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So I’ve got one of these big dogs porting intakes here…

15508 Views 208 Replies 38 Participants Last post by  96pushrod
A kind gentlemen - who is not big dogs, or affiliated with them sent me a big dogs cobra intake that has been ported. I’ll be replacing the box r intake on the car temporarily to see the difference.

I won’t get into the pissing contest, really here as a third party to make a comparison. Here are some pics of it compared to a factory explorer intake. All measurements are in mm.

This will be a strict a to b comparison deal. I’ll look at fuel flow and dragy times to see which one works the best. Engine is a woody built 347 with a f1r blower. Any ideas on which will come out on top?

If anyone wants any other pics or measurements, please Let me know and I’ll oblige if I can.

Saw Tool Machine tool Milling Power tool

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Looks awesome. What was the motivation in staying with a Cobra intake vs going aftermarket?
The box r will eventually be going back on. This is just to do some testing.
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It’ll be interesting to see how the lower matches up to your heads.
I think it will be a bit smaller judging by the 1262r on there now.
Looks nice, can't wait to see the results.

is this the cut and welded upper?

Lower looks huge, which heads are you running?
I believe it’s just welded on a couple runners to allow for more room to port.

They’re 11r 205s
Tech is good, but the upside readings are killing me lol
Lmao. I’ll upload them again and flip them.
this is the cut or uncut upper?

where are you located, i have a R long upper you can try and a systemax. might even have a tmoss lower to compare too.
I believe it’s uncut. What size opening on the long r?
I've always been curious about numbers on the intakes. I have no desire to partake in the pissing matches.

WHat exactly is the test you are going to do? Stock explorer lower and upper, vs the BD cobra upper and lower?
I’m going to see how the cobra intake does against the box r.
Actual measurements are nice, but we need sockets per square inch of port volume to get accurate information.
Hold on I’ll stick a couple sockets in and get back to you :LOL:
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Post up a picture of the welds.
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The side of the upper was cut and welded too. I can get better pics tomorrow if you want of the inside.
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Thats a crazy amount of filler in the throat of that intake Especially on the top by the egr flange, is it all weld or mostly epoxy? I have an old cobra upper the broke apart from a bad nitrous pop that doesn't look that screwed with lol.
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It looks like metal, at least inside.
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Tech is good, but the upside readings are killing me lol
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Flipped them for you.
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#786 is NOT our Stage 3 it's our entry level Stage 2 done in late 2019 fyi. It DID NOT receive our cut, shortened and welded upper. We have a detailed order tracking system to be able to verify everything we port. We even have the name of the original customer (Ricky). At the time the order was placed the original customer paid $250.00 for our stage 2 on that Cobra gt40 manifold. So this is a comparison of our entry level stage 2 which flows very well and designed for street/strip applications from 1,500-6,300rpm plus.
The guy definitely didn’t pay $250, and the upper has been cut and welded back together on the side.

I also don’t think it says 786. I think it’s 756, but it’s tough to tell.
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just curious why measured in mm... canada? or some other county thats non SAE?

wouldnt it be more useful to do measurements in inches in a case like this in 'Merica?
I wanted to spice it up a little bit.
Monday I’ll be doing the manifold swap. I’ll get measurements in English then too :LOL:

Long as I can get the vacuum lines sorted hopefully I can heat cycle it the same day.
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As I said previously, "testing" with a blower will prove nothing.
How do you figure? If the blower makes power at 11psi, and the intake change increases to something like 13, does that not prove a restriction?
It might, but what does that prove? Perhaps you get more useable power with the "restrictive" intake.
I guess we’ll see then?
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Looks like you have an extra spacer on the TFR box what size is it and why do you need it?

Looking at this I'm wondering if you will also see higher intake temps with the cobra intake. I did send you a spacer but really hoping you don't need it.
I had it on there originally for fuel regulator clearance. It really isn’t needed anymore, but all the piping fits well and it makes access to things a little easier so I left it on there.

I doubt manifold temps will be much of a difference at all. Pretty negligible
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Here are some port measurements between the r lower and the BD ported one.


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R Lower

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Had to make a new pipe in the fender well since the intake is so much shorter. Also had to move the fpr. Gonna walk the dog and eat then it should start after I stab the cam angle sensor
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I didn’t realize how **** this picture was until I had the upper bolted on. A little more mismatch than my r lower. The R looks damn close to flush with the heads.
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is that the top or bottom of the port? might of been able to get a thicker or thinner gasket to get better alignment. I hear the top of the port is most critical.
Bottom. It has a .090 gasket now.

Going to have to pull the upper off tomorrow and put the spacer underneath it since the valve cover interferes. Also going to need to move the driver side coil bracket a little since the upper will hit it when it gets spaced up.
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