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3.31 To 3.73 Gear Change????


konakenny

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I used to have a boss 302 that had the 3.73 gears and it was very fun. It accelerated very quickly. It did hit a wall at about 125-130mph and acceleration was very slow at that point (on the straightaway at the track). I don't think the Shelby would have that problem.

 

I raced a friend of mine in his whippled 11' gt500 against my 09' gt500 with kenne bell. We were making similar power. I actually think i had a little more power as i had long tube headers and full exhaust and he had axle backs. I had 3.31 gears and he had 3.73 gears. He pulled me from a roll pretty quickly a couple car lengths. He stopped pulling on me at that point but I couldn't close the gap through 150mph. Both cars were still accelerating at that point. I think I would have eventually closed the gap and even passed him if we kept going. But, where can you go that fast without dying or going to jail?

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I own two GT500s, a 2008 convertible and a 2013 coupe. On the 2008 I put 3.73 gears w/ several other mods and quite frankly it spins the tires in 4th gear at over 120 mph if you step on it hard, and that's w/ the traction control on!

Honestly it has become a handful driving it full throttle in the first four gears because of the tires spinning and you have to be real careful were and when you apply full throttle.

 

On the other hand my 2013 feels great, I put on a VMP pulley, cobra jet throttle body, JLT 127mm intake and a Jon Lund programming and w/ the stock 3.31 gears and in my opinion it's perfect. There is still some wheelspin but it's more controllable and it feels much better than my 2008 without the traction issues. You should definitely consider that if you do any mods other than the gear change it, may become simply a liability driving it because of the limit on traction, unless you change wheels and tires.

 

Also you should consider that your gas mileage will suffer. My only complaint on the 2013-2014 Gt 500s is that it has a small gas tank and w/ gear change you will notice it more.

 

I think it's a matter of choices, it depends on what you want and how much you want to spend.

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Got mine back from the dealer today. I like the 373's much better than the 331. Only thing[which didn't surprise me] the dealer could not calibrate my speedometer so now it's 10 mph off. I'll have to use a sct to get the speedo correct.

 

What year is your car?

 

Ford Racing Performance Parts (FRPP) has this;

!Bs!!pMgEGk~$(KGrHqEH-DkEvDwHEmPOBL2Gsok

 

Here's a e-bay link for it;

 

http://www.ebay.com/itm/370948321049?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

 

My FRPP Pro-Cal allows me to input gear ratio and tire diameter parameters for speedo calibration. I also use it to fool the computer to allow me to override the 150 MPH Vehicle Speed Limiter by telling it I have 6.00:1 gears in it.

 

 

Phill

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I own two GT500s, a 2008 convertible and a 2013 coupe. On the 2008 I put 3.73 gears w/ several other mods and quite frankly it spins the tires in 4th gear at over 120 mph if you step on it hard, and that's w/ the traction control on!

Honestly it has become a handful driving it full throttle in the first four gears because of the tires spinning and you have to be real careful were and when you apply full throttle.

 

On the other hand my 2013 feels great, I put on a VMP pulley, cobra jet throttle body, JLT 127mm intake and a Jon Lund programming and w/ the stock 3.31 gears and in my opinion it's perfect. There is still some wheelspin but it's more controllable and it feels much better than my 2008 without the traction issues. You should definitely consider that if you do any mods other than the gear change it, may become simply a liability driving it because of the limit on traction, unless you change wheels and tires.

 

Also you should consider that your gas mileage will suffer. My only complaint on the 2013-2014 Gt 500s is that it has a small gas tank and w/ gear change you will notice it more.

 

I think it's a matter of choices, it depends on what you want and how much you want to spend.

 

 

 

it's primarily the shitty tires that came with the 2007-2009 model year cars. i had that issue until i widened my rear wheels to 11" and added street legal competition tires. i'm with the other posters here... 3.31 are too tall for daily driving and any 150+ mph advantage is impractical. if you are worried about gas mileage you shouldn't be driving a GT500.

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The frpp procal says it is good up to 2010.

 

Yep.

 

Which is why I asked, "What year is your car?"

 

 

Phill

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The super snake with 850hp gets 3.73 gears!

 

That's not a valid argument.

 

It also gets larger diameter tires (and 20" vs 19" wheels) with the Delta/difference being ZIP.

