THE NEXT BIG THING HIS HERE! 1003 RWHP ON PUMP GAS!!!!

[Jackson1320]

Not to rain on your parade but this has been done. A long time ago so the fact that this was possible has been known. The only problem is the amount of money needed is a lot more than the average mustang enthusiast will ever spend. But if you have deep deep deep pockets it’s there.

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[br_an]

This thread is back from the dead

 

[engineermike]

Man I could write a novel on this after what I've done.

I installed the XDI HPFP45 (same one as the subject car) some time back. With my goals, it was definitely worth it. I was able to realize more timing and/or boost by running a higher GDI blend. At the moment, I'm running the Whipple 3.375 pulley (~15 psi) on true 93 octane at 15-16 deg timing at stock compression. I have the tune set up to stop adding timing before it hits any knock, to be on the safe side.

I've also learned that if you keep the stock GDI injectors, then you can't fully utilize the HPFP45. The lower-cost EVO pump can supply almost all the stock injectors can do. There is a small advantage to the 45 but only at very high rpm and high GDI pressure.

So the question for the user is...if you're committed to pump gas, then is ~40 hp worth the $1700 to you? I'd say the cost/power ratio is on par with most mods like headers and probably better than cams and head porting but not as good as supercharging.

Now here's the real kicker. I wonder which tuners really know how to get the most out of the GDI system. Basically every aftermarket tune I've seen doesn't even get the most out of the stock GDI pump. If they don't know how to do that, then are we to trust that they know how to maximize an XDI pump? It took me over 18 months, hundreds of street logs, and a few dyno sessions before I was confident that I really have it optimized. You have to modify the start-of-injection, end-of-injection clip, max injector angle, and rail pressure. Each has a specific purpose and specific limit. SOI has a firmware limit, EOI loses a ton of power if you get carried away, and I have my rail pressure set up to hold steady to one rpm then linearly ramp up. In the end, it was worth it to me to learn and figure this out myself, but do you trust your tuner of choice to get all this right?

 

[bankyf]

I ran across this thread a few months ago and it piqued my curiosity. I couldn't find any other mention of Hellion offering this as a package or option, either on their website or Google. Did this not play out as expected? Only by special request? It seems that general consensus is that we are limited to somewhere around 800hp with pump gas. Are they really able to repeatedly make 1000+? If this is still a legitimate option, what sounds like 6-7k in additional parts sounds like a bargain.

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