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...

FRPP Boss 302R 302S Comparision.jpg
 
Last edited:

Bill Pemberton

0ld Ford Automotive Racing Terror
8,425
8,354
Exp. Type
Time Attack
Exp. Level
20+ Years
Blair, Nebraska
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

400lb Gorilla
350
216
Denver, CO
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.
 
Last edited:

Bill Pemberton

0ld Ford Automotive Racing Terror
8,425
8,354
Exp. Type
Time Attack
Exp. Level
20+ Years
Blair, Nebraska
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.
 
Last edited:
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

400lb Gorilla
350
216
Denver, CO
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.


I also combined CobraR77's information into a PDF
 

Attachments

  • IMSA Grand-AM Boss 302R Recognition and Requirements.pdf
    4.1 MB · Views: 267
Last edited:
5
7
Exp. Type
HPDE
Exp. Level
Under 3 Years
Alberta
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
 
Last edited:

Bill Pemberton

0ld Ford Automotive Racing Terror
8,425
8,354
Exp. Type
Time Attack
Exp. Level
20+ Years
Blair, Nebraska
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?
 
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?
 

TMO Supporting Vendors

Top