Ford cj hp question

Fred Popov · 11-17-2009, 08:23 AM

How about the '03 and '04 MACH 1 Mustang and the Cobra. They both had the 4.6L DOHC engines but the Cobra's was supercharged. If I remember correctly the Mach 1 had 305 hp and the Cobra 390 hp. I think these engines were the same except for less compression is the Cobra.

Evan Smith · 11-18-2009, 03:18 PM

Most factory supercharged engines are designed with low compression and very mild cams, so it is not really a good comparison to say the blower adds "X' amount of hp. The blower is used in lieu of displacement to make mid-range torque for good throttle response and overall power and economy. Blowers and the output they provide are also greatly affected by boost level and engine tune. Going from 8.5 to 10.5 compression can be worth a ton of power, which is usually the range of blown and unblown OE engines these days. Going from 7 psi to 15 psi can add power, timing advance can also add power, it's not just a matter of adding or subtracting a blower.

Putting an aftermarket blower on most of today's V8 engines can yield anywhere from 125-175 horsepower depending on boost level.

Evan

FED 387 · 11-18-2009, 03:31 PM

Thank you Evan for that explanation---I was aware of compression and valve timing effects but was just trying to get a broad idea of what might be achieved by adding a supercharger. I realize it is not a simple A or B but the melding of parts and the whole combination to achieve a desired level---Just never really had anything to do with either turbo or super charged engines... You really did answer the ? in the broad terms I was looking for---Comp 387

Evan Smith · 11-18-2009, 05:36 PM

No problem, for instance I put an underhood, Roots-style blower on my wife's 2007 automatic Mustang GT last year. It made about 275 hp at the wheels stock, with the blower and about 10 psi, it made 432 at the wheels, with no changes to converter or exhaust. ET difference was 13.28 before and 11.59 (in killer weather) after. 105 mph to 116 mph.

If I added a better exhaust, bigger fuel pump, 5 more psi of boost, and a looser converter it would go mid-10s no problem. That would be the limit of the stock bottom end, though, and daily driveability would suffer. So, I'll leave it as a mid-11-second car (12.00 here in Florida).

11-17-2009, 08:23 AM	#1
Fred Popov Junior Member Join Date: Sep 2007 Location: Chesapeake, VA Posts: 64 Likes: 0 Liked 0 Times in 0 Posts	Re: Ford cj hp question How about the '03 and '04 MACH 1 Mustang and the Cobra. They both had the 4.6L DOHC engines but the Cobra's was supercharged. If I remember correctly the Mach 1 had 305 hp and the Cobra 390 hp. I think these engines were the same except for less compression is the Cobra.

11-18-2009, 03:18 PM	#2
Evan Smith Member Join Date: Nov 2001 Location: Tampa Posts: 400 Likes: 7 Liked 115 Times in 5 Posts	Re: Ford cj hp question Most factory supercharged engines are designed with low compression and very mild cams, so it is not really a good comparison to say the blower adds "X' amount of hp. The blower is used in lieu of displacement to make mid-range torque for good throttle response and overall power and economy. Blowers and the output they provide are also greatly affected by boost level and engine tune. Going from 8.5 to 10.5 compression can be worth a ton of power, which is usually the range of blown and unblown OE engines these days. Going from 7 psi to 15 psi can add power, timing advance can also add power, it's not just a matter of adding or subtracting a blower. Putting an aftermarket blower on most of today's V8 engines can yield anywhere from 125-175 horsepower depending on boost level. Evan __________________ Evan Smith 1798 STK Last edited by Evan Smith; 11-18-2009 at 03:22 PM.

11-18-2009, 03:31 PM	#3
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,418 Likes: 523 Liked 332 Times in 180 Posts	Re: Ford cj hp question Thank you Evan for that explanation---I was aware of compression and valve timing effects but was just trying to get a broad idea of what might be achieved by adding a supercharger. I realize it is not a simple A or B but the melding of parts and the whole combination to achieve a desired level---Just never really had anything to do with either turbo or super charged engines... You really did answer the ? in the broad terms I was looking for---Comp 387

11-18-2009, 05:36 PM	#4
Evan Smith Member Join Date: Nov 2001 Location: Tampa Posts: 400 Likes: 7 Liked 115 Times in 5 Posts	Re: Ford cj hp question No problem, for instance I put an underhood, Roots-style blower on my wife's 2007 automatic Mustang GT last year. It made about 275 hp at the wheels stock, with the blower and about 10 psi, it made 432 at the wheels, with no changes to converter or exhaust. ET difference was 13.28 before and 11.59 (in killer weather) after. 105 mph to 116 mph. If I added a better exhaust, bigger fuel pump, 5 more psi of boost, and a looser converter it would go mid-10s no problem. That would be the limit of the stock bottom end, though, and daily driveability would suffer. So, I'll leave it as a mid-11-second car (12.00 here in Florida). __________________ Evan Smith 1798 STK