DIY Turbo Upgrade

[Bowser330]

The turbo upgrade is actually compounding boost by adding an electrically driven turbo compressor to each intake tube, pre-boosting the air before it enters each S55 turbo.

When compounding turbos the pressure ratios multiply so even if the electric superchargers can provide a pressure ratio of 1.1 they can allow the stock turbos to output 32psi, possibly enough to reach 600whp.

S55 @ 28psi = PR 2.9 ((28psi+14.7)/14.7)

PR 2.9 * PR 1.1 = PR 3.19 or 32psi

The electric superchargers I was looking at are at the link below.
There is currently a more powerful model TQ30024V being developed, they should be more powerful than the TQ250s, allowing for the greater CFM we would need....
http://www.phantomsuperchargers.com/fts-tq25024v.html

This is a link to a guy who used the TQ250 to compound the boost on his 2.4L engine already boosted by an Eaton M45 twinscrew supercharger. The data on his website shows that the electric supercharger and the M45 were compounding boost.
http://www.wildweasel.ca/HowTo/Auto/eturboTest.aspx

Since additional low-end torque is not needed for the M3/M4 the units could be setup to activate when the torque curve starts to taper...so about ~5000rpm.

The systems aren't cheap, the dual setup i'm describing would probably cost around $4000, however the system can be DIY installed/removed and it is universal hardware so it can be resold as two single systems to anyone interested in a used Phantom electric supercharger system, e.g. people with small displacement engines. The FRS crowd is using these and there are several test videos on youtube. Or of course resold as dual system to other M3/M4 owners...

A few questions for the more technical members...

(1) What CFM does a 3.0L engine demand in-order to produce 600whp?

(2) If the CFM demand is 900CFM for 600whp, for example, does that mean each turbo needs to provide 450CFM?

Even if the electric superchargers couldn't increase the peak power higher than the 28psi 540whp @ 5500rpm levels we have now with JB4, if they could at least keep the torque flatter longer and allow 540whp @ 7000rpm, would it be worth it?


Thanks for reading, please provide feedback

[racsos]

sounds interesting hopefully someone can chime in with some knowledge?

[FC4]

You spent way too much time typing that out for this to be a joke...

[CanAutM3]

There is a reason why not a single car manufacturer use electrically powered superchargers: they don't work.

[saxonb]

Production Audi electric supercharger tech confirmed:

http://m.autoblog.com/2014/08/08/aud...rging-feature/

[saxonb]

http://www.kylesconverter.com/power/...ot-per-minutes

[CanAutM3]

Originally Posted by saxonb

Production Audi electric supercharger tech confirmed:

http://m.autoblog.com/2014/08/08/aud...rging-feature/

There is a huge difference between an electrically supported turbocharger (like in F1) and an electrically powered supercharger (like the OP is referring to).

On an electrically supported turbocharger, the main power used to drive the compressor is still extracted from the exhaust gases by a turbine. The electric motor is just there to maintain the turbo rotational speed to improve response (reduce lag). The electric motor can also be used as a generator to recuperate energy from the exhaust gases when no boost is needed.

It takes a fair bit of power (think 100+hp) to drive a compressor to boost the required mass of air that the engine consumes. You would need a hell of an electric motor to provide that power.

[Bowser330]

Originally Posted by saxonb

Production Audi electric supercharger tech confirmed:

http://m.autoblog.com/2014/08/08/aud...rging-feature/" rel="ugc" target="_blank">http://<a href="http://m.autoblog.co...g-feature/</a>" rel="ugc" target="_blank">http://<a href="http://<a href="http...ature/</a></a>" rel="ugc" target="_blank">http://<a href="http://<a href="http...e/</a></a></a>" rel="ugc" target="_blank">http://<a href="http://<a href="http...a></a></a></a>

The article mentions the Audi system is a compound setup using electrically powered supercharger to preboost the stock turbos, thanks for that link!

Wow that rs5 tdi concept had a dramatic improvement in peak power, 240hp to 385hp! Granted we don't know all of the modifications and or tuning involved but the article mentions the Audi eturbo is driven by a 7kw motor.

I understand where you might get your 100hp data though, I've read articles about centrifugal superchargers needing 100hp to spin at peak boost but I think the compressors on superchargers are different since they are lower speed units driven off engine rpm vs high speed compressors on turbochargers.

Turbo compressors are spooled by exhaust gases so if the electric motor can spin that fast then I have to think it makes sense it can create boost using a correctly matched compressor.

