Help! Need advice in lowring my 1/4 mile time

[Joe Fan]

I recently got my new 2007 Mustang GT (automatic) down to 13.682 @102.29mph in the quarter. The only mods I have are CDC Shaker Hood Scoop, Superchips 91 Octane tune, and Corsa Axel-Back exhaust.

My goals are to get into the low 13s and then eventually break into the 12s.

However, I don't want to do a bunch of things to the car to compromise gas mileage since I drive the car everyday. I need advice on what my next step should be to lower my 1/4 mile time and what will give me the most bang for my buck.

I think I need to improve low-end torque because my best 60 foot time is 2.157.

I talked to a guy at a Mustang show who knows somebody who is real good and experienced at putting 3.73 gears into Mustangs. What should I expect to pay for cost for parts and labor? And what benefit should I see in my ET?

I have thought about adding a C&L or K&N CAI but I don't think it is going to help me dramitcally over my existing Shaker Hood Scoop system.

Mickey Thompson Street ETs would give me the necessary grip but I don't want to have to jack with changing tires all the time and buying a new set of wheels. But I know that I will have to do this eventually to get into the 12s.

I don't have the money for a Supercharger.

What will UDPs do for me and what should I expect to pay?

Any ideas?

 

[07gtfolife]

Nitrous? Its not on all the time, its there when you need it and it really doesnt affect gas.

 

[cowtown]

I'd consider the following mods myself.

3.73's (won't hurt economy that much) and run you about $500US installed from what I've seen on here.

With the 3.73's you may see some traction issues so don't be surprised if you need to spring for a pair of drag radials on spare rims.

some UDP will help the motor spin up faster and are good for about 10HP, install and cost are pretty cheap, a guy I met at the track with an 05 put them on and saw a 10th improvment.

I would consider the C&L intake. The reality is that the Shaker isn't really providing a huge amount of extra air and you're still trying to cram it all through that stock inlet. A switch to the C&L should provide a 10HP boost, if anything it'll set the stage for later.

Of course there is the other stuff like running a 93 octane tune (more timing =HP) and ditching as much weight from the car (including running with a 1/4tank or less fuel).

What altitude is your track at? That can provide slightly skewed #'s. For instance at my track the altitude gives me numbers that are 2-3tenths slower minimum than someone at a sea level track.

 

[Joe Fan]

I'd consider the following mods myself.

3.73's (won't hurt economy that much) and run you about $500US installed from what I've seen on here.

With the 3.73's you may see some traction issues so don't be surprised if you need to spring for a pair of drag radials on spare rims.

some UDP will help the motor spin up faster and are good for about 10HP, install and cost are pretty cheap, a guy I met at the track with an 05 put them on and saw a 10th improvment.

I would consider the C&L intake. The reality is that the Shaker isn't really providing a huge amount of extra air and you're still trying to cram it all through that stock inlet. A switch to the C&L should provide a 10HP boost, if anything it'll set the stage for later.

Of course there is the other stuff like running a 93 octane tune (more timing =HP) and ditching as much weight from the car (including running with a 1/4tank or less fuel).

What altitude is your track at? That can provide slightly skewed #'s. For instance at my track the altitude gives me numbers that are 2-3tenths slower minimum than someone at a sea level track.

Thanks. The Shaker Hood is supposedly good for a 2-3% increase in horsepower (6-9hp) and with K&N filter (1-4 hp). So I am getting about 10hp gain from this combo and why I am reluctant for springing for a C&L CAI. I am not sure how much it would really help over what I've got.

Thanks for the info on the UDPs. This is something I need to look into along with 3.73 gears. I am not sure how much the 3.73 gears would help me but it could be the most bang for my buck with an automatic if it is around $500.

Some other things. Superchips doesn't offer a 93 octane tune, just 91 and 87. I think I stretched it a bit with a 91 Octane tune using 92 Octane BP gas. Along with better weather, I think the 92 Octane gas played a role in cutting my time down from 13.74 to 13.68. Someone at the track recommend that I use BP gas over QuickTrip gas. I would recommend the same. Ford does too, its even on the gas cap.

The altitude of the track I run at (KCIR) is 882 foot. The temp at the time of my run was 69-70, humidity 40% and barometric pressure of 30.18-30.19. I calculated my Density Altitude to be 1500 and something, so my DA corrected time for a best run (13.682) is 13.456 @104.04mph. I am confident that MT Street ETs would cut my time down to at least 13.3 since that track is kind of slippery.

I usually run with an 1/8th of a tank.

 

[Hoboattacker]

My mods got me into the 12's on stock tires. Buy them and if you can drive, you'll make it. I get 24-25~ mpg on the highway at 80 with 3.55's.

