Chumpaumpalumpa said:

Yes sir that's why you have people here backing you! What do you mean by heated? At least you found some badass little motors in the process. I think using belt drive would be the best as far as simplicity while using the same motor you were going to for direct drive so you can really get into the compressor efficiency range. Additionally, using a Larger compressor (ie. HX-35 or similar) paired with that motor and you've got a hell of a lot of airflow!!

Click to expand...

I meant geared not heated sorry, I'm still traveling and thinking about this On my way to the airport.

I can't see the image on my phone but I'll take a look at the airport. What would be the difference between a belt and a gear driven system? Which one is more efficient and can belt system hold high rpm?

teknicalissue said:

I meant geared not heated sorry, I'm still traveling and thinking about this On my way to the airport.

I can't see the image on my phone but I'll take a look at the airport. What would be the difference between a belt and a gear driven system? Which one is more efficient and can belt system hold high rpm?

Click to expand...

The belt system uses belts to drive gears instead of gears driving gears, similar to the pulleys on your motor or on Harleys. No oil needed there and yes it will handle the RPM just fine. It is slightly bigger but no oil to deal with.

Chumpaumpalumpa said:

Yes sir that's why you have people here backing you! What do you mean by heated? At least you found some badass little motors in the process. I think using belt drive would be the best as far as simplicity while using the same motor you were going to for direct drive so you can really get into the compressor efficiency range. Additionally, using a Larger compressor (ie. HX-35 or similar) paired with that motor and you've got a hell of a lot of airflow!!

Click to expand...

I think I found a timing belt system online that I could use... On top of that; Instead of having the company build me a motor; I'm going to buy their 25,000 RPM 25.5 KW which will amount to 34.2 HP.

Why am I going with this behemoth of a motor you ask? Because I'm sticking with the 20g and shifted my goals to hit the 640CFM @ 2.0 PR which is 44.16 lbs/min or good for 375hp which will respectively give us 175hp off the batt (from stock). I think that's fair ... Go big or go home right?

Considering that there will be two turbo's, the stock 14b and the electric turbo... should we assume the one with greater cfm will over power the one with lower cfm? or do the cfm of each turbo combine? if that's the case.. then the direct drive system wouldn't limit us to that 20hp as it will be a combination of the turbo that currently exists and it self.. Just trying to understand how cfm works with multiple turbo's....

To make sure the motor can handle it:

(640 cfm * 14.7 PSI) / 229 * 0.68 = 27.9 HP with a bit of overhead to account for friction, heat, etc.. etc.. (@jim95redgsx can you verify this is accurate?)

Because the 640CFM is at the 120,000 RPM point; I try to find a belt ratio of 4.8 to hit the 120,000 on the mark. the motor will run 120,000 RPM @ 25.5KW (34.2 HP)

I will be using the 20G with a 6 blade compressor which is stock. The only different is that I'm going with a 6 blade billet instead of steel for it's weight properties.

Because this is a pulley system and requires no oil; I will redesign the housing and use the 3D printed plastic on the protoype instead of aluminum. I will be using ABS with heat resistant paint that should get it to run well under heat. This is another thing that will need to be tested! but will save $$$ in the long run. I'm still getting rid of the CHRA and keeping the much shorter shaft as well.

Given this data; we should be golden correct?

While the 'transmission' would require no oil since it's a belt, what about all the bearings? Even in sealed ball bearings grease wears out over time.

One might argue that the motor itself has 'normal' bearings, but argument there is that the motor is not the fastest spinning part of the system, the turbo wheel and the small pulley are. And even if all bearings are the same, the ones supporting faster spinning components will wear out quicker.

First of all, I was able to find all of the parts I needed on SDP!



I have a ratio that will make the gear spin at 126k RPM. The reason I chose this ratio and not one that is 120k was to account for RPM loss due to load. It's a bit of a guess and thought that 6k was fair amount of RPMs lost at the shaft wheel.

91-GS said:

While the 'transmission' would require no oil since it's a belt, what about all the bearings? Even in sealed ball bearings grease wears out over time.

One might argue that the motor itself has 'normal' bearings, but argument there is that the motor is not the fastest spinning part of the system, the turbo wheel and the small pulley are. And even if all bearings are the same, the ones supporting faster spinning components will wear out quicker.

Click to expand...

You are correct; Now that we are going back to the gearing system; I will need the bearings I had before. The good news is that the bearings I found are for medical equipment (Bone saws, dentists drills etc.. etc.. ) rated for 300k RPM with no maintenance. One of the things we would have to test is for longevity; Worse case scenario is for me to create a design which is easy to swap out the bearings and provide maintenance kits for the turbo. The bearings are fairly cheap and there should be a total of 3 or 2 in the hole system. For future reference; These will be angular contact ball bearings.

teknicalissue said:

I think I found a timing belt system online that I could use... On top of that; Instead of having the company build me a motor; I'm going to buy their 25,000 RPM 25.5 KW which will amount to 34.2 HP.

