rktskicar

Bruce's 0.02. Some sort of JHM S5 tuning I think

clochner

Interesting. Hard to imagine that a tune will yield any more gains than APR's supercharger kit for the S5.

rktskicar

my guess it is JHM's supercharger version. A tune itself will not cut it, IMO..

Bruce

sakimano

Tune = done
Exhaust = done
Vortech Supercharger capable of flowing air to support 750hp = doing
other goodies = doing

It's going to be pretty awesome for the S5 guys who were stuck with restrictive 2.35" (lol) Milltek catbacks and downpipes + GIAC tuning for the past 3 years.

well certainly a tune on its own won't compete with a $16,000 supercharger kit. Take note of the following though:

APR RS4 with supercharger on 93 octane ran 11.83 best with 10 runs by a great driver who did really well
JHM RS4 with just bolt ons on 91 octane ran 12.30...and the driver (Dan@JHM) was pissed and said he had a terrible day.

Despite the dramatic differences in modlists, the difference is only 0.47. The JHM car just had a clutch/flywheel, tune and exhaust. Also the APR supercharger is probably getting pretty wheezy running high 11s...just as you guys have found the TVS1320 seems to cap out low 12s (pump) on your cars. It's hard to make a blower flow more if it's pretty well maxed out.

For perspective 150 CFM = about 100 crank hp. These superchargers can take between 20-60 hp to run (they're parasitic unlike turbos). The TVS1320 can flow around 800 CFM, thus are good for about 500 crank hp when you net out the loss to drive the unit. The Vortech unit JHM is using flows about 1300 CFM. World's apart. While APR and VF and PES are doing their best to coax the most power possible out of their superchargers (which are getting pretty well maxed out), JHM has to restrict the power of their blower in the tune to protect the engine's internals.

BobbyJim

Surely whether turbo or supercharged, it will be "parasitic" as you put it - the energy has to come from somewhere...

sakimano

well seeing as how superchargers are driven by the engine, that's parasitic. Turbochargers use exhaust gas.

BobbyJim

Yes but to extract kinetic energy from the exhaust gas you have to impede its flow and so the engine has to work harder to eject that gas. No such thing as a free lunch!

rktskicar

cough... that is true for a turbo, but not a supercharger.

Bruce

RedMagma2011S4

As the laws of physics dictate, there is no free lunch, but there are different items on the menu.

The supercharger draws power directly from the engine like the alternator or A/C compressor.

A turbo derives its energy from the exhaust gas pressure and yes it does increase back pressure.

Both are parasitic with differing pros/cons.

BobbyJim

...and I wouldn't call either parasitic. More like beautiful symbiotic relationships