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Bill Kerkhof
03-04-2017, 01:07 AM
Hi all, Im going to be installing tbi on 1979 small block 350. I have not planned on using any emissions crap but was told I still need to use egr valve or I will burn up piston and rings. Any info would be great.
thanks

dave w
03-04-2017, 01:41 AM
I can't say you need or don't need an EGR. What I can say; I've put more than 60,000 miles on a properly tuned (calibrated custom chip) TBI 350 WITHOUT an EGR. Maybe someone didn't know they needed to use a calibrated custom chip when they ran a TBI engine without an EGR????

dave w

steveo
03-04-2017, 01:53 AM
I still need to use egr valve or I will burn up piston and rings

gm ecms usually add some timing advance when the EGR is active. this is to make up for the loss of power from pumping non-combustible gas into the combustion chamber, and if done properly, you don't lose or gain any power from having the EGR active.

you just need to tune that timing out, or tune out the EGR entirely so the ECM never tries to actuate it.

there's no way you're going to burn holes in a piston, though.

engines with more cam overlap can have their own EGR effect in cruising range too, exhaust and intake gasses mix naturally in the manifold, at which point having the EGR is kinda dumb

Dirtybob
03-04-2017, 02:02 AM
....there's no way you're going to burn holes in a piston.... ....engines with more cam overlap can have their own EGR effect.... +1 to the above. With a small (stockish) cam the egr can give a small boost to fuel economy. If your setup is stock and it isn't too much trouble, I would keep the egr. No great loss if you don't though....

Bill Kerkhof
03-04-2017, 08:51 PM
I can't say you need or don't need an EGR. What I can say; I've put more than 60,000 miles on a properly tuned (calibrated custom chip) TBI 350 WITHOUT an EGR. Maybe someone didn't know they needed to use a calibrated custom chip when they ran a TBI engine without an EGR????

dave w
Where can I get custom chip you are talking about? And I assume the chip is the PROM from the ecm
again thanks to all the help

Fast355
03-05-2017, 04:38 AM
+1 to the above. With a small (stockish) cam the egr can give a small boost to fuel economy. If your setup is stock and it isn't too much trouble, I would keep the egr. No great loss if you don't though....

I would not keep it at all. The carbon buildup in the intake side and ports alone causes efficiency loss and power loss as the engine ages. When I still had the EGR on my Express van with the 350 Vortec I played with the EGR in the tune on the black box. I got 1/2 mpg gain disabling the EGR in the tune. You could feel the EGR turn on just off idle with the stock tune and gave the engine a slight hesitation. With it off it made more torque and accelerated better from a stop with less throttle and less rpms. I even disabled the EGR until 65 mph and saw no benifit even at steady cruising speeds. With the EGR active it always took more throttle to run down the road.

dave w
03-05-2017, 07:30 AM
Where can I get custom chip you are talking about? And I assume the chip is the PROM from the ecm
again thanks to all the help

I did the custom chip myself using TunerPro RT software ( http://www.tunerpro.net/ ) and a Burn 2 Chip programmer from Moates.net ( http://www.moates.net/burn2-chip-programmer-p-197.html ). Maybe you can come up to speed and burn chips for yourself also?

dave w

Bill Kerkhof
04-05-2017, 04:52 AM
I did the custom chip myself using TunerPro RT software ( http://www.tunerpro.net/ ) and a Burn 2 Chip programmer from Moates.net ( http://www.moates.net/burn2-chip-programmer-p-197.html ). Maybe you can come up to speed and burn chips for yourself also?

dave w

I'm looking into burn2 and program, but is the program able to add or remove things from it like the egr or do you have to find a pre program to download to chip. All I see for videos is people have a program saved and when they erase the chip they just get new profile from a file. So is it fairly easy to see what each line of code is to change or delete?
Sorry if it sounds stupid, I'm trying to learn this stuff. Also how do I know what prom I have, if they are compatible with burn2
thanks for any help

steveo
04-05-2017, 05:26 AM
I'm looking into burn2 and program, but is the program able to add or remove things from it like the egr or do you have to find a pre program to download to chip. All I see for videos is people have a program saved and when they erase the chip they just get new profile from a file. So is it fairly easy to see what each line of code is to change or delete?
Sorry if it sounds stupid, I'm trying to learn this stuff. Also how do I know what prom I have, if they are compatible with burn2
thanks for any help

none of that adds up. let me square it away for you.

- read your calibration file (aka bin file) from your existing chip using the burn2 or whatever chip programmer you buy. alternatively, download a copy of your original factory bin file from the internets.
- load your definition file (xdf) into tunerpro, so tunerpro understands how your calibration (bin) is layed out
- load your calibration file (aka bin file) into tunerpro
- make changes to the bin with tunerpro, in your case, something like minimum rpm to enable egr = 7000 or something so the egr is never actually used would make sense.... and save. the changes you can make and how easy they are to manage depend on how good your xdf (definition file) is
- erase the chip and write the updated bin back to it, throw it in your car, and away you go

Bill Kerkhof
04-05-2017, 05:56 PM
none of that adds up. let me square it away for you.

- read your calibration file (aka bin file) from your existing chip using the burn2 or whatever chip programmer you buy. alternatively, download a copy of your original factory bin file from the internets.
- load your definition file (xdf) into tunerpro, so tunerpro understands how your calibration (bin) is layed out
- load your calibration file (aka bin file) into tunerpro
- make changes to the bin with tunerpro, in your case, something like minimum rpm to enable egr = 7000 or something so the egr is never actually used would make sense.... and save. the changes you can make and how easy they are to manage depend on how good your xdf (definition file) is
- erase the chip and write the updated bin back to it, throw it in your car, and away you go

That clarifies it all for me, thanks a bunch!