Full throttle Electric Supercharger Build Thread

[Gary in NJ]

Originally Posted by mid_life_crisis

If it's running full out and doesn't need to be

I'm not sure I understand what you are driving at here. The compressor only runs when I choose to engage it. When I engage it, I want all of it...NOW.

[mid_life_crisis]

Originally Posted by Gary in NJ

I'm not sure I understand what you are driving at here. The compressor only runs when I choose to engage it. When I engage it, I want all of it...NOW.

That was from a discussion on limiting the low end boost to avoid a tune.

[rusty959]

Originally Posted by mid_life_crisis

This compressor runs full out when engaged unless in anti-restriction mode.
If it's running full out and doesn't need to be, it's wasting electricity, so I'd rather limit boost with the controller than a bypass.

You seem to be operating under the idea that a motor running at full speed/max throttle means it is pulling the max amount of power it can, which isn't true. The current drawn is dependent on load, so if you had a bypass valve that made it possible for the compressor to spin at max rpm without as much torque needed to keep it there the motor will draw less power.
Now it wouldn't be quite as efficient as using the controller to lower the speed most likely, but it wouldn't be far enough off that you could tell a difference.

[mid_life_crisis]

Originally Posted by rusty959

You seem to be operating under the idea that a motor running at full speed/max throttle means it is pulling the max amount of power it can, which isn't true. The current drawn is dependent on load, so if you had a bypass valve that made it possible for the compressor to spin at max rpm without as much torque needed to keep it there the motor will draw less power.
Now it wouldn't be quite as efficient as using the controller to lower the speed most likely, but it wouldn't be far enough off that you could tell a difference.

True enough, lower rpm under heavy load would consume more electricity than max rpm no load would, but I just don't like waste, especially in a situation where the major weakness is storing and delivering the very thing being wasted, electricity.
Plus, with valves, now we're adding plumbing to the installation with all the decisions/complications that involves. Really don't want to go down that road.

[nlowell]

Originally Posted by MikeW

...My guess is that once you bolt this on there will be minimal gains from additional mods, such as headers and exhaust. People that have already invested in na mods that gave them 20% gains might only get a fraction of what is advertised for the ESC....

Can anyone validate this comment? I'm about to drop ~$2k on exhaust upgrades and will hold off for the ESC if the upgrades will be somewhat redundant on power (and power delivery) improvements.

[fenton]

Originally Posted by nlowell

Can anyone validate this comment? I'm about to drop ~$2k on exhaust upgrades and will hold off for the ESC if the upgrades will be somewhat redundant on power (and power delivery) improvements.

Hard to say, only catback exhaust has been tested with the system. The most you are going to see on a 86 exhaust is MAYBE 10hp. That DSPORT mag comparison had the muffler deletes making the most, even more than some of the full exhaust systems.

That being said it looks like ThaTruth's and Bu-Tang's dyno hold onto their power a bit better than mine. Mine Peaks out at 6750 and tails off a bit while there's holds peak power right to redline.

As far as headers go we aren't sure yet. Anything that you add to free up exhaust flow isnt going to hurt thats for sure.

If there is less exhaust pressure the SC doesn't have to work as hard and will draw less AMP's, which will drain the battery slower.

Until somebody buys a header we really wont know.

[MikeW]

hmm, since the system does not seem to have any limitations associated with battery life it is unlikely there would be any coast benefit to installing headers without a sufficient hp gain. In fact, my understanding is that you want the system to cycle the batteries at good rate so they heat up and perform at peak - all about the right balance and what the system is designed for.

Do we have flow measurements for the system through the rpm range? I know this can be calculated but we all know how reliable calculations can be... I would be curious to know what the flow is at various boost and rpm rates. Regardless, since we know psi putters out around 6500 on stock I think it gives us our answer.

[fenton]

Originally Posted by MikeW

hmm, since the system does not seem to have any limitations associated with battery life it is unlikely there would be any coast benefit to installing headers without a sufficient hp gain. In fact, my understanding is that you want the system to cycle the batteries at good rate so they heat up and perform at peak - all about the right balance and what the system is designed for.

