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Supercharger - From a Mazda Capella (and others)
Posted: Mon Nov 27, 2006 2:34 pm
by jeremyisme
Hi
I am wanting to supercharge my vitara (haha, yeah, dont laugh, but one day I will do it, and I am not just throwing ideas in the air)
Anyway, I am wondering if anyone here is a supercharger expert or know a bit about them?
I have been looking at getting a SC12 (from the Toyota MR2's etc), there have been a few on trademe, just waiting for the right price. I have an offer of $300 for consideration at the moment.
But I notice that many people ask "are there any scratches" on the rotors, whats wrong with a few scratches etc?
Also, I have found this thing
http://www.trademe.co.nz/Browse/Listing.aspx?id=78528937
It doesnt look like any supercharger I know. But it seems to come off a Mazda Capella. Does anyone know anymore about them? Are they roots, screw or centrifugal, I think it is a centrifugal, but am not quite sure.
So, any ideas?
I have a fair idea of what is needs to be done for a supercharged project, fuel, air, compression etc, but just need to find the right parts for this project.
Thanks!
Posted: Mon Nov 27, 2006 4:46 pm
by warlord225
the roots or screw superchargers are the big long ones you normally see on the v8's the big beggers that sit nicely in the valey between the banks, the centifugal type looks like a turbo minus the exhaust housing, the draw back of a centrifugal is they like to work at higher rpm, and thus you will normall need to drive them at 2 to 3 times faster than engine speed, and this also make an intercooler almost a nessacaty, because unlike a turbo there is no wastegate to relever preasure. and as we know the preasure is directly proportional to the rotation speed.
another thing to consider when geering the centrifugal type is engine rpm, where do you want the power to be, and gear it accordingly.
Posted: Mon Nov 27, 2006 5:18 pm
by De-Ranged
Hmmm had a look at the pic's don't know what the deal is seams to have 3 openings into that thing ??? :scratch:
I'd feel confident in saying its not a roots style (same as the toyota one you've got an offer on) these work off two overlapping lobbed "rollers" that have a fine tolerance... hence the issue with scratches that the boy racers go on about
I've been picking the brains of a local targa racer who runs a super charged MR2
I've got a Livin one I'm gona bolt onto the side of my 5M
anyway what he has found unless your planing on running 12pound + don't worry about the scratches and even then don't stress it, all you need is a slightly higher gearing he reakons you do get is a bit more heat from the scratches but at that sort of preasure he recomended an inter cooler anyway
oh buy the way he's running 18 pound on his, and has had it up to 25!!!
reackoned it got a bit expensive tho
Cheers Reece
Posted: Mon Nov 27, 2006 5:45 pm
by jeremyisme
Cool. Thanks for that.
Makes much more sense now.
Posted: Mon Nov 27, 2006 6:07 pm
by jeremyisme
Another question,
Does anyone know where we can get thicker head gaskets for the G16B? So I can lower the compression ratio a bit when I do this?
Posted: Mon Nov 27, 2006 6:30 pm
by Rotazuk
The supercharger in the link is whats called a supresion wave charger . In principle it uses the exhaust gas pressure , as it pulses down the pipe , to compress in intake air and force it into the cylinder etc . The pulley on the front just opens and closes the valves controlling the exh and intake air pulsing , I belive ( never had one in pieces ) .
Luckily when suzuki used that engine in the vitara they fitted a turbo and binned the supercharger .
Depending on what you want to do just get a low boost supercharger , ie 4 - 5 psi and leave the compression alone . Lots of info on aussie sites on what superchargers work etc . Have you seen the size of a sc12 . I am going to struggle to mount it to my cousins vitara ( but thats what he wants ) . Give me a week and then ask rex what has happened to his engine
Chris
Posted: Mon Nov 27, 2006 6:35 pm
by toysuzi
Posted: Mon Nov 27, 2006 6:53 pm
by jeremyisme
Oh, I hadn't really thought about the size, haha. Oh well.
So how big are they? Do you have some measurements handy? If not, I will do some searching.
And thanks Toysuzi for those sites. Very helpful.
