OK, I've been reading Meuller's crap too long, Just little bit of boost Options

[DNHunt]

How about a small electric compressor directly in the intake that runs constantly to provide a small amount of boost maxing out at say 4 psi. Boost is regulated by a stepper motor controlling a very small wastegate or very large idle air control valve. The stepper is contolled by the ECU using input from the throttle position sensor. Not much compression of the air and it could come from a cold air intake so no intercooler. It's pretty simple electronics. Would it work and is it worth the trouble?

Fire away (IMG:http://www.914world.com/bbs2/html/emoticons/ar15.gif)

Dave

[Joe Bob]

Do a search on the E Ram.... (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif)

[bondo]

To get enough volume you'd need more than an electric compressor... A turbocharger would do it though. (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) Electric superchargers have been done, but they draw so much current that they can only be on at WOT or they drain your battery. And they aren't cheap.

[Mark Henry]

QUOTE (bondo @ Mar 15 2006, 01:05 PM)

To get enough volume you'd need more than an electric compressor... A turbocharger would do it though. (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) Electric superchargers have been done, but they draw so much current that they can only be on at WOT or they drain your battery. And they aren't cheap.

Yep I agree Mike...er...I mean Dave (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

[Mueller]

have you "tired" of that torque monster of a motor already???

[rhodyguy]

alas...no. dave seems unable to just go out, get tickets, and enjoy his car. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) V-8 dave.

k

[DNHunt]

I Like my engine just fine. In fact I was just running around wishing i didn't have stuff to do today just so I could drive. Unfortunately, Gerry cooked a hard drive on the family box. So, I get to fix that. I've just been corrupted is all. Actually, I have a couple of core engines sitting around.

[grantsfo]

How about one of these?

http://www.boosthead.com/home.php

[Mueller]

QUOTE (grantsfo @ Mar 15 2006, 12:23 PM)

How about one of these? http://www.boosthead.com/home.php

now that seems like a pretty decent setup.....normally one only uses boost for a few seconds anyways and after 10-15 seconds if you are not traveling at "oh-boy-this'll-be-an-expensive-ticket" or "arrest-me" speeds then you have problems (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

[lapuwali]

Hmmm....

As I recall, an Eaton blower consumes about 9hp to produce 6psi of boost. This gives a 35% net boost in power.

Let's assume an electric setup will operate at 75% efficiency, so to make 6psi would take about 8.8kW to generate. A single 60Ah battery would make 0.7kW for one hour, or 8.8kW for about 5 seconds. So, a 1.7 would be boosted to 100-ishhp for long enough to make one 1/4 mile run by using 3-4 full-sized batteries.

If you had a big enough alternator, it would take about 16hp to get it to generate 8.8kW (about 730A at 12v), for roughly a 15hp net gain in power. The wire used to transmit this power would likely be nearly as heavy as a battery...

A compressor turbine as shown in that link would be more efficient than a Rootes-type blower like the Eaton, but would really need to spin a lot faster, and would likely be more efficient at better than 6psi. Figure 10psi, enough for 65% boost in power (gross), and the power requirements may be close to the 15hp, but with 115hp from that 1.7, not 100. A turbo would still beat it handily in efficiency, doing about 125-130hp net.

My math is very approximate...

[Howard]

Little electric pumper works fine. Just hook it up to a Nitrous tank (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[Porcharu]

QUOTE (lapuwali @ Mar 15 2006, 12:02 PM)

Hmmm.... As I recall, an Eaton blower consumes about 9hp to produce 6psi of boost. This gives a 35% net boost in power.

Hmmm.. I have one of those sitting on my workbench.
I really really want it sitting on top of the Suby. 6PSI should make about 225HP. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[DNHunt]

QUOTE

A single 60Ah battery would make 0.7kW for one hour, or 8.8kW for about 5 seconds.

Even with a dumb idea I learn something.

Dave

[lapuwali]

QUOTE (DNHunt @ Mar 15 2006, 12:45 PM)

QUOTE A single 60Ah battery would make 0.7kW for one hour, or 8.8kW for about 5 seconds. Even with a dumb idea I learn something. Dave

Simple arthimetic, Dave. So simple I screwed it up!

