Do larger throttle bodies really work?

[pjtoledo]

@gaz may be wrong about the numbers. But he may not be reporting under the influence of a placebo effect. After all, the engineers at Ford must have believed that the 6omm throttle body would provide enhanced performance for the Taurus and the Mercury. Why wouldn't the same TB provide enhanced performance in the 3.0 Ranger?

not sure how it works into the equation, but Ranger 3.0 cams are different then Taurus 3.0 cams ( Vulcan ) in that they are tuned for lower RPMs from the factory.
the 60mm TB is for a 3.0 Duratec DOHC 4 valve, so it's not exactly an apples-to-apples comparison.

related question, do the 3.0 Duratec engines have variable valve/cam timing? that would open up the top end.

 

[pjtoledo]

Years and years ago I had a 98 ranger with the 3.0 and 5 speed I did the 3.8 mustang throttle body and a cold air intake factory manifolds but a new exhaust. It was a little bit better on economy and acceleration atleast it seemed that way, nothing to right home about. I put an 8.8 in it after the 7.5 blew apart which must have had a better gear set in it that's when I definitely noticed a change. Also I remember a guy around the same time did a Franken ranger with the 3.0 it maybe on here or it was on the old YouTube I'll look but who knows if it's still out there.

a couple years ago I bought a TB for a 2002 3.8 Mustang from a yard, turns out it was 52mm. shame on me for not doing more research.

 

[Lefty]

not sure how it works into the equation, but Ranger 3.0 cams are different then Taurus 3.0 cams ( Vulcan ) in that they are tuned for lower RPMs from the factory.
the 60mm TB is for a 3.0 Duratec DOHC 4 valve, so it's not exactly an apples-to-apples comparison.

related question, do the 3.0 Duratec engines have variable valve/cam timing? that would open up the top end.

I am glad that you mentioned this. The article in the tech section seems to say that both the Vulcan and the Duratech used 600mm throttle bodies.

"Also note the 1987-2007 Ford Taurus came with the Ford 3.0L Vulcan engine. So the 1996-2005 Ford Taurus could have either the Vulcan 3.0L, or the Duratech 3.0L DOHC engine."

But it says nothing about different cams in the Taurus Vulcan. Now I am not sure if I should go ahead with this.

 

[scotts90ranger]

Completely forget any thought you had on a throttle body spacer or what the Toyota guys do and use a phenolic spacer, both are completely useless, 1" isn't going to drastically change anything... if you think those work wonders might as well get a whistle tip (are those things still a thing?) and a tornado (again, still a thing?)

I stand by the change in throttle size until you get to high rpm mostly changes the throttle curve, it might feel more powerful because you have to use less throttle to do things but you're allowing the same amount of air through to do the same thing so under normal driving it is going to be exactly the same... Personally I like a slow throttle curve like the 2.3L's have with that linkage deal making it exponential, I use ALL of the throttle movement all the time unlike all new cars where you need 1/4 throttle to do 70...

 

[4.0blue98]

I've got two 25th anniversary TRS stickers on the way. If I put one on each side, that should be good for an additional 20 HPs, right?

 

[fastpakr]

I've got two 25th anniversary TRS stickers on the way. If I put one on each side, that should be good for an additional 20 HPs, right?

"Up to 20 HP or more!"

 

[Ramcharger90]

a couple years ago I bought a TB for a 2002 3.8 Mustang from a yard, turns out it was 52mm. shame on me for not doing more research.

I think there was 3.8 mustang throttle body was 10mm larger then the ranger. That's the only reason I did it. Obviously we are talking about 15 plus years. But I don't think I would have wasted my time doing it if it wasn't larger

 

[don4331]

not sure how it works into the equation, but Ranger 3.0 cams are different then Taurus 3.0 cams ( Vulcan ) in that they are tuned for lower RPMs from the factory.
the 60mm TB is for a 3.0 Duratec DOHC 4 valve, so it's not exactly an apples-to-apples comparison.

related question, do the 3.0 Duratec engines have variable valve/cam timing? that would open up the top end.

The fact that there are 2 very different 3.0s in Taurus makes the article in the library confusing.

Depends on the year (both cases).