 

The Super Snake running 3.73's is the same as the GT500 running 3.55's which actually *counters* your point (that lower gears are better/faster/quicker, as "proven" by Shelby's use of 3.73's).

 

 

Phill

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so here's an interesting tidbit of information that i learned by doing... typically, with aftermarket tuners, once you flash the vehicle, your tuner is married to your vehicle and you must return it to stock to unlock it. however, with the FRPP Pro-Cal II, the tune IS considered stock once it has been uploaded to the car. so you can still plug-in an aftermarket tuner on top of that without have to restore to OEM stock first or undoing the FRPP tune.

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so here's an interesting tidbit of information that i learned by doing... typically, with aftermarket tuners, once you flash the vehicle, your tuner is married to your vehicle and you must return it to stock to unlock it. however, with the FRPP Pro-Cal II, the tune IS considered stock once it has been uploaded to the car. so you can still plug-in an aftermarket tuner on top of that without have to restore to OEM stock first or undoing the FRPP tune.

 

Yep. I ran across this with a Superchips tuner too. I have the FRPP Whipple 2.9L tune in my car, loaded the Superchips tune over it and it showed my car has a stock tune.

 

Unfortunately, the Superchips people failed to come up with a tune that will work on my car (all I'm looking for is changing speedo/gear input, VSS limiter removal, RPM limiter, etc).

 

I ended up taking the Supertuner back and getting my money back. 2 months later Superchips called me and said they have the tune for me.

 

 

ARRGH!

 

Phill

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yeah, i was disappointed to find that the top speed limiter was still in place with the ford "racing" tune. actually, i hit 155 mph on an empty toll road and discovered that it wouldn't pull any further. so i ended up getting a 93 octane lund tune with the limiter removed and the shift light disabled. pretty nice to be able to keep the same hardware and change the feel of the vehicle with just a quick (and reversible) software change.

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it's primarily the shitty tires that came with the 2007-2009 model year cars. i had that issue until i widened my rear wheels to 11" and added street legal competition tires. i'm with the other posters here... 3.31 are too tall for daily driving and any 150+ mph advantage is impractical. if you are worried about gas mileage you shouldn't be driving a GT500.

You are 100% right about the wheels and tires. I don't really care that much about gas mileage but it does bother me having to stop to fill up every 200 miles. Have you driven a 2013-2014 Gt500? With the mods I had done, it feels like it has 3.73 gears w/plenty of torque throught the rev range

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yeah, i was disappointed to find that the top speed limiter was still in place with the ford "racing" tune. actually, i hit 155 mph on an empty toll road and discovered that it wouldn't pull any further. so i ended up getting a 93 octane lund tune with the limiter removed and the shift light disabled. pretty nice to be able to keep the same hardware and change the feel of the vehicle with just a quick (and reversible) software change.

 

I was only able to pull a *HONEST* 150 MPH out of my 2010. I say "HONEST" because that was indicated on my GPS *and* the timer at the Mojave Mile event.

 

I have no idea what my speedo incicated, i wasn't looking at my dash.

 

Did your Lund tune just change the VSS and disable the light or is it a completely new tune? Van initially offered me a Lund tune that was a mirror of the FRPP 2.9 tune with the VSS raised to 250 MPH, effectively eliminating the speed limiter but apparent'y Lund changed his policy and wants to retune my car on a dyno to give me the same thing, at a considerably higher cost.

 

I found that I can accomplish the same thing by using my Pro-Cal and telling the PCM that I have 6.0:1 rear gears in it. I haven't found the limit yet (at 171 MPH) and I'm too lazy to sit down and calculate it but I figure if I do hit the limiter, I still have the tire diameter to play with and fool the PCM some more.

 

I'm interested in hearing more about your 'tune'.

 

 

Phill

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You are 100% right about the wheels and tires. I don't really care that much about gas mileage but it does bother me having to stop to fill up every 200 miles. Have you driven a 2013-2014 Gt500? With the mods I had done, it feels like it has 3.73 gears w/plenty of torque throught the rev range

 

 

test drive and then riding with a buddy who owns a 2014. so no, i can't speak for a modded 5.8. but it seems like you could almost drive anywhere you need to without leaving 1st gear or 2nd gear.

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I was only able to pull a *HONEST* 150 MPH out of my 2010. I say "HONEST" because that was indicated on my GPS *and* the timer at the Mojave Mile event.

