Cold Air or Ram Air Intake - will this improve power?

[mic*]

nope where do i get one done and its got a yamaha head on it i believe.


thanks

Jai

Any mechanic. But...

If you are interested in getting to know your car/engine tho, i would thoroughly recommend getting a compression tester from your local supercheap / autobarn and doing it yourself. This will set you back about $30 depending on quality. One with a reasonable length of hose is good, as the short push in types are less precise, and unfeasable on some engines like a 3S variant for example.

For EFI cars simply remove your fuel pump relay, or the fuel pump connector with the engine running to depressurise the fuel system - the car will stall. For carbie i am pretty sure you just remove the fuel line to the carbie and let it run till it stalls. You do this so the engine doesnt start while preforming the test.

The test itself is then just a case of individually removing a spark plug, inserting the comp tester in its place, and observing the reading while an assistant cranks the starter. The reading will take a few cranks to reach max. This is you maximum cranking dynamic cylinder pressure.

It is most dependent on the overlap of your intake & exhaust valves, the static compression ratio, and how well the cylinder itself (head, rings, valve seats etc) is sealing.

Its a very basic test but the results can tell you a wealth of information that will mean more and more to you every time you learn something new.

[JAIFRESH]

thanks heaps

[SillyCarS]

i can vouch for the CAI, and if your car is really well tuned the difference is very noticable.

my first car was a 2 cylinder 600cc subaru sherpa, i used an old warehouse lightglobe shade, some washing machine house and a shitload of sellys all clear, and it worked. I went from a top speed of of 110km/h to 130km/h on the flat

A lot of the old school touring cars used what looks to me like a lathe funnel (the bit that sucks down the shavings) and if theyre using it, it has to be worth it

also, listen to oman, he's right, there are that many diff ways to set up an adjustable dohc motor. You wont notice the difference unless she's firing properly

craig

[Mos]

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Thank you
Mos.

[o_man_ra23]

One thing you forgot with the compression test mic* is that you need to have the assistant give it full throttle while cranking. A better way to stop it firing rather than run it dry (which will take a lot of battery to get it going in a carby motor like the 18RG) is to simply remove the ignition lead that goes from the coil to the dizzy cap. Dont be too alarmed at a low compression reading. Things you want to look for is how many cranks it takes to get it up to pressure, and if all the cylinders are even. If you get a low reading on one cylinder, pour about 5ml of oil down that cyl and test it again. If its still low, then you have a burnt valve (would make the car run REALLY shit), and if it goes high, your rings are worse in that cyl than the others.

Best bet is to buy a book on tuning carburetted cars. Try and get something with twincam twincarb engines in it.

Cheers, Owen