supercharger swap. its crazy...your thoughts?

[unclepaulie]

ok...my brain has been ticking over this for a bit.

the thought of supercharger whine and that narly v6 bark is something i get very excited about.

obviously, the all turbo gear gets ditched, leaving the block and intake manifold.

the throttle could be swapped to the other side if needed

adapted headers from a fto..or custom.

larger supercharger pushin 15psi with drive shaft too

like so

then plumb in a front mount or a water-to-air cooler.

the standard maf and ecu can be retained, i think.

somehow an extra pulley you hav to be mounted. maybe convert to electrical powersteering pump and use that pulley.



what are your thoughts ozvr4? obviously i wont be doing it, but im throwing the topic out there. if you had the time and money i thing it would be a cool think to do

 

[triggs]

http://www.youtube.com/watch?v=u6ALySsPXt0

 

[king_panther]

It's not a supercharger unless you have a huge extension of chrome sticking out of the bonnet.

 

[mchieff]

Sounds like you just want the noise, which i agree is awesome.
But seriously my supercharged 6 doesn't behave much differently to our twin turbos.
Look at some gilmer drive belts or similar and you should get similar noise without the custom work.
Both the above look like centripetal (?) superchargers which have all the issues of turbo's with none of the gains i.e. lag + parasitic losses = :-(
Only reason to use one of them is ease of fitment and better top end over roots style and then the only reason you'll get the whine is because of the custom pulleys you'll need to run it off the crank.
Get some gilmer style belts w/custom pulleys made up (you'll have to do both belt runs i think, and whine away while running twin turbo's - that should make whoever see's/hears the thing confused as hell haha

 

[Scottie]

+1 for the Gilmer Belt Drive. It is where the noise comes from, the drive, not the supercharger itself.

Have seen a few cars with gear drives and just assumed they were supercharged.

 

[unclepaulie]

dennis,

originally it was just for the noise and to think outs side the box, but then i started to research it. it kinda makes sense.

instant response and 20psi. which is what we all want lol.

a twin turbo conversion will set you back about 6k minimum. a centrifugal supercharger and other hardware isnt much more. raptor do the kit with the water to air cooler for 7990. obviously id pipe it down to a FMIC though.

plus it can screw in 20psi, which is similar to Rob's garret conversion.

and pending the layout and design, could use a convention FMIC and relocate the battery to under the strut tower.

 

[Guest]

What sort of power though would the supercharger provide? bang for buck would the turbo upgrade be better though?

 

[frozen]

Hmm those belts sound great lol... youtubed a few videos. I wonder how expensive it would be to do? the first few posts i read mentioned destroying alternators...

 

[Guest]

a twin turbo conversion will set you back about 6k minimum. a centrifugal supercharger and other hardware isnt much more. raptor do the kit with the water to air cooler for 7990. obviously id pipe it down to a FMIC though.

Hmm those belts sound great lol... youtubed a few videos. I wonder how expensive it would be to do? the first few posts i read mentioned destroying alternators...

 

[mchieff]

dennis,

originally it was just for the noise and to think outs side the box, but then i started to research it. it kinda makes sense.

instant response and 20psi. which is what we all want lol.

Maybe on a big displacement engine but you'll find a centripetal (?) supercharger making 20psi on a 2.5l engine is going to be laggy.
I'd hazard more laggy then Rob's setup and at more $$ but with less power.

 

[unclepaulie]

im not sure. the guys from rotrex say its defintily doable. The C38 they recommended. they also mentioned that getting the best out of a supercharger is down to pulley selection. imagine having a GT35 which is spooling at 1500rpm.

Bullet Cars quoted the supercharger/oil/oil cooler/pulley/belts and labour for about 5k.

then id hypothetically need some FTO headers (modded too) and a intake/battery relocation to under strut tower and a retune coutesy of dave/merlin. i would use my exsisting greddy cooler kit/x3e upper pipe kit.

the factory ecu could be retained i think. the maf and O2 sensors remain, and the engine is still boosted, the only thing that would be missing is the wastgate pressure, but this might be able to be taken from somewhere else.

with all this, i think would put it in a similar region to robs TT upgrade cost wise. im not sure the exact dollar value he has spent on it.

i need to find an effecincy pump curve of the rotrex chargers.

 

[sn00ze]

i may be sounding like a bit of a wanker here but it just seems (apart from big block 8's) that turbos just destroy superchargers in terms of power output, especially for money. this is just one example- good friends of mine are brothers, one has vx commy v6 sc with full exhaust and extractors and ecu flash, running 9psi, the other has stock r33 gtst with CAT back only= gtst rapes. just my experience. the sound would be lord-of-the-rings epic though =)

 

[frozen]

...I was referring to the belts and custom pulleys, not the supercharger. I'm not that blind

 

[Kenneth]

Interesting thread. I did quite a bit of thought on this some years ago actually. Unfortunately at the time I didn't have the funds to explore it to the level I would have liked.

