hi folks,

i have done the catback, and air injection on my 01, 5.4L.

i saw this ad in a four wheeler mag and think its for me.

anyone else tried it already? if so, what experience?

http://www.edelbrock.com/automotive_...e_bodies.shtml

thx...

 

bad link... is it the 70mm or 75mm throttle body swap?

 

i cut and paste it directly, i guess the forum munged it?

anway, its the 75mm, edelbrock p#3874.

any comment? thx, jackc...

 

With the mods you have so far, the throttle body isn't going to do anything. Try some electric fans or a new Ypipe for the exhaust. You will be much happier.

 

i dont understand. assuming the oem thyrottle body is a smaller diameter,
a larger diameter would provide more flow. no?

if if better flow through, why not more power?

less experienced minds wonder what they are missing, thx!

 

+1 - I installed one, and couldn't tell any difference. It could help more with more mods / flow or boosted.
The best new addition would be custom tuner. Read some of the threads in the Chips and Tuner forum.

 

With the mods I have, Top end is much better than with the stock throttle body... You will get more responce off the line too...

 

teh next question is, what mods do you have?

that is, in terms of this intake/output path...

as i mentioned earlier, i have some,
but wonder which you have done also?

do you know the oem throttle diameter?
i am trying to find that to guage the % increase...

thx for your reply!!

 

Not sure on the stock diameter, i know low 60's... I have Installed PI heads and stage I comp cams, along with long tube headers, and volant intake. Those are the only mods that I have that affect air flow...

 

Installing a larger throttle body will only help if the original TB is a restriction to start with. Otherwise, it's just a bigger opening that lets a greater volume of air into the engine at lower throttle positions, thereby making it *feel* like you're getting more power. You're not. It's just an illusion thanks to the larger volume of air surging into the engine for the same part-throttle condition.

 

first, i dont have a dyno to measure, but when i swapped the air intake
for the k&n, it provided more air flow in and the result was non-trivial.

now if i expand the TB diameter, i may not get the same huge boost,
but surely i will net some gain even without the headers, etc that
others have.

besides, all the new engines are running 75mm!

is my rationale still flawed?

 

Spend your money elsewhere, I think a tuner or E-fans would be a much better step at this point.

I don't think I will be purchasing a new throttle body as I don't think it will do much for me.

I put a larger one on my 5.0 mustang but only noticed a moderate improvement.

My .02 cents

 

i really do appreciate your time and i also think your actual
experiece is more valid than my expectations.

 

Cool,

You can get a tuner for not too much more than the TB, also E-fans made a nice difference to my 7700lb Expy.

Have fun.............

 

Your all not looking at airflow with the science in mind and just think bigger means more air; not so.
Understand that the displacement of the block minus the loses thru the heads and intake will only flow just so much air.
You can't get around this by just putting a larger throttle body in place.
The only time you may get an increase is at hi rpm where any restrictions begin to make themselve felt in the intake and exhaust tracts as flow losses.
You don't normally run around at 4 and 5000 rpm to get these small gains.
The truck people get confused between mods that show themselves at performance rpm's and those that give a gains at low rpm where the truck is used 99% of the time. You can't have both with these simple mods.
An intake filter system does little at normal operating speeds for most owners because you cannot get more air in the engine than the throttle opening will allow no matter how big the filter is or even taking it out.
Often removing/replaceing the stock exhaust results in less pulling power but may show a percieved improvment at high rpm again where you don't run 99% of the time.
The mods need to be for what you want from the truck.
All this may be a little hard to digest because it is alway talked about in a mixed up fashion, without reference.
People spend big dollars in intake system that don't get them what they thought they would get from them. There is no magic power or fuel mileage from these changes on trucks before about 04 or 05.
Unless you can detect power increases over 10 hp, it is a waist of money for anything but just to have it on the truck.
The moral of this is you cannot put 8 gallon of water in a 7 gallon pail unless the "base capacity" is enlarged.