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!

S197 @4o6racing Build Thread Profile - S197 Mustangs

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

Fabman

Dances with Racecars
6,518
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Nah, it’s that TMO sticker that you gave me - loud and proud on the back bumper!!
Truth right there. They are worth 2.5 seconds a lap. Two of them were worth 5 seconds at Laguna.
I put them on my trailer and now my truck gets better mileage towing!
 

PaddyPrix

If breakin' parts is cool, consider me Miles Davis
725
1,081
Exp. Type
Time Attack
Exp. Level
Under 3 Years
San Diego
I'm only 2 seconds behind his 1:51 so that i can get a better view of that TMO sticker.
It was great seeing you out there and getting to chat, Tom.

It's like a vacation from the madness in the world, a welcome one.
Well you're in luck, guess who has another TMO sticker in their possession?
<--- THIS GUY
 
1,161
2,116
Exp. Type
Time Attack
Exp. Level
5-10 Years
SoCal
Had so much fun with American Muscle Cup on Halloween that I decided to run their 5th and final round for 2020 at Big Willow this last weekend. I really enjoy the added level of competition the series adds, while still functioning like a normal HPDE day where you have multiple sessions to focus on seat time and driver mod.

My PB at Big Willow was 1:32.4, set on Halloween and good for P3 in Modified. (Awarded P2 day of event, but changed to P3 because of an error in registration for the real P1 driver.) That event was run on BF Goodrich Rival S 1.5, 315/30-18. With both cars ahead of me on 100TW tires, stickier rubber was in order to try and close the gap.

I scored a great deal on a set of 305/30-19 Goodyear Supercar 3R’s - 20% off, and the Goodyear Sprinter van delivered and installed them in my driveway!! With all of the buzz about these tires, and witnessing their fast times this year on other cars, I couldn’t pass up the deal. So do they live up the hype?? Well, I dropped 2 seconds from previous PB, down to a 1:30.8! Should have been faster, but a bit of a learning curve with this tire as I kept inching up to the limit. By the afternoon, I was surprised by how far out those limits really go, realizing I could have pushed them harder in the morning sessions before the track heated up. The biggest difference from the Rival S to the 3R’s is the itintial steering response. The 3R’s are immediate, where the BFG’s are more neutral on turn in. The 3R’s had less tread new than tires that I’ve corded in the past, so I expect a short life cycle. Even with the $350/tire normal price, they won’t be my normal track day tire.

The 1:30 was good for P1 in Modified, which was a great way to close out the year! Looking forward to taking these 3R’s to Auto Club Speedway in January to see if the 40’s club is in the cards!

C759971C-DE7D-4036-9870-BF7B502310CA.jpeg
72948DEE-EF48-454F-A07A-ACD65E32BEA3.jpeg
D78D34EE-542E-4C62-A0A3-3E7A9974B5A0.jpeg
 

Fabman

Dances with Racecars
6,518
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Had so much fun with American Muscle Cup on Halloween that I decided to run their 5th and final round for 2020 at Big Willow this last weekend. I really enjoy the added level of competition the series adds, while still functioning like a normal HPDE day where you have multiple sessions to focus on seat time and driver mod.

My PB at Big Willow was 1:32.4, set on Halloween and good for P3 in Modified. (Awarded P2 day of event, but changed to P3 because of an error in registration for the real P1 driver.) That event was run on BF Goodrich Rival S 1.5, 315/30-18. With both cars ahead of me on 100TW tires, stickier rubber was in order to try and close the gap.

I scored a great deal on a set of 305/30-19 Goodyear Supercar 3R’s - 20% off, and the Goodyear Sprinter van delivered and installed them in my driveway!! With all of the buzz about these tires, and witnessing their fast times this year on other cars, I couldn’t pass up the deal. So do they live up the hype?? Well, I dropped 2 seconds from previous PB, down to a 1:30.8! Should have been faster, but a bit of a learning curve with this tire as I kept inching up to the limit. By the afternoon, I was surprised by how far out those limits really go, realizing I could have pushed them harder in the morning sessions before the track heated up. The biggest difference from the Rival S to the 3R’s is the itintial steering response. The 3R’s are immediate, where the BFG’s are more neutral on turn in. The 3R’s had less tread new than tires that I’ve corded in the past, so I expect a short life cycle. Even with the $350/tire normal price, they won’t be my normal track day tire.

The 1:30 was good for P1 in Modified, which was a great way to close out the year! Looking forward to taking these 3R’s to Auto Club Speedway in January to see if the 40’s club is in the cards!

View attachment 60623
View attachment 60624
View attachment 60625
Congrats!
 

