deltaP

I’ve seen some posts in another thread claiming that the Delta P kit is only a bracket and pulleys. This is simply not true! What is true that I have yet to claim to have a “complete” kit, but rather a “comprehensive kit”. The customer may have to come up with an occasional hose or hoseclamp, but all the serious stuff is there. I’ve avoided focusing on the complete package because I am in the midst of some major development.

So now, because of the previously mentioned misinformation, I’ve got to reassure everybody that we are moving forward quite nicely. Yes, I wish it were a bit faster.

I am a very principled individual and have been reluctant to “just get it done”. Delta P has supplied several kits and our customers were satisfied with what they got. Despite having to run to the auto store for a bobble or two. We’ve also upgraded a few FAST kits for some of their customers who want to increase their boost.

You may ask, what’s taking me so long? Thanks for asking!

First of all, for those of you who do not do any design and manufacturing of your own, it would be good to understand how long something takes to accomplish. The answer is always…too long. A comparison would be to see how long it takes the pros to develop something. Take for instance 928 intl’s belly pan. If I recall correctly, Mark A said that it took roughly a year until perfection was reached (Mark, if I’m remembering this incorrectly, please forgive me). In my mind, Mark Anderson is the pinnacle of professionalism with respect to the 928 community. He is extremely cautious and calculating with every step he takes. I’m trying to behave in the same manner. Because of this, something that may seem like it should only take a couple of weeks may take a year to get to market. I can tell you, it’s extremely aggravating.

So what’s specifically holding me up?

First, as I mentioned, we have been selling kits. Unfortunately for us, our customers aren’t quite as vocal on line as others. So don’t think you can’t get a kit from us. We have various stage kits available too, for those of you may try to save some money by finding the generic stuff like the blower, plumbing, blow-off-valve etc on ebay or elsewhere.

But we have been in the process of some unique developments which, I believe, are central to the Delta P philosophy.

The primary thing that concerns me with supercharging a 928 is the fact that you are adding a significant amount of weight over the front axle of a perfectly balanced car. This leaves somewhat of a foul taste in my mouth.

I hope that weight balance is an important issue to most 928 owners. The Porsche engineers broke tradition in many ways with the 928. They chose the costly path of separating the transmission from the engine and located it in the rear of the vehicle with the differential. All for weight distribution. They also went through the trouble to locate the battery in the rear. These guys were serious about a well-balanced car. There’s no real way to supercharge a 928 without screwing that up a bit. It is my intention to minimize the deviance as much as possible. Anybody who wishes to track their 928 and wants to supercharge it should seriously consider these issues. Anybody who likes carving through a canyon or two, may also want to consider it. If we as a community fail to consider the weight balance and handling characteristics of our cars in lieu of more power, we begin to enter the dark realm of the muscle cars and ricers. We’ll progressively see more and more 928’s stomped by the likes of an M3.

Regarding weight, the first thing to think about is the weight of the components. How does a steel bracket stack up to aluminum, for instance? Since steel is three times as dense as aluminum, a bracket made out of 3/8” steel plate would weigh roughly 50% more than an aluminum bracket made with ¾” plate. Notice that steel is a very rare material on the 928. This could amount to a few pounds. Not a huge deal but everything counts in small amounts.

The next thing to consider is the intercooler system. I was disturbed by the proposition of putting several gallons of water in the front of my car…the same place where I’m already going to be placing a rather heavy blower. This is why I’ve been developing an Air-to-Air intercooler. I should hopefully have a couple of prototypes finished soon.

The Air-to-Air intercooler is known to have better thermal efficiency than the water-to-air. The water-to-air intercooler requires a middleman, the water, to help in the heat removal process. Each additional medium that the heat has to pass through is an additional barrier impeding the process. Sometimes the water-to-air intercooler is necessary, but I hope to soon show that this is not the case on the 928. The increased efficiency means cooler air which means a safer engine.

The Air-to-Air intercooler is a much more elegant solution than the water-to-air. There is no tanks full of water, no hoses to leak, no electrical wiring to short, no pump to mount. If you like a cluttered engine bay, you won’t like the Air-to-Air.

I could have just used the standard Vortech water-to-air and been done with it, but I was not satisfied. I even developed our own water-to-air from the ground up for kicks, and will make it available to the public for those who desire this solution. But philosophically, I am standing behind the Air-to-Air.