'02 and later Taurus have 3.0 Vulcans with hp peak at 5,250 rpms (~10% more than the 4,800 rpms for Ranger)​

​

Later 3.0 Duratec engines (e.g. '09-'12 Escapes) have VVT (variable valve timing).​

​

 

[lowspeedpursuit]

the curtain, which is the area available under an open valve to let "air" into the cylinder is the basic determining factor for how much air gets in.
(pre-tuning of runners etc). think of the curtain as a virtual cylinder from the valve head down to the seat.
so, a 40mm intake valve lifted .418"/10.63244mm
pie * 40mm = circumference 125.66 mm, multiplied by lift * 10.63224 = about 1336mm squared, or 13.36 square centimeters to let air into the cylinder.

I have a stupid question from someone who's never taken apart a V-engine: aren't multiple intake valves open simultaneously? Do multiple valves partially open never reach more total area than one valve fully open?

 

[Lefty]

The fact that there are 2 very different 3.0s in Taurus makes the article in the library confusing.

Depends on the year (both cases).

'02 and later Taurus have 3.0 Vulcans with hp peak at 5,250 rpms (~10% more than the 4,800 rpms for Ranger)​

​

Later 3.0 Duratec engines (e.g. '09-'12 Escapes) have VVT (variable valve timing).​

​

@pjtoledo mentioned that the Taurus 3.0 was not the same engine as the Ranger. It was made with a different cam.

That was enough to make me change my mind. That 60mm Taurus TB may provide a little extra power at certain RPM but maybe not enough to make this project worth it.

 

[don4331]

I have a stupid question from someone who's never taken apart a V-engine: aren't multiple intake valves open simultaneously? Do multiple valves partially open never reach more total area than one valve fully open?

I was going to give @pjtoledo a minor hard time about that. If you look at my numbers for the 3.0 cam, you would see that indeed multiple intake valves are open at the same time 198*6 = 1188* > 720* (for 2 revolutions), but the value opening curve is a modified sine wave, so you have to integrate the multiple cylinders to determine total area. It's probably not for the 3.0, but as you get into engines with more cylinders (8s, 10s, 12s) there is considerable overlap. Also, when you get into higher performance engines, you have even longer duration of valves open.

 

[Lefty]

I was going to give @pjtoledo a minor hard time about that. If you look at my numbers for the 3.0 cam, you would see that indeed multiple intake valves are open at the same time 198*6 = 1188* > 720* (for 2 revolutions), but the value opening curve is a modified sine wave, so you have to integrate the multiple cylinders to determine total area. It's probably not for the 3.0, but as you get into engines with more cylinders (8s, 10s, 12s) there is considerable overlap. Also, when you get into higher performance engines, you have even longer duration of valves open.

Well you may be right. We all try to provide good data and numbers, but we sometimes do not take into account many other real world variables.

 

[pjtoledo]

I have a stupid question from someone who's never taken apart a V-engine: aren't multiple intake valves open simultaneously? Do multiple valves partially open never reach more total area than one valve fully open?

for a V6:
yes, getting right down to the exact timing there is some overlap possible. but... that would be only at the end of one valve and the beginning of the other(s)
so lift would be minimal.
there are hundreds, if not thousands of cam profiles.

V8s would always have an intake valve open, I4s would have even less than a V6 open.

 

[pjtoledo]

I was going to give @pjtoledo a minor hard time about that. If you look at my numbers for the 3.0 cam, you would see that indeed multiple intake valves are open at the same time 198*6 = 1188* > 720* (for 2 revolutions), but the value opening curve is a modified sine wave, so you have to integrate the multiple cylinders to determine total area. It's probably not for the 3.0, but as you get into engines with more cylinders (8s, 10s, 12s) there is considerable overlap. Also, when you get into higher performance engines, you have even longer duration of valves open.

I graphed the cam for a 2000 a few years ago, can't find the notes now. I seem to remember some overlap.
maybe I'll put the degree wheel on my spare 3.0 and check it out.
which means I'll have to find the lifters and put them back in.


meanwhile, getting back to the original subject of what a larger throttle body does........

I am absolutely positive that putting a 4bbl on a well worn 283 in a '63 Bel Aire will increase oil blow buy and create rod knock.

 

[Josh B]

I had a 4bbl on a 327 in a 63 pickup, Fleetside I think it was called. After flooring that thing a few times I took the 2bbl off the 283 64 Impala that wasn't running anyway and used it, lots better on the pocketbook