December 2, 2007
Update for the Alternative Auto Shop Car With a 15psi Intercooled Whipple Kit
For the end of the 2007 season our new Whipple equipped ’07 automatic Mustang GT surpassed all of our expectations and knocked out an eye popping 10.91 @ 126+ MPH in the quarter mile. This was all done with 93 octane fuel in the tank.
The Whipple was installed with only 300 miles on the new GT’s odometer, and is showing over 5500 miles as the ’07 season came to an end. Plagued with humid 85 to 90+ degree temperatures every time we took the car to the track, we finally got out with the ’07 GT in the fall with less then 65 degree temps in October, and quickly picked up three tenths & some MPH in the 1/4 mile with only the cooler/fall air to credit for the big increase in ET and MPH.
As a quick recap -- the list of mods to this 3-valve car is very short and simple.
- It has a intercooled Whipple twin screw now producing 17psi of boost along with Alky injection.
- It makes just a touch under 500 RWHP and has no other mods except for a pair of Flo-Master mufflers (changed really only to sound better, and slightly louder).
- Every thing else on the car is totally stock (Rear gears, TQ converter, long-block, Exhaust manifolds, stock cat’s, all stock suspension, etc). It weighs with driver about 3830 lbs !!
The Whipple started out at about 15.5psi with Alky injection right off the bat in early ’07, then in mid summer ’07 the blower pulley was changed to bump it to about 17psi. With a well thought out tune on 93 octane, and a squirt of Methanol --- the entirely stock motor has survived all of the summer of ’07 so far with lots of abuse on the Dyno, street abuse, and about seventy-five 1/4 mile runs.
Can’t say how long the stock motor will continue to go at this power level, but by not detonating it at all to this point, its proving in the short term that with the current state of tune it will continue to go for a while at least at 17psi of boost from a twin screw.
Just like our ’05 GT…. the ’07 makes all of its quarter mile passes on 315/35/ 20” regular street tires – no drag radials or slicks. 60 foots in the ¼ are 1.60’s.
With a stickier tire of some sort, and not really pedaling the car out of the hole, and actually tuning back in some power below 4000 rpm and no other changes, I believe it has some where in the neighborhood of 10.70s in it on 93 octane.
The Intercooled Whipple kit both with, and with out the Alky injection has proven to be the most powerful, well packaged, solid and reliable power-adder money can buy for the ’05 and newer 3-valve Mustangs.
All you need is a stick shift, (or preferably an automatic for better ¼ mile results) 3-valve Mustang GT with this proving Whipple kit and Alky injection and you will have a guaranteed, fully street able and comfortable very low 11 and potentially high 10 second late model Mustang GT with completely un-compromised true street-ability.
Also very worth noting is that because this combo still has the stock 3.31 rear gear and tall 20” tires along with the stock moderately “tight” TQ converter…. It has awesome street manners and also runs very strong from a rolling start and should be capable of every bit of 160+ MPH top speeds with ease.
Today’s properly sized and intercooled Twin-Screw type blowers are proving to be very effective power adders, especially on the new 3-valve Modular motors.
Although the initial cost of these type of blowers is higher then other types of blower kits, it must be noted that the list of other mods needed to accompany twin screw to perform their best is greatly reduced or eliminated. This has been proven with Alternative Auto’s 2007 GT with the automatic trans. Because of the twin screw’s broad TQ and horse power range we did not need to switch to a looser/higher stall torque converter, nor did we have to change out the numerically low 3.31 stock rear gears. With only the exception of a couple of mufflers, the rest of the exhaust system is stock. All of this makes the Whipple equipped 3V GT not loose any day to day street manners. Twin screws are very quite blowers all around with only a slight howl coming from under the hood at WOT while under boost. And unlike centrifugals which need RPM to make power and Turbos which even the best of them will lag on 4.6’s in true street conditions. Twin screws like the Whipple makes the engine feel like a much larger engine all the time, from right off idle to shift points of about 6600rpm.
For now I’ve proved what I knew could be done with today’s intercooled twin screw’s and meth injection on 93 octane --- that you could buy a stock late model 4.6L Mustang and leave most of it alone, run very low 11’s in the quarter with a fully loaded and un-compromised car over all.
There are no immediate plans to enhance the cars power levels much further as it could start to compromise the stock engine and its weak pistons. Near the end of the ’07 season I will be trying one to two more psi of boost or more likely a slightly more aggressive tune and convert the car to E85 in an attempt to embrace the growing trend and availability of E85, and its power potential do to higher octane (105 octane). And many other reasons that are making E85 attractive alternative fuel.
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