On another philosophical note, we are developing an ECU chip which is mapped specifically for the boosted 928. I would much prefer to run stock fuel pressures, which is both safer and easier for the stock fuel pump to supply the demand, than to use the bandaid approach of an FMU requiring pressures over 100 psi at times. We currently have a car running at 7 psi and no FMU. Our design goal will be 12 PSI and no FMU.

Also, we are manufacturing everything ourselves including all the machining, intercooler fabrication including the sheet metal work and welding. Hopefully this will ensure the highest quality product.

We have many other developments in the works. I typically don’t like to discuss developments before they’re done, but I felt that at this point it was needed to address some of the misinformation being brandished about.

I purchased the 928 for philosophical reasons. As an engineer, I have a great amount of respect for what the engineers were able to do with the car. As we know, the 928 was the flagship for many groundbreaking technologies. I’d hate to be the one to break that tradition.

For additional information, I’ve only started a website, but what I’ve got, you can see here: www.deltaPpower.com

Thanks for Listening

Chris
Delta P Power

GoRideSno

Hey Chris,
Weight is an interesting issue w/ regards supercharging.
I have a question you may know the answer to since you are in socal. I was at LACR in Palmdale a while back and there were some guys that said there was a person there some months passed that had a blue 928 that was supercharged and "pushing 700HP". Do you know who this was and what kind of times they ran?
TIA,
Andy K


BTW last time I checked if you weighed an Air to Water core against an Air to Air core capable of flowing the same CFM the Air to Air core would be about 30lbs heavier or 7x as heavy as the air to water core. This more than makes up for the 2 gallons of water need for the air to water sys ( ~15 lbs that's already there if you use the washer reservoir). Now consider the fact that the 30-40 lbs of the Air to Air IC is 2-3 feet further forward than the AIR to Water IC is and we see that use of an Air to Air system will yield a much greater disturbance of ballance.
Another issue w/ weight in regards to SC systems is the crank pulley. Spun weight has several effects on an automobiles acceleration (and deceleration). A heavier crank (pulley) won't gain rpm's as quickly and will not allow the car to move forward as quickly (try moving a gyroscope) The apparent mass of a rotating wheel is much greater than it's actual mass. This means as a cylinder (pulley) becomes heavier and it's diameter increases the less efficient it becomes, lowering the effiency of the system. My crank pulley is a slightly smaller diameter and within 1/2oz of the stock part.
My manifold is lighter than the stock S4 manifold. Forced induction manifolds need not be complex yeilding another opportunity for weight savings. (Just look at the the Ford GT Manifold, one of the fastest cars in the world) A forced induction setup that uses the stock NA manifold is likely wasting space and weight. My manifold serves the purpose of manifold, supercharger mount, IC mount, IC plumbing, and the discharge portion of the IC all in a package lighter than stock. Using the Manifold as an IC mount also puts the center of gravity of the blower 1 to 2 feet further back than if you used a bracket to bolt it to the front of the engine. This gives another advantage in weight distribution.

drnick

cool web site! you have some very nice componentry there, especialy the supercharger bracket which looks great in blue. i think it would go nicely with orange too..

ptk

whoow nice site. I have never seen it before. Maybe becouse I'm new user of 928 (rookie) Are there any problems with SC in 928?? I was thinking about buy one from F.A.S.T. 928.

karl ruiter

Website is very cool. The falling text on the opening screen is uncomfortably slow on my system though. Someday maybe all the forced induction vendors will have websites with all the info we need to make our decisions. Of course..if I have to choose between that and having a system ready for my '82, I'll take the system. The other thing many of us need from a forced induction vendor is california smog approval. I recognize that this is difficult and perhaps impossible, but in all likely-hood I will be staying stock unless it becomes available or I move out of state.

deltaP

GoRideSno,

I can see I'm helping your case, can I get some sort of commission

from what I've seen the 7x intercooler ratio isn't quite that. Especially depending on construction. We are opting to not use crudely cast end tanks but rather custom fabricate sheet metal ones. These should save some weight. Also, the water-to-air will shine better if the reservoir tank is at the rear of the vehicle to balance out the rest of the kit. Until I have my hardware finalized, I won't be able to do an exact comparison.

