Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by CT Grim, Sep 18, 2013.
Ok. Gotcha. Yeah, commented prior to the edits.
Here's what Pro-M's website has to say about the 75mm bullet:
A general search indicates that a Lightning MAF quits somewhere around 450-500rwhp. Pretty close. I learned something here, but the point in the upgrade would be to reduce the restriction in flow. I agree with your assertion that it's not going to be worth the cost or effort, but I think it would definitely pick up something.
A 75mm is no restriction to flow whatsoever. I'm still running the 75mm Pro-M I bought 14 years ago.
Curious, anyone know whats the volume of air in a N/A 302, 331, 347 can bring in at one time. I think then when that's found, one could really taylor the incoming air velocity
calculation is VE*RPM/2*cubic inch displacement/1728 = volume in CFM (cubic feet per minute)
Why do you believe that? When will it become a restriction to flow? Do you have any evidence that indicates that increasing the MAF size on an H/C/I 302 results in no power gain?
Hell, what do I know. Maybe you're right. I don't bother with MAFs these days, anyway.
would anyone care to plug number in that equation, im at work
I'm not sure what you're trying to do.
Ok, for ****s and giggles a 347 turning 6500 rpm at 95% volumetric efficiency, which is pretty good at that RPM, would be moving 620 CFM. This motor is going to make over 400rwhp at sea level under standard conditions.
20 years of experience. A 75mm is huge for a basic HCI engine. Have you seen one? You can fist the damn thing.
I owned a 75mm MAF, as mentioned. FYI, 75mm is just under 3" in diameter. You have very small fists.
Found this on a forum is it right??
73 mass air = 1171 cfm
80 mass air = 1415 cfm
83 mass air = 1598 cfm
70mm throttle body = 726 cfm
75mm throttle body = 845 cfm
90mm throttle body = 1190 cfm
If 5spdGT posted it, it probably was well researched.... sounds like something he's done here. Consider the fact that's airflow at a given pressure differential on a flow bench. Likely, it's at 26-28" vacuum. Just because they will flow that at around a 1 bar pressure differential doesn't mean they won't still cost power. Ultimately, what you're shooting for is minimal vacuum in the intake at WOT. If you have a way to read the factory MAP sensor or if you have a boost gauge, it's a pretty easy measurement.
In one test I saw, a 90mm TB picked up 14hp on a 331 and made extra power throughout the ENTIRE power band. I expected the 75mm TB to make just as much power until maybe the very top of the powerband. Here's the article from dyno proven small block ford performance:
Sounds kind of Kinky......
Gettin' Fresh with a 5.0
Kinky is the way I go. I have a 70mm tb, and I think it's actually a 77mm maf. Vacuum is 0 in the intake all the way to the red line with 192cc heads. I'm sure it would be 0 with 205cc heads.
Kurt, what do you make of the article posted?
My understanding is that I'm limiting my ultimate HP/TQ potential with the Ecam and the tubular GT40. The intake will stay, but the cam might find it's way back on my shelf if picking a new custom/off the shelf cam is worth the $$$. What cams would work best with my set up, and what kind of improvement could be expected?
I like these kinds of discussions.
I suggest the XE264R-12 and you should be 300rwhp+ with good streetability, this is the cam I want!!!!
.55x/.560 lift; 224/228@.050"; 111LSA,
That was my custom with AFRs and a Cobra intake.
One more thing pondering is to port my intake. It might already have been worked on. Is there an easy way to tell? I will post some pictures later today. Just curious what kind of gains I could hope for.