FAQ- Cold air/short ram intakes

Quote:

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Originally Posted by Nepolian

As far as I know, as a rule of thumb, you generally keep it the same size as your t/B.

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Actually, the intake piping should have 25% larger cross-sectional area than the throttle body, which is ~70mm for a stock VTiR throttle body

Quote:

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Originally Posted by ZeForce

Actually, the intake piping should have 25% larger cross-sectional area than the throttle body, which is ~70mm for a stock VTiR throttle body

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are u sure its cross-sectional area and not just diameter?

if u have a 70mm diameter t/b u need to have a diameter 25% bigger ?

a 25% bigger diameter would mean a 90mm pipe

or do u mean

u take a cross-section of the pipe then work out the area of the cross section (area of a circle), then work out 25% bigger ?

so the area of a 70mm diameter circle is 38.5cm2

so 25% bigger is 48cms2

an 80mm diameter pipe has a cross-sectional aream of 50cms2.

so if u do mean cross-sectional, whats the point u r only going 1cm bigger in diameter?

70mm is just shy of 3" so y not just go 3.5 or 4" pipe?

or is it like most other things, too much is bad, too little is bad. u have to get it spot on?

Quote:

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Originally Posted by ZeForce

Actually, the intake piping should have 25% larger cross-sectional area than the throttle body, which is ~70mm for a stock VTiR throttle body

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Remember that the actual butterfly is usually 10% smaller, in most cases. It is a simple rule of thumb. Not all people want to spend their time to work out the E=MC2 when installing an SRI. Its ment to be a quick and cheap effective mod for a mostly stock car.

No way I am knocking about what you said, just trying to give people easy answers.

Cheers

Quote:

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Originally Posted by Simmo2302

are u sure its cross-sectional area and not just diameter?

if u have a 70mm diameter t/b u need to have a diameter 25% bigger ?

a 25% bigger diameter would mean a 90mm pipe

or do u mean

u take a cross-section of the pipe then work out the area of the cross section (area of a circle), then work out 25% bigger ?

so the area of a 70mm diameter circle is 38.5cm2

so 25% bigger is 48cms2

an 80mm diameter pipe has a cross-sectional aream of 50cms2.

so if u do mean cross-sectional, whats the point u r only going 1cm bigger in diameter?

70mm is just shy of 3" so y not just go 3.5 or 4" pipe?

or is it like most other things, too much is bad, too little is bad. u have to get it spot on?

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The second way is correct.... Its like with most things, the biggest isnt always the best. Too big and you sacrifice intake velocity, too small and you restrict the overall flow

Quote:

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Originally Posted by Nepolian

Remember that the actual butterfly is usually 10% smaller, in most cases.

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I was refering to the cross-sectional area of the butterfly

Quote:

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Originally Posted by Nepolian

It is a simple rule of thumb. Not all people want to spend their time to work out the E=MC2 when installing an SRI. Its ment to be a quick and cheap effective mod for a mostly stock car.

No way I am knocking about what you said, just trying to give people easy answers.

Cheers

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I do agree with you, the intake is one of the most basic mods which will only give small gains and yet there are hundreds of threads on this forum about which intake is the best or people dissappointed coz they spent $500+ on an intake setup and didnt get the massive gains they were expecting. At the end of the day if u do want to design an effective intake, then it is important to have correct sizings. Intake piping, throttle body, plenum volume, runner size and lengths all need to be in proportion to each other. Optimising the size and length of the intake piping may not give u huge power gains but they can have a big impact on throttle response or the RPM at which the peak torque occurs.

pi = approximately 3.142

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Originally Posted by Jarkz

I'm not going to debate who is right or who wrong but I did a little multimeter heat testing when I performed my intake mods and the got the lower heat reading on alloy than the metal on my car?

How come most "big brand name" Greedy,Apexi, hks etc use alloy or titanium on there Intake tubes and intercooler piping then.

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What i think that you will find is that they use Alloy/Titanium and Carbon Fiber
more for weight reasons and not for the heat dispersal.

Reason for this is that most high RPM/ high power engines that use these types of intakes are the kind that have other air flow/ cooling methods.

For example cold air ducts etc.

Hey, i recently bought a 5th Gen SI and am really wantin to get some more power out of it... i was on ebay the other day when i saw a TYPE S for sale in Mel, not sure if anyine saw this but it was 17900. Wen i found out i couldnt get another loan to pay mine out and buy that one i came to the conclusion that i should just keep mine for a while... anyways, i was reading a hot4s(no. 158) mag last nite and in the flat chat section said that u cant do much to a honda engine to make it faster (let alone keep the same power rating)......
Any help would be fantastic! thinking about a CAI but then i saw the Short Ram setups above... also preferred exhausts???

hey guys,
sorry about jumping the topic here, i was just wondering about the mugen airbox. is it better off getting a cold air intake for DC5 type S or just leave it stock BUT with mugen airbox....

the tight ass who last ownd my car simply pulled open the box and now a pod rests there.. its just dangles about and looks really embarrassing where is the ram pod setup available from. and also what mods need to be done to be able to fit cai??

So, I was reading up on these intakes and such, because, well i'm in the market for one...

Hmmm, short ram, for quick, noticable change, or cai for the mid to upper rpm band?

Here's my question, could it, by chance be possible to take the two, and, pretty much Y them into one???

that way you have could air coming in, but, you also don't have to wait to hit the higher rpms to feel it...

IDK, if anybody has any ideas, or if you could see something wrong with it, hit me up. lemme know what ya think...

Quote:

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Originally Posted by Fletche

So, I was reading up on these intakes and such, because, well i'm in the market for one...

Hmmm, short ram, for quick, noticable change, or cai for the mid to upper rpm band?

Here's my question, could it, by chance be possible to take the two, and, pretty much Y them into one???

that way you have could air coming in, but, you also don't have to wait to hit the higher rpms to feel it...

IDK, if anybody has any ideas, or if you could see something wrong with it, hit me up. lemme know what ya think...

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If you can enclose the short ram pod in a box and supply that box with cold air, then you have yourself an SRI/CAI hybrid which you are after.

hey has any1 here ever order anyfin from the web site www.nengun.com