Best Style GT-40 Lower Intake For Stock 5.0L

[Terrorist 5.0]

Hello everyone, I have researched the forums and haven’t found a definitive answer as to which intake would work best for me. Stock 5.0L, with 3.08’s and a 5 speed.

I am looking to start making a little more power, but I’m not sure I’m ready to dive into the motor too deep yet. I’ve decided I want to do a GT40 style intake.

It has been repeatedly shown that they seem to work best with a stock 5.0L. The issue have is cost. They are pretty expensive. The second issue is, which one would work best for the stock 5.0L?

I’m looking for a Cobra (or SVO Motorsports as it is the same casting number) upper. That’s for sure, as it would fit like factory. The lower is where my issue comes in.

Contrary to popular belief, the Explorer and Cobra lowers are not the same. The Cobra has bigger ports. In a built motor without porting in the equation, the Cobra should win, but I have a stock motor. I understand the lower is the main choking point in the mix so that is why I feel this is important to ask.

Will the bigger ports on the Cobra give me more power with the stock heads? Or will I just start losing torque? Should I use an Explorer, or Cobra lower?

I am planning on putting in a 3.31 ring and pinion to offset any torque loss, but I prefer not to lose any in the first place.

 

[07GtS197]

I don’t think there is enough of a difference for it to matter. If money is tight, grab a set of gt40’s off of an Explorer and call it a day. The heads and cam are the next choke point anyway.

 

[ttocs]

you are not going to notice much if any difference with the stock heads on there. I put my cobra intake on years ago and it looked nice, as long as you didn't want to run the stock strut tower bar.

 

[Terrorist 5.0]

you are not going to notice much if any difference with the stock heads on there. I put my cobra intake on years ago and it looked nice, as long as you didn't want to run the stock strut tower bar.

Lots of people mention a noticeable difference, including a YouTuber named Shovel, who has it well documented. Regardless, if I were to notice anything, would it be a loss in low end, a gain in high end, both? Part of the reason I’m doing this is for looks too, and that I can have an intake ready if I do tear into the motor.

 

[95opal]

Lots of people mention a noticeable difference, including a YouTuber named Shovel, who has it well documented. Regardless, if I were to notice anything, would it be a loss in low end, a gain in high end, both? Part of the reason I’m doing this is for looks too, and that I can have an intake ready if I do tear into the motor.

You will be fine with any of the gt40 intakes.

 

[Terrorist 5.0]

You will be fine with any of the gt40 intakes.

I'm sure I would, but could I save some money with an Explorer lower without losing power? I'm trying to figure out if the bigger ports on the Cobra lower will actually be useful with stock heads or just lose torque. How much gains should I expect anyway in your opinion?

 

[95opal]

I'm sure I would, but could I save some money with an Explorer lower without losing power? I'm trying to figure out if the bigger ports on the Cobra lower will actually be useful with stock heads or just lose torque. How much gains should I expect anyway in your opinion?

You can save even more money by porting your stock lower.
Your stock heads flow about 160cfm your stock intake flows about 150cfm.
You see where I'm going.

 

[Terrorist 5.0]

You can save even more money by porting your stock lower.
Your stock heads flow about 160cfm your stock intake flows about 150cfm.
You see where I'm going.

I've researched that, and was happy to see that the stock lower was worth a damn, but I like the looks of the GT-40 better, hence why I'm so curious.

 

[Wmac]

I have both the Cobra and Explorer intakes. Installed the cobra about 20 yrs ago with a 70mm T/B. Noticed a little gain in power, but not significant.
Ported the explorer lower half dozen yrs ago. With a set of drag radials and the ported lower, saw about 6 tens gain at the track. Went from slow to not quite as slow.
If there is a difference in ports size between the 2, it most likely will not be noticed on an otherwise stock engine.
Save some money for other mods (like heads), port (gasket match) the lower yourself.

Use the gt40 intake as the foundation of your build. Any significant gains are in the porting. Consider more gear. Don't fear the gear.

 

[Terrorist 5.0]

I have both the Cobra and Explorer intakes. Installed the cobra about 20 yrs ago with a 70mm T/B. Noticed a little gain in power, but not significant.
Ported the explorer lower half dozen yrs ago. With a set of drag radials and the ported lower, saw about 6 tens gain at the track. Went from slow to not quite as slow.
If there is a difference in ports size between the 2, it most likely will not be noticed on an otherwise stock engine.
Save some money for other mods (like heads), port (gasket match) the lower yourself.

Use the gt40 intake as the foundation of your build. Any significant gains are in the porting. Consider more gear. Don't fear the gear.

That’s some very nice insight. Was this on stock, unported heads? And you said you gained some (although not significant) power, did you lose any low end? I am willing to do ring and pinion (I mean it’s part of the Mustang experience), but first gear is already kind of short, and with a 0.68 overdrive, and the speeds I get up to on pulls, doesn’t sit well with me anything above 3.31. If I had a New Edge with the 3650 trans and a 0.62 overdrive, 3.55’s would go straight in.

 

[Terrorist 5.0]

I have both the Cobra and Explorer intakes. Installed the cobra about 20 yrs ago with a 70mm T/B. Noticed a little gain in power, but not significant.
Ported the explorer lower half dozen yrs ago. With a set of drag radials and the ported lower, saw about 6 tens gain at the track. Went from slow to not quite as slow.
If there is a difference in ports size between the 2, it most likely will not be noticed on an otherwise stock engine.
Save some money for other mods (like heads), port (gasket match) the lower yourself.

