Does anyone know the Summit pn# for a TBI spacer that will fit a 91 305? Also are there any parts available to enhance that TBI setup relativly cheap?


Thanks,
Anthony

 

Check out the free mods posted on this site. You can also make a spacer yourself instead of spending the $$$ to buy one.

 

In my opinion the tbi bore holes are the most restrictive part of the motors induction sytem (so what ?), well by extending those bores (making them taller by using a spacer) your increasing the air resistance. I actually think they hurt top end HP, but I can see them adding small amounts of tourque. Do the ultimate mods instead, I noticed a power increase with them.

 

Don't worry about the air turbulence, if anything you would want more to keep the fuel in suspension.
The TB spacer is just like a carb spacer, it'll increase the volume of air in the plenum (air/fuel mix ready for combustion) and in that respect you can run a slightly smaller carb, or in this case TB, and support the same power. It's an old trick but too much plenum and our wet-flow systems have troubles keeping the fuel in suspension = effects neutralize and spacers = no gains. Just make your own anyways and if you've got the hood clearance and are using a stock intake, try it out.

 

If your going to keep the stock intake, go ahead and put on a spacer, you won't notice any power gained or lossed. Indeed if your increase the plenum volume, you can support more power. The reason the carb spacers work is they are much larger volume compared to a tbi spacer which is maybe 1/4 of the carb spacers volume, for a given height. Now back to the resistance factor, their is very little in a carb spacer ( again thats why people use them) but a tbi spacer will just add unwanted resistance, that in my mind which cancels out any gains from increasing the plenum volume.