The conclusion that I came to (and this is, as usual, personal taste as much as anything) was that if I were going to go to the effort of supercharging, the best bet would be a positive displacement unit, such as a whipple supercharger (http://www.whipplesuperchargers.com/product.asp?ProdID=1162)
A positive displacement supercharger displaces a specific volume of air per revolution. This means that if the supercharger displaced 2.5L of air per revolution, then running it at engine speed should give you 2bar absolute (approx 1 bar boost) regardless of RPM. 4 Stroke means that there is only 1 induction per revolution so you in theory only displace half your engine volume (assuming 100% VE) per revolution.
Obviously this is ideal and in practice it wont work out quite as simple, but it has to be better than a device which, like a turbo charger, has a limited speed range at which it can produce effective boost.

My conclusion was that a "Centrifugal" supercharger would be great if you were coming from a fairly high revving naturally aspirated engine as the boost seems to be fairly linear with RPM and you get the best up top. For low down grunt and instant torque, something like the whipple would just blow it out of the water.
With 8.5:1 CR, I reckon the 6a13 would just love a whipple

 

[unclepaulie]

i may be sounding like a bit of a wanker here but it just seems (apart from big block 8's) that turbos just destroy superchargers in terms of power output, especially for money. this is just one example- good friends of mine are brothers, one has vx commy v6 sc with full exhaust and extractors and ecu flash, running 9psi, the other has stock r33 gtst with CAT back only= gtst rapes. just my experience. the sound would be lord-of-the-rings epic though =)

no thats cool and i understand you completely, heck im doubting it too as most of the v8 guys chasing big power are goin for twin turbos. this is just hypothetical/out side the box thinking.

also remember that superchargers are like turbos. they come in different sizes, so the commo with the SC might have had a really small SC, of equivlant size to a T28.

obviously im not talkin an OEM sized supercharger. the C38 is designed for 2 to 5L applications, then it comes down to belts and pulleys, which is akin to choose the right sixed rear housing.


also...

 

[king_panther]

Why not do both Paulie? Twin-charger!!

 

[Madhav]

I was thinking the same? ^^^

 

[Abusive]

Anyone know of a distributor that sells Gilmer kits for our rides?

 

[unclepaulie]

Interesting thread. I did quite a bit of thought on this some years ago actually. Unfortunately at the time I didn't have the funds to explore it to the level I would have liked.

The conclusion that I came to (and this is, as usual, personal taste as much as anything) was that if I were going to go to the effort of supercharging, the best bet would be a positive displacement unit, such as a whipple supercharger (http://www.whipplesuperchargers.com/product.asp?ProdID=1162)
A positive displacement supercharger displaces a specific volume of air per revolution. This means that if the supercharger displaced 2.5L of air per revolution, then running it at engine speed should give you 2bar absolute (approx 1 bar boost) regardless of RPM. 4 Stroke means that there is only 1 induction per revolution so you in theory only displace half your engine volume (assuming 100% VE) per revolution.
Obviously this is ideal and in practice it wont work out quite as simple, but it has to be better than a device which, like a turbo charger, has a limited speed range at which it can produce effective boost.

My conclusion was that a "Centrifugal" supercharger would be great if you were coming from a fairly high revving naturally aspirated engine as the boost seems to be fairly linear with RPM and you get the best up top. For low down grunt and instant torque, something like the whipple would just blow it out of the water.
With 8.5:1 CR, I reckon the 6a13 would just love a whipple

interesting info kenneth. i did look into the whipple, but only briefly. perhaps ill look into them in a bit more depth.

ideally id like to compare the pump curves of a GT30, a C38 rotrex and whipple of appropriate size.

the reason i originally ruled out the whipple was due to the extensive work needed in fitting it with oem computer.

ideally id like to retain and much of the oem equipment as possible, hence moving toward a centrifugal supercharger. there is also many bolt on kits availble for the magna's so it just seemed like an easier path, rather then fitting the whipple and needing a custom intake manifold (be it upper half, or complete intake manifold)

Why not do both Paulie? Twin-charger!!

I was thinking the same? ^^^

shush you two, this idea is crazy enough i dont need to start think about a twin charger setup...although that would be awsome!

Anyone know of a distributor that sells Gilmer kits for our rides?

until yesterday i had no idea these belts even exsisted, but i doubt there is anything off the shelf.

nothing stopping you creating a custom one.

 

[Kenneth]

Why would you need to modify the OEM computer? I can't see how you would need to modify it any more than with the centrifugal unit.

You still have the same inputs and outputs. My main concern is that if you take out the turbos you then get different breathing characteristics due to the lower exhaust back pressure. Ideally you could benefit from exhaust tuning for bigger gains but that is another conversation.