Thinking carb swap

[2.8RS]

I know that I will get flamed for this but I was thinking about going to a carb instead of the MPFI on my Camaro. All of the electronics have just been a nighmare for me. Besides for the carb and manifold I need to know a few things. How can I keep the stock electric fuel pump with the carb? I know carbs are low pressure and it needs to be stepped down, how? Also what vacuum advance distributor should I buy. All of this would be going on a 3.4 when I swap it in place of the 2.8 in my Camaro. It would have ported heads and a 260H cam in it, auto tranny. I am really interested in doing this. Not to mention I really don't know where to start tuning (already looked at moates.net for all the stuff) The car is daily driven so there isn't going to be any 3x00 topend swap if I stayed FI.

[geoffinbc]

You can bolt in a 3.4L and your stock computer will run it. The only thing you may have to do is maybe bump up the fuel pressure or swap injectors.

If you insist on a carb then just keep the stock pump and lines they will work great. Find yourself a low pressure bypass regulator and set it at 5 to 7 PSI or whatever the carb instructions recommend. Aeromotive or Holley have a selection of regulators.

[2.8RS]

I know the 2.8 computer will work fine, but with the cam and heads I'll need a little but of tuning and I don't know how to tune at all. I know some guys who can tune a carb.

[geoffinbc]

A lot of guys claim they can tune a carb. But it is a lot like fuel injection. If you don't have a track or dyno to lay down a baseline and verify your results you have no real data. The plus with EFI is you can plug in a scanner at at least monitor fuel trim an o2 sensor data to get the mixture bang on and then use other means to tune for maximum power.

Also with the old MPFI computers you can send in all your engine and vehicle info to a company and have a chip burned. A lot of them will give you several re burns until you get what you like. Once you are there you wont have to touch it again.

But honestly for a N/A motor and the modifications you have on the car the stock PCM program will work well. The 260 cam is not that far off the stocker it wont cause any running issues. The only thing you will need to do is dial in the fuel pressure or change injectors in order to get the fuel trim to a minimum and you can just leave it at that.

[ForcedFirebird]

I have to agree with betterthanyou. A AFPR and the slightly larger injectors you already have will be enough, especially if you can get a hold of a WBo2. Also the MAF ECM's are a little less sensitive to changes as the SD/MAP ECM's.

[BillS]

Yup - no sense throwing away 25 years of progress to put a less efficient carb on there.

I went to an OBD1 ECM rather than the OBD1.5 from the 95 Camaro whose engine I used just to be able to rechip instead of shipping off the whole ECM for reflashing, but you already have an easily tunable version.

I agree that you won't be making enough changes to the engine that the stock ECM won't be able to run it well.

That Crane 260 is pretty mild.

[Ortie666]

If you do choose to go Power, ground, Ign, (-) of distributor, as your wiring.. I would really suggest the after market 4bbl intakes that are made for the ironheads.