Ok so my friend has one and will give me a good price on it if I can use it. what all will I need to put it on a 91 L03?

What about it bolting up to the heads correctly? Doesnt look like it will (bolt angle). And what abut the TBI. Only a 2 barrel on a 4 barrel intake, adapter? Isnt there another Chevy out there that has a 4 barrel TBI? If so what is it?

 

Im running that exact manifold on my tbi. You will have to elongate the centre four bolt holes slightly to get it to fit the newer heads, Pretty easy and minor though. Im using older style heads so it was a bolt up. You will also need to get a carb to tbi adapter plate and then the throttle body will bolt right on. Check out Transdapt or holley for the adapter plate! Also im sure you can get some pic's of the bolt hole mods if you google it. Hope this helps?? Do you/or can you tune your own chips??

 

Elongate bolt holes? Do you mean on the intake? Couldnt find anything on Google.

Adapter sounds like the way to go. How about hood clearance? I also read somewhere, here on TGO I think, that I could put on a 454 TB and Ill have a 4 barrel and not have to woory about the plate. Or should I stay with the factory TB?

Is it worth all this? Did you feel much difference?

I have no clue how to tune, Ive read read read and read, nor could I afford it. Know of anyone who would burn and send them to me?

 

Yes the manifold bolt holes in the centre will need to be modded due to a different angle on the newer heads. No stay with your factory throttle body for now. The 454 throttle body is not a 4barrell, It just flow a little more air. As for power difference yes there is some but you should be doing a cam upgrade at least as well. You will also have to get into chip tuning to get the most out of the manifold and any other changes. Im not sure if it will fit under the hood or not. Check in the search forums for more info.

 

Damn Im not gonna be able to do all that, guess Ill eventually go carbed.

 

Not the best choice for TBI anyway(airgap).

 

Why is this? Are you saying I should go carb?

Where is a good thread on the pros and cons of going from TBI to Carb?

 

I think if you will switch your tbi to carb on your LO3, you will get noticebly less mpg and loose at least 15+hp.

Why dont you get EBL, gain mpg and get at lest 15+ hp? (I you have a laptop)

Air gap will cause drops of fuel to form ont the intake walls = imprecise fueling and inefficient combustion.

There are no pros of going tbi to carb, except if you have no computer.

 

So your saying that Air Gap intake is a boat anchor. Why would they make such a thing that you kill HP and fuel econ? Are you saying it will still lose HP and MPG if I kept the TBI with air gap? Or no air gap whatso ever?

EBL? 15HP? Point me in the right direction because I dont know what it is. 15hp+ has deff got my attention.

 

I believe the air gap sometimes causes fits in your tune as explained above. If the air temp is low that is. If you live in a warm hot climate probably no issue. I experienced those issues when I had a cold intake on my car here in wisconsin. I have since replaced it and tuning is more consistent. Do a search for "air gap" and you may see some members that used it and have commented. Maybe others that have used it successfully will add 2 cents.

EBL look @ dynamicefi.com

 

I thought air gap intakes were mostly for engines that ran really hot, allowing the intake to be at a safe temperature to alleviate predetonation. In a "normal" engine, it would lower the intake temperature to the point where your fuel will have trouble vaporizing.

 

For a real world street car, probably yes.
May be interesting for a carbed circle trac racing car? Best would be to reseach in what car sports there used and post it.

When the intake manifold is heated up these cars perfom better. You can simply test it.

How are you going to tune it if randomly, you get less fuel delivered then demanded, and then suddenly extra fuel poores in to the cilinders?

 

Well I talked to someome about it at Advance, and apperently he has a stock pile of SBC intakes, including single plane. So he is willing (possibly) to trade one of his for the AIR GAP. Which should ones should I look for?

 

I dont know what your plans are on a LO3+ full exhaust+ fre flowing air intake+ tuning there is nothing to gain by swapping the intake manifold.

The edelbrock TBI performer 3704, bored out to stock or more is a ok replacement that dosent require major modifications once your set up is goin to pull stronger in the 4000+rpm. There is another one pretty popular on this bord were u use the adapter plate, dont recal wich one it is.

Also you may whant to reasearch, on what heads you would like and then look for a maching intake manifold.

 

All I have so far is, 9" non-drop open air element, Flowmaster -no CAT, stock exhaust manifold. No tune...

SO I cant gain any HP with another intake, unless I go matching heads and cam?

Then maybe I can get him to trade for headers then?

 

Do the manifold AND headers and see how that works.

 

Cant afford it. Like I said, hopefully he'll trade for headers. Ill take the advice from the ones who know, and try to use it to get something else.

 

RONNY does know.

 

And thats why I wont use the Air Gap...

 

Its funny that you all hate the Airgap! I live in Vancouver Canada wich has some decently cool winters and fall etc. The only time there is any noticable problems with the Air-gap is in the first 2/5min of driving in the winter. Yes it does run better when hot but no different than any other intake. I have tuned around it very well and I do notice some power difference between a heated intake at any temp above 50degree engine temp. I will be switching to the ebl eventually and with the addition of an IAT it will make life alot easier. Just my thoughts. Some of your systems already have IAT's so why not use them to tune the intake as well??

 

Are you saying report after trying the Air Gap and headers? Try w/o without tune?

I dont believe Ill ever have winter problems so i think im out on that one. Its only hot as hell here everyday. How is hood clearance?


Is it really as thomas says about fuel?
What about EGR?

 

EGR "emissions are directly impacted if combustion temperatures get high enough to break down the nitrogen atoms, yelding oxides of nitrogen in the exhaust. To combat this, EGR is often deployed. Recirculating spent gases back into the intake charge dilutes the energy potential of the incomming charge, reducing its burning temperature potential. Additionally, unburnt oxygen and fuel molecules have a second chance at properly mixing before being wasted out of the tailpipe." from, Engine management Advanced tuning by Greg Banish

Personally I never noticed any power increase with EGR disabled vs enabeled, but fuel consumption is noticebly higher wen disabeled.

Dont waste your time and $, get EBL and start tuning then get headers and full exhaust.

Once you will be experimented at tuning you can always try out an Airgap manifold.

If you had EBL flash you would not even be dabating EGR, since it takes you only around 20 seconds to disable/enable allowing all kind of tests.

 

thanks man, ill take the advice of the experinced such as yourself. im in the middle of taking off the manifolds and its nothing short of a nightmare... Ive even pulled an LS1 today but i cant get these damn things off. i hate the people who made thse things... sorry bout the rant, basically id like to finish up this and fix other things, and then ill move on to trying EBL.

 

Well I newer tried the Airgap manifold, Im just starting to learn how tu tune and a self heating itake manifold were you could set a constant best temperature would rock. Kind a opposite of the airgap, althought its flow capacety is certanly superior to the stock manifold.

Good luck with the header swap.