Why am I going with this behemoth of a motor you ask? Because I'm sticking with the 20g and shifted my goals to hit the 640CFM @ 2.0 PR which is 44.16 lbs/min or good for 375hp which will respectively give us 175hp off the batt (from stock). I think that's fair ... Go big or go home right?

Considering that there will be two turbo's, the stock 14b and the electric turbo... should we assume the one with greater cfm will over power the one with lower cfm? or do the cfm of each turbo combine? if that's the case.. then the direct drive system wouldn't limit us to that 20hp as it will be a combination of the turbo that currently exists and it self.. Just trying to understand how cfm works with multiple turbo's....

To make sure the motor can handle it:

(640 cfm * 14.7 PSI) / 229 * 0.68 = 27.9 HP with a bit of overhead to account for friction, heat, etc.. etc.. (@jim95redgsx can you verify this is accurate?)

Because the 640CFM is at the 120,000 RPM point; I try to find a belt ratio of 4.8 to hit the 120,000 on the mark. the motor will run 120,000 RPM @ 25.5KW (34.2 HP)

I will be using the 20G with a 6 blade compressor which is stock. The only different is that I'm going with a 6 blade billet instead of steel for it's weight properties.

Because this is a pulley system and requires no oil; I will redesign the housing and use the 3D printed plastic on the protoype instead of aluminum. I will be using ABS with heat resistant paint that should get it to run well under heat. This is another thing that will need to be tested! but will save $$$ in the long run. I'm still getting rid of the CHRA and keeping the much shorter shaft as well.

Given this data; we should be golden correct?

Click to expand...

Dam straight, now were talking where are you finding this motor btw

teknicalissue said:

Why am I going with this behemoth of a motor you ask? Because I'm sticking with the 20g and shifted my goals to hit the 640CFM @ 2.0 PR which is 44.16 lbs/min or good for 375hp which will respectively give us 175hp off the batt (from stock). I think that's fair ... Go big or go home right?

To make sure the motor can handle it:

(640 cfm * 14.7 PSI) / 229 * 0.68 = 27.9 HP with a bit of overhead to account for friction, heat, etc.. etc.. (@jim95redgsx can you verify this is accurate?)

Because the 640CFM is at the 120,000 RPM point; I try to find a belt ratio of 4.8 to hit the 120,000 on the mark. the motor will run 120,000 RPM @ 25.5KW (34.2 HP)

I will be using the 20G with a 6 blade compressor which is stock. The only different is that I'm going with a 6 blade billet instead of steel for it's weight properties.

Given this data; we should be golden correct?

Click to expand...

Good work Here. Throw some 264 cams on and bigger injectors and afpr and 255 pump and a couple other supporting stuff and were away! You could make 400whp on that setup with proper supporting mods fuel and good tune.

Chumpaumpalumpa said:

Dam straight, now were talking where are you finding this motor btw[/QUIOTE]

A buddy of mine forwarded me the number for a chinese electric motor company. The motor isn't cheap thought; It's $699. But for good reason.

Chumpaumpalumpa said:

Good work Here. Throw some 264 cams on and bigger injectors and afpr and 255 pump and a couple other supporting stuff and were away! You could make 400whp on that setup with proper supporting mods fuel and good tune.

Click to expand...

Click to expand...

Also keep in mind that this is insta spool... no lag at all .

I'm buying the belt a little thicker (9mm instead of 6mm) as I'm not confident the 6mm would hold up to the strain needed to move the compressor wheel... Thoughts? Their thickest belt is 9.5 so I'm assuming the 9mm wide belt should hold.

teknicalissue said:

Also keep in mind that this is insta spool... no lag at all .

I'm buying the belt a little thicker (9mm instead of 6mm) as I'm not confident the 6mm would hold up to the strain needed to move the compressor wheel... Thoughts? Their thickest belt is 9.5 so I'm assuming the 9mm wide belt should hold.

Click to expand...

Slightly more friction but reliability is very important. Also, if a belt breaks, you get no turbo and the car runs poorly. Replace the belt and you're off; no harm done to the motor so that is excellent as well plus maintenance on the 'transmission'.

I don't know if a belt drive is the right way to go as i received the following email from an engineer at SDP:



The sad part is that i already bought the equipment so the email came a little too late..