 

I have no idea what my speedo incicated, i wasn't looking at my dash.

 

Did your Lund tune just change the VSS and disable the light or is it a completely new tune? Van initially offered me a Lund tune that was a mirror of the FRPP 2.9 tune with the VSS raised to 250 MPH, effectively eliminating the speed limiter but apparent'y Lund changed his policy and wants to retune my car on a dyno to give me the same thing, at a considerably higher cost.

 

I found that I can accomplish the same thing by using my Pro-Cal and telling the PCM that I have 6.0:1 rear gears in it. I haven't found the limit yet (at 171 MPH) and I'm too lazy to sit down and calculate it but I figure if I do hit the limiter, I still have the tire diameter to play with and fool the PCM some more.

 

I'm interested in hearing more about your 'tune'.

 

 

Phill

 

 

so i added the 2.3L TVS kit before it was discontinued by FRPP and ran the Pro-Cal II tune for a while. however, it is a fairly conservative 91-octane tune that felt a little flat in the low rpm's. i initially purchased a remote tuning session and asked for shift-light removal, top-speed limit removal and 93 octane (since i'm in Texas). he said since my mods were well known i didn't really need a remote session but to let him know if i thought i did. he emailed a tune, i added it to my SCT X3 and uploaded it OVER the FRPP tune and the son of a bitch runs like a striped ass ape. it was already stupid fast with the conservative tune (and better rear grip), but there was a noticeable increase in performance running his tune. he ended up refunding me the remote tuning portion, so my final bill was like $200 (i already had an SCT tuner). i'm very satisfied. i know i could add a smaller pulley and long-tube headers for even more kick, but i'm absolutely satisfied with how it runs now.

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test drive and then riding with a buddy who owns a 2014. so no, i can't speak for a modded 5.8. but it seems like you could almost drive anywhere you need to without leaving 1st gear or 2nd gear.

You are right again. The 2013-2014 are a whole different animal, you would think that 400cc increase in displacement isn't that much, but believe me it is. When mildly modified it becomes a controllable beast. There might be a few faster cars out there, but they are at least double the price and not as involving.

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so i added the 2.3L TVS kit before it was discontinued by FRPP and ran the Pro-Cal II tune for a while. however, it is a fairly conservative 91-octane tune that felt a little flat in the low rpm's. i initially purchased a remote tuning session and asked for shift-light removal, top-speed limit removal and 93 octane (since i'm in Texas). he said since my mods were well known i didn't really need a remote session but to let him know if i thought i did. he emailed a tune, i added it to my SCT X3 and uploaded it OVER the FRPP tune and the son of a bitch runs like a striped ass ape. it was already stupid fast with the conservative tune (and better rear grip), but there was a noticeable increase in performance running his tune. he ended up refunding me the remote tuning portion, so my final bill was like $200 (i already had an SCT tuner). i'm very satisfied. i know i could add a smaller pulley and long-tube headers for even more kick, but i'm absolutely satisfied with how it runs now.

 

Okay, I think I have it.

 

If you wanted the OEM/STOCK tune back in the car, you would have to use the SCT to remove the Lund tune and replace it with the FRPP tune, then use the Pro-Cal to remove the FRPP tune and install the *stock* tune. Right/Wrong?

 

That's pretty much what I got from the Superchips device. It recognized my FRPP tune as "stock" and would download it into the Superchips Tuner and replace it with the Superchips tune, IF I WANTED THE TUNE. I didn't want the tune, I only wanted to acces my "stock" tune and raise the VSS and RPM limiter, plus use it for Datalogging.

 

I may end up getting the SC tuner again now that Superchips called me and said they have the right tune. The messed up part of it was that the tuner says "install Superchips Tune # G-32 (or something like that) but when you go to the SC site, there IS no "G-32" tune and the Superchips engineers didn't have it either.

 

It was a messed up situation and since the vendor (4 wheel parts & accy's) dosn't refund or let you return "electronic tools" or tuners, I nearly got stuck with a $350 paperweight.

 

But they sell the SCT and from the sound of it, the SCT will do what I need (defeat the VSS and RPM limiter, AND datalog (MAF and IAT2) inputs).

 

Am i assuming correctly??? (can you do that with yours ON TOP of your FRPP tune?)

