gt 350 fix thread

[SidewaysMike]

Being able to add navi/sync without all the other fluff.

I have leather now, wish I didn't get it. I get burned every summer, its annoying.

If they could make the MFT w/ 8 inch screen a stand alone option my build would be perfected: GT350, Track Pack and MFT. Cloth seats for 4 seasons of comfort and no slipping

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[LindsayEOD]

If they could make the MFT w/ 8 inch screen a stand alone option my build would be perfected: GT350, Track Pack and MFT. Cloth seats for 4 seasons of comfort and no slipping

I'm with you guys. I really do not like leather for a track car but like the navigation for my weekend excursions. The track pack with navigation would be my ideal build. Unlikely to happen though.

 

[Hack]

4.56 gear for a road racing car? Have you guys ever been on a road course?

Without knowing the transmission gears, you can't really know what the perfect gear is for the car. Also, every track is different. 3.73 is a great gear for MOST track oriented high-revving Mustangs.

I've run 3.27, 3.55, 3.73, and 4.10 gears in my road race Mustang. I've also run different trans gears via numerous stock T45s and the close ratio T56. AND I'm getting ready to switch to 3.90 gears. I've also run 4.6 and 5.0 Coyotes from 300 to 400 HP. Every time I make a major change like this, I have to rethink rear gears. It's all a compromise. 3.73 is definitely the best all around gear for a RR Mustang. With the 4.10s I spend too much time shifting.

I know it's fun to bench race online but Ford has done extensive testing on these cars. Is it possible that they actually know what they're doing?

Yep it's a compromise. Ford does know what they are doing, but what they are doing may not correspond with your needs. Do you need to be able to stay in 1st gear above 50 mph? I assume you aren't going to try to downshift into 1st gear on a 20 or 30 mph turn - will that put you out of the power band in second?

So you say you are going to 3.90 gears? What's the engine redline, tire diameter and transmission top gear ratio? Where is peak torque?

I understand that too much gear can slow a car down, depending on how fast the person can perform their shifts. I'm contending that 3.73 isn't a lot of gear for a 8,250 rpm engine in a "track car" with a 6 speed transmission.

 

[Trackaholic]

As mentioned above, without knowing the transmission ratios you can't say one rear-end ratio is better than another. The two work in concert to provide the top speed achievable in any particular gear.

So, look at the tracks you run, think about what speeds you are likely to reach, and decide how many gears you want to be using on the track.

I personally would like to use 2nd, 3rd and 4th. Probably don't need 5th on most of my tracks.

Here is a very quick guess at some top speeds I think I'd like to see in each gear:
1st = 45
2nd = 70
3rd = 100
4th = 135
5th = 175
6th = 220

I haven't looked at the powerband yet, and how these shift points would affect that. Maybe later today I'll see if these really make sense.

-T

 

[Mystic_Cobra]

Yep it's a compromise. Ford does know what they are doing, but what they are doing may not correspond with your needs. Do you need to be able to stay in 1st gear above 50 mph? I assume you aren't going to try to downshift into 1st gear on a 20 or 30 mph turn - will that put you out of the power band in second?

So you say you are going to 3.90 gears? What's the engine redline, tire diameter and transmission top gear ratio? Where is peak torque?

I understand that too much gear can slow a car down, depending on how fast the person can perform their shifts. I'm contending that 3.73 isn't a lot of gear for a 8,250 rpm engine in a "track car" with a 6 speed transmission.

First gear is not critical on a race car like it is on a street car. You don't use first gear on a road course. You are already in second before you leave pit road.

As for my setup, I shift between 7000-7200 depending on where I am. It's a stock F150 Coyote with long tube headers and a tune. That's it. Tire is 275/40-17 (~25.7" tall). Transmission is a T56 magnum close ratio so 5th gear is .80. Since we have limited power and small tracks, I don't use 6th gear. According to my sheet, peak torque is around 4500. Peak torque would have been about the same rpm before we detuned it. I had the wrong dyno sheet, new one coming shortly. Here's my most recent sheet.

 

[Hack]

IMO the Voodoo will want more gear for road racing than your current truck engine.

 

[GrabberBlue5.0]

Why are we already trying to fix things on an untested car?


