Glad you like your pump, Mountain Bob! Giles said he was talking to you and you were pretty happy with it.
As a matter of full disclosure, I work for Giles. So feel free to doubt or question anything I say - it's only fair that I make my affiliations known.
the main reason for the hp/economy boost is still the fact that the pump is calibrated on the new ULSD fuel. these old pumps were calibrated on a fuel that was more viscous and had different properties. obviously more fuel is needed for significant power gains though.
it all has to do with getting the right dynamic timing. if that is off, then you will have crappy economy/power in the higher rpm range. you have to remember that auto manufacturers need to have emissions control in their vehicles. this means less hp due to less dynamic advance.
That's not actually accurate - the pumps are calibrated on VISCOR calibration fluid, just as they have been for years. Here's a link to our supplier:
http://www.rockvalleyoil.com/Calibration_Fluids.htm. You could even buy some yourself for between >$5/L. :shock: At the time when I posted this, the Rock Valley Oil and Chemical Co. page isn't responding, but that is the link where you'll find info about VISCOR diesel calibration fluid, which is what we (and all certified diesel shops) use in their test benches. Either way, the main reason for the hp/economy increase has absolutely nothing to do with the pump being recalibrated on or for ULSD, because it is NOT recalibrated on/for ULSD. They don't need to be.
Viscosity compensation is already part of the pump's design, which is how it functions through a range of viscosities based on different fuel grades and temperatures. I am wrong on that. Some of the newest pumps have temperature and pressure compensation, but the VE pumps used in our cars do not. They don't need to be calibrated with a specific-viscosity fuel, but neither do they have active viscosity compensation mechanisms. Sorry, my bad! [/b] The (fuel pump) manufacturers and refiners consulted with one another and designed ULSD to fall within the range of viscosities and other physical characteristics necessary to function properly in existing diesel equipment; although it's got a few undesirable aspects, it is overall functionally similar. Neither its energy density nor viscosity are such that they appreciably impact performance in modern diesel equipment overall. The obvious exception to that is the fact that ULSD can mess up your seals due to swelling from previous long-term exposure to Low Sulphur Diesel, but that's a simple chemical reality, not having anything to do with the way that the fuel functions in terms of combustion / fuel metering, etc.
With regard to the whole "we need dyno numbers" - Giles and I both totally agree, and we are planning to do a same-day, same-car dyno with a stock pump, clean lines / injectors / etc. and a modified performance pump so that we can put some of the debate to bed. It's probably not going to happen until at least the new year, however. As far as I know, nobody has done a same day, before/after dyno with one of these pumps. One big problem in trying to do such a dyno is that most dynos can't read speed info from the diesel tach. We have access to the right equipment (I say that vaguely because I don't know what equipment I'm referring to, but we've had this discussion, and Giles has or can get it) to make a dyno read the tach from one of these cars - so we're set just as soon as we can get around to it.
A G-tech dyno isn't the best way to provide real data, and butt dyno results definitely don't add much to the discussion. We're not interested in trying to base the performance debate on hype and "We promise, it's true" numbers or subjective measures. I can tell you from working at Performance Diesel Injection that a 30-40% power increase is a conservatively realistic measure for one of Giles' pumps. Fuelling can in some cases be increased by well over 100% above stock - that is to say that the other day, we looked at a ~150% fuelling increase (ceiling - not all through the range) in one pump. The doesn't correlate directly to power, as there are losses, but with an appropriate intake system (including charging system), you can reasonably get 30%, 40% and better out of one of these pumps - not to mention the fact that your ride is virtually smokeless.
Lyeinyoureye is correct as far as Giles' mods - it would be nice if I could just explain everything that he does, but I can't. That's partially because I don't know all of it, but it's also because this is how he makes his living. I can tell you that he has spent a pile of time, effort, and money on the R & D to figure out the stuff that he has. I can tell you that many or most pump rebuilders could not emulate his modifications even if they did know exactly what they were. I can tell you that all custom pumps done at Performance Diesel Injection are genuinely CUSTOM, from the ground up. They're not sitting on the shelf - we have a pile of cores around, but any customer who has dealt with Giles on this will be able to verify that he asks for quite a bit of detail so that he can modify the pump specifically for the intended vehicle, driving style, etc. Giles does some pretty extensive modifications to the internals of the pump - he's not just increasing pump pressures or dialling up the fuelling through the whole range, as people occasionally suggest.
One other thing that I can say pretty clearly: If Giles charged the regular Performance Diesel Injection shop rates (i.e. the same prices as working on pumps for heavy trucks, bulldozers, generators, and whatever else) on custom pumps, they'd be costing more like $2,000. That is a fact, based on the amount of time that he spends customizing each individual pump. That's not to say "Oh, each pump is worth X or Y" - but unequivocally, he could charge that amount of money and still be well in line with accepted diesel injection industry pricing. He doesn't, because he is a complete speed freak (Anybody seen or heard of his 50HP / 300lb wet, with him on it shifter kart? 90mph, a couple inches off the ground on a go-kart!
). He likes helping people go fast, and he takes an incredible amount of pride in his work. Also, he actually enjoys what he does.
People are absolutely entitled to their opinions about the pumps (Worth the money / not worth the money, etc) but as far as the amount of time Giles spends on each one and the level of customization present in each, that's not up for debate. Nobody, and I mean nobody, does the level of work on these pumps that Giles is doing, and the main reason is the fact that in order to make ANY money at it at a price people will pay, you've got to be as good, and as fast, as he is. You'll find guys who charge less, that's correct. But you simply will not find anybody who does a better job. Period, full stop. And just as soon as I have numbers to back that up, they'll be appearing here, along with video so that you can see the difference and see the contrast between a Giles pump and many others - no smoke, silky smooth operation throughout the range.
