FIRST TPI Intake EGR Delete?
Thread Starter
Intermediate
Joined: Dec 2019
Posts: 35
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FIRST TPI Intake EGR Delete?
I'm almost done buttoning up the FIRST TPI intake install on my '90 L98, and initially I had assumed I would be deleting the EGR setup. As I've read more about it, I'm second guessing this approach and potential consequences.
The car is mostly stock, including the cam, with some small upgrades to 1.6 rockers and a MagnaFlow catback exhaust. It's just a weekend car, so it needs to be reliable. I'm not really worried about fuel economy either.
My understanding is that the EGR can be deleted without changing the ECU by faking out the EGR feedback with a diode, but there are some concerns with lean conditions while "cruising".
I've read through several threads on the forum, but I thought I would ask one more time and specifically about the '90.
The car is mostly stock, including the cam, with some small upgrades to 1.6 rockers and a MagnaFlow catback exhaust. It's just a weekend car, so it needs to be reliable. I'm not really worried about fuel economy either.
My understanding is that the EGR can be deleted without changing the ECU by faking out the EGR feedback with a diode, but there are some concerns with lean conditions while "cruising".
I've read through several threads on the forum, but I thought I would ask one more time and specifically about the '90.
- Can it be deleted?
- Should it be deleted? (I'm in Texas, so no emissions test)
- If I delete, what is the best method? Is an ECU mod required/recommended?
Safety Car
Joined: Sep 2001
Posts: 4,157
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From: Glenbeulah Wi
First question, do you have the EGR option with the First intake?
To do it correctly you should really have a chip tuned to eliminate the EGR, very easy to do. If you fake out the EGR operation with a diode the car will probably operate fine but the EGR operation does add some additional amount of timing to try and compensate for the slower fuel burn with the exhaust gasses being introduced into the combustion chamber. If you do not add the exhaust the added timing may not be needed and could cause knock retard in certain conditions.
To do it correctly you should really have a chip tuned to eliminate the EGR, very easy to do. If you fake out the EGR operation with a diode the car will probably operate fine but the EGR operation does add some additional amount of timing to try and compensate for the slower fuel burn with the exhaust gasses being introduced into the combustion chamber. If you do not add the exhaust the added timing may not be needed and could cause knock retard in certain conditions.
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
First question, do you have the EGR option with the First intake?
To do it correctly you should really have a chip tuned to eliminate the EGR, very easy to do. If you fake out the EGR operation with a diode the car will probably operate fine but the EGR operation does add some additional amount of timing to try and compensate for the slower fuel burn with the exhaust gasses being introduced into the combustion chamber. If you do not add the exhaust the added timing may not be needed and could cause knock retard in certain conditions.
To do it correctly you should really have a chip tuned to eliminate the EGR, very easy to do. If you fake out the EGR operation with a diode the car will probably operate fine but the EGR operation does add some additional amount of timing to try and compensate for the slower fuel burn with the exhaust gasses being introduced into the combustion chamber. If you do not add the exhaust the added timing may not be needed and could cause knock retard in certain conditions.