Do we have flow measurements for the system through the rpm range? I know this can be calculated but we all know how reliable calculations can be... I would be curious to know what the flow is at various boost and rpm rates. Regardless, since we know psi putters out around 6500 on stock I think it gives us our answer.

Rob has posted the Compressor map before. Not sure where it is now though

[MikeW]

The more I think about this I continue to come to the same conclusion, ECS will provide boost gains as advertised on a stock car. As additional modifications are added which reduce resistance after the intake, the gains will diminish sooner on the rpm scale. We are essentially already seeing this on the stock care, it just happens (or was by designed) that it maxes out on flow near redline, which is just right if you don't want any future significant gains in whp. Someone that knows anything about internal combustion engines really ought to be able to speak definitively on this issue. I'm not that guy so it's a jumbled mess, but none of this is very technical.

For example, if a stock system produces a peak of 201 whp, then one already modified to achieve 190 whp will start with high gains down low but peak will still be 201 whp, and at a lower rpm (maybe, I don't know). This could essentially generate a curve where the car's whp peaks a few grand before redline and then levels or even starts to actually drop back towards the na numbers before reaching red - flat oscillation also possible. I think this would be bad for lots of reasons and not the optimal feel anyone would choose. Again, there is a reason all systems on the market today sustain hp increases to redline. Although low end power is nice, its not worth making the acceleration to redline anticlimactic or down right irritating. It's very possible the system will always peak about where it is, depending on the nature of the motor, mods, and static pressures involved. I have done zero math to evaluate this but someone could easily. You would also need the compressor map to figure out at what static pressure and cfm the compressor becomes obsolete.

I'm just speculating like crazy so don't take this too seriously. But I know I'm not spending a dollar on any mods until I either give up on this concept and go back to SC, or data is provided to answer these unknowns.

I would also value anyone with the right knowledge to explain just how risky it is to be pumping pressure into an inlet at low rpms. Are the safeguards discussed thus far with regard to low rpm psi and flow rates safe?

[HunterGreene]

Originally Posted by MikeW

The more I think about this I continue to come to the same conclusion, ECS will provide boost gains as advertised on a stock car. As additional modifications are added which reduce resistance after the intake, the gains will diminish sooner on the rpm scale.

For example, if a stock system produces a peak of 201 whp, then one already modified to achieve 190 whp will start with high gains down low but peak will still be 201, and at a lower rpm. This could essentially generate a curve where the car's whp peaks a few grand before redline and then starts to actually drop back towards the na numbers before reaching red. I think this would be bad for lots of reasons and not the optimal feel anyone would choose. Again, there is a reason all systems on the market today sustain hp increases to redline. Although low end power is nice, its not worth making the acceleration to redline anticlimactic.

I'm just speculating like crazy so don't take this too seriously. But I know I'm not spending a dollar on any mods until I either give up on this concept and go back to SC, or data is provided to answer these unknowns.

I would also value anyone with the right knowledge to explain just how risky it is to be pumping pressure into an inlet at low rpms. Are the safeguards discussed thus far with regard to low rpm psi and flow rates safe?

I think you are assuming that this is a free-flowing system. The problem with your reasoning is that in between the intake manifold and the exhaust is the engine itself, which is where the pressure is built up. Making modifications to the system downstream of the engine only increases the flow of exhaust gasses out of the engine, which increases the amount of air needed, but not by the amount you are likely thinking.

[bfrank1972]

Originally Posted by MikeW

The more I think about this I continue to come to the same conclusion, ECS will provide boost gains as advertised on a stock car. As additional modifications are added which reduce resistance after the intake, the gains will diminish sooner on the rpm scale. We are essentially already seeing this on the stock care, it just happens (or was by designed) that it maxes out on flow near redline, which is just right if you don't want any future significant gains in whp. Someone that knows anything about internal combustion engines really ought to be able to speak definitively on this issue. I'm not that guy so it's a jumbled mess, but none of this is very technical.

