Really dumb supercharger question

[bowlsby]

I've already admitted to this being a ridicluaous question, and I almost didn't post it, but there are no dumb quesitons right?

I've been thinking about superchargers (S/C) for my 74 914 2.0 for awhile.

And then I think about the smog air pump on the 75-76's

And then I wonder if retro-ing a smog air pump onto my engine and plumbing it to the intake air plenum makes any sense. I don't know anything about S/C, how much psi boost the smog pump might give, or how the DJet pressure sensor might react (or be adjusted)...but is this a crazy line of thought and would it work?

[sammyg2]

The air pump will not put out anywhere near enough air to build actual boost unless you spin it real fast. By the time you get a pulley small enough to drive it fast, the belt will slip, or the air pump will disintegrate. At least that is my opinion.


------------------
Gerald Gore II (Sam)
73 914 350 small block

[Yargk]

One place offers these little gadgets that look quite interesting to me. They are electric fans that run directly off the battery when set off by a nos style switch in the throttle body. One of these units gives 1 PSI and a claimed 4-6% increase in hp. You can get a dual unit (two inline) for 1.7 PSI and 6-9% increase in hp. I have been thinking of putting one of these on my '85 mazda 626. I feel no need to try it on my already turbocharged Porsche. Here is their website: http://www.electricsupercharger.com/www-electricsupercharger-com/autoprod.htm

Keith
79 930
85 626 (mazda)

[bowlsby]

There was a thread about a year ago about the e-ram...basically its a joke even if it does dyno and $300 for 1psi boost is a waste of time and money.

Maybe the air pump retro idea just needs to find a larger aip pump from another vehicle.

Anyone know where to find air pump output specs?

[TFI]

300 for ONE PSI OF BOOST????? holey cow!! if i were to pay 300 per pound of boost that i'm puttin ginto my engine that hwould be uhmm... 4500 dollars? OUCH. and to think, i'm upping the boost on it even more with a $15 mod to my wastegate.

just my $.02 (but with the inflation around here on boost it might as well be 20 cents isntead of two!)

[iustasail]

E-ram is a solution for someone who is looking for a small gane on their stock D-Jet engine. On a stock 2L you will probably see 7-8 HP with one, 11-12 HP with two. Stock 914's are ideal for the e-ram because the battery is right there to tap into for the 40 or 80 amps. The system works well on a stock 914 engine because they breath so poorly(2L 914 engine-95HP 2L 911S engine-170HP 2L S2000 engine-240HP); a cam with no overlap, spaghetti intake manifolds, pore combustion chamber, bad valve angles; overall very restrictive thus not a very effective air pump. On such an engine 1 or 1.7 psi of boost that only comes on at WOT, thus not interfering with idle and transition operation, when it is needed the most will make a big impact. So $600 for 12 HP on a 95 HP stock motor is not bad; but two E-Rams on a carbed and camed 2.1 will get you almost no HP, such an engine is already breathing ok and will need significant boost to realize any more power ie. roots blower or turbo.

One must be honest in evaluating the benefits and limitations of after market parts. In this case $600 could by a nice set of used carbs and a new cam; but the block has to come apart to get the 15 HP out of the carbs and now you need a new fuel pump, tank cleaning, and must learn how to tune them or pay $'s to have it done; so 1.7 psi of boost and retaining D-jet may be an attractive alternative to a 914 owner that wants 100+ hp out of his low compression 2L D-Jet engine.

In the end the stock setup has to be significantly modified to get more than 110 or so "real" HP and there are a lot of ways to do it; some just take more $'s than others!

just my $.02

[TimW]

Thanks for asking this question. From an engineering standpoint I've always wondered about the theoretical possibilities of such a device. I never knew, until now, that electric superchargers like this existed.

Very cool -- theoretically anyway.

Tim

[Dave at Pelican Parts]

I'll never know if they're any good or not--I won't buy from the guy who makes and sells them. He was such a ****-head on the 911 Rennlist (and others, from what I hear) that there's no way I would ever send him money.

--DD

[campbellcj]

FWIW the e-ram guy plagued the BMW lists about 2-3 years ago. He was basically laughed off the M3 list from what I recall.

[iustasail]

The funny thing is that the people who would consider spending $600 to get more power out of their engines have most likely already modified them thus making the e-ram useless for their application; and the guy who could benefit from the e-ram isn't going to spend the $600 bucks because he doesn't have a problem with the power of his stock engine to begin with.

So the e-ram falls into the same category as coffee can mufflers, big stickers, K&N air filters, and plastic intercoolers!