Posted: Mon Nov 27, 2006 9:02 pm
by De-Ranged
Heres a wee tip for ya don't worry about thick headgaskets just double up a couple of gaskets.... but make certin of your torque settings on the head bolts and retighten after run in
Was told this is good to about 8 pound don't go past that without decompressing things this was for the M series tho so don't know how it would go on your motor
If it helps I can measure up mine for ya mines the 10 not the 12 tho (will just be a bit shorter).... I'm only looking at running 5 pound as I'm not going to lower the compresion ratio other than a double up on the head gasket
Get ya the details tomorrow
Cheers Reece
Posted: Mon Nov 27, 2006 9:10 pm
by jeremyisme
An SC10? I didnt know they made those. What cars were those in?
Posted: Mon Nov 27, 2006 9:15 pm
by NJV6
One of the Kiwi challenge competitors Mike runs a supercharger on his Vitara.
Posted: Tue Nov 28, 2006 3:50 am
by De-Ranged
An SC10? I didnt know they made those. What cars were those in?
That I don't know, what I can tell you is there is three sizes the 10, 12 and the 14 the numbers corrospond to the volume they will flow, the only diff to do this is length.... he was giving me a lot of info at the time some of it sliped through
...
I'll get those dimensions tonight when I get back from work
Cheers Reece
Posted: Fri Dec 01, 2006 10:01 am
by jeremyisme
Did you find those dimensions De-Ranged?
Posted: Thu Dec 07, 2006 7:31 pm
by jeremyisme
Oh well, here goes. I got myself a SC12, so I am committed now,
http://www.trademe.co.nz/Browse/Listing.aspx?id=79364266
I will attempt to document it as I go.
Posted: Thu Dec 07, 2006 7:51 pm
by mroffroader
nice yea please start a thread so one day i can copy you
Posted: Thu Dec 07, 2006 9:59 pm
by Madaz
Howzit going.
If you want a good starting point for pully sizes to run , use your crank pully where your air con is driven off , chuck the drive pully off the supercharger away and replace it with the water pump pully of a 1300 gt starlet engine, this should give you about 5lbs of boost at 1500 rpm and about 12lbs at 6000 rpm under full load with a safari or cruza tied onto the back.
Cheers
Posted: Thu Dec 07, 2006 10:00 pm
by Madaz
And dont forget to intercool it.
Posted: Fri Dec 08, 2006 5:42 am
by Monty
sorry i know its a bit too late but i've just recently had this discussion on the datsun forum, the only really big thing we could think of with selection of supercharger is the volume ie a sc12 came from a 1600cc while the sc14 came from the toyota 2.0l soarers and some old supra's and depending on what motor you got in your suzuki please excuse my stupidity for not knowing!! that should be your choice, i had a sc14 lined up for my rally car which runs an sr20 from a silvia in it but decided to go to na after all that research,
like i said still got a bit of boy racer floating round in me
ciao lee
Posted: Fri Dec 08, 2006 7:00 am
by jeremyisme
Hi, Thanks for that.
I will be intercooling it, but I am not sure how. Maybe a top mount one? So that I only have very short piping?
Does anyone know how to relate the pulley size to boost production for an sc12? I will start looking around the net today, but if anyone know off hand that would be easier.
And yeah, I decided the sc14 would be too big for the g16b, so the sc12 it is.
Thanks
Posted: Fri Dec 08, 2006 7:34 am
by mroffroader
jeremyisme wrote:Does anyone know how to relate the pulley size to boost production for an sc12? I will start looking around the net today, but if anyone know off hand that would be easier.
madaz wrote:If you want a good starting point for pully sizes to run , use your crank pully where your air con is driven off , chuck the drive pully off the supercharger away and replace it with the water pump pully of a 1300 gt starlet engine, this should give you about 5lbs of boost at 1500 rpm and about 12lbs at 6000 rpm under full load with a safari or cruza tied onto the back.
Posted: Fri Dec 08, 2006 8:10 am
by jeremyisme
Haha, yeah, I saw that!!
But I am an engineer and would like to sit down and calculate what I should be getting out of it. It all depends on what the crank pulley size is, and what size the pulley on the SC is.
Then you gotta factor in the displacent of the engine, SC, charge temps (which helps to size the intercooler), effeciencies, etc etc.
