Do throttle body or carb spacers actually help?

[PhotonFanatic]

You must be registered for see images attach

I saw this as a teen back in the 90's, and the guy claimed it had increased his mpg to somewhere around 22 mpg on his TBI truck. If true, it would be an improvement because iirc GM rated them at around 17 highway

 

[Ricko1966]

I saw this as a teen back in the 90's, and the guy claimed it had increased his mpg to somewhere around 22 mpg on his TBI truck. If true, it would be an improvement because iirc GM rated them at around 17 highway

I don't believe that for a second. 5mpg on a 17 mpg truck is huge and the manufacturer would have made the mod factory for the Cafe rating.

 

[bucket]

Someone is now making money off of some rednecks' mod got to love it.

They have made those things for decades.

 

[PhotonFanatic]

Unless that's not the full story and they have a reason for not doing it. Lots of parts and upgrades have that story.

They could probably squeeze another 5 mpg out of a square with little/no drawbacks, but you would have paid another $10k for the truck. And for a $15k truck that ain't happening.

 

[Ricko1966]

Unless that's not the full story and they have a reason for not doing it. Lots of parts and upgrades have that story.

They could probably squeeze another 5 mpg out of a square with little/no drawbacks, but you would have paid another $10k for the truck. And for a $15k truck that ain't happening.

Well we can ask @dd1990 he did the salad bowl mod. Did you pick up 5 mpg?

 

[xm20k]

They have made those things for decades.

I had no idea they were a legit product only ever saw the homemade ones.

 

[bucket]

I had no idea they were a legit product only ever saw the homemade ones.

I never used one, but I know they made them. All my TBI stuff got an injector pod spacer, advanced timing and then I called it good.

 

[xm20k]

I never used one, but I know they made them. All my TBI stuff got an injector pod spacer, advanced timing and then I called it good.

All the TBI stuff I personally messed with either had major issues hence I got it for a good deal and SB swapped it because Buick V6 with external oil pumps that decided they were done being a pump or had a small block with TBI but had electrical/computer issues and ended up with a carb and HEI because I had the parts.

The stuff that came in the shop was stock or had a homemade salad bowl, some were rather interesting to say the least, a Grand prix came in with a backwards add on scoop to fit the air cleaner/salad bowl might not have looked bad had Ray Charles not cut the hood and mounted the scoop with self-tapers and Bondo.

 

[dd1990]

Well we can ask @dd1990 he did the salad bowl mod. Did you pick up 5 mpg?

It may have increased mpg, although 5mpg seems like a stretch. I have never measured mpg before, I'm around 15-16mpg on my suburban but that also after a good tune and tbi rebuild. The salad bowl can be easily felt with how the engine revs more freely.

 

[bucket]

All the TBI stuff I personally messed with either had major issues hence I got it for a good deal and SB swapped it because Buick V6 with external oil pumps that decided they were done being a pump or had a small block with TBI but had electrical/computer issues and ended up with a carb and HEI because I had the parts.

The stuff that came in the shop was stock or had a homemade salad bowl, some were rather interesting to say the least, a Grand prix came in with a backwards add on scoop to fit the air cleaner/salad bowl might not have looked bad had Ray Charles not cut the hood and mounted the scoop with self-tapers and Bondo.

I was lucky enough to own several really good TBI 4.3's and V8's. Have never had a problem child. The injector pod spacer was 20 bucks and the timing was free.

I often did those things for customers too.

 

[PhotonFanatic]

All the TBI stuff I personally messed with either had major issues hence I got it for a good deal and SB swapped it because Buick V6 with external oil pumps that decided they were done being a pump or had a small block with TBI but had electrical/computer issues and ended up with a carb and HEI because I had the parts.

The stuff that came in the shop was stock or had a homemade salad bowl, some were rather interesting to say the least, a Grand prix came in with a backwards add on scoop to fit the air cleaner/salad bowl might not have looked bad had Ray Charles not cut the hood and mounted the scoop with self-tapers and Bondo.

I have the same story, but the reverse. Never had anything but trouble out of carbs, and my TBI truck has treated me great for more than 15 years. Knock on wood of course. But I've always wanted to be able to make carbs work well for me. Maybe electric choke was what I needed, cause I always disliked the cold bloodedness in the winter.

 

[legozombie]

I guess it depends on what your definition of "help" is. I have a dual plane intake and put a single plane phenolic spacer under my qjet incase it was soaking heat. It created more vacuum surprisingly but the right side idle mixture screw doesn't really do anything unless I completely take screw it in or out (lol). I'm pretty sure the spacer has something to do with that. Regardless, I am going to take it apart soon and make sure the idle circuit is clean then I'll try running it without the spacer. I want to try messing around with an aluminum spread bore to square bore dual plane spacer and buying a local Edelbrock 1406 or 1411 carb to test 'em out.

I haven't gotten stranded again after I installed the spacer and did a rebuild on it so I guess it helped?

 

[fast 99]

Sounds like an episode of Engine Masters in the making. I think they covered this, but I can't tell you which episode it was. IIRC, there was a mild improvement. Along the lines of long intake runners.

Yes they did. Single opening, 4 hole and tapered spacer. Came down to the specific combination. There was a distinct improvement with a Wilson tapered spacer on a Wilson manifold.

 

[fast 99]

I am going to take it apart soon and make sure the idle circuit is clean

try removing the screw, use air pressure and carb cleaner. Many times if restricted will fix it.

 

[75BEASTK20]

Been there done that. As everyone says, minimal improvements until high rpms AND a high performance engine. Remember, the old TUNNEL RAM intakes were designed for HIGH RPM. It definitely DOES help for heat dissipation. A better solution is a RAM AIR setup. Easier to do than you think. Buy an old two snorkel air cleaner from some big block, cut the small 'snout's off a bit till you have a decent sized opening, run dryer vent or similar to both horns, attach all of it using gear clamps to a LOW forward facing area with an old nylon over the end to catch bugs and crap and try that. YOU WILL notice power increases over 50 mph. Air has to be pushing in to the hose for it to work. Or go to a factory GM cowl induction system (big bucks). It's probably only good for ten horsepower or so ,but every little bit helps. I chose to go with a custom cowl induction setup on my square body. Hope that helps some. Tinker around with it, change your jets and metering rods to suit you (easy to do on an Edelbrock carb). Check your AFR regularly till you dial it in.