Supercharger vs. N/A build!

[Cobrat24]

Just a heads up, thanks for all the advice and suggestions. My mech picked up the cobra, it goes in today for dyno before he work begins. We wanna see what it puts down at my elevation verses the elevation from where I picked it up. I'll keep you guys posted on the numbers. I'm anticipating a low hp/tq number.

I think the item I'm most excited to see is the exhaust build. My guy will be fabricating my headers and is working with Borla for the custom side pipe fit. Goal is 3.5 inch pipes into the side pipes. He hasn't disclosed the heads or cam combo but he's matching the flow rate, which is why he is changing the exhaust. I can't wait to see this setup. I will post pictures as they come along.


Came to terms with using what I have. And working on a different build down the road when I can really afford the bigger motor.

[cycleguy55]

Originally Posted by Cobrat24

Just a heads up, thanks for all the advice and suggestions. My mech picked up the cobra, it goes in today for dyno before he work begins. We wanna see what it puts down at my elevation verses the elevation from where I picked it up. I'll keep you guys posted on the numbers. I'm anticipating a low hp/tq number.

I think the item I'm most excited to see is the exhaust build. My guy will be fabricating my headers and is working with Borla for the custom side pipe fit. Goal is 3.5 inch pipes into the side pipes. He hasn't disclosed the heads or cam combo but he's matching the flow rate, which is why he is changing the exhaust. I can't wait to see this setup. I will post pictures as they come along.

Came to terms with using what I have. And working on a different build down the road when I can really afford the bigger motor.

No problem with that. One Web site that's interesting to play with is Camquest.com - it's clearly set up to sell Comp Cams products, but you can play with different combinations to get an idea of what to expect with HP, torque, when it's going to peak, etc. Is it 100% accurate? Not likely, but that's not the point - the point is to be able to select different options and see the effect those changes have on the overall result - relatively speaking, of course.

For example, I selected a 351W (close to a 302 stroked to 347 CID), and a cam with some specs to give you solid street performance (RPM Range: 2200 - 6200, Grind: 280HR, Duration @ 0.050" 224/230, Valve Lift: 0.560 / 0.598) and with good heads the Camquest tool shows >450 HP and almost 440 ft./lbs of torque. With a manual transmission that's nearly 400 RWHP.

I'm curious about the use of Borla mufflers between your exhaust manifolds / shorty headers and the side pipes. Obviously short, straight-through mufflers will be much better than catalytic converters, but why not just straight pipes? For that matter, why not go to headers between your engine and the side-pipes?

BTW, which side pipes are those, and have you checked them to see how much restriction is in them?

Perhaps worth checking out is this thread (Classic Roadster exhaust dilemma), the photos starting at post #20 show a re-build of side pipes with new, larger core mufflers to open them up.

[Cobrat24]

Originally Posted by cycleguy55

I'm curious about the use of Borla mufflers between your exhaust manifolds / shorty headers and the side pipes. Obviously short, straight-through mufflers will be much better than catalytic converters, but why not just straight pipes? For that matter, why not go to headers between your engine and the side-pipes?

BTW, which side pipes are those, and have you checked them to see how much restriction is in them?

Perhaps worth checking out is this thread (Classic Roadster exhaust dilemma), the photos starting at post #20 show a re-build of side pipes with new, larger core mufflers to open them up.

Ok so to answer your question, as we all know the existing side pipe setup from the primary's to the collectors are very restrictive, not to mention within the actual sidepipe itself. The idea with this is, headers to high flow borla exhaust and borla to straight pipe no restrictions. This flows better than the exhaust with side pipe setup that is offer currently. I know there are others out there that take care of the sidepipe itself but no one offers an alternative to the collector issues from header to side pipe. If you look at those collectors , a 2 inch primary times 4 is squeezed down to really a 1 inch through that collector.

[cycleguy55]

Originally Posted by Cobrat24

Ok so to answer your question, as we all know the existing side pipe setup from the primary's to the collectors are very restrictive, not to mention within the actual sidepipe itself. The idea with this is, headers to high flow borla exhaust and borla to straight pipe no restrictions. This flows better than the exhaust with side pipe setup that is offer currently. I know there are others out there that take care of the sidepipe itself but no one offers an alternative to the collector issues from header to side pipe. If you look at those collectors , a 2 inch primary times 4 is squeezed down to really a 1 inch through that collector.

I could be wrong, but that looks like the Factory Five J-pipe (1987-1995 J-Pipe Kit - Factory Five Parts Catalog). If so, a better solution would seem to be their headers for the 302 (302 Headers - Factory Five Parts Catalog) - full size primaries all the way to the side pipes.

[Cobrat24]

Originally Posted by cycleguy55

I could be wrong, but that looks like the Factory Five J-pipe (1987-1995 J-Pipe Kit - Factory Five Parts Catalog). If so, a better solution would seem to be their headers for the 302 (302 Headers - Factory Five Parts Catalog) - full size primaries all the way to the side pipes.

Yea I could go this route but then it would be like everyone else's exhaust. I like the idea of a single pipe with no primary's coming out. Besides I was told this flow rate would be ideal for my motor setup. I'll upload he photos when complete.