First of all this is a far out idea I know and I'm not expecting to add crazy hp or mpg's. Please refrain from bashing me if you think this a ridiculous thought. Sometimes bad ideas help pave the way for later great ideas.

Earlier today (day dreaming in physics) I remembered my old high school days when everyone felt they had to add an airaid tbs to their truck for "some extra hp and mpg's". I decided to do some reading online this afternoon about them and opinions vary just like they do on anything that has to do with bolt on performance parts.

I did see on Amazon some for jeeps that were as low as $30. It looked like in the reviews a lot of the guys that used them on jeeps felt that they added about a mpg and noticeable low end torque.

Since none were made for a D2 it left me wondering if one made for something else might fit?? I wouldn't be against blowing $30-50 to see if I could get an extra mpg and some extra torque.

Anyone have any ideas of something that may be a similar size to our D2 throttle bodies? Or any thoughts or personal experience with this?

 

I saw some magazine (maybe 4x4) did a test on those throttle body spacers and they do add HP, the problem is it at around 8000 rpm's.
So legally they can say that they work, you just have to have a wankel rotary engine to get any use out of it.

 

Funny you mention a rotary because the only experience I have with the tbs was in my RX8 in high school. At that point in time I wasn't worried about mileage, I just knew it was fast and sounded sweet around 9000rpms.

The HP increase isn't as big of a concern to me as much as low end torque and maybe just maybe a small mpg increase. Some of the jeep reviews I read say low end torque is the most noticeable between 1200-1500 rpm.

Is there any throttle body gaskets that cross references with the D2? Or maybe someone works at/knows someone at a machine shop that could knock one out to test? I'm not sure what it would cost to have one made for testing.

 

Off topic, but if you want to revive the low-end grunt your money would be better spent buying a fuel rail cleaner and run a fuel/cleaner cocktail through using shop air instead of the fuel pump (aka BG clean). That will works wonders by improving the spray pattern of the injectors (MPGs) and improving torque at a realistic rpm range.

 

My injectors are "newish" (maybe a year old) so I'm not sure that would make much any difference in my current state.

Since we are on injectors though... I have read where some guys replaced their stock injectors with 19lb yellow ford injectors in older range rovers and I think a couple D1's and have seen some better mileage due to a better spray pattern. I'm assuming this has only been done in gem's. Could this be done on a D2 Bosch motor and would it make any difference?

I have some new yellow 19 pounders I've had for a while and have considered giving it a try just haven't had the time to try and find out on my own by trial and (probably) error.

 

Coming from my previous hobby where throttle body spacers used to be a big thing. I can safely say they do absolutely nothing in the way of increasing HP or MPG. Even though they're marketed to do everything from increase MPG, increase HP, lower air intake air temperatures, smooth intake air flow... etc..etc... they are pretty much just a chunk of metal, polymer, or whatever they happen to be made out of.

They are however a great way to add nitrous injection nozzles though, but I doubt your D2 wants that.