Thoughts?

teknicalissue said:

I don't know if a belt drive is the right way to go as i received the following email from an engineer at SDP:

You must be logged in to view this image or video.

The sad part is that i already bought the equipment so the email came a little too late..

Thoughts?

Click to expand...

Return it? The belt is not spinning at 170,000RPM and even so, I thought the goal was "only" 120,000. Where is he pulling 300,000 RPM from. Maybe use a kevlar belt? The only way to know for sure is research and development which is the stage we're at now. That's what makes a solid product is using your resources to test and develop the absolute best solution and unfortunately that means some money will be "wasted" though it is going to improve the product so it is not really a waste. Even so, I still think the belt drive will work because I've seen it work; albeit at 90,000 RPM but those were rubber nylon belts.

Chumpaumpalumpa said:

Return it? The belt is not spinning at 170,000RPM and even so, I thought the goal was "only" 120,000. Where is he pulling 300,000 RPM from. Maybe use a kevlar belt? The only way to know for sure is research and development which is the stage we're at now. That's what makes a solid product is using your resources to test and develop the absolute best solution and unfortunately that means some money will be "wasted" though it is going to improve the product so it is not really a waste. Even so, I still think the belt drive will work because I've seen it work; albeit at 90,000 RPM but those were rubber nylon belts.

Click to expand...

That's why i'm not returning it (I was just bummed out when I received the email) I'm gonna give it a try just for kicks but you're absolutely right! wouldn't the belt spin as fast as the drive gear will allow it to be? which is 25k? It wouldn't make sense if the belt spun faster than the drive gear...... We need @jim95redgsx and his friendly mathematical skills

The goal was 120,000 but I'm looking for products that give me heard room as well. For all we know; this could work and I could make a beast GT30 just by swapping in a faster stronger motor.. Just thinking a tiny bit ahead . idk where he got 300,000.. Probably from my original idea for the gears.

Gotta love R&D right? hahaha That would be my dream job right there!

It wouldn't be an expensive loss if it didn't work... 58 bucks for the belt and pulley's.

I did find an esc capable of 680A bursts (less than 10 seconds) for really cheap.. So i'm also going to be doing some R&D to see how far it can be pushed and possibly; how to upgrade the design. With the bursts; Heat kills the ESC... If I could replace the heatsink with something more efficient; I could potentially increase the burst length.


So we have the motor, we have an esc, we have the "transmission", we have the software to read volts, all we need know is to put some brain juice towards the batteries.

The motor is going to draw 85v @ 300a which is a ton of juice (Expected for an electrical 30hp machine..). The next catch would be the batteries!

My plan was to get 4 6S Lipo high discharge batteries (130C for 10 seconds) that have 5a. The motor draws 300 amps/hr or 5 amps a minute. This means that you would in theory (ignoring battery limitations/esc limitations) be able to run the motor at max speed for 1 full minute. If we limit the full throttle use for 10 second intervals with 10 second coll downs; you would probably get 2 minutes assuming the motor is not running during the cool down.

This should be good for a prototype but we might need to consider the best approach as these batteries are going to run me $380 dollars not including the chargers and voltage readers (can't let the voltage drop too far on LiPo's which will affect mah)

Someone here mentioned super capacitors and I tried looking but I just can't find a super capacitor able to discharge 300A @ 85v... that would be a monster .

While we wait for the belt and pulley's, let's start tackling some battery solutions before I shell out the $380 dollars

teknicalissue said:

That's why i'm not returning it (I was just bummed out when I received the email) I'm gonna give it a try just for kicks but you're absolutely right! wouldn't the belt spin as fast as the drive gear will allow it to be? which is 25k? It wouldn't make sense if the belt spun faster than the drive gear...... We need @jim95redgsx and his friendly mathematical skills

The goal was 120,000 but I'm looking for products that give me heard room as well. For all we know; this could work and I could make a beast GT30 just by swapping in a faster stronger motor.. Just thinking a tiny bit ahead . idk where he got 300,000.. Probably from my original idea for the gears.

Gotta love R&D right? hahaha That would be my dream job right there!

It wouldn't be an expensive loss if it didn't work... 58 bucks for the belt and pulley's.

I did find an esc capable of 680A bursts (less than 10 seconds) for really cheap.. So i'm also going to be doing some R&D to see how far it can be pushed and possibly; how to upgrade the design. With the bursts; Heat kills the ESC... If I could replace the heatsink with something more efficient; I could potentially increase the burst length.


So we have the motor, we have an esc, we have the "transmission", we have the software to read volts, all we need know is to put some brain juice towards the batteries.

The motor is going to draw 85v @ 300a which is a ton of juice (Expected for an electrical 30hp machine..). The next catch would be the batteries!

