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Discussion Starter #1
anybody know what the compression ratio is for the 1.8 16v engine?, thought there was some techinical details on theis website , but seem to have gone ?
 
M

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Discussion Starter #2
Not what you wanted but the 1970cc engine is 10:1
Can't find the figure for the 1.8 at the moment
 
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Discussion Starter #4
Cheers, bit higher than i wanted, never mind, have to be careful with the boost from the supercharger
 
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Discussion Starter #5
Stick an extra head gasket in there and adjust the valve timing to suit.


Ralf S.
 
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Discussion Starter #6
Dont need to do any engine mods, as long as i dont run to much boost, 5to 6 psi hopefully, = about 40% BHP and torque. Need a MAP sensor to drive another injector in the inlet line and maybe a Bypass for the Charger for cruising. About £1400
 
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Discussion Starter #7
fkcream:
maybe a Bypass for the Charger for cruising.
a bypass shouldnt be needed and i cant see what benifit it would have....are you useing a centrifugal type or a twin rotor type..?????
 
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Discussion Starter #8
Well the Eaton roots blowers as fitted to the Mercs etc use a bypass when criusing so that you dont waste fuel powering the blower when you dont need it. Im not quite sure what happens to the boost if you dont use one when the throtle slams shut... just sits there maybe, i just throught it might be better to have a bypass for fuel economy and blower life, dunno.

Ive been offered a sprintex blower, these are the best screw blowers, very high efficency and lots of boost from 1500rpm. But i could by a new centrafugal blower, sealed unit, own oil supply, the size of an alternator but not as much boost low down, then again that can be a bonus in a FWD car.
Waddya reckon?
 
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Discussion Starter #10
I supose that this is an aftermarket supercharger. Where did you get it from, and what do you estimate the cost will be after every thing is working?

What HP/Torque will you be getting?

Nicholas
 
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Discussion Starter #11
The centrafugal blowers cost around £1100 , the map sensor and injector plus a second hand intercooler will add maybe £300. Then need to make a bracket to hold the charger and a new alternator belt, longer one to drive it. It will add 40% power and torque to what ever you engine puts out as standard. Loads of companies in the US sell blowers, the one im looking at comes from www.gmcmotorsport.co.uk
 
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Discussion Starter #12
Hmmm,

looks intresting, pretty good increase in power and not too expensive. i have the 2.0 8V engine.

Since i am a complete idiot when it comes to mechanics, do you think this is simple enough that a alfa mechanic can install everything?

I am only looking for mabe 50HP more, so i could use a smaller supercharger.

Thanks for the help

N
 
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Discussion Starter #13
You would proberly need someone who knew a bit about engines since your goung to need to set the air/fuel rates up on a rolling road, but it should be very simple. Extra fuel from a an injector would be controlled by the MAP sensor (mass air pressure i think), so this needs to be connected to the inlet manifold.
You would need a new valve in the pipe that goes to the brake servo, the brake servo uses vacumm from the inlet manifold, if the manifold gets pressurised by the blower you need a one way valve in the servo pipe to stop this, there fitted to all turbocharged cars
 
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Discussion Starter #14
Nicholas, if you are serious about raising the power of your engine you need to read up on Turbos and Blowers, there are a few books that are good. Forced Induction Performance Tuning by A. Graham Bell is very good.

Also look at this http://www.superchargersonline.com/
 
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Discussion Starter #18
Thanks all, but there is NO rolling road in this shitty country..so there goes that idea out of my mind.. buahhhhhhhhhh :( :mad:
 
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Discussion Starter #19
Dont give up that easily !!!, if you want more speed out of your car, this is the most cost effective and simplist way. The rolling road would make the job quicker, but if you raised the booster presure slowly, changing the pulley rates, using bleed valves you could gradually find the level at which the engine starts to ping, then back off the boost. Using a cetrafugal blower which is essentialy a gear drive turbo, with out all the hassle the turbo gives, you could add 40% power, change the compression ratio and you could double the power !!!
 
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