330hp_91RS

Ok....I just bought a new car, an LT4 95' Trans AM. The car puts out 387 hp to the wheels. I am not going to do much to it besides maintain it, but probably a few easy light mods here and there.

The throttle body is a 58mm BBK. I here that air foils will give a stock LT1 about 3-4 hp.
Is this true?

I figure that I am pulling alot more air than a stock car would and already making alot more horsepower so the benefits would be greater.

Any thoughts? I mean if I can get 5 hp for 50 buck and 20 mins of work....that's pretty good.

UmmaGumma

I don't know exactly how much hp you'll gain, if there really is any. I installed one in my '91 Z28 with the 350 TPI. I notice it pulls a little bit harder, not much though.

Some say it does nothing.. others say it's the best thing for the $$..

MrDude_1

i say it does nothing. money is usually spent better elsewhere.

athough if you're putting 387RWHP, you probly have most things done already......

jfreeman74

Hold on. If you have a BBK 58mm TB then you don't need an airfoil at all. All the BBK TB's that I have seen have an airfoil kind of built into it. The seperater is already thinned down and grinded to a point. Don't waste your money on something you already have.

anticop

jfreeman74, I noticed you've got a 5liter motor. So do I. Here's my mods(almost finished with the build): LT1 cam, '88 aluminum 'vette heads, ported base, ported plunum, air-foil, T/B coolant by-pass, AFPR, headers and true dual exhaust(2.5"), CAI, 2400 converter, Trans-Go kit, 3.42 gear........I think that's it. Haven't had it to the track yet, but did dyno it with just the duals(no headers), air-foil, CAI, and T/B by-pass. 211hp @ the wheels, and 273lbs.ft. Of torque. Curious to see what you think.....and anyone else, for that matter.
-Hammer-

jfreeman74

I sent you a PM.

330hp_91RS

Can anyone else confirm that it's probably worthless to get an airfoil???? The BBK throttle bodies are good as it gets????

As far as money well spent elsewhere......you are right. There is really nothing else to do. It's kind of annoying actually. I almost was satisfied with just tightening my header bolts today. After that I swapped the intake, carb and dist. on my 84' so I can sell it smog legal.

I really don't want to mess with the car that much, just a few things that will make me feel like I contributed to the beast...you guys get me???

Other things I want to do are simple, like getting a high perf. ign. coil, it's sporting a stocker.

mastrdrver

I wouldnt worry about it, its not worth the money IMO. I have had 2 SSs and only 1 has had the air foil. I think you can put that money to better use. Go to Z28.com and run a search there, your not the only one to ask about that over priced piece of crap.

Off-topic what is done to that car?

Guest

As said, there is already a built in airfoil. You couldnt put one on if you wanted.. unless you bought that Jet POS.

Mark_ZZ3

On a stock TB, the air foils are worth 10-20 cfm depending on your TB and size. I had my TB flow benched stock, stock with air foil, with 52mm blades, and lastly with airfoil and 52mm. In both cases the airfoil offered more airflow than without.

Many aftermarket TB already have a smooth entry point, thus you would not need an airfoil.

Pull off you air cleaner hose and check it out.

Mark.

330hp_91RS

Let's just do the motor, okay. Otherwise I'll be here all day.

LT1 bottom end- stock
Morgan Motorsports Aggressor series LT4 heads and intake ( ported and matched)
Custom grind Comp Cam
BBK 58mm TB
Accel DFI
Comp Cams 1.6 full roller rockers
JBA 1 5/8 headers, hollow cat, Borla Adj. system
K&N filtercharger system
Staright pipe in place of MAF ( no need for it with the DFI)


I think that is about it. Results: 386.7 hp @ 6350 rpm and 361 lb ft @ 4400 ( I think, can't remeber the exact rpm for the lb ft, but it's right around there)

I am not sure if the injectors are stock, I know the ign. coil is stock so I am excited to change it, at least I get to do something. There are many other details but I have to talk to Morgan Motorsports to get the details.

bigals87z28

sounds like it pulls like a beast... chances are that the TB has a airfoil already milled into the housing of it. Its a good idea i guess for someone who just wants to start. Its a basic thing. Im 99.9% sure you wont need one due to the aftermarket tb.
I was just gunna ask if the stock LT1 cam was in there... but then i did a double check (work was long today). Do you still have the RS or did you get rid of it?

formul8!!

I noticed a bit crisper throttle response in my '89 Formula 350 and my old '96 Z28.

Try ebay for one. A friend picked up one for $25. For that price, you can't go wrong. Every little piece helps.

89blackGTA

I agree with everyone else.....the BBK should already have one. Yours should look something like this:


I dont think I have seen an aftermarket TB that doesnt have one built in.

Brian

vwdave

HorsePower TV did one of those on a stock LT1 Impala, 0hp gain.

89blackGTA

But they did the test inside without the airflowing while driving. 0hp is 0hp but somethings really do need the flowing air.

Brian

vwdave

I dont think that really matters. They baselined it the same as the tested after, and it came back as 0hp increase.

Thats just what I seen.

Dr G

89blackGTA
See these two in that case:-
LPE/Accel L98 LPE 52mm Throttle Body (Pic below)
http://www.lingenfelter.com/lingenfe...=16&pf%5Fid=49

LPE/Accel 58mm High Flow Billet Throttle Body LT1, L98
http://www.lingenfelter.com/lingenfe...=16&pf%5Fid=50

Dr G

Pic of LPE/Accel 58mm High Flow Billet Throttle Body for L98:-

D Stroy H8

I would like to point out to you that you have overlooked a whole catagory of modification - WEIGHT LOSS. With most everything else out of the way, you can take a serious long look at what kind of extra baggage can be stripped - 150lbs makes a huge difference. Imagine if you can manage 200lbs!

bigals87z28

and its free!!

vwdave

The driver can also lose weight.

330hp_91RS

I'm gaining weight ( Football player) but I'm a defensive back so I don't think I'm the problem, I weigh 195.

I am NOT going to shed weight off this car. This is a daily driver, and it's comfortable, and it's staying that way all the way down to the 10 inch stealthbox.

CrazyHawaiian

Sounds like a fun ride!! My BBK TB looks exactly like the one in the pic 89blackGTA posted. I dont know if they even make an airfoil for the BBK piece, but I do know the airfoil for the stock twin 48mm TB wont fit (of course). Maybe contact BBK and ask them? As for performance, it might not make a difference but I say it all depends on the situation. I've heard airfoils increase flow through the throttlebody by around 12 cfm or so on the stock twin 48mm TB that comes on TPI motors. Since the BBK piece is bigger, the gains might be higher if there is an airfoil avalable. So the questions would be, will the LT4 intake even use the extra cfm (maybe the BBK TB is already flowing more than the intake can make use of), and will the EFI system be able to provide a little more fuel (DFI should be able to). If the answers are yes, then I say find one and do it. Like you said, for $20 and 20 mins its no biggie.

D M N

hey i got a question ok air foil smooths out the air and makes horse power ok there is something called a tornado and that does the opposite and it increases horse power what is that all about thats funny though

bigals87z28

the tornado does the same thing and works on the same ideas of smoothing out the air flow and causing less turbulance... the idea works great, but.... some of that stuff on that infomercial... da CRAP! not worth it for some tin.