Don't forget in your weight comparison to add hoses, hose clamps, a pump, wiring, and another heat exchanger! Also, what is the reliability of all these additional components as compared to a simple air-to-air intercooler? I don't like the thought of even more hoses to have to periodically replace, a pump motor going bad, etc. You get the drift.

I don't know who has the blue 700 hp shark. Lets hope he pops up here and lets us know what he's up to. I am willing to bet he doesn't have a bone-stock motor (these are the guys we're trying to help) and he's not running pump gas. It is great to see what the 928 is capable of.


PTK,

So far FAST, MURPH, GoRideSno, and DELTA (and others?) all have cars running around supercharged. When done properly, supercharging can be very reliable and the 928 has proven to be a choice candidate. If you haven't done so yet, please purchase Corky Bell's book "Supercharged" from Amazon or Barnes.

Because you are deviating from the stock configuration and because you will be pushing things beyond their intended use, there is the potential to do a lot of damage. Learn as much as you can before making any decisions.

Karl,

Some are opting to uninstall their kits for smog purposes. One individual in CA actually smogged his car with the blower on because he had a really good smog tech. The tech used the EO number off the Vortech blower and got him through.

In order for a kit builder to get a kit leagalized in CA, it costs tens of thousands of dollars. This would obviously inflate the cost of the kits even more. Most find it fairly easy to remove the major kit components every two years (not that I'm condoning that!). This is a good time to put on new belts, check all the components for wear, clean and polish everything, and ensure everything gets put back on and retorqued properly.

Old & New

Chris,

Maybe it's just my take, but you put an awful lot of emphasis on the trivial matters - having a cool website (which it is), intercooler weight (which you are wrong about, Mr. Engineer)... Philosophy? C'mon. You've been lurking around for years honing your marketing more than your product.

BTW, What's with your "level III" kits which lack intercoolers?

Still hang with Eric?

Tony

Doesnt mean you have to be quiet?!?
My guess is 99% of the people on this board have never heard of
DELTA P whereas 99% have heard of Andy and Murph!

You cant sell a product if no one knows about it. Advertising 101.

Nice site BTW!!

Tim Murphy

FACT:
The heat transfer coefficient between aluminum to water is 14 times greater than aluminum to air.

2V4V

Originally posted by deltaP
.

I hope that weight balance is an important issue to most 928 owners. The Porsche engineers broke tradition in many ways with the 928. They chose the costly path of separating the transmission from the engine and located it in the rear of the vehicle with the differential. All for weight distribution. They also went through the trouble to locate the battery in the rear. These guys were serious about a well-balanced car. There’s no real way to supercharge a 928 without screwing that up a bit. It is my intention to minimize the deviance as much as possible. Anybody who wishes to track their 928 and wants to supercharge it should seriously consider these issues. Anybody who likes carving through a canyon or two, may also want to consider it. If we as a community fail to consider the weight balance and handling characteristics of our cars in lieu of more power, we begin to enter the dark realm of the muscle cars and ricers. We’ll progressively see more and more 928’s stomped by the likes of an M3.

Sure weight is important. Sure balance is important. If you remove your factory seats, and install aftermarket ones (or just have one lightweight seat for racing) you've done more "damage" to that balance (~120#stock seats v. ~30#race seats). Yes, that weight is closer to the center of gravity, but if you run the numbers, it would be little different than say, an extra 40# nearer the front of the car. Let alone removing all the interior trim which, egads!, everyone who races one (hardcore where the fine line of balance really matters) does. They really "trash" that fine balance. Oh, BTW- have you ever heard of adjustable suspension and corner balancing? The 928 has adjustable suspension, which allows you to mitigate little imbalances.

The next thing to consider is the intercooler system. I was disturbed by the proposition of putting several gallons of water in the front of my car…the same place where I’m already going to be placing a rather heavy blower. This is why I’ve been developing an Air-to-Air intercooler. I should hopefully have a couple of prototypes finished soon.

The Air-to-Air intercooler is known to have better thermal efficiency than the water-to-air. The water-to-air intercooler requires a middleman, the water, to help in the heat removal process. Each additional medium that the heat has to pass through is an additional barrier impeding the process. Sometimes the water-to-air intercooler is necessary, but I hope to soon show that this is not the case on the 928. The increased efficiency means cooler air which means a safer engine.

