Bullitt: GT350 Mani but 0TQ loss?

UAmach1 · Jan 31, 2018

A good question may be how the Bullitt manages to avoid losing TQ when all the 15-17 5.0 dynos I can find lose 10+peak tq at the wheels even after a custom tune when moving to a GT350 intake/TB/manifold. In one dyno I found a modded 5.0 lost 26 peak TQ on an engine dyno with the 350 vs stock manifold.

I wonder if this is due to other changes in the Gen3? or if something else is changed? Maybe cam timing?

Gurjit · Jan 31, 2018

higher compression paired with direct injection

UAmach1 · Jan 31, 2018

Gurjit said:
higher compression paired with direct injection

Unless the 18 intake is similar to the 350 I still would have expected SOME change. I searched but couldn't find any good comparisons of the 18 intake vs others.

BmacIL · Jan 31, 2018

UAmach1 said:
Unless the 18 intake is similar to the 350 I still would have expected SOME change. I searched but couldn't find any good comparisons of the 18 intake vs others.

CAI as well.

UAmach1 · Feb 1, 2018

BmacIL said:
CAI as well.

But on an engine dyno hot/cold wouldn't make a difference. The engines not moving on the stand.

nastang87xx · Feb 1, 2018

Cam profiles. It's easier to tune cams within a smaller RPM band for smoother torque operation too than say 8250 RPM or 8800 from a GT3. Speaking of GT3, I wish the GT350's torque curve shape was more like that than the vtec kicked in yo at 3500 RPM.

DarkestHour · Feb 1, 2018

Torque loss compared to what?

UAmach1 · Feb 1, 2018

DarkestHour said:
Torque loss compared to what?

It says in my post, the Gen 2 5.0 in multiple test show a TQ loss then the GT350 intake mani is applied to it in stock and modified form.

I've only managed to find 1 set of test that the GT350 provided a peak TQ gain and that was by 6ft lbs.

it's making me question of there are other changes/tweaks or if the 2018 stock IM is already very similar to the GT350 manifold.

65Terdlingua · Feb 1, 2018

A new gen engine will always build off of the engines before it. just like the Gen 2 using parts from Boss and specs similar to boss. The development of the Gen 3 surely borrowed tech and architecture from the Voodoo, including the intake. plus the benefits of DI, compression, etc.

DarkestHour · Feb 1, 2018

UAmach1 said:
It says in my post, the Gen 2 5.0 in multiple test show a TQ loss then the GT350 intake mani is applied to it in stock and modified form.

I've only managed to find 1 set of test that the GT350 provided a peak TQ gain and that was by 6ft lbs.

it's making me question of there are other changes/tweaks or if the 2018 stock IM is already very similar to the GT350 manifold.

I'm asking how do you know the Bullitt has no torque loss compared to the standard 2018 GT? Based on what? Do you have a dyno sheet of 2018 vs Bullitt?

The 2018 engine itself is more displacement, more compression, different heads, different manifold, direct injection, and other things. It is naturally making more torque from all that and you shouldn't use the 2015-17 as a comparison for manifold changes. You want to compare the 2018 GT dyno and overlay it with a Bullitt dyno. If there is no torque loss on the Bullitt, then your question is validated.

UAmach1 · Feb 1, 2018

DarkestHour said:
I'm asking how do you know the Bullitt has no torque loss compared to the standard 2018 GT? Based on what? Do you have a dyno sheet of 2018 vs Bullitt?

The 2018 engine itself is more displacement, more compression, different heads, different manifold, direct injection, and other things. It is naturally making more torque from all that and you shouldn't use the 2015-17 as a comparison for manifold changes. You want to compare the 2018 GT dyno and overlay it with a Bullitt dyno. If there is no torque loss on the Bullitt, then your question is validated.

They are both quoted at 420tq by Ford.

You are also missing my question entirely, which is, again, Why does the Bullitt not list a TQ loss when the 15-17's did. I specifically asked if it's due to characteristics of the Gen3 or something specific to the Bullitt.

airfuel · Feb 1, 2018

Peak torque is quoted.

It may have lost torque lower in the rpm range and only chart overlays will show this.

UAmach1 · Feb 1, 2018

airfuel said:
Peak torque is quoted.

It may have lost torque lower in the rpm range and only chart overlays will show this.

Fair point.

Freedom · Feb 28, 2018

UAmach1 said:
They are both quoted at 420tq by Ford.

You are also missing my question entirely, which is, again, Why does the Bullitt not list a TQ loss when the 15-17's did. I specifically asked if it's due to characteristics of the Gen3 or something specific to the Bullitt.

The 2018 intake manifold may already have torque loss as compared to a 15-17 since redline is 500 Rpm later So, after tuning, that additional torque loss on top with the 350 manifold tuned away much easier than a 15-17 manifold. In addition, direct injection allows for better control of fuel delivery and more aggressive timings can be achieved.
Official Ford Performance marketing showed pp3 had 5 ft-lb torque GAIN over factory. So no loss there officially either for peak next movers.

zero_chance · Apr 6, 2018

UAmach1 said:
It says in my post, the Gen 2 5.0 in multiple test show a TQ loss then the GT350 intake mani is applied to it in stock and modified form.

I've only managed to find 1 set of test that the GT350 provided a peak TQ gain and that was by 6ft lbs.

it's making me question of there are other changes/tweaks or if the 2018 stock IM is already very similar to the GT350 manifold.

I wasn't aware of that, what exactly is the benefit of the 350 mani then? I thought, perhaps wrongly, that it would allow for an extended power band, not a loss.

Bullitt: GT350 Mani but 0TQ loss?

UAmach1

Bullitt Hopefull

Gurjit

Well-Known Member

UAmach1

Bullitt Hopefull

BmacIL

Enginerd

UAmach1

Bullitt Hopefull

nastang87xx

Well-Known Member

DarkestHour

Hi

UAmach1

Bullitt Hopefull

65Terdlingua

Well-Known Member

DarkestHour

Hi

UAmach1

Bullitt Hopefull

airfuel

Well-Known Member

UAmach1

Bullitt Hopefull

Freedom

Well-Known Member

zero_chance

Dismember