Where Does Bullitt Get It's Extra 20 HP From?

[Zooks527]

In 2nd and 3rd gear you can use the extra rpm and hp. The bullitt motor pulls strong to redline.

No, not really. The HP difference isn't there in 2nd and 3rd. The car isn't making close to top HP and the engine isn't airflow limited as a result. There's no, zero, not a bit of performance difference between a GT and a Bullitt below 100 mph.

I sold my 15 gt to buy the bullitt. The 435 hp motor had a redline of 7000...but was done at 6500. It had shorter gears to make it quick.

Sure. Except the proper comparisson is to a Gen3 Coyote in a 2019 GT, which pulls to 7500 just as well in the lower gears.

The motor in the bullitt loves the revs. Begs to be driven at high rpm.

As does the GT. Seriously, if you're not on a track with a huge straight, on the autobahn, or driving at felony speed, you couldn't tell a Bullitt from a PP1 GT.

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[Shibaman]

No, not really. The HP difference isn't there in 2nd and 3rd. The car isn't making close to top HP and the engine isn't airflow limited as a result. There's no, zero, not a bit of performance difference between a GT and a Bullitt below 100 mph.


Sure. Except the proper comparisson is to a Gen3 Coyote in a 2019 GT, which pulls to 7500 just as well in the lower gears.


As does the GT. Seriously, if you're not on a track with a huge straight, on the autobahn, or driving at felony speed, you couldn't tell a Bullitt from a PP1 GT.

Felony speed works for me

 

[Schwerin]

Just recently Hot Rod magazine did an intake test on a gen 2 coyote engine and the 18+ intake actually made a few more hp than the GT350 intake. All the gains come from the larger throttle body and tune that the bullitt has. Since for hasn't officially released the power packs and tunes for the 18+ your on your own for a tune. My advice go with an 85 or 90 mm TB and adapter plate, they use the same square bolt pattern as the stock 80 mm where as the 87 from the gt350 uses a slightly rectangular pattern and thus has to rotate the tb 15 degrees counter clockwise so the bolt holes don't interfere. The down side is it also interferes with the ford branded catch can on the passenger side so you can't use one. But if you use a GT350 intake then it doesn't rotate the tb but that intake is over 1K for just the manifold. A waste of money for what amounts to no gain on an 18+

One thing we are forgetting about the test is that they don't mentioned if they did any ECU changes. If not then they ran a 2018 IM on a ECU tuned for it and then ran a GT350 IM on a tune for a 2018 IM. For a fair comparison they would have to either tune the ECU for the changed IM, or they would have to also have a BULLITT ECU handy. So until we find out what the status was for the ECU that test is heavily flawed. No one is going to juts bolt-on a new IM and not get a re-tune. So all it really demonstrates is that if you put on a GT350 IM and DO NOT retune you wont really see any benefits other than a power-band shifted up a few RPM.

 

[Schwerin]

The Gen3 Coyote pulls to 7500 in the lower gears. It can't do it in the higher gears, and is airflow limited as it approaches 460 HP. The Bullitt has a larger intake and can go for just a bit longer.

Look at a dyno, 2018 GT powerband ends at 7k, and a Bullitt's ends at 7250 Even with a tune. Their biggest issue is likely that they need either ported heads, a hi-rev cam, or both. The 350IM was designed with an engine built to rev over 8K in mind. Likely if you put a head package on a Bullitt and GT is when you'd see the benefits from the 350IM.

 

[Zooks527]

The Gen3 Coyote pulls to 7500 in the lower gears.

Look at a dyno, 2018 GT powerband ends at 7k, and a Bullitt's ends at 7250 Even with a tune

The two statements are not incompatible, because I explicitly stated "in the lower gears". The powerband limit shown on a dyno is only relevant at full engine output, which you can't attain in the lower gears on the road.

 

[Schwerin]

The two statements are not incompatible, because I explicitly stated "in the lower gears". The powerband limit shown on a dyno is only relevant at full engine output, which you can't attain in the lower gears on the road.

Why not? Engine peaks at the same RPM no matter what gear you are in.

 

[HoosierDaddy]

The powerband limit shown on a dyno is only relevant at full engine output, which you can't attain in the lower gears on the road.