60 amp hours is roughly the usual rating on a car battery. Watts = amps * volts. 60A * 12v = 700W for one hour, or 42kW for one minute, or 2.5MW for one second (yow!). 42kW/8.8kW = 4.77 MINUTES (not seconds, my mistake).

So, you could get, with one car battery, enough boost to last you for several runs.

There's enough energy in one car battery to give 300hp for 11 seconds, assuming you could actually get that energy out without melting everything.

[Mueller]

so your (new)math pretty much equals the manufactures data...

[Mueller]

qqqq

[bondo]

QUOTE (lapuwali @ Mar 15 2006, 02:11 PM)

QUOTE (DNHunt @ Mar 15 2006, 12:45 PM) QUOTE A single 60Ah battery would make 0.7kW for one hour, or 8.8kW for about 5 seconds. Even with a dumb idea I learn something. Dave Simple arthimetic, Dave. So simple I screwed it up! 60 amp hours is roughly the usual rating on a car battery. Watts = amps * volts. 60A * 12v = 700W for one hour, or 42kW for one minute, or 2.5MW for one second (yow!). 42kW/8.8kW = 4.77 MINUTES (not seconds, my mistake). So, you could get, with one car battery, enough boost to last you for several runs. There's enough energy in one car battery to give 300hp for 11 seconds, assuming you could actually get that energy out without melting everything.

It's more compliacted than that.. 60 Ah is usually based on the 20 hour rate. (20 hours to drain it, at whatever constant current is needed to do that) Thanks to the Peukert effect, the faster you pull energy from the battery, the less you will get. If you pull current at a rate that will use 60 Ah in about 5 minutes, you'll find your battery dead much sooner than that. An AGM bettery will suffer from this less than a "normal" battery, but it still happens and is very significant.

[Aaron Cox]

so i was reading an old weber book....


alfa used twin oilpressure driven superchargers to get 400 hp out of 1 1.5 block.....

[jsteele22]

I think the weak link with the electric supercharger idea is the cost.
And the cost is driven by the sheer size of the numbers involved.
The energy is stored in a bank of (heavy, expensive) batteries. During the several seconds of fun, you've got several 100's of amps flowing through some fat cables. Then once you're cruising, the system gradually kicks in the special high-current alternator required for such a massive store of energy. So even without the control system, there are several heavy, big-ticket items. Anybody that tries to stick a CPU fan in a rubber hose has missed the main point : to get more output power, you've got to expend a proportionately large amount of energy/power to get enough air compressed. So while a well-designed electric supercharger sounds like a very cool project to tinker with, if you just want a lot of power for a little $, keep looking.


I do like the idea of gradually storing up energy that gets used only during the comparatively rare times when boost is really needed. But converting mechanical energy into electricity, then storing the electric energy, then converting that back into mechanical energy is very, very wasteful. One idea that might be fun to play around with is using compressed air. An A/C compressor could gradually pump up a bank of gas cylinders (okay, so a 914 might not be ideal for this...) and the gas could even be cooled to increase the density (like normal intercooling, but done ahead of time). Then open up a valve on a big pipe to let the fun begin. But once again, this would be a pricey, novelty sort of setup that even more plainly begs the question : why not use nitrous ?

[Mueller]

jsteele22,

speaking of capturing and storing

have you seen this:

QUOTE

Ford tests hydraulic hybrid A hybrid powertrain that uses hydraulic pressure to recover energy normally lost during braking will be tested in a fleet of Ford E550 vans in commercial service, according to Ford Motor Co. The system, which was jointly developed with Eaton Corp., could cut fuel consumption by up to one-third in stop-and-go driving conditions. The demonstration fleet is expected to go into service in early 2004. The Ford hydraulic power assist (HPA) system uses a reversible hydraulic motor to compress the fluid with energy supplied by a braking vehicle, essentially capturing energy lost as heat in normal brake systems. The stored pressure is then used to help launch the vehicle from a stop, cutting fuel consumption and exhaust emissions. Ford says its research indicates that such a regenerative braking system is best suited to commercial van or medium-duty truck applications where driving cycles could offer a rapid payback through reduced fuel costs. The hydraulic assist system also offers significant performance improvements, with computer modeling tests showing a 37% improvement in 0-30 mph acceleration times for an E550 loaded to 19,000 lb. Ford also expects that the HPA powertrain would cut brake wear by more than 70% in vehicles with GVWs over 8,500 lb.