 

 

Thanks In Advance/TIA,

 

Phill

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You are right again. The 2013-2014 are a whole different animal, you would think that 400cc increase in displacement isn't that much, but believe me it is. When mildly modified it becomes a controllable beast. There might be a few faster cars out there, but they are at least double the price and not as involving.

 

yeah i know. my friend has one. i'm not really that into those cars to be honest. with my power and suspension mods i'm already exceeding an OEM '13/14 and i prefer the looks of my car. to each his own.

 

 

not to mention i drive with folks who run modded vipers, ford gts, z06s, etcetera, so while i love the shelby's, they are easy enough to beat in the grand scheme of things. but again, i prefer the shelby image, heritage and experience.

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If you wanted the OEM/STOCK tune back in the car, you would have to use the SCT to remove the Lund tune and replace it with the FRPP tune, then use the Pro-Cal to remove the FRPP tune and install the *stock* tune. Right/Wrong?



>>> that is correct.



That's pretty much what I got from the Superchips device. It recognized my FRPP tune as "stock" and would download it into the Superchips Tuner and replace it with the Superchips tune, IF I WANTED THE TUNE. I didn't want the tune, I only wanted to acces my "stock" tune and raise the VSS and RPM limiter, plus use it for Datalogging.



>>> my understanding is that the FRPP tune actually affects more things than most aftermarket tunes do. at least that is implied in the ford racing parts catalog that discusses the value of the Pro-Cal II kits. as such, and i'm guessing here...you aren't exactly replacing the tune, so much as overwriting the parts that are editable by all tuners and not overwriting the parts that are only accessible to Ford Racing engineers. in other words, those things that you CAN change are likely not related or dependent upon the things FRPP will not allow ALL tuners to change. like a shift light change is not going to adversely affect the performance of the vehicle. it just stands to reason that like a software engineer would allow through application programming interfaces (APIs), the ford engineers would only allow manipulation of certain, safe parameters. again, just an educated guess. all that said, i know that VMP can easily create a duplicate tune file of what you already have, but change the few things you want changed, like the limiters, etcetera.



I may end up getting the SC tuner again now that Superchips called me and said they have the right tune. The messed up part of it was that the tuner says "install Superchips Tune # G-32 (or something like that) but when you go to the SC site, there IS no "G-32" tune and the Superchips engineers didn't have it either.



>>> Personally, I would stick with VMP or Jon Lund. I know there are others out there, but those guys are the top dogs, particularly for the GT500. I would NOT go with a "canned" tune from a vendor like Superchips, SCT or DiabloSport.



It was a messed up situation and since the vendor (4 wheel parts & accy's) dosn't refund or let you return "electronic tools" or tuners, I nearly got stuck with a $350 paperweight.



But they sell the SCT and from the sound of it, the SCT will do what I need (defeat the VSS and RPM limiter, AND datalog (MAF and IAT2) inputs).



>>> The SCT is probably the best aftermarket tuning device available. It WILL allow you to personally make changes to a tune file that is loaded onto it, but that EXCLUDES the stock tune.



Am i assuming correctly??? (can you do that with yours ON TOP of your FRPP tune?



>>> Nope. The FRPP tune is not stored on the SCT device as a custom tune, but rather the stock tune, which cannot be manipulated. However, as mentioned above, a reputable tuner can make an exact duplicate of your FRPP tune and tweak it to your liking, email it to you as a custom tune and then you can do whatever the SCT device will allow you to do with it (which is a fair amount of adjustments). Hope that helps clarify.


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I own a Ford dealership in NYC and I changed mine within a couple of hundred miles. My Saleen Extreme had 4.10s and I considered going to that. I think the 3.73s are the right gear for the car. So does Shelby. I had to get a tune from JDM to correct the speedo. They added some power at the same time.

 

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That's not a valid argument.

 

It also gets larger diameter tires (and 20" vs 19" wheels) with the Delta/difference being ZIP.

 

The Super Snake running 3.73's is the same as the GT500 running 3.55's which actually *counters* your point (that lower gears are better/faster/quicker, as "proven" by Shelby's use of 3.73's).

