My engine build plan did a flip flop. Bottom end is all together. Heads all assembled, Brodix IK200's. Already bought a crower 00468 cam. But at the time was going carb. Now switching gears and thinking strongly about putting it in my gta. I dont want to burn a chip or go with a aftermarket ecm if possible. I will probably go aftermarket on the tpi or send my stuff out for extrude hone. What would be the biggest cam i can go without pissing off my stock ecm? The car is a A/T with 3.27's. Any ideas would be much appreciated. Scott

 

CompCams 292XFI? I'm real close to swapping out my OEM305 for my custom 383 build. I got a build thread around here somewhere...

 

The stock ecm is going to play nice with that?lol

 

That remains to be seen on my end... My stock ECM is 165. I'm going with the EBL 730 ECM thus losing MAF, for the preferred MAP...

Anyway, my max expected engine RPM's would be close to 7K+. This is doable with "stock" ECM's of third GEN camaro. Like 1992, last year.

 

i know i have the 165 in mine as well. Electronics are by far my weak link. I try avoiding them like the plague. I was looking at a herbert cam 220/225@.510/510 with 114 deg lobe. Id be happy with a 6k-6500 redline.

 

With larger than stock displacement and heads you really need to tune your setup.
You could use a cc 264hr. Or really setup and go with a cc 276hr or 290 with a higher stall converter.

 

You need to rethink tpi, The base and runners are a big bottleneck.

 

Agreed. However, I would state it this way: Rethink base and runners. Stick with TPI.

 

Hog out the stock base and get aftermarket runners . Afaik As&m and tpis are the only choice new.Used Slp ,accel , edelbrock , hsr, super ram .

 

My bad, I'm from old school. Let me rephrase: Stick with EFI, start with TPI but that setup will be restrictive when you need 350 or more HP.....

Use the OEM TPI ECM and go with something like a single plane EFI manifold and elbow + LS TB.

 

The mindset on this forum needs to be that any cam/head/intake and cubic inch changes should ALWAYS be tuned. Aka need a chip burned to account for the changes or else you will risk hurting the motor or simply not getting the performance out of it you could have.

Your options are learn yourself or pray you can find someone local to do it.

 

Someone local just got tossed out the window.lol

 

Thanks gents. Without datalogging, how close will the guy that writes the tune based off the info i give him? Like i said, im not into the electronics part. Me datalogging and sending the info out is prob not a option.

 

Its a guess. Ive never been fond of mail order tunes. They make the tune based on what it should be and doesnt account for actual conditions. By far best thing to do is have it tuned or learn to turn it yourself.

 

Tuning tpi maf isn't that hard to tune. I have done a few 383 but with a starter tune it still takes me 1-2 more tunes to dial it in. Why wouldn't you want to tune a expensive engine!

 

Fear of the "black box", I have it as well..
You don't wana know what I'm running around with... untuned...

 

Learn to datalog, learn to tune or buy a carb setup and teach yourself that.
One way or another you need to tune the car. Ridiculous not to.

 

Indeed its not super difficult to do. Its very intimidating at first but with proper help and reading, its easily learned imo.
Wideband o2 sensor, like aem uego for 170$ goes a long way in helping. I dont tune without it

 

It's so easy I used to tune for free...

 

Thanks again. Looks like i have some homework to do. Just wish there was someone in my neck of the woods that could do it. scott

 

In my case, might be similar to the OP's?

I have 40lb injectors and I am fearful of starting up the new engine build with an initial test of the PCM with original programming. Scared of washing cylinder walls with too much fuel.

 

I wouldnt do it. Just end up running poor and foul the plugs. Then be chasing start up issues when you go to tune

In your case its easy to setup a starter bin. Set injectors and desired idle rpm. Smooth out the timing table and set desired base timing. Generally if its a decent size cammed setup i set base timing to 10 or so and command idle timing of 25 or so.

Try firing and see what air fuel does.