I'm about to get my intake manifold ported, and I was just wondering if anyone has actually documented a before/after comparison, not just guessing what it will gain. I did a search, and I couldn't find anything.

 

listening

 

im with him im listening and waiting

 

I think you would only benefit from that if you are upgrading to 58mm tb and a stroker stock i wouldnt think so... there is nothing you can really do stock .

 

I dont know of any documented gains, but when I was building my 383 lloyd said that a ported intake is worth 10 hp in the upper rpms.

 

A stock intake will loose ya about 15% of your head flow. A ported one will loose ya whatever ya get it ported too,I guess maybe 9/10%, a GOOD sheet metal will loose ya about 2/3%

 

That aside, I would imagine, you would feel alot better throttle response as well from having all the extra plenum volume. Thats that much more air, that is right there, right then.

 

I have a 52 mm bored out stocker right now, but I have a 58 I'm going to put on when I get the intake ported, I guess I'll go dyno at the same place as last time and see if I gain anything.

 

Not the ideal comparison, but I can give you an estimated guess next time I go to the dyno. Since the last time I went I have added an electric w/p and ported manifold. Elec. W/P is worth approx. 10 rwhp so I can give you a ballpark figure. Consistently I hear 8-10 rwhp peak, not really anything under the curve to get excited about though.

 

when i fixed my intake seal leak i ported mine, nothing documented but the car pulled alot harder once the boost hit. It would light up second at 4500-5000rpm when it wouldnt before

 

Keep in mind that "porting" isn't just making the TB holes bigger,
a lot of work goes into enlarging the runners and shaping the inside of the
plenum for improved flow.

Sorry, no numbers, because I would never install ported heads without a ported manifold.
The stock manifold is a bottleneck for flow.
If you are going to spend time and money opening intake ports on heads,
why wouldn't you make sure the manifold ports are the same size?

Lloyd removed 3lbs of material from my manifold.
NRT did a similar job on my '95 about 6years ago.

 

Port matching probably isnt a bad idea with ported heads to help the flow transistions.

 

I'm curious, did anyone end up trying stock (or even ported) manifold VS sheetmetal?

 

Has anyone done this comparison yet?

 

I know some guys who've done stock vs. ported vs. HIGHLY MODIFIED vs. hogan sheet metal intakes on various 350's, 396's, and even 18* heads.

Porting the ski slope out is good for 5 to 10 ponies in stock and modified trim. Over 7000 rpms you get into large plenum benefits (highly modified intakes include this... and it's NOT cheap, nor useful below 7000rpms). The sheet metal is nice, but to do the runner's justice you usually end up with a TALL manifold that may or may not fit under a hood, costs you well over $2000, and is only good for a handful of ponies over a modified intake (which will likely run you into similar costs) at HIGH rpms, and HIGH air flow (> 300cfm).

Without spending big bucks you're way better off doing some mild porting of the runner and matching your throttle body opening.

Just my 2 cents... sorry I can't elaborate more, friends of mine spent big money on learning these lessons and unless you're tossing the stock PCM and turning over 7000rpms or have MONSTEROUS heads (i.e. heavily ported AFR 215's or 18* stuff) more than a port is pointless.