A/A works. No doubt about it. But ultimate efficiency is not one of those reasons. True enough, every time you try to move energy you are never 100% efficient. However, what you have failed to mention is the additional 6/8/10 feet of 3" silicone plumbing (and bunch of 90 degree angles) that A/A will require. This is not good for your velocity, and will cause you to drop pressure. It will also have the bonus of hanging more weight out there, way in the front of the nose. Bad for polar moment of inertia. And last time I checked, our cars were watercooled. Perhaps, because it's more efficient, manageable, and consistent. Much less disturbance of airflow is required for even a primitive A/W system, and since it's much smaller, it is closer to the ultimate injestion of the charge. This keeps it denser.

The Air-to-Air intercooler is a much more elegant solution than the water-to-air. There is no tanks full of water, no hoses to leak, no electrical wiring to short, no pump to mount. If you like a cluttered engine bay, you won’t like the Air-to-Air.

One can argue the philosophy of 'elegance' all day long. IMHO, A/A was a far less pretty addition to any engine bay I have ever seen, bar none. It takes up way more room (air is a far less efficient heat transfer mechanism than water, but you know this right?) and takes up more room = more clutter. Agreed A/A certainly IS mechanically a simpler transaction. But I have't seen (or heard of) Benzes or Jags having big probs with their A/W intercoolers, so if it's designed properly, it'll work just fine. But if you prefer it, OK. It is mechanically simpler.


On another philosophical note, we are developing an ECU chip which is mapped specifically for the boosted 928. I would much prefer to run stock fuel pressures, which is both safer and easier for the stock fuel pump to supply the demand, than to use the bandaid approach of an FMU requiring pressures over 100 psi at times. We currently have a car running at 7 psi and no FMU. Our design goal will be 12 PSI and no FMU.

Doubtful unless you upgrade the size of the injectors. There's not enough pulsewidth left in the equation to run stock injectors at even 5000 RPM with a blower at 12 PSIG and stock fuel pressures. You can't fix it with a chip, unless you upsize the injectors, the line pressure, or both.


I purchased the 928 for philosophical reasons. As an engineer, I have a great amount of respect for what the engineers were able to do with the car. As we know, the 928 was the flagship for many groundbreaking technologies. I’d hate to be the one to break that tradition.

As an engineer, you should know that the 928 contained exactly ZERO "groundbreaking technologies". It featured some neato whizbang cutting edge stuff (tire pressure monitoring in a street app), but NONE of it was groundbreaking tech. Porsche was oft-times an early adopter, and generally thought stuff through better than anybody else at the time (given the limited computing power available) but Porsche never has been much of an innovator, merely a great executor. It finds things that others don't fully understand the potential of, then exploits that by putting it on street (and race) cars. But if you think Porsche invented the transaxle, aluminum fenders and door skins, an aluminum V-8, 50/50 weight distribution, or power windows, you need to hit a history book or two. NONE of it is novel. All of it together in one car is a bit unique, and I like it too, but c'mon.

Don't worry, you won't be breaking any tradition, upgrading and redesigning Porsches has been going on since Herr Doktor was selling hot-rodded VWs. Oh wait, they still do....

Greg

Rufus Sanders

Tim, So is THAT why there s an alum. radiator with water in it? ? I always wondered that...ha ha. - Ruf

Randy V

Chris (Delta P) -

For the 'Rennlist Philosophy', check your PMs (you have disabled the email sending option on your forum account).

bcdavis

Time will tell...

It's the same with John's turbo project...

I think all the different methods are cool, and when they are all finished, it will become clear which one is cheaper, which one is simpler, which one is more elegant, which one gains more power, etc...

You can't tell any of that until the kits are finished, installed, and dyno tested.
Until then, it's all just a bunch of talk...

PS: The association with Projekt928 (Munck) does not help.
Too many promises of "sophisticated engineering", with nothing but blown engines to show for all of it.

Shane E.

Ok who besides FAST has a kit ready to ship for an '85-'86 shark?

GoRideSno

I'll be shipping this week and next week. 11 of the 12 initial setups are gone. I was keeping a blank for my-self but if anyone wants they can get it. It could be either an Eaton or Whipple.

Andy K