'07 Gt/cs W/ Roush Supercharger - Check Charging System

joshw0000

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Jul 1, 2014
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Hey guys, I just purchased my first Mustang. I've always told my wife I was going to buy something with power when we paid our house off. Well, it's not paid off but last weekend on a whim, we both fell in love with my new daily driver. I bought it this way so here's what I know about it so far:

101K miles (not too bad for a '07 I guess)
California Special edition GT convertible
Roush supercharger
Cervinis hood
Hurst short shifter
Corsa exhaust
Pioneer touch screen head unit
Shaker 10's mounted inside trunk
Drilled and slotted brake rotors

I was told by several different people (sales and service) that the previous owner was an older guy (hopefully he took care of it) who traded it in for a Roush. It's super clean. As close to new condition as I've ever seen a 7 y/o car.

Now for the questions:

Soon after I took this car home, it gave me a check engine light and a check charging system error. I took it back to the dealership and they replaced a hose and a O2 sensor. The tech intentionally avoided my questions about the charging system failure. As soon as I got home today the charging light came back on. From what I've read, it's most likely the altenator, a ground wire, or a bad battery. I plan to take it back to Ford tomorrow. Has anyone had experience with this?

This car is sooo much fun to drive. At 2K it starts to open up. At 3K it roars. Every car on the road wants to race and it's so hard not to do it because I finally have a 400+ HP car. I'm trying to drive this car easy and keep my shifts around 2K, no more than 2500.

What do you guys typically shift at?
What's your gas mileage like?
Do you use premium or regular? Why?

I just bought this car so I have no idea what maintenance was done it. Of course the dealer will tell me it's had all recommended maintenance but what's the chance that this is true?

Do you guys use regular oil or synthetic?
Any special maintenance required for a supercharger?

There are no special guages in this car so aside from taking it to someone I don't really know how to tell how much boost it's running. Maybe you guys know more about my set up than me from pics:

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This car will be my daily driver and I want to extend the life of the car as long as possible (at least until it's paid off). Thanks for any advice!
 
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For starters, pull the battery and alternator out and take it in to a store like Autozone or Advance Auto -- they can test them to see if they are within specifications or not. If they're good, start hunting for corroded grounds or faulty cables.
As for shift points, it all depends on how aggressive your driving style is. Just make sure you keep shifts below 3,000 until the engine has reached operating temperature for several minutes. This ensures that your supercharger is at normal operating temperature...there is a very small possibility that too much stress on a cold blower can cause supercharger failure. This mostly applies to cold weather, but better safe than sorry. When I'm really getting on it, I shift at about 6,500.
I have a highly modified, naturally aspirated engine with a high stall torque converter that makes about 13-14 mpg city but over 26 mpg highway. Again, your driving style is the biggest factor, but you definitely have the potential to have better mileage than that.
Premium fuel is a must. While you could get away with regular gas for just puttering around, premium gas is necessary if you ride the throttle hard at all. Superchargers increase cylinder pressure and operate with different spark timing than naturally aspirated engines, so hard throttle on 87 octane causes detonation, or pre ignition of the fuel before the spark plug fires, which can result in severe engine damage.
Since it broke 100k I'd do a full tune up. ..fuel filter, replace or wash the air filter, have the transmission flushed, the differential fluid replaced, coolant flushed, power steering flushed, and the brake fluid replaced with DOT 5.1 fluid. Don't use DOT 5 because it is silicone based and will destroy the seals in your brakes, but DOT 5.1 is glycol based and has the highest wet and dry boiling points out of all none race brake fluid. An oil change is a given. I stick with full synthetic oil because I have so many modifications done and it maintains its properties of lubrication better than conventional engine oil. That being said, as long as you change oil regularly at 3,000 miles, 3 months, or 200 hours of operating time, whichever comes first, there's nothing wrong with conventional oil. As far as the supercharger, get on the phone with Roush and figure out if it's an engine lubricated or self lubricated supercharger. There should be a part number on it somewhere. If it uses the engine to lubricate you don't have to touch it, but if it's a sealed, self lubricated blower you have to change the supercharger oil with whatever the manufacturer recommends. If you measure the outer diameter of the crankshaft pulley and the supercharger pulley, you can establish a rough estimate of boost. Your actual boost will be probably 2 psi lower due to different factors that bleed pressure. Also, if your supercharger uses an air to water intercooler, you should change the coolant as well.
Lastly, the spark plugs are very poorly designed and can snap off in the cylinder heads, so it would be a good idea to have a shop pull the plugs and check them for fouling, scoring, etc, or just bite the bullet right away and have them replaced with single piece spark plugs.
 
