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Location:
Rocklea qld
Registered:
February 2003
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turbo or s/c the time has come
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Sat, 17 April 2004 07:29
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ok this is the story...i have a 18rgeu and the time is pretty much here to start buying the engine parts for the rebuild and upgrade.I was wondering what peoples opinions where on turbos and superchargers and what work i should do to the engine.
I planning on using 18rc pistons as i have been told it lowers the compression to around 8.2-1. Would this be about correct. Im gonna use 7mgte injecters and most likely run it off megasquirt and also run a spark only computer as the chuckster is doing. What are your opinions on superchargers vs turbo. I was thinking the s/c as there is no exhaust manifold to be made and then i can just run extractors. Also the sc14's can be picked up for around $250. Can u regulate the amount of boost you want to run as you do with the turbo. Or would the turbo upgrade be more sensible for the application. What other work should i also do. Im looking to get around 250rwhp and anything over that is a bonus. Machine flywheel, balance crank, cams maybe and what size should i run...Just get them ground down??? Any other info on this subject would be awesome i am gonna start pricing a few things and buying the parts week by week. All help is appreciated and look foward to your responsis.
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Registered:
March 2004
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Re: turbo or s/c the time has come
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Sat, 17 April 2004 21:53
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"Personally" I prefer S/C for the reasons of 1. ease of installation,2.easier to calculate max boost.3.ya don't have to lie with your insurance broker "Is the car fitted with Turbo ?" 4.Instant boost from Idle.
There has been heaps on this forum regards Super/Turbo.Different strokes for different folks.As several have stated ya can get more "boost" from a turbo,no parasitic drag when not on song,(not 100% true regards backpressure)different adiabitic and dynamic/mechanical eficentcies.
Have fun !!
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Location:
Rocklea qld
Registered:
February 2003
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Re: turbo or s/c the time has come
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Sat, 17 April 2004 22:23
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i wanna run the car in street sprints. If i go the s/c what sort of revs will i get to before the s/c stops working basially speed etc??? Can you run the s/c of just a fan belt or are special belts needed...Do you still run blow off valves with s/c 
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Registered:
March 2004
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Re: turbo or s/c the time has come
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Sat, 17 April 2004 22:51
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What sort of "blower" are you refering to.?? Roots type.Centrafugal,Axial (my favorite but bloody hard to get)Wankel type.Blowers(Roots) don't stop working at big RPM's,they just become inefficent,that is the air is heated (thined out)to the stage that it's energy co-efficent drops (there is a formula for it some thing like 7 PSI boost at 25 degrees K (kelvin scale)has the same oxy content as 30 PSI at 40 degrees K )Big reason for intercoolers.
Yep they are all Mechanically driven (belt or gear)Some S/C have internal pressure relief,some external relief and "NO' a standard fan-belt (single V) would slip (check out the belts on any of the 4agze or 1ggze)
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I supported Toymods
Location:
melbourne.victoria.austra...
Registered:
June 2002
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Re: turbo or s/c the time has come
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Sat, 17 April 2004 23:32
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so you want to make around 180kw at the rears? turbo then my friend - the sc14 won't be able to efficiently make enough boost to give you that sort of power (its a little PD blower remember)
you will also have to custom make a bracket to hold the charger on the front of the engine.
and you'll have to then get a multi rib pulley for the front of your 18RG with a pulley decently sized to run the supercharger at a certain level of boost (nothing over 11psi from what i gather as the insides heat up quite dramatically and become in-efficient)
personally i'd look at a nicely sized turbo for your application - maybe a ct26 from a 3sgte if you're on a budget or rb20det bb turbo?
just my thoughts...
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Registered:
March 2004
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Re: turbo or s/c the time has come
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Sun, 18 April 2004 00:07
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Grega is probaly on the money for ease and cost...The little SC12 or SC14 would be working it guts out and as several have said the fluroresin coated rotors would probaly "Expire" if pushed to hard (don't like big heat)As I stated earlier its personel preference.BTW the axial flow blowers are mechanically very inefficent but thermo/dynamically tops,45,000 Shaft horsepower on a RB211 (fitted to the Boeing Jumbo).
Have fun
P.S. It all eventually comes down to "MONEY".
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Location:
Rocklea qld
Registered:
February 2003
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Re: turbo or s/c the time has come
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Sun, 18 April 2004 00:44
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Ok ill most likely go the turbo option. Ive seen the skyline turbos etc for around $350 so will probably go down that road. what would be the best turbo option for the engine....Anyone got any ideas on other engine work i should do to get a good engine with high hp. Thanks
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Location:
Rocklea qld
Registered:
February 2003
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Re: turbo or s/c the time has come
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Fri, 23 April 2004 10:19
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BUMP
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