3.15 vs 3.55?

[mejohn50]

NA tend to go 3.31 and like you said boosted tend to go 3.15. But hey with 3 overdrives go 5.13's lol

I remember a guy on another forum comparing the gearing on a 6R80 with 3.15s to a Ford C4. IIRC gears 1-3 of the 6R80/3.15 combo was the same as a C4 with like 5.13s.

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[revinto7]

Lackluster yikesssss

yes i owned a shelby gt that made 730/590 a 14 1LE 801/646 and currently a Hellcat A8 they all make tq the Hellcat makes it really early like my 04 Cobra did too ...

 

[revinto7]

I have 3.15's :shrug:




I like the "laziness" when the car isn't in "Mexico" or at the 1/4 track.

that tach sweep is slow see how long it takes to sweep to red line on each shift extention ... 3:55 would help that quite a bit .also the need to roll from 4500 rpm just to get the motor into a sweet spot due to a dessert gear ..Even a scatpack 392 with a 6400rpm red line and a much more stout low end tq curve uses a 3:09 ratio with an A8 - The small cube Modular can use the shorter gear to get it into and keep it on fire ,to each there own. You choose what ever you like but Theres a reason the Performance package is 3:55 ..

 

[Timeless]

3.55s for more low end pep
3.55s for more robust diff (iron I believe)...same as comes with PP1
3.15s for better gas mileage and less shifts

 

[Aliaszero]

depends on what you want. I think for street fun the 3.55 is the way to go. I love the peppy feel of the car during daily driving. It seems that most of the higher end N/A quarter mile guys are putting even higher gearing in their cars to keep in the power band. I think that steeda said they had like 4.09 gears in their N/A car.

 

[c-rizzle]

3.55 feels faster and is more fun. Its part of the performance pack for a reason. I think Ford engineers know what they're doing. If 3.31's were better that would be the option in the A10 Performance Pack.

If you're going to boost your car soon after buying it, then keep the 3.15's.

 

[Jetnoise]

How much $ is the 3.55 option?
You will not notice the gas mileage difference but will notice the seat of the pants feel

 

[gmupatriot]

How much $ is the 3.55 option?
You will not notice the gas mileage difference but will notice the seat of the pants feel

I believe its around $500.

 

[Jetnoise]

Some window stickers show no charge.
It's a no brained for me. It would likely be a future mod for you so just get it up front.
It does not come with the PP1 differential as someone mentioned it does.

 

[Grintch]

The 3.55 will make the gears seem shorter meaning you will shift more often. The trade off is faster acceleration for less gas mileage with the 3.55's and vise versa with the 3.15's.

When you have 10 gears does it matter if 5th gear with a 3.15 is the same as 6th gear with 3.55s at 65mph? If you want more acceleration, shift down or put it in sport mode where the tranny does it for you.

1st is still very low geared even with the 3.15s, and 10th is still very tall with the 3.55s. I doubt you will notice a real difference either way. Unless you are a hardcore drag racer or fuel miser.

 

[Myshelby3425]

For 2018 models. 3.15s seem to be faster than 3.55s in the low end. Due to longer gearing the 3.15s are in the torque band longer. While the 3.55s are going through shifts the 3.15s are pulling. I know this bc I’ve tested this a few times running my buddies 3.15 vehicle. We both have the same base 2018 a10, just different gearing. On the low end from 20-40 rolls, he pulls away right away a car gap between us and doesn’t pull anymore. We tried from a 60 just for fun and it’s an even run until my car slowly starts to creep forward.

 

[MX Raptor]

For 2018 models. 3.15s seem to be faster than 3.55s in the low end. Due to longer gearing the 3.15s are in the torque band longer. While the 3.55s are going through shifts the 3.15s are pulling. I know this bc I’ve tested this a few times running my buddies 3.15 vehicle. We both have the same base 2018 a10, just different gearing. On the low end from 20-40 rolls, he pulls away right away a car gap between us and doesn’t pull anymore. We tried from a 60 just for fun and it’s an even run until my car slowly starts to creep forward.

Do both of these said cars have the 301A package with driver modes? Or are both 300A's? From a 20-40 roll I don't think the 3.15's would pull a car length :shrug:

 

[Lonmon]

This is probably gonna be one of those overly argued splitting hair threads. I would say get the 3.55 if you are gonna stay NA and keep the 3.15 if you are gonna eventually go FI. In the end we are only talking about a few hundred RPM difference in each gear and as others have mentioned both cars will get similar mileage and do equally well at the track. I have raced my e85 tuned 18 with 3.15 a10 against my buddies 15 1LE FBO with cam and actually walk ahead a bit then hold him off to 140mph (in Mexico). My 15 FBO gt350 IM car on e85 was dead even with him and that was a PP car with 3.73. Both cars were within 100lbs of each other (on the same scale) with the 18 being slightly heavier. I just don't think the gear difference makes as much difference as some of the 3.55 guys make it out to be with the a10 trans. I would gladly race anyone with a 3.55 car and the same mods and believe it would be down to best tune and who hit the pedal first.

 

[Lonmon]

My 18 also makes 40 more ft lbs of torque to the wheels then my 15 did BTW. No hellcat bottom end but it is better then previous versions by a respectable amount.

 

[Myshelby3425]

Do both of these said cars have the 301A package with driver modes? Or are both 300A's? From a 20-40 roll I don't think the 3.15's would pull a car length :shrug:

The 3.55 car, mine, does have 301a and the 3.15 doesn’t. You might not think, but that’s what happened in my case. And it’s actually 2 car lengths. Car gap would make that 2 cars. We’ve tested it about 6-7 times with same outcome.

Another thing I noticed driving the 3.15s is that the transmission is much smoother. 3.55s can be jumpy. .

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