[saxonb]

Originally Posted by CanAutM3

It takes a fair bit of power (think 100+hp) to drive a compressor to boost the required mass of air that the engine consumes. You would need a hell of an electric motor to provide that power.

The Phantom BRZ/FRS electric supercharger kit consumes 5Kw of power to produce this:

[CanAutM3]

Originally Posted by saxonb

The Phantom BRZ/FRS electric supercharger kit consumes 5Kw of power to produce this:

So 7hp invested in boost yields back 26hp on a 167hp engine, it is plausible IMO.

I wonder how fast the 12V battery would be drained at the rate of 5kW (417amps) though.

How much power would be needed to boost a 425hp engine by an additional 100hp? I figure quite a lot more than 7hp. Imagine the size of battery that would be needed. Audi in their new technology most likely have incorporated a suitable electrical system.

[saxonb]

Originally Posted by CanAutM3

So 7hp invested in boost yields back 26hp on a 167hp engine, it is plausible IMO.

I wonder how fast the 12V battery would be drained at the rate of 5kW (417amps) though.

How much power would be needed to boost a 425hp engine by an additional 100hp? I figure quite a lot more than 7hp. Imagine the size of battery that would be needed. Audi in their new technology most likely have incorporated a suitable electrical system.

1. Additional air is added with additional fuel. This is how you get more power out than consumed to drive the compressor.
2. According to the site, you get 1.5 minutes peak boost until you need to recharge the 24v battery.

http://www.phantomsuperchargers.com/...ubaru-brz.html


DYNO TESTED: Torque Gain +33% / HP +20%: BEST GAIN: 50% HP & TQ @ 4000 rpm

Kit includes All parts, plug and play, easy 1-2hr installation:

-The FRS / BRZ kit uses the TQ-25024V compressor head

-Full activation is triggered with pedal switch, ~ 75% WOT

-Partial activation is triggered with sensor to retain stock intake vacuum

-MAF sensor reads additional air

-Stock emissions (crankcase check valve)


-In cab volt meter with arming switch

-24V pack is automatically recharged (nominal 8:1)
after each use

-Up to 1.5 minutes of continuous boost, on demand

-Safe, low pressure non-parasitic boost (~4 to 2.5 psi)

-Install manual

-No modifications to vehicle required

-91 Octane fuel recommended

-Reversible in a few minutes

-1 Year warranty

[JNoSol]

Originally Posted by FC4

You spent way too much time typing that out for this to be a joke...

+1, lol but it's not April 1st. The electric charger will just create a bottle neck for the turbos, it will never keep up. A super charger require around 100hp to power a 600hp engine. No 12v source electric motor will give you 100hp unless you use a power source from a tesla modelS.

Roadkill crew stuck 5 high powered leaf blowers in a car, they gain a couple HP and out a few grands let alone a 12v electric blower. Vid below...

For $4k, just get JB4, down pipe, and still have cash to spend...

[Bowser330]

Terminology trip-up...

The electric supercharger system is using a turbo compressor NOT a supercharger compressor. The reason it's called a "supercharger" though is because some terminology experts said you can't call it an electric "turbo" because turbo's MUST ONLY refer to exhaust driven compressors. Which makes no sense to me because by that same logic you could say the word supercharger MUST ONLY refer to belt driven compressors. ANYWAY....yah, that's why its called an "electric supercharger" NOT because its using the compressor from a supercharger, which I agree can take up to 100hp when spinning fast enough to boost up to 600+hp levels...

Turbo compressors have much lighter turbine wheels because they have to spool up from exhaust flow, The motors used in the e-turbo/supercharger can spin the compressor wheel @ 50,000rpm, which do create pressure and flow, how much flow is required for 600whp is the question I asked in my original post.

The chart below is from the TQ250 compressor system, all we would need is a PR of 1.1 to multiply the boost from 28 to 32psi. The air flow is the question, is 60lb/min (30x2, for two systems) enough for 600whp out of a 3.0L? I read on a Supra forum that 1lb/min = 14.472CFM, so 60x14.472 = 868CFM....

[crashtestdummy81]

Instead of asking how much air is required to produce a certain power, start by looking at what you can provide and working back to see how well it fits the problem.

You propose fitting 2 units which would provide you 60lb/min at your desired pressure ratio of 1.1
60lb/min x 2.20462 = 27.2Kg/min
27.2 / 1.2754(free air density in Kg/m3) = 21.3 m3/min
21.3 / 3.19 (desired total pressure ratio) = 6.677m3/min or 6677 l/min at boost pressure
6677 / 1.5 (engine displacement l/rev) = 4451 rpm

After this rpm the electric chargers would not be able to keep up with the engine and would become a restriction to air flow.