 

 

Phill

Hi Phill, The gears are changed from 3.31 to 3.73's...that is lowering...doesn't matter how or what one compares it too....I agree that wheel diameter and tire profile effect the end result of gearing (so does the gear ratios in the transmisssion)...but wheels and tires are variables that can change throughout the cars life. I feel your argument that lowering the gearing from 3.31 to 3.73 doesn't improve the performance of a 13-14 gt500 or by stating that Shelby proved that lowering the gearing doesn't improve performance "as proven by Shelby's use of 3.73's", sorry and not meaning to be disrespectful, but that statement does not make sense, of course it improved performance...thats why he did it.

Read the threads, and especially from people who have done a gear change...or magazine reviews, or talk to car people.

My comment was never meant as an argument...only a statement. We all bring something different to share at the table...it is nice to hear what others have to say, wheither we agree or not.

 

Respectfully,

Ken

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..your argument that lowering the gearing from 3.31 to 3.73 doesn't improve the performance of a 13-14 gt500 is not valid.

 

Yeah, I keep forgetting they come with 20" wheels from the factory!

 

 

Phill

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Hi Phill, Your car discription and mods sound pretty nice! Kona blue is an amazingly beautiful color! Is your profile thumbnail a pic of your car? Sweet looking!

 

Yeah, that's my car in my sig pic.

 

Thanks for the compliments. I'm about to install the Shelby/Baer rear brakes too since I'll have the rear drained for service (sounds like a good reason to tear the cover off and add the brakes!).

 

 

Phill

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I own a Ford dealership in NYC and I changed mine within a couple of hundred miles. My Saleen Extreme had 4.10s and I considered going to that. I think the 3.73s are the right gear for the car. So does Shelby. I had to get a tune from JDM to correct the speedo. They added some power at the same time.

 

do you still have your stock tires? how is your traction? what power mods did they do?

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  • 4 weeks later...

Hi Phil and others.

Just read this entire thread with curiosity and high interest......

I took possession of my 2014 Super Snake a couple of weeks ago and thought it was slower in the first 2 gears than my 2011 GT500 with a TVS and 3.73 gears, even with the 850HP /3.6 Kenne Bell blower. I made the mistake of leaving the stock 3.31 gears in it, and not choosing the 3.73 option on the SS package, (thinking the added HP would compensate for the higher gears, but it is just not the case when launching). This setup is perfect for going 200 mph but impractical for street enjoyment. After reading all of your posts I am now convinced 3.73's are the way to go. With that said I need to get permission from SA to make the change to not violate my 1 year warranty, and then have my local Ford dealer do the work(and have the same warranty chat). Other than that the car is a beast and just wants to run and ignore any kind of speed limit....

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do you still have your stock tires? how is your traction? what power mods did they do?

I just changed the tires to Michelin Pilot SS last week. I blew out two tires in a pot hole and wasn't going to spend money for two G/Years. It grips much better with the Michelins. The only power mod is a tune.

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  • 1 month later...

You are right again. The 2013-2014 are a whole different animal, you would think that 400cc increase in displacement isn't that much, but believe me it is. When mildly modified it becomes a controllable beast. There might be a few faster cars out there, but they are at least double the price and not as involving.

I agree. the 14 gt500 is definitely a beast. I've just received my parts from Evolution ( off road H pipe, jlt big air, oval throttle body and sctx4 with a custom tune). Should be around 800 hp when done I'm thinking. I think 3:73 gears would be a waste as you would be battling wheel spin constantly and thus your acceleration would suffer. I put 3:73 in my 89 5.0 along with some other minor changes and that was perfect. It spins all day long.

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Hi Phil and others.

Just read this entire thread with curiosity and high interest......

I took possession of my 2014 Super Snake a couple of weeks ago and thought it was slower in the first 2 gears than my 2011 GT500 with a TVS and 3.73 gears, even with the 850HP /3.6 Kenne Bell blower. I made the mistake of leaving the stock 3.31 gears in it, and not choosing the 3.73 option on the SS package, (thinking the added HP would compensate for the higher gears, but it is just not the case when launching). This setup is perfect for going 200 mph but impractical for street enjoyment. After reading all of your posts I am now convinced 3.73's are the way to go. With that said I need to get permission from SA to make the change to not violate my 1 year warranty, and then have my local Ford dealer do the work(and have the same warranty chat). Other than that the car is a beast and just wants to run and ignore any kind of speed limit....

I don't think there is any real torque gain with the Supersnake package - could that be the problem? Does it make its power down low like a stock gt500 or later on in the rpm range?

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