Adding power to a manual w/ 3.73?

[Emt1581]

I was talking to another S550 GT owner this weekend. His is a base non-pp manual so I'm guessing 3.55 gearing. He said he planned to add a Whipple supercharger in the near future and then mentioned contemplating lower gearing. He also said that guys were destroying their cars with 3.73 gearing because adding power is too much for that setup.

Is this true or was he full of crap?

I'm enjoying my car right now. Absolutely love it! And I don't know even a fraction of what I need to in order to feel confident enough to add significant power. I won't do it for at least another 5 years anyway or whenever the warranties run out. Just learning as much as I can for now.

I know a bunch of parts will require upgrading when increasing the power, but does that include the gearing on a performance pack car?

Thanks

-Emt1581

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[WestCyril]

I know people making over 800+ and go with 4.10s in S197 cars. Its really personal preference.

The more gear you have the quicker the car is off the line and accelerates quicker.

Shorter gears bring the power in a little more gradually, higher top speed, and slightly slower acceleration. Most of this is not noticeable unless pushing the limits of the car.

3.31 is the go to gearing for most of the forced induction guys. 3.73 can work great and have no issues with making power with that gear. Its just personal preference.

 

[TexasGT]

I have a PP manual car with a Roush blower. Currently making 741whp. I had the 3.73 gears and recently went to 3.15's. My main reason was to run the Texas Mile. The 3.73 gears wouldn't have worked, as it would have maxed out well before the mile and shifting to 6th isn't a good idea due to engine load. So, using the 3.15's, I will be able to stay in 5th.

Since the change, I personally like the 3.15's better. Less shifting while in town cruising. And, 3rd gear is hella fun now. Pulls FOREVER! And this gearing will make for good highway roll races, as it's only one shift to 140+. I mean, not that I would do this, but it could

 

[Emt1581]

I have a PP manual car with a Roush blower. Currently making 741whp. I had the 3.73 gears and recently went to 3.15's. My main reason was to run the Texas Mile. The 3.73 gears wouldn't have worked, as it would have maxed out well before the mile and shifting to 6th isn't a good idea due to engine load. So, using the 3.15's, I will be able to stay in 5th.

Since the change, I personally like the 3.15's better. Less shifting while in town cruising. And, 3rd gear is hella fun now. Pulls FOREVER! And this gearing will make for good highway roll races, as it's only one shift to 140+. I mean, not that I would do this, but it could

...somewhere in Mexico. ;)

Thanks for sharing. For some reason I thought the Roush topped out at 670 but that might just be for the setup that retains the factory warranty.

Just curious but what'd it run you out the door to install 3.15's and did you do it yourself?

Thanks

-Emt1581

 

[TexasGT]

...somewhere in Mexico. ;)

Thanks for sharing. For some reason I thought the Roush topped out at 670 but that might just be for the setup that retains the factory warranty.

Just curious but what'd it run you out the door to install 3.15's and did you do it yourself?

Thanks

-Emt1581

Had a shop do it, when we did the E85 conversion. They changed out the entire pumpkin, not just the gears. I think it was 5 hours of labor, if I recall correctly. The 2 basic Roush kits are the Phase 1 at 670 crank HP and the Phase 2 kit at 727 crank HP. I have since switched to E85 and changed pulley from the 80mm that comes with the Phase 2, to a 75mm pulley. Also installed the 1050x injectors.

 

[jrsimon27]

Shelby builds the supersnakes and they throw in the torsen 3.73 gears. Look into it.

 

[Emt1581]

Shelby builds the supersnakes and they throw in the torsen 3.73 gears. Look into it.

Yup, I see that now.

http://http://blog.caranddriver.com...e-marks-a-50th-anniversary-with-up-to-750-hp/

Looks like the guy I was talking to was full of shit.

Thanks

-Emt1581

 

[WhiteyDog]

I added the Roush/Ford Racing Phase 1 SC to my PP about a month ago and I like it fine. I have a Lund tune and never had the Roush calibration because of having headers and I wanted more HP anyway.

 

[dubster99]

I'm currently 3.73 and swapping to 3.31 to help with power delivery, and to stay in boost longer.

 

[Matt M]

depends what Trans is in the car.

With the MT82 and 650rwhp 331 is best

 

[Roh92cp]

3.73's and love them and know many others who do as well. The torsen 3.73 is a great setup and actually the lower gears with sticky tires will be harder on the drive line than 3.73's.

 

[Boduke0220]

Mt82 stay 3.31, tr6060 needs 3.73 or 4.10..6r80 3.15 is money

 

[Emt1581]

Those talking about the 3.31's...is that primarily to slow down when you have to shift? Is there something that makes it more healthy for the car?

Trying to understand the logic.

Thanks

-Emt1581

 

[wireeater]

First tip. Don't listen to other people who aren't well known in the car community. The only reason people prefer to change out of the 3.73 gearing is because the power is harder to put to the ground in the lower gears. I have been on this forum and the facebook pages for nearly a year and haven't seen anyone blow out the diff besides one car I think and I don't even think they were 3.73s. He pretty much grenaded the pumpkin. I think it was a video I seen posted on SVTP forum.

 

[Synyster06Gates]

Those talking about the 3.31's...is that primarily to slow down when you have to shift? Is there something that makes it more healthy for the car?

Trying to understand the logic.

Thanks

-Emt1581

Traction is a problem with lots of power and steep gearing.

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