Fox TB Conversion

Yeah it did suck. I was really happy with how well the swap cleaned up the engine bay. It really looked sweat. Only thing I can figure is with the SN95 set up the bend in the intake piping is more gradual rather than the abrupt 90* bend on the fox set up. The butt-o-meter felt like the car was a bit crisper & quicker, but the time slips showed otherwise.

Oh well, if I ever want to get a vortech aftercooler I'll have all the parts I need to swap back over to the fox set up. Provided I get a blower one day.

I had some decent gains from doing my Fox swap. It's been long enough ago since I did it I am not sure how much I gained. I also think I did headers at the same time though.

The major gain from swapping IMO is that you get rid of those crappy adapters they make for the 94-95's. I had an Edelbrock adapter that I spent tons of time porting. I believe the 75mm Pro-M AFM, Mac cold air kit, 75mm BBK THB, and the Edlebrock elbow only flowed 500 cfm's as an assy. After finding that out I switched to a fox set up with a Pro-M 80mm shorty, Power pipe and a 90mm THB.

final5-0 said:

Does anybody have factual or hard data to back up the claims of gains

Anyway, has anybody come up with some proof?

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Yeah.
oh no..not again...

final5-0 said:

Not really sure!

I took mine off years ago and have not thought about it since then, lol

Later
Grady

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i just put one on after a year of not having one, and let me tell you, and it made a huge difference in the way the car drives. much less wobbly up front and just tighter all around. try putting it back on just to see if you notice a difference.

then again, i have a vert ...

final5-0 said:

What do all of you have to say about My95.0L's conversion experience?

It is true that he used a different tb but it was the same size.

He claims a loss of 2 tenths & 2 mph from the swap.

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I can't see the Fox being any -less- efficient than the 94/95 setup, so I'd chalk up his experience to coincidence. Or perhaps something about the swap screwed up the tune. A 2 mph loss is like 20 horsepower, which would imply quite a restriction...

For what it's worth, I improved my ET by 3 tenths and my trap speed by 2 mph when I did my swap, so I guess I cancel out his experience . But I was going from the Edelbrock elbow, which looks to be quite restrictive (it isn't the 45* bend, it's the 1-inch gain in height that constricts airflow). The TFS elbow is rumored to be less restrictive. The 70* bend I used to do my Fox setup definitely had no change in cross-section.

Dave

I don't see how a aftermarket 94-95 set up with the edelbrock adapter could possably flow nearly as well as the Fox style. If you have a mild or med built motor they might work just fine. On a larger CID higher reving engine I don't think you could go wrong with the fox swap. I have never seen the TFS adapter but the edelbrock ones suck and flow crapy.

final5-0 said:

I also have seen peeps say the TFS elbow has the least restriction and I think WhiteDevil told me he saw an increase in air flow in his data logs from switching to that elbow.

Later
Grady

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Yeah i have the TFS 75mm elbow and a BBK 75mm throttle body and then i ported the opening of my EDel to match the 75mm. I went form the edel elbow and a 65mm to this set up. I saw a good gain in Kg/hr from my old set up when i did it. As for dyno numbers i dont have any, lol of course. But it seems to work fine this way.

final5-0 said:

Would you please give a sentence or two to explain things in a bit more detail about the 1 inch gain in height thing you talked about. I am now using the Edel elbow and things don't look too restrictive to me but maybe I just did not see what you are talking about.

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I'll use pictures to illustrate what I think the restriction is. No comments from the peanut gallery about the dirty elbow ... I never bothered to clean it up after taking it off.

What bothers me is the "slide" the airway takes upward to match the opening of the intake. I say slide because it looks like what would happen if you took a slinky and slid the ends in different directions rather than letting it bend. It's like Edelbrock decided they didn't have enough room to make a constant radius bend.

Maybe this'll help. Look at how much the opening moves upwards (the intake end of the elbow is on the left, throttle side on the right).



Here is a shot with the intake side of the elbow laying flat on the counter, and the camera is exactly perpendicular to the counter. There is quite an altitude change between the two openings, in a very small distance.



I think that a lot of people only take into consideration the 45* bend you see if you look from the top. Using that logic, it would seem the 94/95 setup would be better. But when I see the side-view, I think that the 70* bend on the Fox body, especially if you do it aftermarket, is much less restrictive. To be honest, I don't think it matters much how many bends there are in the path, I think the most important factor is whether or not the cross sectional area is maintained throughout the entire intake tract.

Or perhaps I'm smokin' crack and this isn't an issue at all. I had a definite improvement when I went to the Accufab 75mm ... one other person had opposite results. Who the heck knows. I will say one thing, however -- knowing what I know now, I would probably opt for trying to correct the 94/95 elbow if I were faced with this situation again. I like the 94/95 throttle response much better -- the Fox setup is too touchy IMO.

Dave