i feel like i shouldnt need to ask but..

[ShelbyOwner858]

For a stock 08 shelby,

 

what rpm is ideal to upshift for maximum performance?

 

also which speeds are recommended for downshifting to each gear??

 

 

these babys are touchy and i want my transmition to last as long as possible,

 

thanks,

-Quintin

[03reptile]

For a stock 08 shelby,

 

what rpm is ideal to upshift for maximum performance?

 

also which speeds are recommended for downshifting to each gear??

 

 

these babys are touchy and i want my transmition to last as long as possible,

 

thanks,

-Quintin

 

 

I'm no expert, but 40 plus years of driving performance cars has taught me that up-shifting about 500 RPMs short of factory redline should net you max HP. Downshifting is, for me, a subjective decision. Obviously downshifting resulting in hitting the redline is not good and familiarity with your car and six speed is the best teacher. I know this isn't very helpful, but I think most of us rely on our past experiences with manual transmissions to gauge our downshifting techniques. The safest advise I can provide on downshifting is to drop to the next lowest gear and not skip down, that assures you, at the very least, of preserving that wonderful Shelby engine. Hope this helps your decesions.

[ZXMustang]

To actually KNOW what RPM to shift at, you would need to make a dyno run with your car to see where your peak HP is. It all depends on YOUR specific car and mods.

[9599svt]

To actually KNOW what RPM to shift at, you would need to make a dyno run with your car to see where your peak HP is. It all depends on YOUR specific car and mods.

[/quote

 

You need to look at were your peak hp is, and how much the rpm's drop when you shift, so you usually shift above peek hp so that when your rpm's drop after shifting you are still maximizing the horsepower. You loose a little hp at the very high rpm's but then after you shift you are higher up in the hp curve so it is usually more benificial.

[mullens]

I shift at 6000, but I like to play it safe. My shift light/tone is set at 5800 to account for lag time. I don't know if you have a custom tune, but most importantly DO NOT raise the rev limiter on these engines. Ford makes it 6250 for a reason.

 

Downshifting is just common sense. You can tell when you're putting undo stress on the tranny.

[SPEEDY168]

Shift when the SVT light turns red !!!!!!!

[me32]

Shift when the SVT light turns red !!!!!!!

 

 

so the SVT light stock comes on at 3000RPM, hahhaha

[mustangshelbygt500]

For a stock 08 shelby,

 

what rpm is ideal to upshift for maximum performance?

 

also which speeds are recommended for downshifting to each gear??

 

 

these babys are touchy and i want my transmition to last as long as possible,

 

thanks,

-Quintin

 

Right before the red line, no matter what rpm is your hp peak, when you rev it to 6k, in the next gear you are going to start at higher rpm

[gt50035]

Right before the red line, no matter what rpm is your hp peak, when you rev it to 6k, in the next gear you are going to start at higher rpm

 

 

+1 That always works best for me.

[formervettowner]

I'm no expert, but 40 plus years of driving performance cars has taught me that up-shifting about 500 RPMs short of factory redline should net you max HP. Downshifting is, for me, a subjective decision. Obviously downshifting resulting in hitting the redline is not good and familiarity with your car and six speed is the best teacher. I know this isn't very helpful, but I think most of us rely on our past experiences with manual transmissions to gauge our downshifting techniques. The safest advise I can provide on downshifting is to drop to the next lowest gear and not skip down, that assures you, at the very least, of preserving that wonderful Shelby engine. Hope this helps your decesions.

 

Do these motors like to run at high rpms?

[03reptile]

Do these motors like to run at high rpms?

 

 

I think they are certainly capable of reaching toward 7000 RPM, as they are multiple cam engines and very strong. That being said, its also a 5.4 L. engine, and with the supercharger, it develops substantial low end torque. Its not really necessary to bump off the limiter to get full enjoyment out of these engines. I don't think these motors are happy to run for long durations at high RPMs,,,,,,,, Doesn't mean they can't. They are not BMW engines which have that capability designed into them because of the useage on the autobahn. These Shelby engines are super strong and in stock form will take a lot of abuse from drivers. Our highways really don't allow for much high RPM driving and therefore we really don't find ourselves in situations where we'll use high RPM for any length of time; of course professional racing is another subject.