are tpi airfoils anygood or are they garbage?
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From: Toronto,Ontario
Car: 1989 IROC-Z
Engine: 346 LS6
Transmission: T56
Axle/Gears: Hybrid 8.8 3.73
are tpi airfoils anygood or are they garbage?
hello
I was wondering if airfoils for stock throttle bodies actually work or if they are useless/a restriction.
thanks
Speed
I was wondering if airfoils for stock throttle bodies actually work or if they are useless/a restriction.
thanks
Speed
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From: Michigan
Car: 1987 Trans Am
Engine: 5.0L TPI
Transmission: 700R4
Axle/Gears: Richmond 3.73
I got one on my car, And if you were to look at the throttle body itself....it looks like it needs that air foil to flow a little better. Your nor going to see anything just driving around town. Its made for Wide Open Throttle....when the airs rerally forcing into the throttle body. I'm sure it has to work. LOL....Like I said I have one!
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From: Hamilton
Car: 1990 IROCZ Camaro
Engine: 350 4bbl, 200cc Heads, 270hr Cam
Transmission: 700R4 w/ Trans-Go shift kit.
Axle/Gears: GM 10 bolt Posi
Originally Posted by GuitarJunki17
Essentially, the air foil just increases airflow by about 30cfm. By plugging this 30cfm gain into desktop dyno on multiple 350 smallblock setups, I found a gain of 1hp in random spots along the RPM band. Definately not worth the 60$ for the big companie's foils, and not even worth the 20$ you could get the same foil for on ebay. Just take that 60$ and put it towards a set of SLP runners, or even fill up your tank 2 times.
Originally Posted by GuitarJunki17
Actually, let me try and put it on a 350 with an HSR intake...brb folks...
Yes, the gains even with an HSR are the same.
Although there is this, and it's the only reason I could see it working on an HSR.
When the air comes into a TPI throttle body with an air foil, yes, it smoothes out the air, but then that air has to make a complete 90* left or right turn into a runner, which is then wrapped around and under the plenum to the head. Thats a long distance to travel, 25.25" to be exact, and with all the restrictions inside the TPI, that air will not be smooth for long.
Now, with something like an HSR, that air is smoothed out from the throttle body, and shortly after is sent directly downward and JAMMED into the head. The air has less of a distance to travel, 12.26", which is essentially half the distance that the air in the TPI intake travels, and travels less direction, so in theory it has less time to become unstable again. This is the only application where I can see the air foil working.
Yes, the gains even with an HSR are the same.
Although there is this, and it's the only reason I could see it working on an HSR.
When the air comes into a TPI throttle body with an air foil, yes, it smoothes out the air, but then that air has to make a complete 90* left or right turn into a runner, which is then wrapped around and under the plenum to the head. Thats a long distance to travel, 25.25" to be exact, and with all the restrictions inside the TPI, that air will not be smooth for long.
Now, with something like an HSR, that air is smoothed out from the throttle body, and shortly after is sent directly downward and JAMMED into the head. The air has less of a distance to travel, 12.26", which is essentially half the distance that the air in the TPI intake travels, and travels less direction, so in theory it has less time to become unstable again. This is the only application where I can see the air foil working.
Something l ike this is discussed often, try searching
I got one before the car came off the road for the winter and it literally made my CAI sound like a supercharger. Even sittin in the car driving around, I could hear my CAI sucking air harder. So I would say that yes, they do help.
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From: VA
Car: Z28 / GT
Engine: TPI 5.0 / 3V 4.6
Transmission: A4 / M5
Axle/Gears: 3:23 / 4:30
Yeah Guitar you're right about the airfoils, I got mine at a custom speed shop for $30 , but I had to get one eventually because the original one was all cracked up and old.
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Think about it for a minute. An airfoil on the T/B is a waste. Once the air goes in, then it has to flow into the runners. Now, if there were 4 airfoils between each runner entry, then I might believe that the airfoil works. Getting the air in through the T/B is only half the battle, IMO.
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From: Hamilton
Car: 1990 IROCZ Camaro
Engine: 350 4bbl, 200cc Heads, 270hr Cam
Transmission: 700R4 w/ Trans-Go shift kit.
Axle/Gears: GM 10 bolt Posi
Originally Posted by brutalform
Think about it for a minute. An airfoil on the T/B is a waste. Once the air goes in, then it has to flow into the runners. Now, if there were 4 airfoils between each runner entry, then I might believe that the airfoil works. Getting the air in through the T/B is only half the battle, IMO.
