GT350 vs. Cobra Jet Intake Test

[EditorTurner]

Shelby Jet
How the Cobra Jet intake compares with the factory intake on a GT350
By Steve Turner

We recently found out that the intake manifold atop the GT350’s Voodoo 5.2-liter engine is a great upgrade for the Coyote 5.0-liter in the Mustang GT. The intake seems to gain horsepower on the smaller engine without giving up any torque. That got our wheels spinning. How might Ford Performance Parts’ racy Cobra Jet intake perform atop the rev-happy Shelby’s engine? Fortunately VMP Performance owns a new GT350 and has the wherewithal to facilitate such a test.
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[DSG2003SVT]

I've been dying to see this comparison!

The gains from the CJ in the 5000-7000 range are very impressive. No significant torque loss versus stock either. Win/win for the CJ. I wonder if the drivability can be dialed in well. With a plug and play CJ setup, I'd definitely make the swap after I did headers and E85.

 

[Tob]

A bit surprising that the CJ has such a limited area of improvement.

Also interesting how the intake gasket was changed for '15 such that it wasn't a direct swap but the earlier intake was. Thanks for reporting this Steve, and thanks to Justin and Co. for taking this one on.

Tob

 

[DSG2003SVT]

A bit surprising that the CJ has such a limited area of improvement.

That dip after 5300 may be able to be tuned out with some more time, but typical FPC dynos look kind of wavy. So, I don't know. I want to see them both tuned on E85. That's been the largest single gain I've seen on the GT350 so far.

 

[03VertGT]

That dip after 5300 may be able to be tuned out with some more time, but typical FPC dynos look kind of wavy. So, I don't know. I want to see them both tuned on E85. That's been the largest single gain I've seen on the GT350 so far.

Wish E85 was more available around here. Don't think I've seen a single pump.

 

[TORQUERULES]

I think that the CJ is not really being given enough credit in this article. It pretty much has gains everywhere and where there are random dips, with more tuning those could probably be taken care of. I think that on a GT the intake upgrade of choice should be the stock GT 350 intake. Maybe not for a full effort engine, but for most applications it would be ideal. On the GT 350 it looks as if the CJ intake is showing decent gains with room to work with once the rest of the engine is opened up. I think the CJ showed well given its short runners and race orientation. If I could afford a GT 350 I would run one for sure.

 

[DSG2003SVT]

I think that the CJ is not really being given enough credit in this article. It pretty much has gains everywhere and where there are random dips, with more tuning those could probably be taken care of. I think that on a GT the intake upgrade of choice should be the stock GT 350 intake. Maybe not for a full effort engine, but for most applications it would be ideal. On the GT 350 it looks as if the CJ intake is showing decent gains with room to work with once the rest of the engine is opened up. I think the CJ showed well given its short runners and race orientation. If I could afford a GT 350 I would run one for sure.

I agree. A 25-35whp gain right in the meat of your power band is huge for an NA motor. This looks to be the best bolt-on so far. It appears significantly better than LTs and 3" exhaust.

 

[bambinov8]

Following

 

[GT Premi]

Wonder how much longer before an aftermarket shop comes up with a twin intake manifold setup. It shouldn't be too hard to design. I would imagine it could be two rows of velocity stacks with an ABS plastic shroud enclosing each row. Add two throttle bodies, and an electrical splitter and a few more volts to use the existing throttle body sending unit to control two throttle bodies simultaneously.

 

[SID297]

Awesome article Steve.

 

[200MPHCOBRA]

Id like to see it with a CJ single blade.

 

[50 Deep]

To keep things in perspective the cobra jet benefitted from a CAI and larger throttle body.

If you add a JLT and larger throttle body to the voodoo intake you are going to close the margin up top by a lot. The added cost and fitment issues of the cobra jet aren't all that impressive.

Kudos to them for doing the test and keeping it as even as they could, but it's not a stock for stock setup.

 

[65sohc]

A lot of variables at play here. Since the CJ manifold was tested with a JLT intake they should have used one with the factory manifold as well since that CAI is already reputed to add about 12 hp.

 

[DSG2003SVT]

To keep things in perspective the cobra jet benefitted from a CAI and larger throttle body.

If you add a JLT and larger throttle body to the voodoo intake you are going to close the margin up top by a lot. The added cost and fitment issues of the cobra jet aren't all that impressive.

Kudos to them for doing the test and keeping it as even as they could, but it's not a stock for stock setup.

There isn't a larger throttle body for the GT350 IM, nor would one as large as the oval TB even fit. Not to mention that the stock CAI isn't giving up much, if any, to the aftermarket CAI. I know the claims, but the manufacturer's dyno is the only one that's shown those gains. The stock CAI is no slouch. Maybe the stock throttle body is the bottleneck, but you need the CJ IM to accommodate a larger one.

I think the CJ is just better suited for high RPM. On the JDM 2015 Coyote with Voodoo IM, TB, and Kooks LTs, power started falling off after 7300RPM. We all know that the CJ IM on a Coyote with LTs will pull all the way to 8000RPM. A shorter runner IM, plus provisions for a larger TB, equals more top end power. I will hand it to Ford for building a long runner IM that makes power up to 7500+ though. That's amazing to me.

 

[DSG2003SVT]

Steve, do you have a dyno chart with just the CJ IM and tuned GT350 IM only?

 

[65sohc]

Not to mention that the stock CAI isn't giving up much, if any, to the aftermarket CAI. I know the claims, but the manufacturer's dyno is the only one that's shown those gains. The stock CAI is no slouch.

I don't recall Steve calling into question the validity of the 18 hp gain when he wrote the JLT article in December.

 

[DSG2003SVT]

I don't recall Steve calling into question the validity of the 18 hp gain when he wrote the JLT article in December.

Once I see it from a third party, I'll believe it.

 

[65sohc]

I agree 100%. I was playing devil's advocate. Virtually all the mod results we see originate from those who are either manufacturing or selling the product. I am still baffled by the fact that the Lund Flex Fuel article came out two months ago and yet not a peep from an end user.

 

[gt500_sti_guy]

You need to go over to 6g. Handfuls of people have posted about their flex fuel tunes from lund.

 

[DSG2003SVT]

You need to go over to 6g. Handfuls of people have posted about their flex fuel tunes from lund.

Only on the Mustang GT though. None of them have posted about the GT350.