Use the gt40 intake as the foundation of your build. Any significant gains are in the porting. Consider more gear. Don't fear the gear.

I only ask because if I’m not wrong, you’re saying a ported lower GT-40 intake is netting you more power with stock heads? Are you not losing low end at that point?

 

[Wmac]

Was with an aode auto trans. Very "soft" stock converter, p!ss poor 60' times. Yes on stock heads with 1.7 cobra rockers and 3.55 gears.
Your T-5 would give better results than mine.

 

[RAU03MACH]

I will say the gt 40 tubular intake is the better one

 

[shovel]

This is not scientific, just what I was able to put together from dozens of collated, old forum posts and magazine articles. GT40 in this case is the tubular one and Stock 5.0 is the 94/95 unit.

No reason to overthink it.

 

[Terrorist 5.0]

This is not scientific, just what I was able to put together from dozens of collated, old forum posts and magazine articles. GT40 in this case is the tubular one and Stock 5.0 is the 94/95 unit.

No reason to overthink it.

View attachment 38384

Thank you, that is useful. Good video too.

 

[95opal]

If you really want to make your brain spin dip into some of TMoss writings.

Tmoss Porting

tmoss.efidynotuning.com

 

[Terrorist 5.0]

I’ve studied his website pretty well, that’s actually where I found out about the difference between the Cobra and Explorer lowers. I really liked his information regarding the gains on porting the stock HO manifold, back when nobody else did. Definitely the way to go money wise, but the Cobra intake just looks so good. Only reason I haven’t done it yet is I haven’t chosen what lower is better for me, and at this point, I might just email the man himself and see what he has to say. The pains of an overthinking mind. It still is nice seeing the history of his work, definitely something that has kept me occupied for hours, just seeing what kind of tweaks he has thought of on our cars

 

[duh09]

The likelihood of you finding a 94/95 Cobra or SVO upper without the matching lower is relatively nil.

You will not gain any real power by running an Explorer lower with a Cobra upper.

If you have the funds for the Cobra setup, do that. If you don't, an Explorer will get you ALMOST the same results. Swapping from an Explorer setup to a Cobra setup would very likely not give you any feelable power, but might show a slight difference on a dyno.

Don't be afraid of running lower gear ratio gears. 3.31 is going to be a very small difference from the 3.08s. I've had 5.0 cars with 2.73, 3.55, 3.73, and 4.10s - 3.73 is generally the sweet spot IMO on a manual 5.0.

 

[Mustang5L5]

I went down this rabbit hole a long time ago. There is a difference between the Cobra and Explorer intakes. And while you are right about the lowers being different, the major difference is the uppers. Combine, an unported cobra intake combo flows about 10 cfm per runner more than the explorer based on the info i've seen. In dyno testing this translates to maybe a 5-10HP bump in favor of the Cobra intake. I don't think there was a significant difference between the Cobra intake and GT40, and I think the 94-95 cobra intake had a very slight edge over the '93 but it negligible.

The difference in the lowers is also documented. The earlier F2/F3 and F4/F5 lowers offer more cross-section in unported form than the later Explorer and GT40/Cobra catalog intakes with the F87E lowers. Tmoss has written about this.

http://tmoss.efidynotuning.com/Ford_GT40_Cobra_Explorer_Intake_Design_Observations.pdf

F2/F3/F4/F5 lowers tend to sell for a lot more than the F87E lowers. Sn95 cars can use the "cheaper" F78E-BB lower since they don't need the ACT boss now the internal EGR. For this reason the fox guys chase the F78E-BA lower which is more desirable to them.

Porting the intake adds another variable to the equation and can get you those additional CFM you are chasing with regards to obtaining an earlier lower. Is it enough to exceed the flow of the earlier F3-F5 intakes? Probably.


For my Combo, i wanted to retain the Catalog 1993 Cobra intake I purchased new back in 2000 or so. First "real" mod i bought when i was a broke teenager for my Fox, so i had some sentimental attachment even though a Holley intake would be much better for my AL head/custom cam combo. I had Tmoss port the lower, and run the 93 cobra as is with a 70mm TB.

 

[Terrorist 5.0]

The likelihood of you finding a 94/95 Cobra or SVO upper without the matching lower is relatively nil.

You will not gain any real power by running an Explorer lower with a Cobra upper.

If you have the funds for the Cobra setup, do that. If you don't, an Explorer will get you ALMOST the same results. Swapping from an Explorer setup to a Cobra setup would very likely not give you any feelable power, but might show a slight difference on a dyno.

Don't be afraid of running lower gear ratio gears. 3.31 is going to be a very small difference from the 3.08s. I've had 5.0 cars with 2.73, 3.55, 3.73, and 4.10s - 3.73 is generally the sweet spot IMO on a manual 5.0.

Actually I have found quite a few SN95 Cobra and even one SN95 SVO uppers for sale. The information you posted is exactly what I was looking for, and I’m glad someone went through the same thing I am now. So on a stock setup, you are saying that a Cobra lower is worth more than an Explorer. I like my gears longer, thus choosing 3.31. Makes for a nicer drive IMO. That’s awesome. When you did the upgrade, assuming you were stock at the time, did you feel any loss in low end torque? That is what is most important to me, since you went through the same thing.