Fabman

Dances with Racecars
6,518
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Thank you! Are you gonna try out Super GT Cup in 2021? Half the events are up in your neck of the woods.
Probably not but never say never. W2W is more my cup of tea.
 
1,161
2,116
Exp. Type
Time Attack
Exp. Level
5-10 Years
SoCal
Alright @blacksheep-1, need your expert 8.8 setup advice. I used the Ratech pinion depth tool to measure for the proper pinion shim. After several times checking and double checking, I was satisfied that I had it correct. It took a couple crush sleeves for the preload “learning curve” on the pinion, but finally nailed it at 20 in lbs in each direction. Set the new Torsen in and used the same carrier shims that we’re previously in it for a starting point. Backlash was right on the tight end of the spec range at .008”. All good to this point.

Moved on to checking gear mesh pattern, and here’s what I’ve got:

Drive side:
2B8C442A-15E8-4B76-A1BB-D9AF386F6C42.jpeg

Coast side:
ECE49113-47E2-4932-9B8E-F657BF48A2B8.jpeg

So what’s your read on this pattern?
 
6,361
8,182
I'm not the world's expert on diffs, but if it were mine, I'd say the ring gear needs to be pulled away from the pinion a couple thou.
If you can fudge that and keep the backlash in spec, I'd do it. Other than that, I think it looks fine. There is a " competition pattern, and a street pattern" , the comp pattern will be a bit noisier, I'll try to find an example.
 
6,361
8,182
Here's what I was looking for, you can fix the " drive" side and it could be a little high, but livable, the coast side you pretty much have to live with sometimes. The tighter the backlash, the more heat. I PMd a buddy and he usually ran .008 to .010 on the drag cars to prevent " slap". But over .010 on the stock cars to stop some of the heat buildup.

 
1,161
2,116
Exp. Type
Time Attack
Exp. Level
5-10 Years
SoCal
OK, I’ve been trying to read up a bit more on what the pattern is telling, and it seems the more I read the more confused I become. The Ford Performance instructions seem opposite of the adjustments recommended for a face-hobbed gear set (which I understand all Ford OE and FP gear sets are face-hobbed and not face-milled). Here’s two examples I’ve found - first is the FP instructions for this specific gear set, and the other is a setup guide from Weber State University that I found online:

To my untrained eye, the drive side appears high and toward the heel, and the coast side is way down on the toe. I’m thinking that “C” seems to best match:

7096C762-7DB9-4C47-8748-A75FCD009B29.jpeg
Here’s the explanation of each adjustment. I circled “C”,as that is the only adjustment that moves drive side from Heel to Toe, and Coast side from Toe to Heel.

93256623-1A76-4F93-8694-273369F29554.jpeg

And here’s the instructions specific to face-hobbed sets. This describes a similar pattern, however the suggested adjustment is opposite the FP instructions of adding pinion shim thickness.

39F06ADB-AAB2-4F78-9E05-0F63F0AFDA0C.jpeg

I'd say the ring gear needs to be pulled away from the pinion a couple thou.

Just for clarity, are you suggesting a thinner pinion shim - which would match the 2nd example? Or moving the ring gear from right to left and increasing backlash?

Appreciate any and all input!
 
6,361
8,182
Move a ring gear shim, this will give you more backlash, and it might improve the gear pattern, it's also the easiest thing to do right now. You may blindly luck out... it happens
 
1,161
2,116
Exp. Type
Time Attack
Exp. Level
5-10 Years
SoCal
Agree, simplest change and recheck pattern. I’ll have a set of the OE cast shims here tomorrow to move the carrier .002” right to left and give it a shot.
 
1,161
2,116
Exp. Type
Time Attack
Exp. Level
5-10 Years
SoCal
just for fun, what pinion shim are you running?
because an .020 with Ford gears will get you right in the ballpark first try, normally.

Great question. I installed .0475” based on measurements with Ratech pinion depth tool. The shims on the pinion that I removed were .0335”, and I assume these to be the factory ones that were installed on the original 3.31 gear set and were just swapped over to the FP 4.10’s.

That’s where I’m second guessing everything, because the FP instructions would indicate more pinion shim, but everything I’ve read states the .020-.030 range is most common, and I’m already way past that.
 
6,361
8,182
That is so odd with FP gears... and you are positive the inner pinion bearing race is fully seated in the housing?
and the race and the bearing are the correct parts numbers for each other?
Like the rollers are completely seated in that inner race, not riding around the edge because of compatibility issues?
IF moving the ring gear doesn't work, I have a plan, hopefully you saved the old bearings from the old R&P.
 

TMO Supporting Vendors

Top