Hey guys... ok i will make this short and sweet... Is there any real hp/tq gain from installing a throttle body spacer or a larger diameter throttle body to your trucks intake?
If so what kind of numbers are we talking about and is it really worth it?

The reason i ask is that while researching hp/tq mods for my 1995 5.0 f-150, I came upon throttle bodies and throttle body spacers. Some companies claimed un-real gains from them and i don't know whether to believe it, or if it is all just bs. Also, if anyone has added a spacer or larger diameter throttle body to their truck and was either satisfied or did-satisfied with it, i would love to hear about your results... Thanks for all your help, Joe

 

I installed a Airraid spacer on my '94 4.9L I couldn't tell much difference if any. But I have since fixed some parts on my motor and I'm going to reinstall the spacer plate and see if it actually works.

I would say even if it did, it's not worth the $70 cost.

 

An aftermarket throttle body can improve on stock performance. To realize the maximum gain you need to address the system, from intake to exhaust, though and create a system to meet your needs. Dual exhausts, for instance are not the be all and end all, especially if more torque is the goal. A BBK throttle body will perform as well as the system it's installed in.

 

I noticed a gain by upgrading to a BBK 56mm throttle body, but I'm also running an Edelbrock EFI truck intake, headers and dual exhaust.

 

A larger throttle body will allow more airflow into the engine, however there is a limit to how much increase you can have because the speed density computer only understands vacuum, not airflow. But, mild increases are okay as you're within the data tables in the computer.

As far as throttle body spacers, it's a waste of money. Carb spacers on the other hand did make a noticable difference, and here is why.

As the air passes through the carb, it picks up the fuel, and carries it through the intake. Since right under the carb, there are sharp bends to the intake runners, more often than not the fuel would "fling" out of the air against the intake runner wall. By adding a spacer between the carb and the intake, the angle is a little less, and more often than not, the fuel stays suspended in the airflow, with more if it going into the intake runner evenly, rather than as sucked-in puddles of fuel.

On an EFI engine, no fuel passes through the throttle body, so the spacer doesn't provide any benefit. They claim it does, by "swirling" the air however testing two such products on a friend's car on a dyno, we got the same results before and after each of the spacers - essentially zero gain.

 

LOL - That reminds me of that idiotic Tornado insert I saw on TV a few months back. What a joke! You could even see their fake if you watched their dyno, on the 'before' they don't let the engine rev up as high as on the 'after'. I feel sorry for all the suckers they found.

Popa Tim