Great, sounds good Brian.

 

Thanks, Tom. I went for an extended drive last night after work and almost didn't go home as it was so much more fun to drive! The car pulls so much cleaner and harder now with the new colder plugs that I suspect that slight misfire was hurting hp a bit. Feels like the car picked up an easy 20-30 hp. Now I have the itch to have the car dyno'd again to see how much more is getting to the tires.

On a side note Tom, I was reading your signature. Does your car really weigh 3,880 lbs? Last time I weighed mine before racing it was 3,620 lbs (3,440 lbs without me in the car).

 

Brian
3440 lbs is an inetresting number for +05 automatic gt since ford advertise 3500 lbs for an auto
did you reduce your car wt by any means?

 

Yes, I weighed it with me in it..... around 1/2 tank of gas, spare tire, etc. Plus remember that I have a complete audio/video system that with 2 amps, speakers, etc. plus body parts (chin spoiler, side and rear spoilers, 18" chrome DD wheels, etc). From the 3880 I removed the weight of my subwoofer box, because I pull it out when I race. With it, I'm closer to 3950. I weigh 200 lbs personnally FWIW. I would say that my 18" wheels weigh probably around 15lbs per wheel heavier than the stockers.

 

Yes, I do remove some weight for track days. 3,440 lbs is my car's race weight. Lighter 17" wheels & tires, spare tire & jack removed, rear seat removed, and 1/4 tank of gas (3/4 tank of gas "removed"). Only takes about 30 minutes to swap wheels and remove the spare, jack, and rear seat, and it's good for about a tenth of a second and 1 mph improvement in the 1/4 mile.

My car weighs about 3,560 to 3,580 lbs in street trim (factory 18" wheels & tires, spare & jack back in the trunk, rear seat in place, and a full tank of gas). A 2007 GT automatic coupe is supposed to weigh 3,532 lbs plus any options. I have heavy heated leather seats, Shaker 500 stereo, 18" optional wheels, etc., so my car weighs an appropriate amount given the optional equipment that came with it.

I actually haven't weighed my car since adding the supercharger. However, the box with all the parts (blower, injectors, extra fuel pump, tuner, etc.) weighed 48 lbs. The stuff that is removed in the blower install weighed about 20 lbs (factory airbox/inlet, injectors, tuner, etc.) so the net weight gain was less than 30 lbs. I also added BMR front & rear driveshaft loops and rear tunnel brace, but removed the the rear wind deflectors under the car (to make room for the tunnel brace), so there's another 10 lbs or so that was added. Gonna have to find about 40 lbs I can permanently remove to counteract what I've added.

 

thanks Brian for ur quick, detailed reply
btw in terms of wt, what about swabing the original exhaust manifolds,factory h pipe with the aftermarket lt headers and o/r h pipe ?
sorry for chnagning the discussion topic in here and enjoy ur ride

 

That's the fastest 3,880 lb car I've seen in a long time! Glad to see you can have all the luxury amenities and still rip 11's with your GT!!!

 

I'd love to swap the exhaust, front to rear, but several reasons why I'm keeping the exhaust stock...

1. $'s (or lack, thereof).
2. My car is a daily driver and they smog test us frequently (no o/r h-pipe).
3. I need my car quiet for stealth. I drive way too fast on the street and don't need the attention of the local police.
4. I also need the stealth of a quiet exhaust to go with the V6 appearance mods I've done. Trying to fool people into believing my car is just a 210hp V6 (instead of a supercharged GT)would be tough with thundering exhaust.

 

Mine also weighs in excess of 3800 lbs (with me in it)... and I'm expecting to see a 10-sec timeslip next weekend!

 

mine... a V6 with the intercooled Vortech 10psi is around 310-320 rwhp and tq... I think you need a better tune

 

Hi Bill,
The only problem you'll have is if you deside to install a charge cooler later down the road,then you'll probly have to switch the locations of the canton units. engine bay looking good.

 

Your V6 is making some very good numbers! Here's a few thoughts about the relatively low 351 rwhp for my '07 GT....

• Drivetrain loss in an automatic is 20-23% versus just 15% for a manual transmission, so the same blower in a manual GT would post 30-35 more hp.
• I have the non-intercooled Vortech. The intercooled systems can be tuned more aggressively and typically show about 40-50 more hp.
• My car has the big heavy factory 18" wheels and tires, plus 4.10 gears - two items that both rob horsepower on the dyno.
• I have no other power mods. 100% factory exhaust. Many who've added blowers have also done bigger cams, heads, off-road exhaust, etc. and dyno higher #'s, accordingly.
• My dyno tuning was done on a Mustang Chassis Dyno, which tends to read about 10% lower than the much more commonly used Dynojet. I believe that had I dyno'd on a Dynojet, I'd probably have shown an additional 20-25 hp minimum.
• Per post #22 above, my car had been misfiring. With new, colder/coppper spark plugs installed, the car feels much stronger and is running much better at wide-open-throttle. I suspect there's quite an improvement to be seen next time I dyno the car.
• My car is a daily driver with stock internals, so I had the tuner create a very conservative tune to protect the car from self destructing. I wasn't chasing big dyno #'s or bragging rights, just a car that could run low 12's in the 1/4 mile safely and consistently.
• Lastly, based on a 20% drivetrain loss minimum for the automatic trans, my car is making about 440-460 hp at the flywheel. Vortech advertised this system to make 420 hp at the flywheel, so my car exceeds their claim.

Could my car post much better #'s on a dyno? Of course it could. But, considering the factors above, I think it's making plenty of power.

 

Thanks Brian.

Yeah but atleast I shift my car manually...... just kidding ya Don, your car rocks.

 

Sucks for you, huh?

 

hahahaa, yes at times.

 

I have a feeling that this was your issue. I'd take it to the dyno and see how she is running. With the colder plugs, you shouldn't be getting spark blowout.

 

I should have trusted my instincts (and Vortech's recommendation) in the first place and done colder plugs at the same time as the supercharger install. I had never had spark blowout before, so it took awhile to figure out what the stuttering was. At first I thought is was pinging, then a lean condition, then a rich condition, etc. Finally dawned on me that when it happened I was getting a bunch of black smoke (unburned fuel) out the tail pipe, so the spark plugs and coils came to mind to increase spark. I'm not always the smartest guy with hot-rodding, but I eventually catch on. Glad I caught on before I blew up the engine!

 

Spark blowout is typically more related to the plug gap, and not so much the heat range of the plug itself. In fact, you may be more likely to have spark blowout with a colder plug.

 

I'll keep my fingers crossed that it doesn't. The car runs awesome now and all it took was a quality set of spark plugs to cure the issue.

 

Just wanted to update this thread with the actual results from my first run down the 1/4 mile since the supercharger was installed. Went to Bremerton Raceway about a week ago and ran a best of 12.57 @ 110.18 mph. So, I achieved the mph goal, and came up just a bit short on the ET's (ran mid 12's and some high 12's). 60' times were bad, so that's where I have to improve, then the ET's will be in line with the good trap speed.

Here's the 12.57 @ 110+ timeslip. I was car # 2725 in the right lane...