top speed tranny

jhg516

New Member
Jun 21, 2003
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I have an 88GT making about 600rwhp I'm currently running 3.73 gears.This car is set up for top end racing.I am looking to get a new tranny and have narrowed my choices to either a G-Force T-5 or a T-56.I would like to know which will give me more top end.The T-5 is available with a .59 ratio for 5th gear and the T-56 has .63 for 6th or .50 for the viper spec.
 
...out of curiosity, what exactly are you using for suspension components? IMO most Fox mustangs, even those with warmed over suspensions, just aren't set up right for driving over 100MPH. Almost double that... you're talking about a hardcore integrated system of serious components... at least in order to not be considered an idiot by anyone who knows what they're talking about.
 
You also need to know what rpm your power peak occurs. Even then you'll have to do some experimenting to match the overall ratio with peak power rpm so the two cross at top speed. 180 might be do-able with 600 crank HP if it's geared properly. You can play with rear tire overall diameter to fine tune things. With 24.8" tires, 3.73 rear gear and .625 5th, 180 mph will happen at about 6000 rpm - give or take a couple hundred.

As stangbear said - I sure hope the unibody/suspension/brakes are up to the task.
 
With those gears, and a car that has power to reach 6000 rpm, with a TK0 600 with the .64 you'd be capable of 190 or so.
Which i don't doubt 600rwhp could reach.
I've had mine at 5100-5200rpm in 5th with the same exact gearing, and it wasn't done yet, but the race was, and i was starting to sweat. My car makes nothing down low, all of it 2200-6200.

Be careful with what trans you choose as regards to the 4th to 5th or 5th to 6th drop, because if it drops you out of the powerband too far, you may not be in a HP range capable of pushing your car through the air.
Probably get there, but may use up a ton of road.
 
190 is a going to be tough for a Fox. I do some high speed road racing and the fastest Fox I've ever seen went almost 170, for a sustained period, during the Silver State Classic a few years back. Even when the suspensions are heavily modded they are a handfull after 135. A Camaro would be a better choice. There is a Camaro that has won Silver State at least once and has hit 225. At 190 you will likely die. These cars are shaped like loaves of bread and were never intended for those types of speeds. I love Mustangs but high speed isn't what they are all about.
 
timewarped1972 said:
would the sn95's be more capable for that kinda stuff or is that still pushing it even for them?

Yes, there's been more than one magazine test where they have taken vortech superhcharged DOHC cobras to 190+ (NOT 03,04's) I believe the gearing used was also 3.73.

Hell, in Road And Track a couple months back, they tested all high end cars in a flat out mile.
One of the cars was the Vortech 05 mustang, i think it had exhaust a vortech, removed mirrors and rear seats, and lowered, and it went 192 mph.