TBI spacers, are they really worth the money?

[sethel]

Upping airflow effiency like the TBI mods should not hurt mileage. At least i wouldent think so. This being said, i am not sure but maybe the combination of raising the injector pod, and removing the ridge on top of the TB throat is whats causing this problem.

The small lip on the TB throat around both venturis may be there to shroud the injectors slightly to help them direct their spray more efficiently. I am no TB expert by any means, so maybe someone can chime in here.

I think i am going to try raising my injector pod the 1/4" since its cheap and easily reversable, do the salad bowl mod and leave the ridges in place. But may concider tapering them outward for airflow.

I would be very interested in hearing how this goes for you if you do it. I am interested in knowing what the difference is with the ridges left in place. I may try to pick up a TBI from a junkyard with the ridges and keep all the other mods I've done to test that difference as well.

 

[Moparmat2000]

May be a little while. I got a bunch o honey dos around the house. I bought a nice new cardone select dizzy to replace my old one that has a bad module, and cracking pickup magnet. I may get lucky to mess with it next week. Then i got to get the salad bowl. Either walmart housewares, or thru jegs lol. Not joking either. Thankfully i have a DD and this isnt my only transportation.

 

[Moparmat2000]

Whats the average thickness of a TBI spacer?

 

[SkyHighColorado]

i can measure mine on Saturday if you like. I think its 1" no more than 1.5". I dont recall losing any mpgs with my ultimate tbi mods. How did you calculate mpgs?

 

[Moparmat2000]

Not sure what your asking, but this is what i think your asking.

Fill tank all the way till pump clicks it off, write down odometer reading. Drive till next fillup. At second fill up, fill tank again until pump clicks off then write down new odometer reading, and write down total gallons it took.

Subtract 2 odometer readings to get total miles run between fillup, and divide with number of gallons truck took at fillup.

This should give you an average combined mpg.

Ex 300 miles ÷ 20 gallons = 15

The only way to ensure it to be close to accurate is completely fill tank both times till pump clicks off.

It sucks the trucks up to 94 did not have an option of a D.I.C. and we have to do this the old fashioned way lol

 

[95Escahoe]

On a a TBI they are worth it, if you are gonna do one, take the TBI off clean it up, do the TBI mods maybe send the injectors out to be cleaned if u got another car or truck to use, add an injector spacer too

 

[Moparmat2000]

I been researching this, going to make my own TB spacer, going to do the mods one at a time. Cant afford to do it all at once.

 

[Moparmat2000]

2 pieces of Grade A plywood vacuum laminated together with aircraft composite adhesive. It is 7/8" thickness. The plywood will be coated with composite resin to seal it after its final cut and sanded.

Reason for plywood is it will help insulate the TB from picking up intake manifold heat. I used to do this years ago under carburetors.

Heres pix so far.
Matt

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[sethel]

Yea, I measured my MPG in that fashion, between fill ups I divide the my odometer by gallons at the pump. I'm at about 12-13 city 14-15 @ 90% hwy. and it use to be 14-15 city 17-18 hwy. I have a TBI spacer (I'll have to measure it when I get back to my truck but it's right about an inch). I did TBI and injector spacers at the same time, also an open air filter for the stock set-up, all new gaskets, plus cleaned up everything. I may be loosing vacuum somewhere...

The wood spacer is an interesting idea. Never seen it before. What resin will you be sealing it with?

 

[Moparmat2000]

Resin i am using has a working cure temp of 150°F. Epocast 50A/946. It is designed with flame retardent properties for inside aircraft. Sands nicely when cured, dries clear.