My plan was to get 4 6S Lipo high discharge batteries (130C for 10 seconds) that have 5a. The motor draws 300 amps/hr or 5 amps a minute. This means that you would in theory (ignoring battery limitations/esc limitations) be able to run the motor at max speed for 1 full minute. If we limit the full throttle use for 10 second intervals with 10 second coll downs; you would probably get 2 minutes assuming the motor is not running during the cool down.

This should be good for a prototype but we might need to consider the best approach as these batteries are going to run me $380 dollars not including the chargers and voltage readers (can't let the voltage drop too far on LiPo's which will affect mah)

Someone here mentioned super capacitors and I tried looking but I just can't find a super capacitor able to discharge 300A @ 85v... that would be a monster .

While we wait for the belt and pulley's, let's start tackling some battery solutions before I shell out the $380 dollars

Click to expand...

Supercaps can drop WAY more current than any batteries. Problem with them is that energy density if you will is very poor. Hard case lipos are very expensive but best performance option. Thunder power makes 2S LiPos that will discharge 130C burst and 65C continuous and are 5300mAh but that is old tech i'll look for better stuff.

http://www.thunderpowerrc.com/Products/8000-mAh_2/TP8000-5S4PLV
Here we go

DEAR LORD THESE ARE RIDICULOUS!!
http://www.thunderpowerrc.com/Products/6800velocity/TP6800-1SV70
952A burst

Chumpaumpalumpa said:

Supercaps can drop WAY more current than any batteries. Problem with them is that energy density if you will is very poor. Hard case lipos are very expensive but best performance option. Thunder power makes 2S LiPos that will discharge 130C burst and 65C continuous and are 5300mAh but that is old tech i'll look for better stuff.

Click to expand...

cool beans! I appreciate the help guys. I travel a ton (As I write this waiting for my flight at the airport) so I do need help with some of this stuff. I'm a software developer not a mechanical engineer! haha

Asside from it being old tech... I'm petrified of those things blowing up in my face... I looked in to LifePO4 but those are hella expensive in comparison to the LiPo. I wonder how I could hook up tiny supercapacitors together to create one giant supercapacitor capable of this much power?

We need an electrical engineer!

Chumpaumpalumpa said:

http://www.thunderpowerrc.com/Products/8000-mAh_2/TP8000-5S4PLV
Here we go

DEAR LORD THESE ARE RIDICULOUS!!
http://www.thunderpowerrc.com/Products/6800velocity/TP6800-1SV70
952A burst

Click to expand...

Keep in mind that we are looking for 24 cell batteries! ol the 952A burst one will leave me broke if I bought 4 of those hahaha

call these guys and ask for 4 at a deal for R&D maybe. http://www.maxamps.com/Lipo-11000-222-Pack.htm

Better yet hit these guy up, the apparently make custom stuff. They have a 24S available but only 150A
http://www.batterysupports.com/contact_us.html

Chumpaumpalumpa said:

call these guys and ask for 4 at a deal for R&D maybe. http://www.maxamps.com/Lipo-11000-222-Pack.htm

Click to expand...

I'll give it a try but I would need four of these. I would also need a custom charging solution for each of the batteries as well. LiPo are a PiTa without a discount; I'd be looking at $1600 bucks just on batteries alone.

Chumpaumpalumpa said:

Better yet hit these guy up, the apparently make custom stuff. They have a 24S available but only 150A
http://www.batterysupports.com/contact_us.html

Click to expand...

I actually reached out to them! They said that because of shipment limitations (as LiPo can explode) they would be able to send me the cells separately and I would have to make the battery from scratch... I don't want to do that.. Especially with Lipo's and this much power.

EDIT: I just reached out to a super capacitor battery company and they said that an 85V 300A super capacitor would be the size of a house XD hahahahaha

You may be going for a little overkill here.

While that motor will provide the power at 7000 RPM engine speed, it will definitely have to be throttled back at anything less than around 6000 RPM. You may hit 50 psi at low engine RPM if the compressor wheel doesn't choke first. You'll have to do this with programing as there is no wastegate to control boost. You'll need an RPM sensor, not just a TPS.

At 45 lb/min, you're right on the 60% compressor efficiency line. Allowing for the heat of compression:
45 lb/min @ 2:1 PR @ 60% eff = 50.16 HP
35 lb/min @ 1.75:1 PR @ 60% eff = 30.8 HP
1.75 PR = 12 psi
25.5 KW X .9 eff / 746 =30.76 HP

The motor RPM will probably drop until the motor HP equals the required HP.

I can't see a 9mm wide belt being able to transmit 30 HP. Belts, in general, do not like high RPM.

