Whose made 700+whp on pump?

[80FoxCoupe]

Not true. It depends on what you are looking for. I can put a stock coyote in a hacked up fox body and go 9s all day. I would not drive it to pick up my kids. So it really all depends.

I wasn't responding to you. But thank you for your valuable opinion.

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[engineermike]

You can lower compression by delaying intake closing because you reduce how much is in the cylinder to compress by pushing it back into the intake...

This would be true with any sort of centrifugal compressor, but not with a PD blower. That blower is pumping, say, 3 liters of air into the plenum every time it turns one revolution regardless of IVO timing. If IVO is delayed and the cylinder attempts to pump air back out the intake port, there is nowhere to go because the blower keeps on cramming in 3 liters/revolution. The measured boost level in the plenum will increase but the total airflow and mass trapped in the cylinder will not change unless there is another way out (exhaust during overlap or open bypass valve).

 

[Bullitt69]

I just had my car on the dyno today - made 717 hp / 588 tq on straight 93 through the factory exhaust on 7.6 lbs of boost.

2019 Bullitt, Hellion Sleeper, Hellion Headers, precision 62 jb turbos, stock fuel system with a BAP and 1050 injectors.

Definitely room for more, will need to replace the factory exhaust with a 3 inch and if that brings the boost down we should be able to throw another 1-2 lbs safely.

750 should be very attainable.

I'm gonna drive it around as is, get a feel for it and ultimately do the exhaust and a fuel system w'E85 flex tune. Next year probably!

Cheers,
-Bullitt-

 

[80FoxCoupe]

I just had my car on the dyno today - made 717 hp / 588 tq on straight 93 through the factory exhaust on 7.6 lbs of boost.

2019 Bullitt, Hellion Sleeper, Hellion Headers, precision 62 jb turbos, stock fuel system with a BAP and 1050 injectors.

Definitely room for more, will need to replace the factory exhaust with a 3 inch and if that brings the boost down we should be able to throw another 1-2 lbs safely.

750 should be very attainable.

I'm gonna drive it around as is, get a feel for it and ultimately do the exhaust and a fuel system w'E85 flex tune. Next year probably!

Cheers,
-Bullitt-

Need to change your name to BulliTT69 !!!!!!!

 

[sigintel]

How do you figure? The gen3 needs less boost to make the same power as a gen2. Gen3 has less chance of detonation. Gen3 has more knock sensors to cover your ass. So how do you figure? The smallest procharger can put a gen3 over 700whp on 93

Dunno about that "Gen3 has less chance of detonation" ? I think that only applies comparing both at 500hp crank. As you go above 500hp, the percentage of fuel delivered by port injection greatly increases over the DI charge percentage and you are 'diluting' your DI charge cooling effect as you try and get to double the crank hp.

For both motors, the economy FI setup (just FI - no fuel system, exhaust, etc.) the typical power limitation seems to be detonation due to fuel octane limits.
The fuel is the same for both: Pump 93 octane. Chemistry and Physics does not change.
Direct injection helps cool air charge allowing the higher compression ON 93 OCT PUMP; however, the DI system effectiveness at cooling charge is diluted as the percentage of the charge from DI decreases near WOT max RPM and highest fuel load.
The DI system is simply NOT capable to providing majority charge at 500+ hp; as this happens, you are getting closer to the same combustion physics as Port injection alone, BUT you are now at 12:1 instead of 11:1.
Some tuners have already documented modding the DI system to overcome this.

No matter how you slice it, to maximize hp with a fixed given fuel like 93 oct pump, you are better getting the air compression done before the cylinder where you can cool it with an IC. The lower the static compression, the more cooling you can get done by accomplishing more compression where it can be cooled by IC BEFORE introducing fuel and compressing further.

For continuous road course high power output, this is even more so the case: hence the 52XS, FP350 crate motor, GT350, GT500, etc dont run direct injection. Note: the 12:1 52XS and FP350 are 93 only engines with little to no room for FI at road course continuous use temperatures. Just look at the GT500 compression ratio to see the most cost effective compression to support 91 and 93 oct FI in a tight 5.x liter block....

Dunno, but my perception is for the same dollar spent using 93 oct, the 11:1 is a better starting point for hp/$.
Thoughts? I could have perception wrong on this..

 

[engineermike]

@sigintel, you are a man after my heart. Everything you posted above is dead on.

I have two examples that prove your point.

