Crash Nemesis's Supercharged 323i

[Burgy]

I R EXCITED :inlove:

 

[moranor@axis]

crash i think your calculations are wrong the kit makes just over 200kw on 0.6 bar there is no way it will make 190kw on 0.3... but i cant wait to see your dyno graphs :rollsmile:

what tires you running?

 

[killua]

Just did some comparison numbers...

133kw on the wheels at the reef is effectively 191kw on the fly. According to this converter I have on my iPad. That includes the 24% loss at reef altitude. Or am I wrong here?

Pics to come soon.

Loss at the reef is at most 15%, but effectively it would be less than that if your charge pressure is regulated. If you are boosting 1 bar, it is half that...

Yes, Both right. using half of 15% as altitude loss and ~18% tranny loss I also get near 24% for total loss (fly->wheel->altitude) and assuming 1bar boost.

Mathematical gain from stock to charger: 0.3 boost will give 30% increase in power (assuming coast)... so from 125kw->162kw... Wonder where the other 30kw came from :fencelook:
Maybe dyno was already compesating for altitude, which you should then ignore in your calculation?

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crash i think your calculations are wrong the kit makes just over 200kw on 0.6 bar there is no way it will make 190kw on 0.3... but i cant wait to see your dyno graphs :rollsmile:

Yes, that sound better... 200kw at 0.6bar and 160 at 0.3bar...

 

[Burgy]

Didnt see the correction factor on the dyno,

Will post all graphs as soon as we get them.

 

[Inspector_Gadget]

So, page 10 coming to an eventful close..........
Can't hardly wait to see the gains made by the VF!
Already saved 20% for the install since I lost my cash to the wife for the driveway paving...
So just another R 48,000.00 to go...

 

[Gizmo]

Don't forget, the power loss is higher for N/A cars (around 17% @ reef level). Supercharged or turbocharged cars compensate for the altitude and don't lose as much power (around 10-12% @ reef level). Even a little bit of boost @ reef level makes good gains, when I bolted an eaton charger to the 316i engine @ 0.1bar it made a big difference!!

My calculation is: 133wkw X 1.17 for 17% drivetrain loss = 155kw on the flywheel @ reef level. Add 12% to get 173.6kw on the flywheel @ sea level.

Now lets see those graphs because its the torque I wanna see.

 

[moranor@axis]

here are VF charts for the 323i while we wait

238hp = 177kw
203ftlbs = 275Nm

 

[Crash_Nemesis]

Like I said... I could be wrong... lol

Maybe this KW conversion App is crap. It compensates for reef altitude. maybe it doesn't do Supercharger conversions and only NA versions.

Hmmmm.

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Ok. I found this cool little website that does the conversions from wheel KW at the high veld to what is happening on the fly.

LINK

Just place the 133kw in the high veld section and it gives a reading of 169kw on the fly.

make sure you set the settings to Rear wheel drive and that its supercharged, not NA.

 

[moranor@axis]

169kw seems more like it seeing as it lines up with most people calculations

 

[killua]

Don't forget, the power loss is higher for N/A cars (around 17% @ reef level). Supercharged or turbocharged cars compensate for the altitude and don't lose as much power (around 10-12% @ reef level). Even a little bit of boost @ reef level makes good gains, when I bolted an eaton charger to the 316i engine @ 0.1bar it made a big difference!!

My calculation is: 133wkw X 1.17 for 17% drivetrain loss = 155kw on the flywheel @ reef level. Add 12% to get 173.6kw on the flywheel @ sea level.

Now lets see those graphs because its the torque I wanna see.

Sorry for the stupid question, I have zero experience with these things, but how does a super-charger compensate for altitude? AFAIK the boost will decrease with altitude because its not like the gearing to the engine is increased. Except if there is a waste gate type of device at the intake which would regulate the pressure, and the supercharger is set up to have more boost than is needed? If there is no such thing, the loss for supercharger should be the same as NA?

 

[moranor@axis]

superchargers normally use a bypass valve to regulate pressure its normally vacuum actuated im not sure how it will adapt to ambient pressure differences if it does then that would be how it can lose less...

 

[killua]

superchargers normally use a bypass valve to regulate pressure its normally vacuum actuated im not sure how it will adapt to ambient pressure differences if it does then that would be how it can lose less...

Aaah, ok. If it is spring loaded with no ECU, then it will always boost specified amount, but will not "compensate" for altitude in the strict sense. That is how it will lose just as much power with altitude as an old turbo car without ECU intervention :thumbs:

 

[Crash_Nemesis]

Just to throw my 2cents in, this supercharger conversion has a Forged Dump Valve installed on it...

 

[moranor@axis]

thought the VF was supposed to have a bosch bypass valve... im not sure if centrifugal chargers work the same, but on the roots type the bypass is used to feed to air back into the charger so it works less when not boosting... this is controlled by a vacuum actuator so its very different to a manual turbo boost controller...

 

[sidewayz]

crash, looks like we need a day on the track

 

[Crash_Nemesis]

I agree!!! =D

 

[Burgy]

The kit did come with a bosch dv but we decided to put a forge splitR valve in.

The DV on this setup works similarly to a turbo setup. Air is recirculated back into the system.

 

[Gizmo]

crash, looks like we need a day on the track

Not unless he upgrades his brakes first!

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Sorry for the stupid question, I have zero experience with these things, but how does a super-charger compensate for altitude? AFAIK the boost will decrease with altitude because its not like the gearing to the engine is increased. Except if there is a waste gate type of device at the intake which would regulate the pressure, and the supercharger is set up to have more boost than is needed? If there is no such thing, the loss for supercharger should be the same as NA?

To be honest Im not sure about superchargers and altitude, I just know that the power doesn't drop off as much as 17%.

 

[moranor@axis]

wheres the update :fishwack:

 

[Burgy]

Update time!!!

I just spoke to Ross, he is still busy with all the wiring, he says the car should be ready this afternoon