Superchargers in rally?

[moto356]

ive been doing some research lately and i was looking to do a turbo build but i started to notice people build supercharged motors instead. the setup of how they work seems like for rally it would be much better as it uses a pulley system to rotate the intake instead of the exhaust gases. that way there is better low end response and no turbo lag.

im curios if anyone has tried this for rally or if its even legal

[hoche]

Sure it's legal. Some of the Group B cars had both a supercharger and a turbocharger, and the VW G-Laders (Rallye Golf, Corrado) were supercharged.

There is definitely more low-end response with a supercharger, but there's also more parasitic horsepower loss - the engine has to work to turn the supercharger. With a turbocharger you get the extra power essentially for free, since it uses gasses you're just blowing out the tailpipe anyway.

[Hitokiri]

Well the bigger the turbo, the more loss you have also. Unless you're willing to pay $5000 to $6000 for a sustainable ALS system.

[UP2MTNS]

Well the bigger the turbo, the more loss you have also. Unless you're willing to pay $5000 to $6000 for a sustainable ALS system.

???? you talking about turbos here, or a super charger?

with a regular turbo, ALS/antilag doesn't have anything to do with creating HP in a turbo of any size.

But I don't know too much about superchargers, can you run ALS with a super charger? I thought that was supposed to be one of the main benefits of a superchager? (fast spool, and it stays spooled when off throttle since its the engine that's running it?)

[bue car]

ALS with charger. no.

I will be running m90 magna charger on a 2.5 block. STi short block, 2000 2.5 RS SOHC heads matched up. I plan to run 15 psi.. you can follow my build soon. Ill make a journal.

[bue car]

mmmm

http://i146.photobucket.com/albums/r255/thyfacelessgod/95%20L/supercharger019.jpg

http://i146.photobucket.com/albums/r255/thyfacelessgod/95%20L/supercharger018.jpg

[rollo]

There is definitely more low-end response with a supercharger, but there's also more parasitic horsepower loss - the engine has to work to turn the supercharger. With a turbocharger you get the extra power essentially for free, since it uses gasses you're just blowing out the tailpipe anyway.

Kinda free.. obviously it increases back-pressure, and there's a lot more heat involved than in an NA engine. But yeah, it's generally considered to be "less expensive" than a supercharger, which is literally driven (directly or indirectly) by the rotation of the crank pulley.

with a regular turbo, ALS/antilag doesn't have anything to do with creating HP in a turbo of any size.

But I don't know too much about superchargers, can you run ALS with a super charger? I thought that was supposed to be one of the main benefits of a superchager? (fast spool, and it stays spooled when off throttle since its the engine that's running it?)

Right. It's really quite a different driving experience IMO. The direct correlation between engine speed and charger speed means that power comes on in a much more linear fashion. The faster you go, the faster you go, kinda thing.

You don't get that "surge of boost" feeling that you get with a turbo because there's no spool time, but where it kicks in such that you can feel it depends on many things - the operating range of the supercharger, the size of the pulley you use (i.e. how brave/rich/stupid you are), how much you value fuel economy, how the engine is tuned, ambient temp, how big your intercooler is, etc etc

Chris.. dude an Eaton on that engine will be very, very interesting.. and more boost is always just a pulley away :D

[bue car]

i cannot wait to get the project done .. gimmie a year at minimum :(

[rally592]

I don't know. I have always said a 4 cyl motor I prefer turbos. V8 on the other had I prefer super chargers. V8 can take advantage of the low RPM torque and 4 cyl usually makes more power once you rev them up (think Honda B16 etc).

As for ALS. No you would not need one on the super charger but would have to do a 34MM restrictor which would hurt performance big time! ALS sounds cool until you learn your driving style will probably require more braking than a WRC driver and you will start replacing parts like motors, turbos etc.

Now if you make your car RWD and supercharge it 2WD cars do not require restrictors! (mostly because you will not go anywhere without traction and you will not have any)

[A1337STI]

(theoretical build) Take an Audi Maybe A3, use the 2.8L turbo 6 banger, and put on a super charger . now sure where the boost would end up with a 34mm restrictor in there but i would imagine a 12 psi limit would yield power still fairly high up , muahahaha

:D

[moto356]

this is some good info guys thanks. im startingn to lean towards the turbo now. also im getting a 2.2 here soon in place of the 1.8. should i keep it to turbo (ive read the ej18t thread on rs25) or save for a wrx motor trans swap. i would want to do just a very cheap build if i kept it refresh the e internals and add the bare necessities

[bue car]

just swap it.

[A1337STI]

totally swap it, if that's an option.

[KevinWelker]

If you are interested in any budget, stay away from all forms of forced induction. You don't need it to go faster than you can drive for a couple of years (at least). Forced induction is best at going through cubic dollars at a faster rate than NA.

[cystem]

If you are interested in any budget, stay away from all forms of forced induction. You don't need it to go faster than you can drive for a couple of years (at least). Forced induction is best at going through cubic dollars at a faster rate than NA.

IMHO, though im a bit biased, there is no reason to consider adding a turbo to an N/A until your driving skills are the no longer the limiting factor. Now i don't know what the OP's background is but in my experience its not the lack of a turbo that's REALLY holding my time back but my driving skill.


As such i will be going for a 2 day rally class somewhere next spring =)


With all the being said i cant wait to see someone slap a super charger on a H4. Thanks in advance bue for being a guinea pig.

[Function Autosport]

How does a restrictor affect a supercharger vs a turbo?

[bue car]

cystem,

check out rs25.com for a few m62 builds. and spud made a monster m90 out of the hood...

my m90 will be more that a 6 psi blower on a na motor tho.. so i am super stoked to see some power. 14.5 psi target on oem sti block should be good. its not excessive power, thats not what im looking for. well.. i hope it's not ;)