Forgot to mention that I had taken out the spare tire, jack, trunk carpet stuff, and the rear seat when I ran my 12 second pass. It was also pretty cool out (november). I run consistent 13.1-13.2 at the track all day long.

 

[spyder7724]

it's not quite as easy to do with an auto but there's a couple mods that will drop some e.t. without killing the drivability.
3.73 or 3.90 gears -.20-.30
bamachips tune+++ this may drop up to 4 tenths off your times alone. doug gave me a tune that dropped me from 12.62 to 12.29 with no other changes!!!
spydershaft aluminum driveshaft -.20
i have a friend that ran 12.99 with just the bama tune, cai and LCA's
also consider L/T headers. they are worth about .15-.20 when used with an off road h-pipe.
my car is totally drivable n/a with a stock longblock and i've run 12.29 @110.9mph and still get 18mpg with the 4.30 gears i have now. the change from 3.73 to 4.30 didn't gain me much so if you want to keep it good on the highway stick with the 3.73 or 3.90 gears and you should get about 19-21mpg.
i've got a bunch of little things done to my car that all add up to make it quick while still being streetable except for when the bogarts are on

 

[kooldawg6]

I'm fairly confident I can see 12's with UDPs, D/S swap and stickier tires. My best ET(in sig)is at FULL weight(nothing removed...spare tire/jack or even the Shaker1000 sub box). I want to run all my times in decked out street trim I avg 19-20 MPG with a best of 24 MPG with my current mods.

 

[AlloyGT]

The altitude of the track I run at (KCIR) is 882 foot. The temp at the time of my run was 69-70, humidity 40% and barometric pressure of 30.18-30.19. I calculated my Density Altitude to be 1500 and something.

Dang, I think it's time for a roadtrip to KC! My track (Bandimere) is at 5800 feet. Last Friday when I was out there, the Density Altitude was 8100 feet. At least it's pretty here.

 

[ScottM]

Just out of curiousity, how are you launching? Are you getting any wheel spin? From the look of your best 60' of 2.157, I'd say you are but wanted to be sure. If you work on getting that down to a 1.8-9 (stickier tires, better launch, LCA's), you'd drop your 1/4 mile time a couple of tenths (however, I'm not sure how difficult that is in an automatic). What makes you think it's lack of torque that's slowing your 60' time? I'm by all means not trying to be "smart", I was really wondering.

 

[Joe Fan]

Just out of curiousity, how are you launching? Are you getting any wheel spin? From the look of your best 60' of 2.157, I'd say you are but wanted to be sure. If you work on getting that down to a 1.8-9 (stickier tires, better launch, LCA's), you'd drop your 1/4 mile time a couple of tenths (however, I'm not sure how difficult that is in an automatic). What makes you think it's lack of torque that's slowing your 60' time? I'm by all means not trying to be "smart", I was really wondering.

I have tried just about everything and I can't get my 60 foot time below 2.1. I've launched at various RPMS, different tire pressures and even tried Traction Control, and found that I get too much wheel spin if I try to launch higher than 2500 RPMs. Basically, my car needs more torque and grip in first gear to get a better launch. I think I have enough horses to cut low 13s if I can squeeze more out in the launch and 60 foot run. Drag radials seem to be the imple solution but they are a hassle since you can't use them for everyday driving due to rain and snow.

 

[Joe Fan]

Nitrous? Its not on all the time, its there when you need it and it really doesnt affect gas.

I am kind of scared to use nitro. I have heard people blowing their engines but maybe they were using to high of a shot.

 

[Joe Fan]

I'm fairly confident I can see 12's with UDPs, D/S swap and stickier tires. My best ET(in sig)is at FULL weight(nothing removed...spare tire/jack or even the Shaker1000 sub box). I want to run all my times in decked out street trim I avg 19-20 MPG with a best of 24 MPG with my current mods.

Mickey Thompson Street ETs on the rears on a cool day probably could get you into the 12s alone. I have heard that they cut .4 to .5 of a second off your 1/4 mile time. I am not sure I want the hassle of changing tires on race day all the time.