I'm pretty sure they rev to the same RPMs regardless of what gear they are in. If the engine makes more power at X RPM it makes more at X RPM in all gears.

 

[Zooks527]

Why not? Engine peaks at the same RPM no matter what gear you are in.

I'm pretty sure they rev to the same RPMs regardless of what gear they are in. If the engine makes more power at X RPM it makes more at X RPM in all gears.

Both of these are making the unstated assumption that the engine is running at full throttle, minimum vacuum, and an appropriate A/F ratio. While a valid assumption on a dyno, it's not on a road.

Consider the engine sitting in your driveway. You can rev it to the rev limiter to your heart's content, and it will hit it every time. Total power output, however, is likely trivial. The car is limited only by the rev limiter, and has no constraints based on fuel or air supply. You might be making 25 HP at the crank,

Same deal in first gear. You can tool along at the rev limiter in first gear, bouncing off it as much as you want, and the engine will keep doing it. Total power output remains low (probably sub-100 HP). The constraint remains the electronic limiter. Air and fuel are available in excess.

Now consider the car (assuming a removed speed limiter) at top end on a road. Put your foot to the floor in any gear you wish, but you're not going to go faster and you're not going to make it to the rev limiter. The car is at the peak level of power based upon the amount of air and fuel it can get into the cylinders.

 

[BrettT]

Now consider the car (assuming a removed speed limiter) at top end on a road. Put your foot to the floor in any gear you wish, but you're not going to go faster and you're not going to make it to the rev limiter. The car is at the peak level of power based upon the amount of air and fuel it can get into the cylinders.

You are now introducing Drag into the "equation" I don't see how this is relevant to how much power the engine makes in any gear.

"At top end on the road" What does this mean? If you mean top speed (Drag limited), because as you stated (assuming a removed speed limiter), then you already have your foot pegged to the floor. So by definition, you cannot be at top end without having the throttle to the floor, and cannot ("Put your foot to the floor in any gear you wish").

 

[18usc371]

FWIW:

2018 GT Conv - 2109 Bullitt

https://www.wardsauto.com/test-driv...m=email&elq2=53beee7a65e84d428b859880f8a00415

 

[Bear_Stang]

Soo...

I did not buy my bullitt over the gt for the 20hp. Nor do I think the bulk of bullitt buyers did. I also do not think it was about the magniride (mine does not even have it). You can slap magniride on gts nowadays (when ordering from ford).

I think (I have no data to back this up) the point of the air intake is about engine tone more than hp. The extra hp is a byproduct of fords attempt to reproduce that half gurgle / crackle that makes you smile a bit. While I might not be able to differentiate between a similarly speced 19 gt and 19 bullitt as far as performance. I can degenerate based on ambiance.

I suspect, based on steeda's NA tune, that you can coax more out of the 350intake/coyote setup, but if ford where to have done that, the bullitt would have likely been labeled a true gas guzzler. The stock bullitt tune keeps carb / epa happy, allows ford to overbuild a bit, & provides a nice tone for the vehicle.

 

[BillyJRacing]

I understand that. I was answer the question of “ Where does the Bullitt get its extra 20hp from?” .

The answer is it doesn’t. It already has it and Ford changed the 6 to an 8 in the sales book.

Incorrect, and an asinine claim. The Bullet does make 20hp more than the 2018 GT due to the GT350 intake manifold, throttle body, intake, and calibration -which flows better at high RPM than the 2018 manifold.

The often quoted HotRod manifold comparison (2018 vs GT350 vs CobraJet vs Boss) used a Gen 3 Coyote with long tube headers, a JLT open element intake, and E-85 (tuned). This is a far departure from a stock Coyote on pump gas. In addition, the CMCV's weren't working during their test of the GT350 manifold, so the low-midrange power is worse than if the CMCVs were working, and you can't draw a proper conclusion from that test.


The GT350 intake, throttle body, and manifold is proven to make a lot more power over the 2015-17 manifold on a Gen 2:

https://motoiq.com/tested-ford-mustang-gt-power-packs-1-3/8/

I wish I had the time and money to do a proper comparison on a Gen 3, since no one has.

