If you have your choice...

I put a 75 shot of nitrous on my 98 Mustang GT a/b a month or so ago. Loving every bit of it.

If I had to pick... I'd probably go with a built motor w/ a supercharger (ie: 03/04 SVT Cobra). After that.. I'd probably pick a built motor w/ nitrous OR more cubic inches... torn between those 2 (weight issue comes into play though w/ more cubic inches--not THAT much though).

-Mike

A twin screw blower or turbos is the best route, IMO. A twin screw blower on an '03-'04 Cobra gets you a reliable 600 rwhp/rwtq out of

4.6L. Plus when you keep your foot light you get the mileage benefits of a smaller displacement engine. When an engine is properly designed for forced induction it is very rugged and reliable, even under high boost conditions.

Of course more inches, because as they say there's no replacement for displacement. Blow it, turbocharge it, juice it, cam the shit out of it, but big inches still rules. You can run 10s without any of that crap on a junkyard 460 with the right induction and exhaust. I know a guy who does every weekend.

And do those mods to a BB motor and you're talking four-digit horsepower that you can actually drive around. And screw gas mileage. That's what beaters are for. In street trim, the 1970 Ford 460 put out 505 lbs/ft. of torque. You can rub the damned valve covers clean and get 10 hp out of those things due to improved heat dissipation. ;^)

You are a wise man. All that stuff complicates things and affects reliability. Big-inch motors rule, period.

I'm with MJ. Two small turbos, an air-to-air intercooler, and EFI on a

302 or 331 -- that's the ultimate. Nitrous is only good till the bottle runs out. Anything over 350 ci, you're stuck with terrible gas mileage all the time. A turbo small block doesn't need all that much cam, and if gas hits $3-4/gal, you just dial back the waste gate. A big block destroys handling and braking, and because you can't eliminate the low end torque if you want to have anything left up top, it's alot harder to hook up. The twin screw is attractive, but it's not easy to control the low end torque either. 180 Out

One other benefit of twin screws and turbos is that will actually produce more torque across the rpm range than a N/A big block. My '89 LX with a stock short block, twin screw blower, and 16 psi made 460 rwtq at 2,500 rpm on a dyno pull. It held 400+ rwtq until 5,500 rpm. On a

331 stroker, using an 8.5:1 CR, A302 block, forged parts and heads/intake/cam to promote high air flow the torque curve would bring a tear to your eye.

That being said there are benefits the large displacement engines. They are less complex. This is why I still plan to drop a 427W into the '89 LX one day.

Depends on what you want to do.... and what your future goals are. Your auto enhancements are part of a complete package. When you set out to increase performance, you should have a goal and work towards it. Willy-nilly mods are counterproductive and can even limit performance capabilities.

I like your style. The more BB posts I read, the more I want to drop a 460 in the '71.

Scott

hello all - good discussion...

is it not true that a positive displacement supercharger effectively "adds" cubic inches? for instance the stock eaton m-112 on the 03/04 cobra actually adds (taking into account inefficency losses) approx 80 cubes to the 281 modular (4.6), effectively making it around 350 ci engine? and a

2.2 kenne-bell twin-screw which equals 134.4 cubic inches, would add 90 or so (after losses)? and then the 2.4 kenne-bell even more? i had read that the inefficiencies of a supercharger equate to only about 70% of the total displacement.

with regards to the gas mileage argument, and it may or may not be directly related to the above, my experience is showing that although there is a very small displacement modular under that blower, it's as thirsty as a big block. i'm not talking about around town driving when i'm constantly into the boost from light to light. i mean the best highway mileage i can get out of this car is about 21-22... real highway 6th gear cruising. i average only 10-12 city with an overall average of 13.5. those numbers remind me of

60's big block muscle type mileage - pretty bad. i know that this is a heavy car, and rear end gearing and transmission overdives play a big part in it. but the idea that you can take a small engine and get the benefits by staying out of the boost does not seem to be working for me in the real world. my 96 gt vert (stock with a 3.27 rear) would get around 21/22 city and 28/30 highway, and that is with only 1 overdrive gear. it was a lighter car than this 04 cobra, but still, that is a pretty big difference - and gas aint cheap these days. that being said, trying to get good gas mileage is NOT why i buy an american v-8...

from what i understand, the chevy ls-1's which are powerful engines, get 30 highway - even in the heavier cambirds. i think they have 3.55 gears with the t-56 like my car, but are a little lighter? so i can see the logic in the argument that cubic inches is king and why chevy has stuck with their simple ohv small block but just kept the displacment large and the compression high.

chris

04 comp orange cobra vert

Bennett Racing in AL has a windsor based 427 stroker supposedly good for

600hp naturally aspirated on 91 octane. I'm thinking one of those with a KB Blowzilla stuck on top.

Wabbitslayer

01 GT vert

It all depends on what you want to do with the car. Forced indiction is not generally ideal for a road racing car because of heat soak and the additional weight over the nose. But a drag car is a whole different story...

MC

True, but look at how many Mustangs there are in road racing that have forced induction.

Ok, perhaps I missed something. Why not use a centrifugal S/C? Is it less reliable than a roots?

Procharger power baby! I have all the torque I need for the street and top end pulls like wild horses. With the big intercooler up front there's no need to keep filling a damn water/alcohol bottle, run race fuel or pull timing too much.

With the new generation of Kenne Bell blowers for the 4.6L Mustangs you can have massive low-end torque and great peak hp numbers. Best of both worlds short of twin turbos.

Hell yeah!! Go for it. BB is an Attitude. Come to the dark side, it's a lot of fun.

Now, we're getting somewhere.

It is absolutely true that it effectively quote-unquote adds displacement. So does high RPM in terms of CFM. But it is forced induction creating this contrived (and subjective) mathematical equivalent of displacement, not actual swept volume. You're absolutely correct, and many opt for this route. But there is nothing like actual cubes there, all the time, not measured as boost pressure on top of what you actually have... JMI...