For example, if a stock system produces a peak of 201 whp, then one already modified to achieve 190 whp will start with high gains down low but peak will still be 201 whp, and at a lower rpm (maybe, I don't know). This could essentially generate a curve where the car's whp peaks a few grand before redline and then levels or even starts to actually drop back towards the na numbers before reaching red - flat oscillation also possible. I think this would be bad for lots of reasons and not the optimal feel anyone would choose. Again, there is a reason all systems on the market today sustain hp increases to redline. Although low end power is nice, its not worth making the acceleration to redline anticlimactic or down right irritating. It's very possible the system will always peak about where it is, depending on the nature of the motor, mods, and static pressures involved. I have done zero math to evaluate this but someone could easily. You would also need the compressor map to figure out at what static pressure and cfm the compressor becomes obsolete.

I'm just speculating like crazy so don't take this too seriously. But I know I'm not spending a dollar on any mods until I either give up on this concept and go back to SC, or data is provided to answer these unknowns.

I would also value anyone with the right knowledge to explain just how risky it is to be pumping pressure into an inlet at low rpms. Are the safeguards discussed thus far with regard to low rpm psi and flow rates safe?

Are you saying you think the ESC is flow limited by the compressor? If so, I'm not sure if that's correct. I think the compressor could make much more power, but the system *is* limited by the battery system/controller/motor.

[MikeW]

Hunter:

The less pressure downstream of the combustion chamber the faster the bad air is moved out and the good air is moved in. I believe this is the reason people change manifolds and pipes, no? Typical gains are in the 20 to 30 hp range so I would not call that insignificant in the context of a static FI system that can only keep up with a 60 hp gain over stock and nothing more.

So with a static FI system (ECS), you have a max flow rate that is determined by something independent of engine rpm (electric motor and condenser size). The fact that this ECS currently peaks at 6500 is a function of design for the stock brz motor. We have seen that once the vacuum of the engine results in a flow rate higher than the compressor max flow, the game is over.

Removing restrictions after the combustion chamber results in increases in flow throughout the rpm range, these gains will be additive to the corresponding ECS gains up until max flow is reached. So as the curve creeps higher on the scale as a result of new pipes or other mods the benefit of the ECS is diminished, or visa versa. I still can't decide on whether the system will peak earlier than 6500 since I don't have all the data. But we know that it does peak (e.g., run out of usable cfm), so it stands to reason that if this flow is consumed earlier at the same psi than the party is over sooner.

It was interesting to observed that with the ECS installed it did not matter whether the stock CAI was attached or the car ran with an open inlet. If you made that same comparison on a stock car I'm pretty sure there would be a noticeable delta. This gives us some insight into the issue, maybe.

[MikeW]

bf, I have not seen the compressor map and I don't think that is something they wish to make public since it would make it easier to DIY. However, I believe the blower will work to maintain a specific - fixed rpm. The more static pressure in the system the harder it works, but it should not exceed the cfm rating. It could be variable speed but I have seen no evidence of that.

[HunterGreene]

Originally Posted by MikeW

Hunter:

The less pressure downstream of the combustion chamber the faster the bad air is moved out and the good air is moved in. I believe this is the reason people change manifolds and pipes, no? Typical gains are in the 20 to 30 hp range so I would not call that insignificant in the context of a static FI system that can only keep up with a 60 hp gain over stock and nothing more.

I'm no expert either, just pointing out the logical issues with your thinking. I mostly agree with what you have said so far. We'd need an expert (plus an actual test car with your hypothesized systems) to really prove it.

The only issue that I have with the part above is your "typical gains." 20-30 hp can be achieved with the proper parts and--only with--a proper tune. Most bolt on header/exhaust systems I have seen on 4-bangers add usually 10-15 hp without a tune. So, if you get the ESC and tune it for just the ESC, you will likely not see as much loss as you are thinking.