 

[BlackandBlue]

Incorrect, and an asinine claim. The Bullet does make 20hp more than the 2018 GT due to the GT350 intake manifold, throttle body, intake, and calibration -which flows better at high RPM than the 2018 manifold.

The often quoted HotRod manifold comparison (2018 vs GT350 vs CobraJet vs Boss) used a Gen 3 Coyote with long tube headers, a JLT open element intake, and E-85 (tuned). This is a far departure from a stock Coyote on pump gas. In addition, the CMCV's weren't working during their test of the GT350 manifold, so the low-midrange power is worse than if the CMCVs were working, and you can't draw a proper conclusion from that test.


The GT350 intake, throttle body, and manifold is proven to make a lot more power over the 2015-17 manifold on a Gen 2:

https://motoiq.com/tested-ford-mustang-gt-power-packs-1-3/8/

I wish I had the time and money to do a proper comparison on a Gen 3, since no one has.

You are correct. I did a poor job making my point here. My point wasn’t that the Bullitt doesn’t make more horse power but more that the regular gen 3 already makes great horsepower.

Here is supposed to be the completed stock power pack calibration with 91 octane fuel. Stock catted header.
https://www.hotrod.com/articles/ford-5-0l-coyote-dyno-test-cai-e85-tune-makes-532-hp/

 

[BillyJRacing]

You are correct. I did a poor job making my point here. My point wasn’t that the Bullitt doesn’t make more horse power but more that the regular gen 3 already makes great horsepower.

Here is supposed to be the completed stock power pack calibration with 91 octane fuel. Stock catted header.
https://www.hotrod.com/articles/ford-5-0l-coyote-dyno-test-cai-e85-tune-makes-532-hp/

You pretty much said Ford lied and just "changed the 6 to an 8in the sales book".

But I digress:

In that HotRod baseline test. 496.8hp STD = 484.35hp SAE (1.0257 correction factor from STD to SAE).

From my test, a bone stock 2018 GT put down over 416.82whp and picked up 12.91whp from a Borla cat-back exhaust.

Loosely backing out some math:

416whp = ~10.5% drivetrain loss from a marketed 460bhp. That would mean the Borla-equpped 429.73whp run would = 474.85bhp.

Since the speed limiter came in before these pulls reached peak power, the car is actually making over 416whp stock and over 429whp (over 474bhp), which is about 10hp shy of HotRod's baseline with an open exhaust after the cats.

*The HotRod baseline pulls do not have any exhaust after the cats, and the power would be lower "as-installed" in a car with a full exhaust. Nevertheless, the Gen 3 Coyote is impressive and makes a lot of power. But it's inaccurate to assume your stock Gen 3 in your stock 2018 Mustang GT makes 496.8hp. It may make 496.8hp STD (484.35hp SAE - which is the correction factor used by all auto manufacturers) with straight pipes after the exhaust, but not in a stock car.

 

[BlackandBlue]

You pretty much said Ford lied and just "changed the 6 to an 8in the sales book".

But I digress:

In that HotRod baseline test. 496.8hp STD = 484.35hp SAE (1.0257 correction factor from STD to SAE).

From my test, a bone stock 2018 GT put down over 416.82whp and picked up 12.91whp from a Borla cat-back exhaust.

Loosely backing out some math:

416whp = ~10.5% drivetrain loss from a marketed 460bhp. That would mean the Borla-equpped 429.73whp run would = 474.85bhp.

Since the speed limiter came in before these pulls reached peak power, the car is actually making over 416whp stock and over 429whp (over 474bhp), which is about 10hp shy of HotRod's baseline with an open exhaust after the cats.

*The HotRod baseline pulls do not have any exhaust after the cats, and the power would be lower "as-installed" in a car with a full exhaust. Nevertheless, the Gen 3 Coyote is impressive and makes a lot of power. But it's inaccurate to assume your stock Gen 3 in your stock 2018 Mustang GT makes 496.8hp. It may make 496.8hp STD (484.35hp SAE - which is the correction factor used by all auto manufacturers) with straight pipes after the exhaust, but not in a stock car.

You are correct. Your due diligence has proven that I was wrong.

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