So yeah, I wanna be able to do the calcs myself, (not that I dont trust Madaz)
But I am a little skeptical about those boost pressures Madaz has stated, as I thought with a supercharger, the boot pressure should not rise, as when you spin it faster, that means the engine is going faster, and using more air. Also, when superchargers spin faster they start to lose efficiency and hence lower boost pressure. Any thoughts?
Posted: Fri Dec 08, 2006 8:34 am
by Monty
i would try look into water cooled intercooler like the gt4 celicas use, they do require a lot more parts but lag is kept low and intake temps drop really well i would suggest water sprayers etc but they really only work well with speed to get the wind chill not so good for what your looking at where it wont be travelling to fast, i did read a while ago some guys in aus spray nitrogen onto the coolerand were getting intake temps into the minus's?
Posted: Fri Dec 08, 2006 9:06 am
by jeremyisme
Yeah, a celica intercooler sounds like a good idea. (i have always had a thing for gt4's)
And nitrogen spraying sounds very clever, I will investigate more!
Posted: Fri Dec 08, 2006 9:34 am
by lilpigzuk
Be watching as well. My 1600 16v powered flatdeck is in at the exhaust shop today (Papakura mufflers and exhausts - shameless plug but he does a lot of the trials vehicles up our way so knows his shit and at very good prices
) Still not running but once oxy sensor is in, rotazuk will be full steam ahead sorting out tuning with the supercharger on it. Using an AMR300 of a 3 cylinder subaru engine. Tiny blower, but only wanting too run low boost
cool thing with these is that they are just about bolt in on the vitara aircon mounts - pully lines up and everything. Have also picked up an intercooler off 300tdi discovery. Is a reasonably small unit and cost me some beers. Unsure where the hell too put it..
The only thing to work out now, is whether I can run a BOV
I think I have read somewhere they dont work with roots style blowers, no hooning down the street with PSSSSHHHHHH between gearchanges....
Posted: Fri Dec 08, 2006 9:13 pm
by Goose
eeeeeeeeheeeheeeheeee!!!!!!!!!
as you have found, grasshopper, the answer to any problem is MORE POWER!!!!!!!!!!!!
we want audible proof of said engine screaming!!!
oh yes, and BOV = GAY
Posted: Fri Dec 08, 2006 10:07 pm
by lilpigzuk
Goose wrote:eeeeeeeeheeeheeeheeee!!!!!!!!!
as you have found, grasshopper, the answer to any problem is MORE POWER!!!!!!!!!!!!
we want audible proof of said engine screaming!!!
oh yes, and BOV = GAY
my engine or the thread starter??
Posted: Sat Dec 09, 2006 8:05 am
by Goose
lilpigzuk wrote:Goose wrote:eeeeeeeeheeeheeeheeee!!!!!!!!!
as you have found, grasshopper, the answer to any problem is MORE POWER!!!!!!!!!!!!
we want audible proof of said engine screaming!!!
oh yes, and BOV = GAY
my engine or the thread starter??
Your engine!!! Superchargers sound guuuuuuuuud!!!!!!
Posted: Sat Dec 09, 2006 9:15 am
by Madaz
Yeah calculations would be a good way of working out pully size and I did do a bit of that, but it ended up being easier to start off with a big pully to get some boost readings then swap to a small pully and get boost readings and then work out the ratio of difference between the two.
I think you can vary the way that boost is delivered by the way your bypass valve is set up, mine just ended up running like that and it tended to suit the way I drive quite well.
I also used a mazda 1600 dohc turbo intercooler because I found that it fitted in nicely in front of the radiator(on a samurai)
Posted: Sat Dec 09, 2006 2:08 pm
by Monty
a pressure controlled wastgate is what you need even if you had a puleys running x psi you can set your wastegate to open at say 7psi and no matter what you run the gate will open at that set psi does your suzuki have any vacuum? sorrry i know stuff all about the suzuki's are they petrol or deisel?
Posted: Sat Dec 09, 2006 2:28 pm
by jeremyisme
Yeah, that is what I was thinking, just to have a wastegaste set to 7psi. but i dont want to be boosting to 10 etc for no reason, cos that will take some power out of the engine, and increase the charge temperature.
And yeah, the suzuki does have vacuum controls, for the brake booster etc, so I will have to put non return vavles on the lines, but I am not sure if that will affect brake performance etc. Any ideas?