2017 3.7.. what should be my next mod?!

Probably because I just did it but steering wheel mod is pretty nice. Whether you buy a new wheel or get it upholstered, I definitely recommend it.

Just installed Steedas rear sway bar, put it on the stiffest setting, and loving every minute of it.

Since you live in Florida and don't have to deal with snow I'd think about lowering the car with some new springs. Nothing more I'd like to do but with snow around here I need every inch.

Performance wise there's not much more you can do besides getting a procharger or changing the gearing.. shortys will help a little but not much, they definitely give the exhaust note a crisp sound under load.

3.7 mods For S550 platform

UPR 4 stage catch can, if you change gears you will need two tuners for install as the "easy swap" got harder after the S197 platform, S550's require a 2nd tuner to "recognize" the gear change. I did a DSS aluminum drive shaft that got my attention the most in my S-197 DIB 3.7

Coyote Red said:

if you change gears you will need two tuners for install as the "easy swap" got harder after the S197 platform

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Is this confirmed anywhere? I'm pretty sure there are a lot of people out there swapping 3.15s to 3.55s without worrying about anything. Check ctandc72's recent build thread and I don't see anything about extra tune being required for it.

Just asking/pointing it out because a lot of conflicting things get posted and it makes it confusing for others and for people that come in from search engines looking for info.

I swapped out 3.15 to 3.55 in a 6M no tune needed.

I don't mean to make a "misinformed post", I read on another forum that a special tuning devise 2nd tuner, is needed to complete a gear change in the newer platform mustangs. I am trying to confirm what I read presently. Thanks.

Coyote Red said:

I don't mean to make a "misinformed post", I read on another forum that a special tuning devise 2nd tuner, is needed to complete a gear change in the newer platform mustangs. I am trying to confirm what I read presently. Thanks.

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No worries, I researched it a ton and here's what I found.

The S550, you change the gear ratio inside the BCM (Body control module) so the common tuners cant do this. However, since the wheel speed is determined by the ABS / wheel sensor, if the difference in the oem gear vs. the new gears isn't huge (Say 3.15 to 3.55 in my case) no change is really needed. The speedo and everything on mine (GPS verified) was dead on.

I have since changed it via FORScan, just because I was in there making other changes as well.

DANA44 said:

I swapped out 3.15 to 3.55 in a 6M no tune needed.

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Me too

Thanks

ctandc72 said:

No worries, I researched it a ton and here's what I found.

The S550, you change the gear ratio inside the BCM (Body control module) so the common tuners cant do this. However, since the wheel speed is determined by the ABS / wheel sensor, if the difference in the oem gear vs. the new gears isn't huge (Say 3.15 to 3.55 in my case) no change is really needed. The speedo and everything on mine (GPS verified) was dead on.

I have since changed it via FORScan, just because I was in there making other changes as well.

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Now I understand this better, thank's a million. I am tired of posters "Knocking down" or talking down to people just trying to contribute & learn these new hot rods. Can't we just all get along?Again thank's.

Coyote Red said:

Now I understand this better, thank's a million. I am tired of posters "Knocking down" or talking down to people just trying to contribute & learn these new hot rods. Can't we just all get along?Again thank's.

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I will say - that Whipple sells a "flare tool" that can change the gear ratio. It's like $500 if I remember correctly. Also you can change it via HPTuners Scanner software ($300+).

superblur said:

Turbos!

JMP makes twin turbo kits for the S550 starting at $3700.

https://www.facebook.com/jack.markgraf/posts/1751618454869480

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How would you compare that with procharger in build quality wise?

$6000 for a centrifugal supercharger kit is really too much consider how simple the mechanism is. I really would like to see some competitions for FI V6 solution.

ctandc72 said:

I will say - that Whipple sells a "flare tool" that can change the gear ratio. It's like $500 if I remember correctly. Also you can change it via HPTuners Scanner software ($300+).

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Can you use an SCT Tuner for this? That's just for correcting the speedo right?

Your not following. You don't need to change anything on the MT. The speedometer reads correctly. I don't know about the automatic needing a change for the transmission shift points. I went from 3.15 to 3.55 and 17 inch wheels to 18 and it works without changing anything. I don't know about larger than 18 inch wheels. But to answer your question, no an SCT will not let you change the ratio of the gears in the BCM.

D24112 said:

Your not following. You don't need to change anything on the MT. The speedometer reads correctly. I don't know about the automatic needing a change for the transmission shift points. I went from 3.15 to 3.55 and 17 inch wheels to 18 and it works without changing anything. I don't know about larger than 18 inch wheels. But to answer your question, no an SCT will not let you change the ratio of the gears in the BCM.

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Ah ok, that's what I figured thanks. I ride around on 20in wheels so I stopped caring about my speedo accuracy a long time ago lol Probably going to do 3.55s after Uncle Sam shovels me my tax money. I would do 3.73s but I can't justify the price difference especially coming from 3.15.

TURTL3 said:

Can you use an SCT Tuner for this? That's just for correcting the speedo right?

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The SCT tuner (I have one) gives you the option to change the gear ratio - but it doesn't actually do anything, since the '15 and up Mustangs hold this info in the BCM (Body Control Module) and the SCT modified the ECU (Engine Control).

If you have an automatic transmission - the change in gear ratio will need the tune adjusted for shift points. If you already have an aftermarket tune, simply email / call them and request a change. Most of them should be well versed in making the needed changes.

If you want to more about the BCM and the changes you CAN make in there (including gear ratio) with a computer, FORSCan (Free software) and an adapter that lets you access it ($30-50 depending) check out this thread:

https://www.mustang6g.com/forums/showthread.php?t=61773


Tire / wheel size doesn't really matter unless you make drastic changes. It's all about tire diameter.

Also if you make a more drastic gear ration change - from 3.15 to say 3.73 for example - you MIGHT need to make the change in the BCM for gear ratio, as I personally don't know the limitation of the automatic compensation the ABS / Wheel sensors / system is capable of.

Clear as mud?

Keep in mind - there are 15-17 owners out there who THINK the SCT can change gear ratios - like I said it HAS the option (it just doesn't do anything, it's applicable to the older cars) but it does NOT write to the BCM where this info is stored.