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[IGJoe2192]

That Coyotes torque curve is just awesome!

 

[wproctor411]

Don't some people who are more serious about racing change gears depending on the track and top speed on the track? I run fairly regular at a few of the road courses within a day's drive, but never in competition, my point being I see guys swapping gears at some of the tracks with garages.

 

[Mystic_Cobra]

GrabberBlue- The car has been thoroughly tested by Ford. We have seen the video and spy shots for a year. They obviously used the testing to choose gear ratios among other things.
IG-Yes! I'm making 80 more ft lbs at mid RPM than with my 4.6 and the same peak HP and same weight! Awesome!
Proctor-Absolutely, the top teams and drivers change gears for different tracks and even for different weather! Some even retune and add weight depending on the class.
This gear choice is a compromise! That's why I previously said... best gear for MOST tracks.

 

[GrabberBlue5.0]

GrabberBlue- The car has been thoroughly tested by Ford. We have seen the video and spy shots for a year. They obviously used the testing to choose gear ratios among other things.
IG-Yes! I'm making 80 more ft lbs at mid RPM than with my 4.6 and the same peak HP and same weight! Awesome!
Proctor-Absolutely, the top teams and drivers change gears for different tracks and even for different weather! Some even retune and add weight depending on the class.
This gear choice is a compromise! That's why I previously said... best gear for MOST tracks.

Yep, I know FORD has tested it, but no consumer has tested one yet.

My point is how can anyone complain about something they've never even driven touched, or likely even seen in person?

I guess it's poor word choice on my part but my questions is still the same.


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[Trackaholic]

Yep, I know FORD has tested it, but no consumer has tested one yet.

My point is how can anyone complain about something they've never even driven touched, or likely even seen in person?

I guess it's poor word choice on my part but my questions is still the same.


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Um, it's the internet forums. Perhaps you aren't familiar with these, but forums are where people go to bitch and moan about everything prior to any real world experience with it.

It's really a lot of fun! Come join in!

-T

 

[Trackaholic]

As mentioned above, without knowing the transmission ratios you can't say one rear-end ratio is better than another. The two work in concert to provide the top speed achievable in any particular gear.

So, look at the tracks you run, think about what speeds you are likely to reach, and decide how many gears you want to be using on the track.

I personally would like to use 2nd, 3rd and 4th. Probably don't need 5th on most of my tracks.

Here is a very quick guess at some top speeds I think I'd like to see in each gear:
1st = 45
2nd = 70
3rd = 100
4th = 135
5th = 175
6th = 220

I haven't looked at the powerband yet, and how these shift points would affect that. Maybe later today I'll see if these really make sense.

-T

As an amendment to my earlier post, I basically extended the GT/PP engine speeds out to 8200 RPM, and used the same gearing and overall tire diameter (not even sure if this is the correct diameter, but the results are still interesting).

I ended up with the following top speeds in each gear (3.73 rear end ratio, and each gear ratio is in () after the speed):
1st = 49.4 (3.657)
2nd = 74.4 (2.430)
3rd = 107.2 (1.686)
4th = 137.5 (1.315)
5th = 180.8 (1.000)
6th = 277.7 (0.651)

Interestingly, those are pretty close to what I thought might be good for the tracks around me, except for 6th, which is better to be taller anyway to improve HWY F/E.

Not sure if the GT350(R) transmission has similar ratios as the MT-82, but I wouldn't be surprised to see something close to what is above, maybe a bit shorter in most of the gears.

-T

 

[Mystic_Cobra]

Trackaholic- we get that, but listening to people bitch about why a road race car isn't set up for the drag strip gets old real quick. Please bring a little bit of sense when you go out to the internet (not you, general request).
You can easily calculate the tire diameter since we know the size of both the GT350 and GT350R rear tires. Also, we were talking about 3.73 not 3.77, right?
It doesn't make sense to gear fifth to 180 mph, when you'll never see more than about 160 on most road courses. Why don't you use the gear ratios from the close ratio T56 Magnum XL, the correct tire sizes, and 3.73 rear?

 

[65ffr]

I always get a kick out of the guys that claim "Ford engineers designed it, they are gods, so it must be perfect" or some such nonsense. If they only knew....

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