The TBI Air Flow Enhancer, a.k.a. the Salad Bowl
I just installed the TBI Air Flow Enhancer from Jegs. You can also get it at Summit Racing under the name Hypertech TBI Power Chargers 4001. And you can also make your own for much cheaper. I had read mixed reports of the effect these bowls have on performance. Some say it doesn't do anything and some say you can definitely feel an increase in power.
TBI Air Flow Enhancer, a.k.a the Salad Bowl kit from Jegs
The tipping point for me to buy one was an old hotrod.com: 1993 GMC 350 Pickup – Project Jake, Part III. This is about the only "proof" I could find that the bowl makes a difference. These guys actually have a before and after dyno run for the Salad Bowl mod:
TBI Air Flow Enhancer Dyno Results from Hot Rod Network
They show that the bowl gave an increase of 8 HP and 8 LB-FT of torque at the rear wheels. However, I've watched enough dyno runs (thanks Roadkill and Might Car Mods!) to know that pulls can vary quite a bit without anything changing on the vehicle. But I wanted one anyway, just to see.
This is the stock TBI collar for a GM 350
At first I thought my air cleaner stud would be too short. I had read somewhere that you might need a longer one. Then I realized you can just back it out a bit. It will still have plenty of threads left in the throttle body, but you'll still be able to attach your lid, as well.
Just unscrew your air cleaner stud a bit to make it stick up enough with the bowl.
And there it is, with everything buttoned back up:
TBI Air Flow Enhancer installation complete
So now for the big reveal: my very own opinion on the effect of the Salad Bowl mod with the TBI Air Flow Enhancer/TBI Power Charger. I definitely feel more power. Everything from taking off from a dead stop to accelerating on the highway seems to take less throttle. The truck feels like it has more "grunt". So if you're on the fence about getting a bowl, I'd say go for it. Or make your own.
Hopefully less throttle means more miles per gallon. I track the gas mileage of the truck here: Chevy K2500 Fuel Economy Log. I happened to fill up the tank the day before I installed the bowl, so this tank will be 95% with the bowl. We'll see what it does to the gas mileage.
Update 05/09/2017: Did the first fill-up after the salad bowl install. It was 14.4 mpg, which is about 1.3 higher than my average before of 13.09 mpg. I also got a free-flowing exhaust installed that raised the next tank to 15.4. I'll write about that soon.
And someone at Jegs got a little carried away with their packing: