I have an 07 Mustang GT 5spd with about 2,500 miles. I recently installed a JLT II and Dougs 91 tune (Race). It definetly felt better, pulling strong to redline. Doug is great also - as we all know.

Anyways, I came from a 97 Z28 6spd (LT1) that only had a K&N cold air and Flowmaster exhaust. Yes, hard to compare torque of a 5.7 pushrod to a 4.6 mod motor, but none-the-less, I was able to depress the clutch and from any RPM from just off idle up from a role - light up the tires and make haste with a little throttle modulation. In this car, if I do the same thing it's kinf of like being in a Honda - BIG lag until about 3,000 RPM and THEN it's off.

I have heard that these motor's really wake up around 5,000 miles - is this true? What can I do to get this motor feeling a little more potent with not much cash outlay?

 

2007? Which rear end ratio 3.31 or 3.55

IF you have a 3.31 that could be part of the issue. The other factor is Ford's fine Drive by wire throttle control.

Exhaust is always a good mod, x pipe too. and of course gears.

And if the BANK account (read: wife) permits.

SUPERCHARGER

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Forgot to mention that...I have the 3.55 gears. I thought the factory exhaust is pertty close to optimal on flow, sure some long tubes and and x-pipe would help though.

 

I felt the same way after this replaced my 5.0 Cobra. I love the torque. But I also realize that this car as a whole is head and shoulders above my old Cobra...so it's worth the trade-off.
However I just view this as an in-between until they come out with a Boss/Mach variant with a bigger engine than the 4.6!

 

Go with 4:10's, Doug's race or torque tune, and a Pypes O/R H pipe will help a little on the low end also.

 

If I was graced with the wonderful 6spd tranny that I had in my Z28 with a .50 6th gear I would do 4.10s, but not in this car. Even with the 3.55s I sometimes feel like I need to shift into an imaginary 6th gear when on the highway.

As I mentioned, I have Dougs Race 91 tune and JLT II intake installed right now. I'm wondering how much long tube headers would do for me?

 

With 4.10 you'd be at around 2300 RPM at 65MPH in 5th gear. What's wrong with that?

 

The engine would be running at 3000 RPM at 85 mph.

 

Exactly - you beat me too it!

 

400 RPM greater? So?

 

Well, not to split hairs, but more like 700 greater. It's just to much for me. If this was an 8,000 RPM motor then I guess it would not matter.

 

My calculations:

RPM x 4.10 / 3.55 = 3000

3000 x 3.55 = RPM x 4.10

10650 = RPM x 4.10

10650 / 4.10 = RPM

RPM at 85 MPH with 3.55's = 2597.

3000 - 2597 = 403

What did I miss?

 

.68 5th gear:

http://www.csgnetwork.com/multirpmcalc.html


GOTO:

Transmission Final Gear Ratio Manual Entry

235/50R18 = 27.3" tire

85MPH 3.55's 5th gear: 2525
85MPH 3.73's 5th gear: 2653
85MPH 4.10's 5th gear: 2917

392 RPM difference!! Not a big deal for the big improvement imo. You can also see that the 3.73 is a waste of money if you have 3.55's on your manual. Provides little increase in mechanical advantage.

 

I just made a spreadsheet, attached

 

I have to agree, I'm still missing my lowend from my old chevy. A/C is nice though

 

You are indeed correct. I stand corrected. I was just going off of the other posters "3,000" RPM figure.

 

You like my ss? It actually helped me a bit lol, I had never calculated everything that far...

 

Here's the spreadsheet I use.

You can tweak the gear ratios, RAR, and tire rev/mile to see its effects. I never use the tire diameter calculated from the size, instead I use the rev/mile spec from the tire manufacturers. I am assuming the OEM Pirelli 235/55R17s for the TR-3650 (no interest in the 18" combos).

 

From an LT1 owner:
It has a rated 285 HP (flywheel)@ 5800 RPM and 325 ft-lbs of torque @ 2400RPM. 2400 is LOW for a torque curve and it's ability to light up the tires proves this. From a stop--even with an automatic, the wide tires cannot hold the torque and muscle, smoking them at will. You will even break loose the tires at 25MPH when you stomp on the gas pedal!

In comparison, our GT's put out 300 HP at 5750 PRM and 320 ft-lbs of torque at 4500 RPM.

BTW, if you want to get rid of the 'Honda feeling' and shred the rubber off your tires, all it takes is a little finesse of the clutch pedal. Like this!

 

Wouldn't that also wear out your clutch a bit faster?