Modding a 4.6
05-16-2008, 03:21 PM
#22
4th Gear Member
Join Date: Aug 2007
Location: Shelbyville, Indiana
Posts: 1,088
RE: Modding a 4.6
ORIGINAL: 72MachOne99GT
I know it's beating a dead horse over and over, but if you compare a 14.0 281 C.I. motor to a 400+ C.I. motor from the 60's, you'd be surprised how close they are. Technology has come a long way. Look at the 05+ 4.6's. 300+ hp from a 4.6 compared to 215 from a '96 4.6
I know it's beating a dead horse over and over, but if you compare a 14.0 281 C.I. motor to a 400+ C.I. motor from the 60's, you'd be surprised how close they are. Technology has come a long way. Look at the 05+ 4.6's. 300+ hp from a 4.6 compared to 215 from a '96 4.6
People forget that they changed the way the measure horsepower in 1972. Before 1972, the numbers published were gross horsepower. 1972 and after are net horsepower. Both were measured at the flywheel but for net horsepower the motor had all of the accesseries installed. The rule of thumb conversion is that net horsepower is 80% of gross. I had a 69 Camaro SS350/300hp. Using today's horsepower measurements it would have had 240 hp. A friend owned a '68 Chevelle SS396/375hp. This was considered one of the kings of the highway. By today's measurement it would have had around 300 hp. Even my 66 Dodge Coronet 500 with a 426 ci wedge with headers, intake, dual line Holley, etc. was probably only pushing around 425-435 hp. That's roughly 340-350 hp by today's measurements. It was running about the same horsepower as the 68 Shelby GT-500. The rule of thumb calculations could be off a little, but it definitely illustrates the point that today's cars are as fast or faster then the old muscle cars.
By the way, none of the published numbers have been adjusted to reflect the differences between gross and net horsepower. Anything that you read will still have the 68 Chevelle SS396 at 375 hp. You have to do the conversions yourself.
05-16-2008, 03:31 PM
#23
4th Gear Member
Join Date: Aug 2007
Location: Shelbyville, Indiana
Posts: 1,088
RE: Modding a 4.6
Because I drove the old muscle cars, I sometimes like to convert today's numbers to gross horsepower. 370 rwhp would be approximately 425 net hp (using 13% loss to the wheels) which is aroud 531 gross hp. If the loss between gross and net is only 15% instead of 20%, it still comes out to 500 gross hp. That's not bad, not bad at all for a little 281 motor running stock rods and pistons.
05-16-2008, 04:23 PM
#24
2nd Gear Member
Thread Starter
Join Date: Feb 2008
Location: Connecticut
Posts: 343
RE: Modding a 4.6
If a mustang has such bad flow, you would think if you just switched the heads you would gain a ton. Can you get 4 valve heads for a 2 valve or is the bore to small to? If you switch to heads with more flow it would seem like you would gain a ton seeing as it has no flow.
05-17-2008, 08:06 PM
#25
RE: Modding a 4.6
ORIGINAL: Mr Graystang
one of the best explaination I have seen yet on the 4.6 2valve and bolt ons.
Mustangs are the underdogs in the muscle car world , so ye they aint as fast as a ls1 or lt1 or a sti is way faster then a stock GT but when you mod a 2valve and smoke them rides its a awsome feeling. the 4.6 2valve engine can be a dangerous car if modded the right way , Look at livernois motorsports 2valve mustang ! that car is sick !!! and theres a middle aged lady that drives it too ! If you want a 400 ishhp car right out the box then you need to save for a GTO , Challanger or Terminator. Whats the fun in have a already souped up car ??? thats why theres all the euro cars out there, Modding a Stang is fun , great bordem killer and when you get some nice numbers out of it and dust a Z28 theres not a better feeling in the world ..... well maybee there is but I can list them on here.
ORIGINAL: MoKo_04GT
full bolt ons should get you close to 50hp. true... it isnt a whole, whole lot...BUT its 50 more horses than it had, and most def. makes a difference.
i spank stock gts all day.....not really even much of a race really.
plus....if you wanna be like ford, and try to make your stang sound like it has more horses than it does after full bolt ons you can tell everyone you have around 310 horsepower. OF COURSE this is only at the crank, and not the wheels.
if you figure a stock stang is about 225 to the wheels (which ford says 260hp stock), and full bolt ons will put you around the 270 - 275ish mark....take 275rear wheel horses and add your 13% drivetrain loss = 310 horses to the crank.....or......as ford would say...310 horsepower.
thats lame tho....
anyway....each bolt on does not add much by itself, and they are all close to the same. roughly $200 for 5-7hp. they do start to add up tho, as you keep doing them. your car gets faster, and faster....and runs smoother, and smoother.
full bolt ons should get you close to 50hp. true... it isnt a whole, whole lot...BUT its 50 more horses than it had, and most def. makes a difference.
i spank stock gts all day.....not really even much of a race really.
plus....if you wanna be like ford, and try to make your stang sound like it has more horses than it does after full bolt ons you can tell everyone you have around 310 horsepower. OF COURSE this is only at the crank, and not the wheels.
if you figure a stock stang is about 225 to the wheels (which ford says 260hp stock), and full bolt ons will put you around the 270 - 275ish mark....take 275rear wheel horses and add your 13% drivetrain loss = 310 horses to the crank.....or......as ford would say...310 horsepower.
thats lame tho....
anyway....each bolt on does not add much by itself, and they are all close to the same. roughly $200 for 5-7hp. they do start to add up tho, as you keep doing them. your car gets faster, and faster....and runs smoother, and smoother.
Mustangs are the underdogs in the muscle car world , so ye they aint as fast as a ls1 or lt1 or a sti is way faster then a stock GT but when you mod a 2valve and smoke them rides its a awsome feeling. the 4.6 2valve engine can be a dangerous car if modded the right way , Look at livernois motorsports 2valve mustang ! that car is sick !!! and theres a middle aged lady that drives it too ! If you want a 400 ishhp car right out the box then you need to save for a GTO , Challanger or Terminator. Whats the fun in have a already souped up car ??? thats why theres all the euro cars out there, Modding a Stang is fun , great bordem killer and when you get some nice numbers out of it and dust a Z28 theres not a better feeling in the world ..... well maybee there is but I can list them on here.
+1 Really great way of explaining things.......
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