To get your 600hp at this speed would require a torque of 708 lbft (960Nm) assuming you can burn enough fuel


Also the system has only a short intermittent run time, the rest of the time it will act as a restriction to the intake at all rpms.

[JNoSol]

JB4 tune + Catless DP + Drop in high flow filter + 100 octane fuel = 600WHP/600lb ft. Our cars cost too damn much to make it a science project. There ain't no such thing as free power, turbos are the closest to being free power because they use the engine's waste (hot gas). Electric turbos, super chargers, etc will rob the engine's power to make power (directly - belt or indirectly - alternator/battery).

[Bowser330]

Originally Posted by crashtestdummy81

Instead of asking how much air is required to produce a certain power, start by looking at what you can provide and working back to see how well it fits the problem.

You propose fitting 2 units which would provide you 60lb/min at your desired pressure ratio of 1.1
60lb/min x 2.20462 = 27.2Kg/min
27.2 / 1.2754(free air density in Kg/m3) = 21.3 m3/min
21.3 / 3.19 (desired total pressure ratio) = 6.677m3/min or 6677 l/min at boost pressure
6677 / 1.5 (engine displacement l/rev) = 4451 rpm

After this rpm the electric chargers would not be able to keep up with the engine and would become a restriction to air flow.

To get your 600hp at this speed would require a torque of 708 lbft (960Nm) assuming you can burn enough fuel


Also the system has only a short intermittent run time, the rest of the time it will act as a restriction to the intake at all rpms.

Thank you for replying, so I worked backwards from 7500rpm and got 100lb/min, so each e-turbo would need to push out 50lb/min to keep up with the demands of the engine @ 32psi.

[saxonb]

Volvo's just done a 444bhp triple charged 2.0 four cylinder with the same e-booster tech from Valeo:

http://www.autocar.co.uk/car-news/in...ylinder-engine

Volvo engineers claim that this new forced-induction set-up “enables a very dynamic drivability without any turbo lag.” The company's suppliers AVL, Denso and Volvo Polestar Racing have all been involved in the system’s development, while the e-booster has been sourced from Valeo.

[boostaholic786]

lol why dont you just order the "tornado" that you put in your air intake and see what kind of results you get with that!! They say it makes the air from the intake "spin" and force more air with its "tornado effect" into the engine!!!! Haha I cant believe this is even being discussed right now...COME ON GUYS...stop referring a Scion FR-s engine to an S55 engine. People that have FR-S's that want to make power put a big fat turbo on them and add fuel. Not this retarded E-supercharger, It is a RESTRICTION for our turbos since its RESTRICTS the air flow by being in the way that a TURBOCHARGER MUST HAVE and no way it could be incorporated into our engines. If you wanna get 600whp, go FBO and build the internals of the factory turbos with bigger compressor and impellers with upgraded shafts ect.. kind of what PURE Turbos is doing. This discussion should be finished

[saxonb]

e-booster turbo systems require bypass valves in order to give the turbos unfettered air when required. There's nothing overly complex about this. Harrop's fantastic E92 M3 TVS positive displacement supercharger system has such a bypass mechanism. Eliminating turbo lag really is the nirvana for M car and other NA enthusiasts. Outright power isn't the point and as you have rightly pointed out is quite easily achieved with traditional approaches.

[saxonb]

And one more thing: You did read that Volvo is making more power (444BHP) from their tri-charged 2.0 four cylinder engine than the S55 (425BHP), and it purportedly has zero lag due to the e-booster. Now that, is some impressive mutherfucking shit esse.

[JNoSol]

Originally Posted by saxonb

And one more thing: You did read that Volvo is making more power (444BHP) from their tri-charged 2.0 four cylinder engine than the S55 (425BHP), and it purportedly has zero lag due to the e-booster. Now that, is some impressive mutherfucking shit esse.

Very cool. That prototype costs millions to develop and the technology probably has series of patents to protect it. No after market company is going to do this for our M3. I'm sure BMW is aware of this and probably working on something similar. To power that electric motor, there has to be a large plug-in battery pack. As I said before, no such thing as free power.

Before the F8x, there were speculations of tri-turbo (one smaller turbo to eliminate lag). It was probably cost prohibit or created a problem.

Cool vid though.