sleeper2

I really enjoyed reading the second installment of the 4 part article in Modified Mustangs about the top 17 myths of supercharging. I missed part one of the series (myths 1 through 4). Can someone list 1 through 4 for me? Thanks.

Sleeper2

leatherlungs

ditto

mygt500

Me too! Thanks!

marcuskeeler

I believe the first four myths were based around Turbo charging being better than Supercharging [8D]

That should get our wannabe rice boilers going hehehehehe

157dB

December
1. Supercharged engines use more fuel.
2. Supercharged engines must use high octane fuel.
3. Superchargers need an ignition system upgrade.
4. Superchargers must run retarded ignition timing
January
5. Superchargers make the engine run hotter.
6. Superchargers cause engine knock.
7. Superchargers are noisy.
8. Bolt-Ons can make more HP for less money.
Febuary
9. You must run forged pistons and rods with a supercharger.
10. Superchargers need maintainance and rebuilding.
11. Raising compression makes the same HP as supercharging.
12. Both turbos and superchargers have instant no lag boost.
13. Superchargers blow out head gaskets.
March
14.Superchargers are less efficient than turbochargers.
15. Supercharging adds excessive weight.
16. Superchargers "heat soak".
17. Higher compression ratios cost less than supercharging.

Derf00

I assuming those are the myths right? I know most of those are false.

marcuskeeler

I don't about myth, mostof those are just plain BS LOL

exx1976

I'd be interested in more information on #14.. I know if KB said it then it's correct, but I've seen the opposite argued so many times, it'd be nice to have the correct information at my fingertips to correct the naysayers.

MustangGT0405

Well in total power output yes they are. A S/C has more parasitic loss from having the motor work to turn the supercharger. How much HP is that. I dont know but it takes some, turbos run off exhaust so it is called "free" horsepower.

I like them both personally, each has strengths and weaknesses.

SlideWRX

http://www.opcon.se/www/files/lyshol...m_lys2300r.pdf
There's the chart for a typical KB/Whipple/Saleen style supercharger; there's more on thier site for various sizes. Adiabatic efficiency is the one we are interested in. Up to 66%. Paxton/Novi Centrifugal superchargers are better, 70-75% and get pretty close to Turbo chargers. Turbos spin 3-4 times faster and often are 5% more efficient. The only supercharger I know of that can match turbos for speed & efficiency is the rotrex, and those areexpensive/rare. Regardless, the supercharger sucks up engine power to make the same output horsepower. Our 4.6l engines run ~13-14 m^3 at 6000ish rpm n/a; at 8 psi on that graph (1.6ish PR and now ~22 m^3 flow) we're pulling 25-30 Kw, or 35-40 hp. Turbos introduce large backpressure, which costs power, but that power loss is 1/4-1/3 of the superchargers loss.

Personally? I couldn't care less. I always wanted to replace my turbo onmy wrx with a supercharger to annoy all the turbo fanboys, and so did a lot of calculations on where my power would end up. Pretty close to eachother, although the torque curves have different shapes.

Tom