Fox TB Conversion Observation

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
I just saw the below pic and was absolutely blown away.

This is the first time I have seen the fox conversion in a way that clearly shows the path air has to flow in order to get to the intake. :eek:

I run the regular SN95 elbow setup on my car. I got a single, straight pipe connecting my ProM 80/filter in the fender to the elbow.

No bends other than the one 45 at the elbow.

No way in hell the fox conversion is less restrictive with the TWO 90 degree bends than what I'm using now. :nono:

I know this has been talked about before but this pic ..................

To me ... the pic tells the whole complete story here.

Thoughts or comments ............. Anyone :D

Grady

foxtbconv.jpg
 
I've thought about that every since I first heard about people swapping to Fox TB setups ..... but I never said anything because I figured there's got to be a benefit somewhere. You think there is?

I know throttle response is one biggie that they point out ... but is it THAT different?
 
that's very interesting grady, i've never really thought about it before. I'd always taken other peoples word for it, but by the looks of that CAI the FOX TB style looks far more restrictive. I wonder why people say they feel more throttle response when they switch to the Fox Style. Weird.
 
Well

I guess I should have made it known my main concern is from a performance perspective.

I really don't care how it looks but that is just me.

I do wanna make it clear I don't think the conversion is the wrong thing to do or anything like that
BUT
I have to think there is a reason you've not been able to see accurate, fair, documented data showing the conversion is a proven mod for a performance gain.

As for the better throttle response thing.

It was pointed out when lots of peeps first jumped on the conversion band wagon, the throttle opening rate of the older fox was not the same as the more gradual opening rate of the SN95 setup.

To me, at that time, it just seemed like nobody acknowledged that fact.

As for the air flow resistance

The air has to pass two 90 degree bends. Bends in a pipe are a restriction to air flow. The more of them ... the more restriction
AND
The degree of the bend matters as well. A 45 degree bend will offer less restriction to air flow than a 90.

My best friend is an engineer and deals with air flow in his job. We've talked about the fox conversion several times. He always shakes his head and says

"Less total bends and smaller angle or degree of bend is how you cut down on restrictions when talking about passing air through pipe"

Anyway ...... Just a few more thoughts as I see it.

Grady
 
I think that the whole throttle responce thing is from the way the cable connects to the bracket and pulls the tb plate open. I did it this mod and it feels snappy but I can feel the difference on the tb opening when I give it gas. I think that the only two reasons anyone should consider doing this mod is 1.to make a little more room and 2.make it look "prettier" underneath the hood.
Also, the whole airflow disccusion seems weird to me since I don't see the fox setup chocking any hp up. Maybe .00000000017 hp. I'm not bashing on you Grady. Just mho. :D
 
pleasehelp said:
I think that the whole throttle responce thing is from the way the cable connects to the bracket and pulls the tb plate open. I did it this mod and it feels snappy but I can feel the difference on the tb opening when I give it gas. I think that the only two reasons anyone should consider doing this mod is 1.to make a little more room and 2.make it look "prettier" underneath the hood.
Also, the whole airflow disccusion seems weird to me since I don't see the fox setup chocking any hp up. Maybe .00000000017 hp. I'm not bashing on you Grady. Just mho. :D

I don't see your reply as being negative in any kind of way. :nono:

I'm glad you gave your opinion. :banana:

I was hoping for some discussion even though the topic has been talked about a good bit. :D

I can offer a bit more info on the air flow restriction part of the discussion.

When I first got my maf & tb, I had the maf/filter setup on kind of a temporary install. It was like it now is but, at the fender hole, I had a 90 degree bend with the maf/filter sitting down low by the frame rail.

After putting the maf/filter in the corner of the fender right behind the head light, which eliminated the 90 and allowed a straight shot to the elbow, I showed an increase of air flow in my data logs.

Grady
 
Grady, I understand that this post was to be performance oriented and I agree with you on the restriction. But that goes for most of these new intakes and intake tracts to me, they just don't look like the most efficent design that someone could come up with but because the car companies and aftermarket companies have to deal with hood room, emmissions, noise and such you lose out on what would probably be much better designs.

So I just wanted to point out that although I agree with you, I simply stated my reason for going to a Fox TB conversions was cosmetic and not done for performance reasons.
 
Anytime air velocity is rerouted it slows the flow rate down. In that picture it clearly shows there is no way it would out flow a straight shot made out of the same material. A bend in front of a meter is also a No-No. It would make more power with the air filter bolted to the meter and that 45 degree peice gone. Not Earth shattering numbers per say but since we are thinking out loud.

