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2004 350 MAG MPI cam, ecm upgrade?

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Old 02-10-2016, 04:09 PM
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Eddie, is it nessary to have forged piston or can you run hyper pistons? right now I'm making 400hp/425tq on a pair of 383 MPI vortec engines. what would it cost for pro chargers and tune MEFI-3

Originally Posted by Young Performance
In order to take advantage of any internal work, you will need to change the exhaust. You won't see any gains from the exhaust alone, but it's necessary to realize the potential of other mods. The only way that you will see any appreciable gains will be by changing the cam, springs (and any other needed components like pushrods, lifters, etc.) and bump the compression. You can surface the heads while they are off changing the springs, etc. and raise the compression a bit. Obviously, you would need some tuning to go with the above. There is no one size fits all tune for those mods. You will need to get YOUR engine tuned. You should be able to find 50 or hp.

The other option is to install a supercharger like a Whipple or Procharger. I've done quite a few of both in the past and they make great power. You can easily get near 500 hp with either one.
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Old 02-10-2016, 04:17 PM
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I did one a few years ago. Pistons, Heads, Cam, oversized Throttle Body. It made 425HP. The boat picked up over 10mph.

Doing the ECU programming was the most challenging part since no one really has a base program for SBC's or at least no one is willing to share one. We had to start from scratch.. It took the whole day.
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Old 02-10-2016, 04:25 PM
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Some Videos;
https://youtu.be/Pykm0boxvdE
https://youtu.be/xrwGNg3Ze58
https://youtu.be/TO4_uuVpXL8
https://youtu.be/ozMkIbKQxg8

Pics
[ATTACH=CONFIG]550874[/ATTACH][ATTACH=CONFIG]550875[/ATTACH]
Attached Thumbnails 2004 350 MAG MPI cam, ecm upgrade?-tbmo.jpg   2004 350 MAG MPI cam, ecm upgrade?-mag.jpg  

Last edited by Panther; 02-11-2016 at 07:58 AM. Reason: Adding pics
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Old 02-10-2016, 06:33 PM
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Originally Posted by 01scarab29
Eddie, is it nessary to have forged piston or can you run hyper pistons? right now I'm making 400hp/425tq on a pair of 383 MPI vortec engines. what would it cost for pro chargers and tune MEFI-3
I personally would not put a supercharger on an engine with Hyper pistons in it. But that's just me. I can't take a chance that a piston will break.
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Old 02-11-2016, 10:16 AM
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Originally Posted by Panther
I did one a few years ago. Pistons, Heads, Cam, oversized Throttle Body. It made 425HP. The boat picked up over 10mph.

Doing the ECU programming was the most challenging part since no one really has a base program for SBC's or at least no one is willing to share one. We had to start from scratch.. It took the whole day.
Too bad we didn't connect because I have a base 350 Mag bin file off a MEFI 1.
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Old 02-11-2016, 10:33 AM
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You ever test without the flame arrestor ? Although we can't always go by looks, that FA looks super restrictive.

Originally Posted by Panther
Some Videos;
https://youtu.be/Pykm0boxvdE
https://youtu.be/xrwGNg3Ze58
https://youtu.be/TO4_uuVpXL8
https://youtu.be/ozMkIbKQxg8

Pics
[ATTACH=CONFIG]550874[/ATTACH][ATTACH=CONFIG]550875[/ATTACH]
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Old 02-11-2016, 03:41 PM
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Originally Posted by SB
You ever test without the flame arrestor ? Although we can't always go by looks, that FA looks super restrictive.
It was actually dyno'd without it. Besides, it doesn't have any element inside, it was more for show. There was just an inner and outer screen. It was fabbed by my friend from scratch to fit the over sized throttle body.

This pic is a little better but not the best.... Yeah, the hatch cutout and necessity to raise the hatch was an unplanned project.. Sorta didn't account for the height of the new throttle body compared to the stock engine...but at the end it turned out really nice.
[ATTACH=CONFIG]550897[/ATTACH]
Attached Thumbnails 2004 350 MAG MPI cam, ecm upgrade?-hatch.jpg  

Last edited by Panther; 02-11-2016 at 03:52 PM.
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Old 02-11-2016, 03:48 PM
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Originally Posted by Trash
Too bad we didn't connect because I have a base 350 Mag bin file off a MEFI 1.
Man, that would have saved me a half day right there! But it was a good learning experience.

We got everything worked out as far as tuning and cruise AF on the dyno but there were a few minor bugs in the boat. It had an off-idle lean stumble and the ECU needed to be programmed to cut a specified amount of timing when the shift interrupt was engaged. The MPI's don't cut ignition like the old days, it whacks timing out of it momentarily. Tyler Crocket helped me to set the IAC, shift interrupt and tune out the lean stumble off-idle while I was at the OPA race in Lake Hopatkong.
https://youtu.be/VT7TSMGD-_Y
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Old 02-11-2016, 03:57 PM
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yeah...that hatch thing.... engines, drives...fiberglass, paint...we do it all here! lol
[ATTACH=CONFIG]550898[/ATTACH][ATTACH=CONFIG]550899[/ATTACH][ATTACH=CONFIG]550900[/ATTACH][ATTACH=CONFIG]550901[/ATTACH][ATTACH=CONFIG]550902[/ATTACH]
Attached Thumbnails 2004 350 MAG MPI cam, ecm upgrade?-hatch.jpg   2004 350 MAG MPI cam, ecm upgrade?-hatch1.jpg   2004 350 MAG MPI cam, ecm upgrade?-hatch2.jpg  

2004 350 MAG MPI cam, ecm upgrade?-hatch3.jpg   2004 350 MAG MPI cam, ecm upgrade?-hatch4.jpg  
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Old 03-06-2022, 07:37 AM
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Originally Posted by Panther
I did one a few years ago. Pistons, Heads, Cam, oversized Throttle Body. It made 425HP. The boat picked up over 10mph.

Doing the ECU programming was the most challenging part since no one really has a base program for SBC's or at least no one is willing to share one. We had to start from scratch.. It took the whole day.
Currenty having my 350 mags rebuilt/upgraded, where did you get that oversized throttle body?
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