Silver City GT

Some might remember the post Newbie with some Questions. Will I've got a few more.

So I bought this Mustang and it turns out it has alot more aftermarket accessories than I originally knew about. The list is:

Cold Air Intake
62MM Throttle Body
MSD Coils
BBK Long Tube Headers into Dual Cats into a Borla Exhaust
Underdrive Pulley
Sneada Short Shift Kit
and I'm thinking 4:10 rear end - 2300 RPM @ 70MPH seems high to me??

My questions are:

Any idea on what the Horsepower and Torque would be with these modifications?

I am assuming the computer has been re-done, any idea how to tell?

Am I guessing right on the 4:10 rear end?

The original owner is from Alamogordo New Mexico and I sure would like to talk to him, if any of you all traded in a 2008 Red Mustang GT at Bormann's Autoplex in Las Cruces in the past few weeks please let me know.

Still love the car!

Thank you

Tang 72

Not sure about the 4.10s there is a way of jacking the back end up and rotating one tire by hand and watching the yoke to figure out the diff ratio but im not too clear on the math. My guess, and it would be a guess, would be around 360 hp at the crank but its really hard to tell some cars shoot low and others will really surprise you. Enjoy the car either way friend.

alkemist

If it runs fine, I'm assuming the tune is still in there, but there isn't really a way to tell. Did it come with a handheld tuner? Possibly 4.10 gears but without knowing from the original owner, you'll have to calculate. And you probably mean Steeda

Congrats and enjoy.

Nuke

Cold Air Intake-with a GOOD custom tune, about 20-25 RWHP gain; with a FRPP or other canned tune about 12-16 RWHP; w/o a tune about 4-6 RWHP (with all these mods I suspect the original owner had a good tune; seems he knew what he was doing. What octane are you running and does it ping with 87?)

62MM Throttle Body-No RWHP gain NA; minor gain if you're FI

MSD Coils-No RWHP gain NA; minor gain if you're FI

BBK Long Tube Headers into Dual Cats into a Borla Exhaust-5-10 RWHP depending on if those cats are Hi-flow or not (probably are). The Borla (or any other pipes after the H-pipe) do nothing for power.

Underdrive Pulley-about 5 RWHP free-up

Sneada Short Shift Kit-no power gain but may gain a tenth or so with quicker shifts

and I'm thinking 4:10 rear end-no power gain but quicker off the line

You're probably looking at about 300-305 RWHP.


With my 3.55's, I turn about 1900 RPM at 70 MPH so it sure sounds like 4.10's. I have a spread sheet that you can plug your tire size, tranny and gears into that'll give you all gear RPM vs speed. PM me with your addy. Any chance you missed an aluminum 1 piece drive shaft? That would free-up about another 5 RWHP.