db2797

Had my new 3600 Circle D converter installed a few days ago in my car. Now if the weather will just improve so I can actually test it out heavily! I'm planning on hitting the track this weekend as long as the weather doesn't end up closing it.

Five Oh Brian

Love my Circle D converter. Installed a 1-pc aluminum driveshaft at the same time and dropped my 1/4 mile ET's by six tenths. Please let us know how quick you run next time you hit the track.

db2797

Oh wow..that's a huge drop! I'm not expecting that big of a drop but I did also have the 1-piece drive shaft also installed at the same time as well. My previous best was 12.16 so I'll be happy to be hitting 11's which I should be able to do I'm thinking.

Five Oh Brian

A 12.16 with a stock converter = easy high 11's with the Circle-D, maybe even mid 11's.

db2797

Well, I successfully hit the track yesterday. I'm pretty happy with my numbers but this car has A LOT left in it still.

Yesterday was opening day so the track was really green the first few runs. But after the track starting coming around, it really started to bite nicely. I was also still launching conservatively. I never launched higher than 2000 RPM's. So I have about another 800-1,000 RPM I can most likely foot brake the car up to.

I also installed a 2 step and it was working the night before great. And then all of a sudden it just wouldn't shut off. I checked the wiring, removing my button attached to it, etc. And it just won't shut off. So I had to dial the limit all the way to the max to artificially shut it off. Oh well...that's the next project to get resolved. Regardless of that, I did find some consistency, I actually had 3 out of 5 runs at the end of the day where I had identical 1.761 60's. So I'm happy with the consistency. The only other thing that had me worried some was that my car seemed to bouncing off the rev limiter in 1st gear after launching. So I decided to let my car run longer in the staging lanes. The car seemed to come around and began to shift correctly. These cars definitely seem to like to stay on and running and don't like shutting off to cool and then take a run down the track. I also seem to get my best times hitting the track at normal operating temperature.

So my best run was:
RT: .026
60': 1.761
330': 4.994
1/8th: 7.679
MPH: 91.64
1/4: 11.93
MPH: 117.70

The three same 60's were ET's of 11.93, 11.944, 11.965 so the car ran nice and consistent eventually. With that MPH though, I know there is at least a tenth to 2 tenths left.

Mods:
ET Street 18"
Pype Catback
4.10 gears
Bama tune
1-piece driveshaft
JLT CAI
Circle D 3600 Stall

2014GHIGGT

Real nice!

Ltngdrvr

Did you have the tune adjusted to take advantage of the new converter?

And, I also think it would be faster with the original 3.15 gears.

db2797

Yes the tune was adjusted. The tune actually feels real good. Other than those few times bouncing off the rev limiter in 1st, it felt really good with its shift points. There was some spin occuring in the first few runs which may have been messing with it. And not running at a consistent temperature. Once I dialed those issues in, I didn't have any issues with it bouncing. I'm going to do more testing to make sure it was really those variables.

The other thing is that I do mainly bracket racing...so I like where the 4.10 gears put me on the track with the tires I run. I have more tire than I need (305's), so they are heavy big tires, and my car is at the top of the RPM range when crossing the stripe, which gives me room to work in the peak torque curve when chucking it to the stripe. Even if I run it all out, the car will shift just feet past the finish line. 4.10's will also give you more consistent 60's which makes the top end much more consistent.

Ltngdrvr

The 4.10's are contributing to the rev limit hit in first, so much gear multiplication with the super low first gear that it actually revs too fast and hard.

All the fastest automatic 2011+ Mustang GT's run 3.15 or 3.31 gears and 28" or 29" tall tires.

db2797

Did you read my post? The car stopped hitting the rev limiter when it was running at normal operating temperate and the track got stickier thus eliminating tire spin. Also, I'm not trying to be the fastest Auto GT. I'm trying to be as consistent as possible which 4.10's are going to be better at. If that were the case I was trying to be the fastest, the first thing I'd do is get rid of my massive 18", 305 MT ET Streets and go to 15" 275 or 255's. As it is, I was at over 117 mph on my "slow" 4.10 gears and launching super conservative. You pick gears based on where you want to be on the track RPM wise...not just randomly picking 3.15's. The 4.10's are not holding me back in way and are on my car for a reason.

Five Oh Brian

No issues with 4.10's in my car either. Makes great use of 4th gear. Best my car went with 3.15's was 12.0's. The 4.10's didn't make my car any quicker in the 1/4 mile (still ran 12.0's with the same tune from my 3.15's, but adjusted for the gears).

However, a new tune from Mike Rousch really helped, though, getting me into the 11.8's with the 4.10's). Just as importantly, I love how the 4.10's feel on the street. Fuel economy improved around town for me, as well (even though highway mileage dropped), and I drive 90% around town so that was a nice side effect.

Overall, I'm glad I went with 4.10's for a variety of reasons.

Plenty of people run 4.10's with 6R80's and go just as quick (some quicker) than the 3.15 cars. There's not one "correct" gearset, as the 6R80's seem to run just as quick running through the 1/4 mile traps in 3rd gear with 3.15's or 4th gear with 4.10's.

Five Oh Brian

My momma told me long ago to avoid using words like "all," "never," and "always" when trying to state your case.

The naturally aspirated S197 4V 1/4 mile drag list over at S197forum.com shows 3 of the 4 quickest using 3.73's or 4.10's. Heavier street cars like more gear to go quicker. Now, if you look at Coyote/Automatics with power adders and/or weight reduction, the gearing is less of an issue and 3.15's or 3.31's work great (sometimes better). So, it all comes down to your combination and intended use.

Worth noting, my heavy GT auto is 3800 lbs with me in it. I run 28" tall 275/45/18 M&H Racemaster drag radials. My car has 100% stock suspension, airbox, engine, exhaust, etc. and has just the couple of mods in my signature. Our local dragstrips are full of '11+ 5.0L's and mine is typically the quickest one by a fair margin (several tenths to a second normally). The only two that have come close on our local tracks when I've run are two acquaintances of mine that run 11.90's, but they have 4.10's in their Coyote/automatics, as well. I get a lot of people in the pits coming over to my car asking how in the heck my car is running so consistently in the 11's when most Coyotes at our local tracks are running mid '12's to mid '13's depending on mods, tires, and driver skill.

Don't get me wrong, these cars go quick with 3.15's, but 4.10's work just as well.