Questions about intake manifolds

[OW99]

So I read that cobras and the mach 1s had different casting techniques while making intake manifolds. I read the post by nazman that the mach1 intake flows a considerable amount of air more. 300cfm compared to 230-240cfm. Is this true?

I might be building an engine for the cobra down the road, (might be building a 5.4 but still debating it). I was wondering if it will be worth it to find a mach1 lower? On a stock 4.6 I would think that the gains will be minimal but what about a 5.4 with adapter plates and some work done to it?

 

[snakeraper11b]

So I read that cobras and the mach 1s had different casting techniques while making intake manifolds. I read the post by nazman that the mach1 intake flows a considerable amount of air more. 300cfm compared to 230-240cfm. Is this true?

I might be building an engine for the cobra down the road, (might be building a 5.4 but still debating it). I was wondering if it will be worth it to find a mach1 lower? On a stock 4.6 I would think that the gains will be minimal but what about a 5.4 with adapter plates and some work done to it?

I don't know the exact cfm that either intake flows, but It's considerably more than that...One intake port almost outflows those numbers lol. There is no gain by swapping the cobra for the mach. Both will need to be ported. Depending on your combo the runner length may need to be shortened to match your combo.

 

[OW99]

I believe that is per intake manifold runner. I heard that you want roughly 15% more flow on the intake manifold runner than the intake port on the head at max valve lift.

Here is the link for the thread. http://www.svtperformance.com/forums/showthread.php?t=451950

 

[na svt]

I don't know the exact cfm that either intake flows, but It's considerably more than that...One intake port almost outflows those numbers lol. There is no gain by swapping the cobra for the mach. Both will need to be ported. Depending on your combo the runner length may need to be shortened to match your combo.

There is a difference between the Mach and Cobra intakes. As for the CFM, what Naz posted pretty close to correct; there is no way it's considerably more. The difference between the 99 (non-fixed) intakes and the Mach 1s is probably 60cfm, but the difference between the Cobra and Mach 1 intakes is probably more like 10-20cfm. I've had enough of these apart and can tell you that the Mach and 01 Cobra intakes look almost identical.

 

[OW99]

Where is the blue or green dot located? Is it visible without removing the intake?

 

[na svt]

Where is the blue or green dot located? Is it visible without removing the intake?

on the tab behind the alternator

 

[OW99]

on the tab behind the alternator

Thanks!

Welp, looks like I need to get a different intake.

 

[thebestdj07]

im in the same boat. my 99 with a p1-2 made 20hp/tq less then my buddy's mach with cats still. same tuner and boost he has just a p1 though. yes i know they are all different but i think that its the non fixed intake that plays a big factor on it.

 

[snakeraper11b]

There is a difference between the Mach and Cobra intakes. As for the CFM, what Naz posted pretty close to correct; there is no way it's considerably more. The difference between the 99 (non-fixed) intakes and the Mach 1s is probably 60cfm, but the difference between the Cobra and Mach 1 intakes is probably more like 10-20cfm. I've had enough of these apart and can tell you that the Mach and 01 Cobra intakes look almost identical.

He didn't specify he was asking about 99 non fixed intakes vs mach 1's. I would say 10 cfm is about as close to no difference as you can get...1-3 peak hp more...maybe? Also, 300 cfm per runner is 800% more than 300 cfm over all, I would call that considerable as I was just taking the op's post for what it was.

 

[snakeraper11b]

im in the same boat. my 99 with a p1-2 made 20hp/tq less then my buddy's mach with cats still. same tuner and boost he has just a p1 though. yes i know they are all different but i think that its the non fixed intake that plays a big factor on it.

Your buddys mach has higher compression and is a newer motor...Taking all other variables into account when comparing peak numbers on a dyno between 2 different cars on possibly different days, those numbers are just about right and can still change.

 

[OW99]

He didn't specify he was asking about 99 non fixed intakes vs mach 1's. I would say 10 cfm is about as close to no difference as you can get...1-3 peak hp more...maybe? Also, 300 cfm per runner is 800% more than 300 cfm over all, I would call that considerable as I was just taking the op's post for what it was.

I apologize, I should have specified whether the data was per runner or not. But if these intake manifolds only flowed 230-300cfm at the thottle body it would be a serious restriction above ~4000rpm, I would have ditched it fast lol. I think 10cfm may play a big role if the engine was flowing much more on the head side.

Na svt: how is porting between the 01 intake compared to the 03+? Is there one you prefer more?

 

[po-po 5.0]

Thanks!

Welp, looks like I need to get a different intake.

I've seen VERY few 99s that did not have the intake fix performed. You sure you need a new intake?

 

[OW99]

I've seen VERY few 99s that did not have the intake fix performed. You sure you need a new intake?

I do not have the blue or green dot. I have not looked at the casting number yet to be sure though.

 

[4valved]

its on the lower intake by the alt bracket and number 4 cyl fuel injector

 

[OW99]

This that it?

 

[na svt]

This that it?

I'm not sure what you are asking but you sir have an extrude honed intake.

 

[OW99]

I'm not sure what you are asking but you sir have an extrude honed intake.

Yep that's what I wanted to hear! Thanks!

So I guess I'll just port the entrance to the runners on the top of the intake and then the bell mouths on the bottom through the freeze plugs and be set.

Thanks guys.

 

[na svt]

You'll need to cut the bottom off so you can shape the inlets.

 

[OW99]

Alright, I guess I need to find a shop that can weld aluminum. I don't think I have the skills needed to weld it back together with my crappy mig.