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Electric supercharger

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Old 10-21-2005 | 03:35 PM
  #46  
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Originally Posted by jhunt@huntinter
Guys don't get your hope up on this thing.

There is a huge difference between bolting a hair dryer on the intake of a high compression NA civic and a 930.
Exactly. These things will work on a small displacement low HP engine and will increase peak HP on those little things.

Not that you guys frequently turn RPMS lower than 3000, but my guess is that your HP in the lower range is similar to a civic's peak HP @X,000 rpm and airflow would be similar. If you could get a little nudge in the lower range as you wait for turbo spooling, it might make make a difference. Probably not enough to thrill anyone. But maybe enough to notice.

I might be happy to bolt on something for $300 bucks that could give 10 hp between 2000 and 3500 RPM while providing nothing beyond that. This would help me scoot off the line better.

Getting an electric motor to spin the turbo unit's shaft would probably have a more profound effect on eliminating lag. That would require a different turbo, and a whole lot more money. I hope someone tries it in the name of science.
Old 10-21-2005 | 03:45 PM
  #47  
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this would be a way it "could " work, although not by design.

however, keep in mind that even at high flow rates, (ie max hp of a slightly modified 911 turbo engine), there would be no down side as far as restriction, as the eRAM can produce flow rates far in excess of the intake requirements of some pretty big HP. (we did tests on my race car 928 with 335h at the rear wheels and there were no losses, but only 1-2hp gains. but with the 240hp cars there were more gains across the entire HP curve starting at the moment it was turned on, about 7ftlbs of torque from 2500 all the way to redline)

tell me a little of the turbo air box configuation, and how the eRAMs (yes, it may be a case for using two of them, one on each intake air box inlet if there is two of them)

MK

Originally Posted by James-man
Exactly. These things will work on a small displacement low HP engine and will increase peak HP on those little things.

Not that you guys frequently turn RPMS lower than 3000, but my guess is that your HP in the lower range is similar to a civic's peak HP @X,000 rpm and airflow would be similar. If you could get a little nudge in the lower range as you wait for turbo spooling, it might make make a difference. Probably not enough to thrill anyone. But maybe enough to notice.

I might be happy to bolt on something for $300 bucks that could give 10 hp between 2000 and 3500 RPM while providing nothing beyond that. This would help me scoot off the line better.

Getting an electric motor to spin the turbo unit's shaft would probably have a more profound effect on eliminating lag. That would require a different turbo, and a whole lot more money. I hope someone tries it in the name of science.
Old 10-21-2005 | 03:50 PM
  #48  
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I am sorry I shouldn't have called it a hair dryer. That wasn't polite. I do actually have a pretty good understanding of what you are trying to accomplish and in theory (roughly speaking without giving it too much thought) it may add something to a normally aspirated-high compression <=4 cylinder engine, especially if it ran off it's own battery that is not connected to the alternator. I think it would be a waste of time for Stephen to dyno this, other then to put it to rest once in for all as this conversation pops up on Porschelist from time to time.

As you can see I am skeptical of it. Just like I am skeptical of K&N filters and turbonators.
Old 10-21-2005 | 04:44 PM
  #49  
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I don't understand the negative attitude. Just test it and let the unit speak for itself. Look at what happens when you tromp the pedal from a stop; what was ambient atmospheric pressure is now a negative pressure because of the suction of air into the engine, then as the inertia of the air and the friction of the intake are gradually overcome, the negative pressure becomes positive again. If you can eliminate that negative period can that not be good? When I contacted Mike he told me that I would not see a top end gain but MIGHT see a drop in turbo lag. He was straight up with me and I think that is more than some others are. Mike, send one of the units to AI and be done with all of this bull****!
Rudy
Old 10-21-2005 | 04:51 PM
  #50  
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Thank you, much appreciated.

The bottomline, as i have seen gains even on my older V8 4.7 liter racer.
In fact, one of the tests on the larger engines we did, just ported the eRAM to an airbox that was showing vacuum on the back side of the air filter(ie, between the filter and the mass flow sensor) and when the eRAM was ported in, the vacuum was totally neutralized and some slight pressure measured. this is what its all about. a quick test would be to put a vacuum guage on your air box and go down the highway and go WOT, and see if you get negative pressure in the air box. if so, there are some gains to be made here. ESPECIALLY, if your air box is designed for a 300hp 911, and you have got the boost turned up to 5-600hp. at worst, the eRAM is the same ram effects as if you were going about 160mph (which is about .36 psi by the most effcient hood scoops, with the rear 911 inlets are not!)

I agree, this is not the desiged application for the eRAM on a 911 turbo, but there could be gains. One of the things im doing on my 335 rear wheel hp 928 racer, is to attach the eRAM to an aux inlet and then see if i can get the MAF to respond to the denser air. for some reason, not shown on some 911s and BMWS, the 928 S4 , has a problem with the metering of fuel. seems at WOT, there is not enough feed back to the ecu to get more fuel. even with brute force efforts using adjustable fuel regulators, the system can fight this and restrict the flow of additional fuel to a certain extent. On systems where there is better control of fuel flow, like the early Ljet sytems, the eRAM can be made to work very well ,as we can get the fuel air ratios to a level of 12.5:1 and keep it there. this key.. some tests we have done that dont do this ,show gains in the max torque area, but then no gains at the top, while the air fuel ratios go leaner by 6% torward the top rpms. sometimes we have seen this with bad electrical systems as well, that cant keep the 50-60amps flowing with a bad battery or a bad alternator. if in good shape, the 5-7 seconds of WOT eRAM current demand is not an issue. alternators replace current based on voltage drop of the battery. the better the battery, the less the voltage drop, the less that the alternator has to replace on the spot. (slow recharging)
so, we have done tests with and without the cars battery and electrical system being used. as suspected, there was no difference in the gains.

MK

Originally Posted by jhunt@huntinter
I am sorry I shouldn't have called it a hair dryer. That wasn't polite. I do actually have a pretty good understanding of what you are trying to accomplish and in theory (roughly speaking without giving it too much thought) it may add something to a normally aspirated-high compression <=4 cylinder engine, especially if it ran off it's own battery that is not connected to the alternator. I think it would be a waste of time for Stephen to dyno this, other then to put it to rest once in for all as this conversation pops up on Porschelist from time to time.

As you can see I am skeptical of it. Just like I am skeptical of K&N filters and turbonators.
Old 10-22-2005 | 06:35 AM
  #51  
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Originally Posted by jhunt@huntinter
So that pretty much eliminates all Porsches except early 911's and 914's. Back to bolting it on 4 cylinder Hondas.

Honda drivers like these also http://www.shoplaser.com/index.html



OMG its free energy its amazing what they come up with!!
Old 10-22-2005 | 05:25 PM
  #52  
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What we really need to put this to rest is some dyno numbers using this setup on a 930



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