I recently purchased a modified upper intake from a fellow member ( thanks Jeff, it was a pleasure ). The modification is the "Dawg style intake" where the restrictive part of the upper plenum throat is cut out and a round piece of aluminum is welded in it's place to enlarge the passage and increase airflow.The EGR port is intact and will be hooked up.
I have the tools to bore the intake out to 56 or 57MM but I don't have the resources right now to buy a bored out throttle body. I'd rather not install it and later have to remove the new intake for modification so the question is, can I bore it out now, install it and add the larger throttle body later?
I don't see why not. The throttlebody opening will be the restriction at that point... BTW, this is pretty good pricing on a bored throttle body. $135 if you send them one. http://www.throttlebodys.com/FieroTBs.htm
Isn't it strange that after a bombing, everyone blames the bomber, his upbringing, his environment, his culture, his mental state but … after a shooting, the problem is the gun?
[This message has been edited by MulletproofMonk (edited 09-11-2013).]
Yes you can. I have done it both ways. You will want to wait until you have your bored out TB before having the chip remade however. It's not a big deal at all though to r& r the upper intake. Personally I wouldn't bore the manifold until I had the TB.
BTW, I don' think I'd need a 63Mm Throttle body. All I plan to do is the intake and exhaust porting to go along with already installed UD pulley, the cat delete and eventually, 1.6 rockers.
Thank WILL be it, I swear.
But what's this about a chip change?
From what I've read here there's no need for a chip upgrade with these particular improvements.
When we did our flow-bench testing on our intakes we did it with a stock TB opening and the data/numbers -{ http://trueleo.com/Fierointake.htm } confirmed that the stock intake was main CFM limiter and not the TB. Most of our customers use stock TBs the including me.
I built a highly modified 2.8 and it has a stock TB on it. - the red 2.8 on the cradle shown here- Now I may go with a larger TB after a get some dyno numbers on that engine.
Basically, if you can find a bored out Tb real cheep, get it, if not more than likely a stock TB will do fine. Save your money for something more cost effective.
I posted up some flowbench numbers testing a bored TB and DAWG modified intake as well as the stock parts. I have not updated that post in awhile though so it's not at the "top of the list". Still looking for a stock air cleaner housing so I can test it also, as well as test some various air filters. So far nobody seems to want to sell a V6 air cleaner housing?
------------------ "There is no more formidable adversary than one who perceives he has nothing to lose." - Gen. George S. Patton http://www.flowbenchtech.com
[This message has been edited by Brucepts (edited 09-12-2013).]
As for the chip, if you flow more air with the opened up manifold it will change your a/f ratio. I had a modified intake like yours except with egr delete and a bored TB. It had a bad tip in problem that I was never able to solve. The modified "stock type" manifold that West Coast Fiero's sell has a seventh injector to compensate for this issue, http://www.westcoastfiero.com/intake/intake.html. I agree that the stock TB would be the best way to go.
As for the chip, if you flow more air with the opened up manifold it will change your a/f ratio. I had a modified intake like yours except with egr delete and a bored TB. It had a bad tip in problem that I was never able to solve. The modified "stock type" manifold that West Coast Fiero's sell has a seventh injector to compensate for this issue, http://www.westcoastfiero.com/intake/intake.html. I agree that the stock TB would be the best way to go.
I'm guessing it went lean. When you enlarge the throttle valve, it lets air rush in the intake faster when you step on the go-pedal. As a result, you need the fuel to rush in faster as well, or the engine will go lean when you hit the gas.
I had a similar problem after installing a Trueleo intake with a Buick GN (59mm) throttle body on my engine. It went lean on acceleration, enough to make the engine stumble. I fixed the problem by making the acceleration enrichment (in the ECM programming) more aggressive.
As for the chip, if you flow more air with the opened up manifold it will change your a/f ratio. I had a modified intake like yours except with egr delete and a bored TB. It had a bad tip in problem that I was never able to solve. The modified "stock type" manifold that West Coast Fiero's sell has a seventh injector to compensate for this issue, http://www.westcoastfiero.com/intake/intake.html. I agree that the stock TB would be the best way to go.
We found the stock chip to work fine on 2.8s with using our intakes and headers and no other engine mods. I'd put it on a wide band before you shell-out money for a chip.
I never found out if it was lean or rich but I'm sure it was leaning out. It just fell on it's face at tip in. I fought it for a year and gave up and put a stock TB and manifold on and it runs dramatically better than it did modified. Gm tuners was helping me with it but I kept running across other issues. The chip I have now is modified quite a bit. At last resort we were going to check what the 02 sensor was reading but I threw in the towel and my tune time ran out. It felt exactly like a carb with a bad accelerator pump.
[This message has been edited by raysr11 (edited 09-14-2013).]
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