Dyno Question., Short ram or cold air?

[DatSRBoi]

Going to be dyno'ing soon and I got a quick question. Is it better to dyno with a ram intake or a cold air extension. Ive always been told cold air intakes draws cold air from outside. But at a dyno your hood is up, so basicly its drawing cold air too. Also People says ram air are good for top end. And on the dyno you go all the way up right? So would a ram air be a good choice of set up or cold air?


My moment of truth this saturday to see if hard work paid off.. Hoping to hit 200Whp If Not Im going to cry.

[trdkamuri51o]

your manual i would think u would hit 200whp...

maybe not..

how bout cp-e intakes... 14whp on their maps... get a tunable one..

[Nyyankees3511]

Im thinking that you would get better numbers with a cai, because the car will be running at highspeeds while the car itself is sitting in the same place causes a lot of hot air in the engine bay. So if you had a sri youd be sucking a lot of hot air which will give you lower numbers.

[DrakkkarDarkbladE]

SRIs(short air intake) tend to give you more HP and CAIs(cold air intake) tend to give you more torque. This is due to the properties of sound waves and wave dynamics.

Basically sound always travels at the same speed so if you increase the frequency the wavelength decreases. Basically high frequencies give you shorter wavelengths and vice-versa.

The CAI is better for torque because it has longer piping; therefore it supports longer wavelengths at lower frequencies, or torque and low-end.

On the other side the SRI supports shorter wavelengths at higher frequencies, or HP and high-end.

The same theory can be applied to headers. If the piping for each individual cylinder is long then it is better for torque and if it is shorter it is better for HP. So in this case if you have a 4 cylinder car 4 to 1 headers are better for torque and 4 to 2 to 1 headers are better for HP.

So basically if you are going for HP then you should go with the SRI.

[lilmike2069]

Drakkk... that doesnt make any mother flippin since... air does not oscillate in AND out of an intake piping. And it doesnt oscillate up and down WITHIN the piping... therefore you can't have a wavelength or any of that other bullshit you talking. Where the hell you comming p with this s#it???

[StockSolara]

Guys he is talking about dynoing with either the CAI or SRI NOT which is better for daily driving. . . Dat I think the CAI will be better because since you do have the hood up but the heat from the engine will still be colliding with the cold air. . . Plus if you have the CAI w/ the fogs removed that big fan they use will blow direct cold air to your intake to suck in so I say CAI but maybe you can ask them to let you dyno with both. . . This is just my theory so the only way to know is test it out

[DrakkkarDarkbladE]

Last I checked sound was a longitudinal wave. Basically it is the expansion and contractions of air particles. This is exactly what the engine is doing. The engine compresses the air and the combustion expands it. So every time that happens you get a sound wave.

[wiz2]

Its not really going to matter which you have on a dyno. Your hood is open and your car is standing still.
Unless you close your hood and had a fan blow over the front of your car to try and simulate real world conditions its not gonig to matter IMHO.

I would make sure you reset your ECU prior to a dyno run. My first run was 207, 2nd run reset ecu 217, 3rd run had fan blowing over front of car I hit 237.5. A 30 hp swing, but the torque only had a 15 ftlb swing. It was nearly 90 degrees inside the building when we dyno'd so I feel temp was a factor since teh ambient air temp was so high. I think EricSol hit 242 hp with the same mods,so its in the ball park.

Remember its just a tool for bench marking. Get your baseline and build from there !

[DatSRBoi]

I guess I forgot to tell my specs and how its setup on the dyno.

First yes Im going for numbers. Im not much of a hard core racer. This is just strictly how much Hp I can cram out on the dyno with what I have. Real life my car is fine the way it is. So Im guessing this is more of a show purposes and not a daily tuning checkup (That will be later once I get all the other parts in if someone ever finds me a 5 psi pulley for chea )

Now reason Im asking for either CAI or SRI is because the car will be on the dyno with the hood up and a fan up on the engine bay... meanin free nice cool air blowing against it. So either way SRI and CAI will be sucking in cool air because theres cool air present in both case. I was just wondering what will cam out more numbers. I only get 2 pulls and I would try both mods but its a dyno day and there will be allot of cars.. I dont want to waste peoples time and spend 10 minutes installling and taking off the extension and moving the filter back and forth.. Just very time consuming.

[dominoSLEV6]

For those saying the hot air would build up you have your hood open on a dyno as such...


My car on the dyno around 5k RPM. Camera phone picture, sorry about size.

If it's a semi warm temperature you'll have fans on it. They asked me if I wanted fans on my car since it was a cool night anyhow, I told them not to bother with it. With all that air around there and the fact that heat rises, the short ram will be sucking in air from around the car, not really the hot air from the engine bay, and because it takes a more direct route into the manifold, I would suggest that a short ram intake is overall better on a dyno.

-chris

[DatSRBoi]

Cool thanks. I just wasted my intake today and danggg it was dirty. Its back on SRI setup right now. Car seems to run happy since its cold down here right now still. Lost of low end but not allot.. But high end sure does cranks up.

[Mole]

alright... who here has actually GONE, DONE and WITNESS a dyno ?

imho

sri/cai = the same thing... same amt of air flow, same temprature / ambience of air.

when a car is on the dyno and the fan is blowing, it can only simulate a maximum of 10mph. engine heat can not be as efficently dispersed as if the car was moving in speeds of 70+ mph. hence short ram/cai doesn't do much since the pipes conduct/retains heat.

if you're looking to get the highest numbers possible, put the stock air box on, make sure your tire pressure is set and if you have lighter wheels, smaller series tires you will get a higher numberic value as opposed to not having those.

this is from my experience.

[Grazi07]

^ word.

Even if you have a CAI, whatever wind the fan will create will be diffused over the bumper... Dat might be in better shape due to the removal of his foglight, but the difference will be minimal.

I had my automatic done with my CAI and Evo II and got 153/162...

[wiz2]

If you just want the highest number. Tweak the air pressure upe,reset ECU, take off the cone air filter,ice pack sitting on top of the charger,change your oil the day before.

I'm not going to say you may not throw a code though. But those are a few dyno cheat tricks for Eaton type blowers.

Pics of my dyno biotch about 3 yrs ago...man time flies.