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Thanks for your response. This is some very useful information. I just got word from Ford that they've pulled my altenator and are having a hard time finding a bigger one by tomorrow....which means I may not have my car for the 4th of July weekend.

I'll definitely be checking the supercharger model and calling Roush. I was unaware that they had different lubricating methods.

I am pretty anal about oil changes and I agree that synthetic would be best in a performance car. I'll most likely be doing a lot of maintenance to it once I get it back.

I've been trying to shift at 2000-2500 and don't think I've went over 4K when I'm getting on it. I also agree with using premium gas. Some of the supercharger listings I found online last night said I MUST use premium so regardless of what I actually have, I'll just use the higher octane fuel.

Can't wait to get this thing back and hit the road with it.
 
One plus side to buying this car already modded is Ford has to fix these check engine lights (properly) and I got a 4 year / 85K extended warranty on it. It covers all major components including the supercharger.
 
Why does Ford say it needs a bigger alternator? Did they test it and say it for sure is bad?
Engine lubricated superchargers use oil feed lines that run from the engine's oil pump, cool and lubricate the supercharger, and drains back into the oil pan via a second line. Self lubricated superchargers use a sealed system that uses an oil slinger to slosh oil onto moving parts. They're easy to install, but you're limited with the amount of power you can make because oil singers in most superchargers begin to fail at around 600 rwhp. They're fine for most cars, but not if the engine is intended to produce serious power.
Yes, 93 octane fuel is absolutely necessary for engines producing boost, my point was simply that you seem pretty keen about taking it easy on the engine, and at 2000-2500k you are (if at all) building very minimal boost. Although, given the supercharger, your ECM is more than likely programmed to run off of 93 octane.
Warranties are always nice!
 
They didn't say. These guys aren't big on communication. They only said they've pulled it out and don't currently have a replacement.

Just looking for longevity. Doesn't mean I won't it open it up every once in a while.
 
That's definitely not good business. I'd take it up with whoever is the local management and if they don't start getting more communicative, get in touch with Ford Corporate. It's your car, not theirs.
 
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So the extended warranty take you to 185,000 miles right? It is not until the car has 85k on it? I'm sure it does, just verify. The supercharger probably requires on heat range colder spark plug. Keep that in mind when changing them (Put what ever is in it, back in it). The advantage to the colder besides preventing spark knock is that most aftermarket colder spark plugs are a one piece design which prevents them from coming apart inside when taking them out.
 
So the extended warranty take you to 185,000 miles right? It is not until the car has 85k on it? I'm sure it does, just verify. The supercharger probably requires on heat range colder spark plug. Keep that in mind when changing them (Put what ever is in it, back in it). The advantage to the colder besides preventing spark knock is that most aftermarket colder spark plugs are a one piece design which prevents them from coming apart inside when taking them out.
Correct. 4 years or 85K miles, whichever comes first.

Did a quick search and you're right. Everyone recommends cold plugs on a supercharged engine. I'm going to have my mechanic check this car from top to bottom when I get it back. If the plugs haven't been swapped for new ones, that'll be the first thing I buy. Thanks!
 
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...and my car won't be ready today.

This Camaro is nice but I'm ready for my car back. I'm still holding the spare keys and title to the car I traded in as collateral.
 
I got my car back a couple days ago. So far it runs great. I also got in touch with the Roush dealer who installed the supercharger. It's a 2300TVS single belt phase 2 kit. The invoice for the kit, Exeddy stage 1 clutch, installation, and dyno came up to nearly $9,400.

I looked up the kit and it promotes 550 HP but the dyno shows 474.79 HP and 432.31 torque. I'm not complaining.
 
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