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From: southern maryland
Car: 2012 Ram express
Engine: 5.7 hemi
Transmission: auto
Axle/Gears: 3.55
Originally Posted by 87tpi
Mine was on it when I bought it, otherwise I wouldn't have spent the $ for one.
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From: USA
It is not about straightening the air for the rest of the intake tract,, it's about keeping the air from stacking up and becoming turbulent at the hollowed out center section of the T/B. Whether they help or not will depend on whether or not you're making enough power to "stack" enough air that it becomes an air-flow restriction at the T/B. If you're not,,, you won't see anything. If you are, they will help. Adding one to a totally stock 305,, is a waste. However, I've seen as much as a .2 drop on a 14.2 TPI 350 by adding one after K&Ns and the air box and MAF sensor were gutted. If you put the T/B air-foil in first, you wouldn't see a .2 drop, you'd just gain more ET from doing the K&Ns, air-box, and MAF sensor later, but the end results of all the mods would be the same regardless. $30 is not a lot of cash,,, but if you have some Manley epoxy laying around, you can fill in the center section,, making your own and save a few bucks.
EDIT: - just be sure to put a peice of tubing to feed the IAC opening if you fill in the openings - also drill some some small anchoring holes in the center section to hold the epoxy to the smooth center. AND,,, I wouldn't run nitrous before the throttel body opening (spraying on the epoxy) with a homemade airfoil.
EDIT: - just be sure to put a peice of tubing to feed the IAC opening if you fill in the openings - also drill some some small anchoring holes in the center section to hold the epoxy to the smooth center. AND,,, I wouldn't run nitrous before the throttel body opening (spraying on the epoxy) with a homemade airfoil.
Last edited by BadSS; Jun 24, 2006 at 01:17 PM.
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From: Carson, CA
Car: '88 GTA, 90 Formula
Engine: 5.7 TPI, fed growth hormones
Transmission: 700r4 4u2?
Axle/Gears: 9bolt
Lots of opinions without any facts
I didn't think they'd do much, but you need to TEST your opinion, or it is worthless. I've seen the round-looking ones give about 1 hp2-3 lbs/ft on the dyno. However, I have seen the Holley version supply over 5 HP on a build motor on a CHASSIS dyno. I agree with BadSS's post, but add that the results you get depend on which airfoil you use and how much air your particular combo is trying to pull past the throttle plates. The way the airfoils work is to eliminate turbulence or "air tumbling" coming into the throttle bodies. Smooth airflow allows more air to go through the same size openings. If your engine can't use the extra air, it makes no more power than before.
'88 350 (GTA)
Slp cold-air box, Plenum entry ported, coolany bypass (this was all dyno'd before installation of the Holley Air foil)
car otherwise TOTALLY Stock
W/0 Holley Air Foil 188.75 HP 244.71 lbs/ft
with Holley Air Foil 189.13 HP 253.60 lbs/ft
Pay careful attention to torque, it is what accellerates the car. Something is happening there.
Good luck
Troy
'88 350 (GTA)
Slp cold-air box, Plenum entry ported, coolany bypass (this was all dyno'd before installation of the Holley Air foil)
car otherwise TOTALLY Stock
W/0 Holley Air Foil 188.75 HP 244.71 lbs/ft
with Holley Air Foil 189.13 HP 253.60 lbs/ft
Pay careful attention to torque, it is what accellerates the car. Something is happening there.
Good luck
Troy
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From: Memphis, Tn
Car: 92' RS
Engine: 357
Transmission: TH350
Axle/Gears: 4.10
This is how i have always seen it.
If you make enough power and flow enough air to need a larger TB then you might be able to make use of an air foil. But most aftermarket TB's are premade with an airfoil built in.
If you make enough power and flow enough air to need a larger TB then you might be able to make use of an air foil. But most aftermarket TB's are premade with an airfoil built in.
Joined: Jul 1999
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From: Orange, SoCal
Car: 1990 Pontiac Trans Am
Engine: 355 TPI siamesed runners
Transmission: Tremec T56
Axle/Gears: 12-Bolt 3.73
I agree with 91GTABird. Dont buy one for your stock 48mm throttle body. Buy a 52mm throttle body with one already built in.
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