 

[Joe Fan]

it's not quite as easy to do with an auto but there's a couple mods that will drop some e.t. without killing the drivability.
3.73 or 3.90 gears -.20-.30
bamachips tune+++ this may drop up to 4 tenths off your times alone. doug gave me a tune that dropped me from 12.62 to 12.29 with no other changes!!!
spydershaft aluminum driveshaft -.20
i have a friend that ran 12.99 with just the bama tune, cai and LCA's
also consider L/T headers. they are worth about .15-.20 when used with an off road h-pipe.
my car is totally drivable n/a with a stock longblock and i've run 12.29 @110.9mph and still get 18mpg with the 4.30 gears i have now. the change from 3.73 to 4.30 didn't gain me much so if you want to keep it good on the highway stick with the 3.73 or 3.90 gears and you should get about 19-21mpg.
i've got a bunch of little things done to my car that all add up to make it quick while still being streetable except for when the bogarts are on

Thanks for the info. I am leaning towards 3.73 gears.

 

[cowtown]

Doing some reading about this, a lot of people are saying a Torque Converter is worth more at the track than better gears. This would also allow you to launch harder as you can spool up higher before the converter flashes. Do the gears and the converter and you'll likely be exactly where you want.

And with the intake system, the "bottleneck" is actually between the airbox and the throttle body so changing to a C&L system should provide some additional improvements, but that being said given what you have now the gears and converter would be a good path.

 

[07gtfolife]

I am kind of scared to use nitro. I have heard people blowing their engines but maybe they were using to high of a shot.

Its not bad if you have a good tune and a good kit. I run a 75 shot and its pretty sweet. The bottom line is if you want to go fast and race your car, you are running the risk of breaking something. You put tires that hook now the drivetrain is at risk. You boost, now the motor is at risk. So you have to face it, are you gonna do things that really make the car faster or are you going to add little odds and ends here and there and just have fun picking on slower cars. You might do the little odds and ends but want more in the end. Once you get bit by the modd bug there is no turning back.

 

[ScottM]

I have tried just about everything and I can't get my 60 foot time below 2.1. I've launched at various RPMS, different tire pressures and even tried Traction Control, and found that I get too much wheel spin if I try to launch higher than 2500 RPMs. Basically, my car needs more torque and grip in first gear to get a better launch. I think I have enough horses to cut low 13s if I can squeeze more out in the launch and 60 foot run. Drag radials seem to be the imple solution but they are a hassle since you can't use them for everyday driving due to rain and snow.

If that's the case, you definately don't need to be adding more torque or horsepower, you'll spin even worse. Gears are a great mod, but again, if you're spinning now, you'll spin like crazy afterwards. Also, you should never turn traction control on at the track. If you are getting better times with it on, you must be spinning a hell of a lot with it off. Basically, when you start to spin and TCS kicks in, it's going to slow you down, plain and simple, but after regaining from the wheel spin, you'll take off just fine. That's what is hurting your 60' with it on I bet. Of course, you're getting a bad 60' with it off because of the excessive spin. If you work on traction with it off, your times will greatly increase over it being on. At your power level, you should be able to cut a 1.9 60' assuming you had good traction.

In my honest opinion, you should look at mods that improve traction rather than add more horsepower or torque. Get the power you have to the ground first and then work on adding more. I would highly suggest looking at a decent set of LCA's and UCA first, they will help out with any wheel hop you are getting as well as plant the power to the ground. Also, I'm not sure what type of tires you have now, but have you thought about some tires that grip better, like BFG KD's since you don't want to use a drag radial? They aren't drag radials, but still will help hook better than the stockers (assuming that's what you have).

Again, this is all just my opinion, either way you go, good luck!

 

[V8JamesGT]

I would also consider an aluminum driveshaft and UDPs. Both should also slightly improve gas mileage.

 

[Bullitt2343]

Here are some before and after facts-

AUGUST 2006- Stock
2006 Roush Auto
13.89 @ 101 mph- 2.15 / 60'
w/stock BFG's 24psi
25mpg hiway 70+

Then I installed the following mods:
C&L Racer Kit/maf
3.73's FRPP gears
Basanni catted x
Steeda/Roush Under drive pullies
Xcal2 93 Tune from Brenspeed

MAY 2007- modded
2006 Roush Auto
13.31 @ 103mph - 2.02 / 60'
w/stock BFG's 24psi
23mpg hiway 70+

The key is either a Brenspeed or Bama tune, they make the tranny work amazing. Very firm shifts and with no torque convertor slippage...

Dynoed stock was 258 RWHP / after mods 296 RWHP even on the 92 Tune

Hope this gives you some direction,

 

[ponygirl74]

Mickey Thompson Street ETs on the rears on a cool day probably could get you into the 12s alone. I have heard that they cut .4 to .5 of a second off your 1/4 mile time. I am not sure I want the hassle of changing tires on race day all the time.

I put M/T streets on some 15" v6 rims for the track. It cut .40 off my ET. Yeah, it's a hassle to swap the rears but how often are you going to the track? Cheap mod and it won't affect gas mileage.