Tell me your opinions on this intake manifold. What would I need to make it work on a 305 tbi, would it be hard to adapt, would it be a good choice, etc. I will be eliminating egr so that is of no concern to me. Thanks

http://www.holley.com/HiOctn/ProdLin...SM/300-70.html

 

Unless I am mistaken the square bore intakes like that one don't work well if you want to use a larger TBI like the 454 or Holley.

If I am wrong, someone please speak up.

 

This is the manifold I plan on using when I replace mine.

http://www.holley.com/HiOctn/ProdLin...SM/300-66.html

 

im probably going to go with this one . its the super victor #2913. I have an adapter for the tbi to carb intake that has 2" bores and from what they say, it can work on both square and spread bore intakes. Its machined to be used on either of the two.

 

Why won't they work well?

 

what adapter are you planning on using?

 

from what i hear the tbi bores get real close to the sides of the intake with a square bore. Im going to be using the adapter im using now. Its the one holley makes for use with their 2bbl tbi unit. Hopefully ill have enough clearence around the tbi but with the extra space from the adapter it may not be a problem if i use a 454 tbi.

 

yeah, if you put a 2" bore TB on a square bore intake, you will run into problems. here is what it looks like...



i had to get it machined so that the throttle body could work with it, and to smooth out the transition between the two. here is a pic of that...



another one...



and another....




it's not a HUGE deal, but you will have to get it taken care of if you want to go that route.

for more info, check out the site in my sig, then go to "MODS" and "INTAKE". there are more pics, etc.

-Brian

 

Thats what the holley adaptor looks like on a square bore manifold. No machining required but its tall, I cant run a wing nut because the top of the air cleaner hits the bottom of the hood.

 

what about intakes? i've been talking to the former owner of traco engineering. they put a 305 on a dyno and tested the performer tbi versus the carb performer with an adapter and found the carb intake with the adapter flowed MUCH better.

further testing showed even more improvement with an adapter they made over the ones commercially available at the time.

does anyone else have an actual dyno or flowbench numbers on intakes for tbi applaications?

 

It will be too high for the stock hood. 3.5" front and 4.5" back manifolds will just clear on the stock hood.

 

huh.. thats about how i though the square bore manifold would be. The holley adapter is thicker so not as much radiusing would be needed, but its impossible to get it uder my stock hood with teh extra hight. Im using the stock air cleaner with my performer and it jsut barely sqeaks under my hood. Z28 boy, i like how you notched the divider out. From what i hear allowing crossflow between the bores helps quite a bit.

 

the divider actually comes like that...but i did have them make it a little sharper. the "notch" or whatever is actually one of edelbrock's features...i think they actually have a name for it.

my adaptor is actually smaller than the holley. they holley is HUGE and there was no way that i could use it. mine is from turbo city.

-brian

 

Ive noticed that the holley adaptors have the holes more towards the front of the intake manifold. Why is this? Wouldn't it be better to center the holes to get more even distribution?

 

anyone know why this is?

 

im pretty sure it has to do witht he fact that the holley adapter is meant to be used with their commander system, whcih they intend for use to replace carbs. I think the reason they locate the tbi like that is so the linkages line up on a carb car. On a tbi car, thats a different story.

 

it might also have to do with part throttle fuel distrobution, but the carb linkage thing is probably correct.

 

I always thought they moved the TBI unit foward in the manifold to clear the HEI distributor, but the linkage theory sounds good to me.

 

hmmm, i had heard it made more power further up front, but the linkage could be the reason. Anyone else know?