i am in the process of making a intake for my car 95 integra gsr...here is my question would a 3 inch intake in diameter perform better or would a 4 inch intake in diameter perform better. i been doing a bit of research here on h-t and alot of people say 3 inch is the best but i haven't seen anyone say anything about a 4 inch

 

i know this question is probably very noob but i would just like to know if you anyone here on h-t has tried a 4 inch piping for an intake.

 

I've got a 4 in k&n aircharger for a v8 grand cherokee and it works great but u gotta make sure u get a special coupling so the air goes into the throttle smoothly. PasswordJDM.com makes a mean 4in intake that goes to a 3in nexto the throttle

 

The PasswordJDM intake is known not to make power. Making an intake is easy but tube length and diameter have a really important effect on the size and shape of the torque curve. Changing intakes can have a huge effect on the performance of the car. Overwhelmingly the preferred intake among knowledgeable engine builders is the 3" 'ITR' AEM CAI, sometimes cut slightly to a tuned length. If 4" was better people would be using it. My guess is that for our size engines, 4" moves the powerband too high to be useful.

 

Really I never heard a bad thing bout the passwordjdm one good thing I didn't buy it
My k&n breathes nice tho. Got it off a jeep at my job.

I heard putting 3in pipe with a airfox n good filter is good for torque??

 

AIRBOX***

 

hmm ok i just wanted to see if it really was a difference but 3 inch it is.

 

i have noticed intakes like the k&n typhoon and injen use close to the same diam. as the tb. k&n especially. ive seen them on a v6 accord,mazda3,mazda6,eclipse v6, they all had the intake almost the same size as the tb

 

Yeah that's how the AEM CAI is, it uses a 2.5" tube and special K&N filter with 2.5" neck.

 

Bigger tube lower velocity, (plus you don't have that much room to play with) it's not about your tube size, you'll ending losing power or gain minimal. Identical intakes system acts or perform differently on any two vehicles. Size your tube according to engine and mods.

 

What kinda of car u working on? Tegs have tons of room to play. Guy at the track last week managed to fit a small cooler around his intake in a da u got plenty of room to play and if u don't u can make room

 

What kinda of car u working on? Tegs have tons of room to play. Guy at the track last week managed to fit a small cooler around his intake in a da u got plenty of room to play and if u don't u can make room

 

95 gsr (which my_gsr_teg has) is different from a DA, the way the intake manifold is designed on a B18C1 makes it sit lower than an IM from an B18A/B, B16,17,18C5. If you can get a 4" tube to fit more, power to you, post up a picture I for one would like to see it.

 

i tried playing around with the 4 inch tubing already....it is basically the same as the stock intake but just 4inches in diameter except it curves in more to bypass the ac pipes....hopefully by friday when i get my wielder i can make curves and take a good picture of it.

 

do not put a 4inch intake on ur dam teg. 3inch is known good to an itr. i dynoed a 3inch on my teg with some mods it did best. cai will outperform shortrams anyday. and prove the piping loses velocity then we can talk. i ran a 2.75 till i got cams

 

There is no reason to go larger then a 3in. I ran a 70mm with a 3in intake pipe and it was about the best combo I could run. Your not going to see gains if your TB is stock. Remember it's the smallest point, so I would focus on getting that larger before worrying about a 4in intake.

 

yeah i have done research upon the 3inch vs the 4inch right now i am still in the process of making my cai but right now i am keeping it stock with the intake box open. that is basically it for now.

 

"and prove the piping loses velocity then we can talk."

Think of a water hose with constant 14.7psi, increasing it from 1" to 2" causes a lost in velocity and decreasing the size from 1" to 1/2" increases the velocity but at the price of lower volume. Honda designed their intake system so that it supplies a sufficient amount of air/flow for proper combustion. That said, the diameter that honda used (for that particular stock vehicle) was probably the best size derived from their calculations. Atmospheric pressure is 14.7psi, Honda knowing that factor, didn't use a larger size (because of the sweet spot they calculated) because as I mention a "lost in velocity" when going with a larger diameter for the stock engine requirements. Now as you mod your engine and it requires more air,that sweet spot shifts upwards but again within a certain tolerance. Overkill will end up hurting your performance.