I am looking at getting a throttle body airfoil for my 94 Formula. I have narrowed it down to the TPIS, and the Holley. My question is which one of the two would ya'll recommend, and has anybody notice a difference in throttle response and power. Also, is there any problems after the airfoil has been installed like idle problems and PCV valve breathablility. I read a while back that one guy said that it would cause the PCV valve system not to operate as normal. Thanks, everybody please respond if you would.

 

no problems lots of people have em. they're good for 0.1hp if you're lucky. but better flow is good for the system overall bottom line.

 

save the cash

 

most in depth questions i've ever seen about an air foil...

 

airfoil will only starves your PCV system of air and give you little to no noticable gains in power... put the money towards somethin else.

 

get one they are cheap, but say away from the holley i think i heard you had to grind it to fit the tb blades so it wouldn't block the holes

 

if you are planning on getting a different throttle body in the future i wouldnt get an airfoil now , cause most aftermarket throttle bodies already have them built in, but if you arent planning on getting one , then oreder the airfoil. as far as which one, i got the tpis. no complaints here

 

Can't verify performance gains, but I discovered that whoever owned my car before I did had bought one (found it when I did the TB bypass). It was the Holley airfoil and it didn't block the blades. However, I wouldn't spend $50 on one, it could go towards much better mods.

 

actually, if you ask me, id probably get it, couple of years ago i had an 85 corvette l98 TPI, i think they are the same part if im not mistaken, anyways i put it in and honestly i felt immediate resaults, off the line mostly, but then i sold the car because it never ran right, i had a problem with my mass air that no one can fix, even after replacing it, but i dont think the airfoil had anything to do with that......i think im gonna get one, plus i also read somewhere that its good for at least 5-10 hp.

 

That 5-10hp is like saying a K&N filter gives you 15hp. A lot of people say you get 0hp from it but some have seen as much as 2 or 3hp. So why not get one, if you have a chance at getting 3rwhp for $30 then do it. Notice I said $30, buy one used otherwise its not worth it in my opinion.

The throttle body airfoil was flow tested and gave approximately a 40cfm increase. Therefore, its benefit will be more noticeable(or existant) on a modded motor in the same way the benefit of a 52mm throttle body is more noticeable on a modded motor and worth almost nothing on a stock motor. So if a larger throttle body adds horsepower buy increasing airflow and a catback and headers do the same, it makes sense that a airfoil would too, just on a smaller scale; NOT a ZERO scale.

 

That 5-10hp is like saying a K&N filter gives you 15hp

but it does.

since we had free access to a dyno....
On a friends 91 Z28 (350 TPI) we dynoed 2 baseline runs and then started modding things. First thing we did was the K& N filters.
got us 8 HP &18 torque. we dynoed it 2 times, i still didnt believe it, so on the dyno we swapped back to the paper and got the baseline #s again.
a 350Cu motor at 4500 RPMs needs 72 cu in. of filter media. with the paper ones its far less than that. the pleated cotton ones give it that extra surface area.

And we actually tried a holley and BBK 52 and 58 mm throttle bodies and the airfoil. got 2 hp from the airfoil and lost power from all of the rest, but thats probibly because we didnt port match the intake to them.

 

i made my own. i went to autozone and got two tubes of liquid steel and molded my own smooth custom one. then i just took a dremel tool and smoothed it out and drilled a hold for the IAC and i was done. it was about an hour of work and $12 or so in parts.

 

there ya go, custom airfoil =P

 

That is good info. You do not have to portmatch the intake for the 52mm throttle body, but you do for the 58....
You got a PM by the way.

 

First off, I would never recommend anyone going to a 58mm throttle body, 52 at the most. But as far as the air foil is concerned, I think that the only way to show you what the benefits are is with a dyno graph. So here you go.

http://ws6.com/mod-4.htm

can't argue with that.