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-   -   How to Modify / Tune your car - 2 - Superchargers! (https://www.team-bhp.com/forum/technical-stuff/55393-how-modify-tune-your-car-2-superchargers.html)

Turbo's

Have any way mentioned it as far as it goes in one of my previous articles, as well as using nitrous so will just move on to superchargers

Supercharger's

Typically are driven off the crank and are compressors (Kompressor of the Merc era) that compress air straight into the intake manifold / plenum. They may or may not use intercoolers depending on the boost run. So what are the types of superchargers available:

Two of the most famous types of superchargers in the world are

• Centrifugal - Good only for low RPM's but the newer ones are much better
• Root’s - Good for automotive use as they tend to last longer
• Vane - vanes tend to wear out quickly

So how do we get boost out of them?

• Boost is based on the RPM the supercharger is running on
• The gearing / pulley sizes define the rpm and hence the boost

What are the effects of Supercharging on an engine mechanically

• Puts greater stress on the engine
• Piston edges and valve seats tend to burn due to higher temps
• Requires a lot more fuel
• It is parasitic on the engine for the power required to turn
• Intake temps are lot higher so depending on ambient temperatures it is also reccomended to use an intercooler

So what mods are effective with supercharging

• Better intakes and exhaust
• Good Headers
• Plugs in the right heat range 8 - 9
• Race Cams with a lot of overlap
• Porting and Polishing
• Fuel pump upgrade / Additional Fuel Pump
• Forged parts - Pistons, Con Rods, Crank
• Aftermarket ignition controller especially for distributorless cars
  or a Good ECU - piggy back or stand alone
• A good clutch and drive train to transfer the power
• good tyres to grip and not spin out
• A good tuner who knows what he/she is doing

When does one choose to go the supercharging way and not the turbo route?

• Most effective on high torque engines
• Has the car set up for NA / Nitrous use and would like to take the next step
• Loves linear power delivery
• When the car sticks to one RPM range all the time
• Might not be the right choice for track conditions when one needs power at the drop of the hat
• Turbo's are a lot more complicated to set up and tune
• You get more than enough plug and play kits out there (mostly for American cars and typically for Jap cars too which are over 2.5 lts in displacement... remember the high initial torque requirements)

Next I think I will delve on the aspects of tuning ECU's particularly on the ones typically found here in India.

Fantastic details Keshav, Thanks for the information!

very informative and precise. great read even for a me who does not know how these mods are done

Good information keshav. Nice to see your posts after quite a long time. :)

I've always wondered why people prefer "plonking" (not as easy as it sounds) a turbo rather than a supercharger. Is it the availability of parts or overall reliability that drives people towards turbo's?

Guess that is because supercharger kits are genrally more expensive than turbo kits. While basic turbo kits can be had for 1000$, supercharger kits start at 2500$. Also another factor that might put off people could be the trade off between power to be gained and the power used up by the supercharger.

so even though it is more linear it does not have power on the tap? but aren't they more responsive and have a quicker power delivery as opposed to turbochargers?

I thought the two famous types of superchargers are :
a. positive displacement
b. dynamic

Roots is a type of positive diplacement supercharger.

Any idea which category the Eaton supercharger falls under? The ones manufactured by Jackson Racing to be more particular?

Recently got my hands on one of these Jackson Racing Superchargers. I think they have screws like Roots ones. Now I have two superchargers but no car to plonk it in.

It is a parasitic on the enginer for the power required to turn - I always thought this was negligble?

Might not be the right choise for track condition when one needs power at the drop of the hat - Superchargers dont have Lag, which is a trait of Turbos. - Superchargers are driven off the crankshaft and do not need the exhaust gasses to reach a high enough velocity to drive turbines.

Piston edges and valve seats tend to burn due to higher temps
Requires a lot more fuel - Are these comparision to N/A engines or Turbos? I thought Superchargers and Turbos both help increse combustion efficiency?

Not it isn't negligible. The engine on the McLaren SLR produces 617BHP of which some 100 plus BHP is taken by the supercharger. Superchargers can take as much as a third of the engine power produced at the crank.

Turbos are more efficient than superchargers because of their inherent methods of operation. Superchargers run off the engine crank while turbos take the energy from the exhaust to operate. One is taking a part of the usable energy produced by the engine while the other is salvaging wastage.

sorry that is old school the new generation superchargers have a 90% to 98% efficiency. This has no engine loss and is Negligible

IIRC, jackson racing uses Eaton blowers which they brand as thier own when they sell kits.
VOrtex is the other type.

Now how much of that 617 bhp was due to the supercharger ?

im getting a bit confused here...

SC helps to bump up the BHP of the engine ( without having to increase displacement etc )

SC then takes up part of the BHP to run itself

so SC has to deliver more BHP than it takes to run itself, so as to make a material difference to the useable BHP

is that how it works ?

Yes, that is correct.

Only at low boost levels. Bump it up and you're looking at 50% max.

Narayan, yes, the net effect is a bhp gain.

98% efficiency is close to a perfect machine -- not possible. BTW, gotta love your signature!

check the website of the brand we were discussing clearly states 98%