A few years ago at UPR (when it was a reputable shop) we dyoned like 6 homemade ram air kits. The one that made the most power was the smallest. Meaning the old saying the quickest way from point A to point B is a straight line. It was bascially the meter only inches away from the TB. A straight shot, no bends.
 
I think a lot of the throttle response etc., and better idle quality comes from the older electronics. I know i have heard Silvrbullit(tommy), say that when he spliced the wires and connector and put the fox IAC on his car it pretty much solved his idle issues. That tps is also receiving a faster sweep of the voltage range due to the path the cable takes. my .02 cents as well.


Im with you on this one Grady



jason
 
69clark said:
So I just wanted to point out that although I agree with you, I simply stated my reason for going to a Fox TB conversions was cosmetic and not done for performance reasons.

I could not agree more when talking about how some of those cai kits look.

Some I have seen are so slick looking :D
AND
kinda have that high tech look to them if you ask me. :nice:

Grady
 
the only reason im doing it is because over on corral i saw a 11 hp 5tq diffrence with a vortech setup

but i did not see a dyno sheet

if anyone has a stock s-trim set up they know what im talking about the little elbow that vortech sends doesnt cut it and now i can run my bypass valve that i been wanting to run since im getting a custom ceramic pipe made just for my car

another good reason
is fox T/B are cheaper then sn95 i got a 75 mm t/b for $20 cheaper that might not make a diff to u but some one on a tight budget like me it does

and overall better looks that elbow is f***ing ugly
and it cost money to when ur upgrading ur intake manifold

Val
 
Hear this point of view from somebody that had performance parts on the 2 different setups. First of all most people that go to a Fox setup go with the home made cai, like I did. I havent seen that many people go with the fox Mac cai for instance for their new conversion. IMO the homemade version cannot be beat as far as velocity and all that crap. Take a look.

IM003742aa.webp




From the 80mm ProM mass air filter, in the 75mm pipe,to a small 45degree 75mm bend to the 75mm tb, and in the 75mm intake opening. Not much obstruction there, so in this case I see a good improvement with the relocation of that upper bend, compared to the stock place (tb wise). About the throttle response, I dont know what to tell ya. Its not the old electronics. There is definately a difference in it. Guess you'd have to try it to see it cause its there. The Fox TB conversion is not a myth if you know how to take advantage of it...
 

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Stangfreak95 said:
Hear this point of view from somebody that had performance parts on the 2 different setups. First of all most people that go to a Fox setup go with the home made cai, like I did. I havent seen that many people go with the fox Mac cai for instance for their new conversion. IMO the homemade version cannot be beat as far as velocity and all that crap. Take a look.

From the 80mm ProM mass air filter, in the 75mm pipe,to a small 45degree 75mm bend to the 75mm tb, and in the 75mm intake opening. Not much obstruction there, so in this case I see a good improvement with the relocation of that upper bend, compared to the stock place (tb wise). About the throttle response, I dont know what to tell ya. Its not the old electronics. There is definately a difference in it. Guess you'd have to try it to see it cause its there. The Fox TB conversion is not a myth if you know how to take advantage of it...

Hey Mario

I'm with you on this one :D

The way you have got things setup has to offer the least restriction to air flow IMHO.

Looks good to me :nice:

btw, is that 3 inch pipe?

Grady
 
Just to add fuel to the fire..........

Doesn't the SN95 setup actually create a larger effective intake manifold volume than the Fox setup?

Think about it, the throttle body is now further from the intake valves and the air has to go through a bend after the throttle body.

That's my theory. :shrug:
 
I don't have a long air intake like that in my fox. I have an 80mm pro m with a c&l pipe going into my 75mm accufab. Short, sweet and to the point. The shorter the better.
 
final5-0 said:
Hey Mario

I'm with you on this one :D

The way you have got things setup has to offer the least restriction to air flow IMHO.

Looks good to me :nice:

btw, is that 3 inch pipe?

Grady

Yeah it was my old setup when the engine was still running. It is in fact a 3" pipe. I decided to go with that instead of a 4" to keep the same size everywhere I guess. For me it was best but I might be wrong.


I also used to have it in shorter form but I made it longer so I dont get the hot air from the engine. I dont think the lenght was a bad thing since it was straight. To a point for sure...