Electric motors are not rated in amp/hrs, batteries are. That motor will be pulling 300 amps constantly...but you're right, the batteries will last 1 minute @ 60C discharge rate. At a max 15C recharge rate, it will take 4 hours to recharge. Not very practical.

Jim

Ok don't shred me on this one is hypothetical and I'll research it later on but what about just using 4 or 5 agm batteries, hooked up in series for amp boosting, then use a high powered voltage amp? In that book I have they used 5 lead acid batteries in the trunk to power a electric supercharger and a Peltier junction intercooler, which the junction also required significant power.

mercaholik said:

Ok don't shred me on this one is hypothetical and I'll research it later on but what about just using 4 or 5 agm batteries, hooked up in series for amp boosting, then use a high powered voltage amp? In that book I have they used 5 lead acid batteries in the trunk to power a electric supercharger and a Peltier junction intercooler, which the junction also required significant power.

Click to expand...

Li-pos are more efficient and lighter and can discharge enough but they are expensive so AGM might be something to at least consider, but I think I've heard about that too somewhere.

Exactly, cost being the issue as it seems like the motor will cost a good amount on its own. And each person can upgrade to any type they want. One more thing is maybe you should consider how you'll package the charger and intercooler, piping, room for cooling ducts, and lubrication supply demands. A 20g is designed to work on pressurized oil, this can help dampen harmonic vibrations. Not sure if a self contained system would work right, but maybe that was just for the gears. One good thing is the heavy turbine wheel won't be slowing the spool down anymore, and that's probably gonna help the required horsepower to drive just the compressor wheel, right? Or is that already taken into account?

Lead acid batteries may not be the best solution. You would need 7 batteries wired in series to reach 85 volts.

The amp/hour ratings of almost all auto batteries are rated at a 20 hour discharge rate. The higher the discharge rate, the lower the amp/hour rate becomes. This is known as Peukert's Law.
http://all-about-lead-acid-batterie...amentals/peukerts-law-and-exponent-explained/

Most auto batteries are rated between 80 and 100 amp/hours. At a 300 amp discharge rate, you would drain those 7 batteries in minutes.

k = Peukerts exponent
k = 1.3 - 1.6 for lead acid
k = 1.2 - 1.3 for AGM
k = 1.09 for lithium ion

At 300 amps discharge rate:
100 amp/hour battery = 5.86 minutes @ 1.3k
100 amp/hour battery = 3.89 minutes @ 1.4k

My Advance Auto "Silver" battery is rated at 85 amp/hours.
85 amp/hours = 4.7 minutes @ 1.3k
85 amp/hours = 3.1 minutes @ 1.4k

An Odyssey PC680 battery is rated at 16 amp/hours.
16 amp/hours = 32.44 seconds @ 1.3k

With the batteries wired in series, the voltage goes up but the amp/hour rating remains the same.

The batteries must be wired in parallel to charge them off the stock alternator. The stock alternator is rated at 75 amps. This 75 amps divided between 7 batteries will take approx. 10 hours to recharge the batteries.

Jim

jim95redgsx said:

Lead acid batteries may not be the best solution. You would need 7 batteries wired in series to reach 85 volts.

The amp/hour ratings of almost all auto batteries are rated at a 20 hour discharge rate. The higher the discharge rate, the lower the amp/hour rate becomes. This is known as Peukert's Law.
http://all-about-lead-acid-batterie...amentals/peukerts-law-and-exponent-explained/

Most auto batteries are rated between 80 and 100 amp/hours. At a 300 amp discharge rate, you would drain those 7 batteries in minutes.

k = Peukerts exponent
k = 1.3 - 1.6 for lead acid
k = 1.2 - 1.3 for AGM
k = 1.09 for lithium ion

At 300 amps discharge rate:
100 amp/hour battery = 5.86 minutes @ 1.3k
100 amp/hour battery = 3.89 minutes @ 1.4k

My Advance Auto "Silver" battery is rated at 85 amp/hours.
85 amp/hours = 4.7 minutes @ 1.3k
85 amp/hours = 3.1 minutes @ 1.4k

An Odyssey PC680 battery is rated at 16 amp/hours.
16 amp/hours = 32.44 seconds @ 1.3k

With the batteries wired in series, the voltage goes up but the amp/hour rating remains the same.

The batteries must be wired in parallel to charge them off the stock alternator. The stock alternator is rated at 75 amps. This 75 amps divided between 7 batteries will take approx. 10 hours to recharge the batteries.

Jim

Click to expand...

I think hat is a tad to long. So Lithium Ion or polymer or maybe Lithium Iron phosphate?