1) PBD couldn’t get a stage 2 Whipple supercharged 2018 much over 700 rwhp on 93 because it was detonation limited. But the same folks/same dyno made nearly 900 rwhp with a gt500 on 93 with no octane booster. The gt500 has 9.5/1 compression so they compressed more in the blower, cooled, then compressed less in the cylinder. Controlling the temp of the compressed charge is the name of the game when detonation limited. Compression ratio has the most dramatic effect on the temp of the charge before spark. The gt500 will actually have a cooler compressed charge temp at 18 psi boost than a stock NA 2018 GT.

2) I had a 2015 f-150 with a stage 2 Whipple. Back then, the truck was only 10.5/1 compression. I was able to run the 3.5” pulley on 93 and made more power than the gen 2 mustangs right up until hitting the lower f-150 rev limit. Just half a point lower compression allowed more boost and ultimately more power.

Also correct about the GDI system being limited. I believe the stock 2018 gt runs like 90% GDI at WOT. The supercharger kits turn that down because they run out of fuel.

 

[robmustang201528]

My take is this, most 18+ cars on true pump (no e85, no octane booster, no methanol) will make less than but close to 700. It gets to the point where more boost means more timing retard and buys you no power when you’re dealing with 12/1 compression. Getting rid of cats helps a lot because of reduced pumping losses and more spark timing. Turbocharged cars have an advantage here because they don’t have a blower sapping 100+ hp off the crank.

Don’t get me on my compression ratio soap box because it upsets the coyote-loyal.

I wanna hear about it lol. Im in the process of building my motor and I'm dropping down to 10:1

 

[SolarFlare]

I’d have a online discussion on torque and compression....but that simply takes away from racing. And I’ve never raced a car where I could say “damn, his torque beat me”.

 

[Nate_V8]

Those were the days when 300whp felt fast!

Wouldn't that still be fast? I had an '85 GT making 328rwhp and it ran 11.23@121. Just not the safest for a family car so it had to go. God I miss my 85.

 

[Bullitt69]

Need to change your name to BulliTT69 !!!!!!!

80Fox, I just got your Joke LOL..... (Duhhh)

Sounds good, will do!

 

[Jackson1320]

This would be true with any sort of centrifugal compressor, but not with a PD blower. That blower is pumping, say, 3 liters of air into the plenum every time it turns one revolution regardless of IVO timing. If IVO is delayed and the cylinder attempts to pump air back out the intake port, there is nowhere to go because the blower keeps on cramming in 3 liters/revolution. The measured boost level in the plenum will increase but the total airflow and mass trapped in the cylinder will not change unless there is another way out (exhaust during overlap or open bypass valve).

The pistons is going to make more pressure than the blowers 15-20psi so the piston will overpower the incoming air and move air back out of the cylinder. This is exactly how it was designed so that the engine could push exhaust gases back into the intake manifold thus doing away with egr. The blower moves 3liters of air but that’s what the bypass does. So it could be moving 3 liters but not always 3 new liters I could be recycling 1.5 liters

 

[engineermike]

At WOT the bypass valve is closed.

 

[Jackson1320]

At WOT the bypass valve is closed.

Ok. With bypass closed the cylinder pressure is still going to overpower the supercharger and push back into the intake track. If the pressure is high enough it will stop the supercharger from bringing in more air. Doesn’t matter if it’s trying to move 3 liters of air, if it has nowhere to go it will not be able to add more air. The cylinder pressure from pistons on the power stroke 1000-1500psi pushing the piston up on compression stroke will overpower the superchargers 15-20 without any real
effort

 

[engineermike]

I’m sorry Jackson, but you would be 100% correct if we were talking about dynamic compression (centrifugal). But for positive displacement compressors, it’s going to move the air or die trying. This is Compressors 101, but “These blowers deliver, practically, a constant flow rate independent of the discharge pressure conditions.” There are hundreds of resources that show this but here’s one that sums up the characteristics nicely:

https://www.maintenance.org/fileSen...d/399590942964857107/understandin-blowers.pdf

Rotary lobe and screw compressors share these same characteristics.

 

[Ishyne22]

Meth injection is awesome. Until the pump fails. Went out twice on my Ford Flex. One time it turned my ecoboost block into Swiss cheese. So I won’t be using meth.

ive been running methanol for 15 years and never had a pump fail. My guess is garbage pump or garbage install. There are also failsafe devices. You turned it into swiss cheese not the meth.

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