Computer Reaction To EGR Delete

I wanna get the HSR or the converted LT1 manifold for my 350, but you gotta delete the EGR, how does the motor and computer respond to this, will it run real crappy...Also how will the motor run after the change in flow when i put a new intake on, will it be able to learn it or no?

i wouldn't recommend deleting the EGR valve becuase not only is it an emmisions piece but it also helps to cool your cylinder down by putting inert exhaust gas into the chamber. i'm not sure what the damages might be but unless your running alot cooler than stock (which is well over 200*) i wouldn't recommend it. but the egr on my car is not computer controlled so i don't think it would be on your either

well what does everybody else do when they put the lt1 intake or the HSR on? They delete it i'm pretty sure, and for the cooling, i'm gonna be running at about 160 at ALL times...

An intake change like that can be run by the stock computer programming, but it would really appreciate a custom chip to make it all work well together. And you can have the EGR valve deleted in the programming so the ECM doesn't try to activate the system, which is the right way to do it.

The EGR systems on 3rd gens have been computer controlled for a long time- even back into the carburetor days. The valve is still mechanical and operates by vacuum but the AMOUNT of vacuum sent to it is controlled by the ECM via the EGR solenoid.

In the case of a TPI motor there is actually a temp sensor in the intake system to positively verify that EGR gasses are flowing through the valve when the computer is calling for it. In short, it'll know very quickly that you have defeated it and throw the penalty flag.

A TBI system there is no such sensor but the computer does other tricks to INFER whether the system is working or not. Some have gotten away with deleting it without throwing a code, some have not.

It will not cause any driveability issues. I have a block off plate on my TPI and it throws the code all the time, but I have not noticed any performance loss from it. If you dont mind seeing the idiot light all the time, its not biggie. The best way to do it though, is the correct way which is turning it off in the computer.

yea i realize that, its just i'm gonna reprogram the computer, but its not gonna be RIGHT away, it'll be during the summer sometime when i figure out how to do all that stuff...i just wanna make sure it will run close to normal with out fine tuning...also while i'm changin out the intake and fuel rails, will the computer act about normal with the change of bigger injectors too?

look more into it but i dont think it should effect performance of computer cause the egr is only an output signal and not an input,so it wont read it as a problem in which it needs to adjust for

anthony is correct, it will not affect anything. You will just get the idiot light as I have already mentioned. As far as the bigger injectors, what size are you putting in? I have 24# SVO injectors in mine right now and it runs really fat (10:1) and we tried backing off pressure and still couldnt lean it out any. I have a buddy running 24#'s in his car and it runs around 13:1 where it needs to be. Of course he has a Hyperjunk Stage 2 chip in his care as well, so that probably helped out a little.

well what is in there for stock? its a 90 corvette TPI, i'm guessing around 18 or 20#?? i would say 24# would be big enuf, i'll never go over 500 HP, so 24 should do it right? i'm gonna get an adjustable fuel pressure regulator too, so that maybe help out a bit, but if it runs real fat, that will just get me more motivated to get the computer tuned i guess...how much HP can the stock injectors handle?

Im not sure about the vettes, but I am going to guess that they are 22# stock like the L98. 24# would be plenty big for a 350. I have an AFPR and backed the screw all the way out and still didn't lean it out any. As for the AFPR, make sure you get one that has a side adjustment. The BBK like I have has a top adjust screw and is a PITA to adjust. I think I have almost rounded of the screw head, but I take it easy so I can keep from it.

I was recently doing some datalogging with the Outside Air Temperature (OAT) at about 30* and saw that the EGR did not operate at all. It does operate normally during warmer weather. It is effected by MAT. I also have my MAT relocated to the filter cover which could affect EGR operation when cold. The MAT was indicating 29* - 31* in the datalog. The engine runs with no ill effect and passes emissions with flying colors. I have reprogrammed the computer insofar as the MAT and to compensate for 24# SVO injectors and higher F/P. I've also deleted the AIR pump and related plumbing and tuned that out too. The engine runs darn good. I plan to work on John Millican's LT1 mod. for my L98 so I will experiment with EGR delete. It can be deleted in the ECM by turning off the EGR diagnostic flag and changing some of the EGR constants and tables. If like me you need to pass emissions you will need to work on that too. Get yourself the necessary programming gear and learn to program, you would not believe what you will learn. I have only scratched the surface but have enjoyed the experience.

i don't have to pass emissions, so thats no concern to me...i just wanna make the money i put into the engine worth while, and get everything outta it...i was looking at something the other day called the PROMinator, it replaces your EPROM, so you never have to burn another chip, its just a repogrammable prom, so i figure that would be the right way to go about doing that, but i wish thirdgen.org would come back up so i could read a bit more into DIY computer tuning....about how much would you say it would cost for all the parts and stuff to actually get me started on tuning my own motor? i downloaded tunerpro already, and if i need an aldl/USB adapter, i get one of those for free....i'm not really sure on what all has to be had to do the complete tuning, but how much would it be? so 24# injectors would be enuf for me, then if i run a blower in the future switch to something higher? I saw some guy the other day running 55# injectors on a blown 383, WOOW :bow: ..

The Prominator is good I use the romulator and Tunercat. Datamaster is my datalogging choice because you can view all parameters on one page although I have also used Tunerpro it is good too. You can datalog and reprogram from one program. I also use the Zeitronix WB O2 system. If you aren't careful you can get deep into your wallet on this stuff. I bought more software than I needed because I wanted to find out what I liked best. I bought the Transtronics PP2 first and later the romulator. I've probably got about $250.00 in software. Then the WB was about $300.00
To get going good the Prominator, Tunerpro and a laptop is great but the WB is also an invaluable tuning tool.

i downloaded tunerpro for free...it was the right price, but what exactly does the 02 WB system do? so your telling me all i need to get started is tunerpro, a laptop with a USB cord and an ALDL adapter, plug it in and i'm good to start tuning? then get the the PROMinator and i'm all set?

First you need to read your factory .bin. this is done by using the Transtronics Pocket Programmer 2. READ on TGO TRAX's articles. Then with the Romulator or in your case the Prominator installed in the ECM you can load the.bin into the Romulator or Prominator (I assume it works similar to the Romulator) and then you can modify the .bin as you run the engine and datalog your mod to evaluate your changes. The information in the romulator says not to make changes while driving for safety reasons. My engine stumbles during a VE table change while running so I avoid that.
If you decide not to leave the emulator permanently installed in the car (I did) you can burn your modified .bin to an EPROM and install that in the ECM. READ TRAX's articles again. This guys work is awsome.
The Wideband is another tuning tool that once you get the hang of it can cut your programming time immensely. It reads air fuel ratios over a much broader scale of ~9.5:1 to 19.5:1 than a factory type Narrowband which reads around stoich or 14.7:1. Mine also was optioned with the EGT sensor not needed but the info is interesting and can be used to tune timing so I've been told. I also hooked up the RPM and TPS for datalogging the ZT-2 on my laptop. As I said before if you aren't careful you can get deep in the pocket but for a tech freak like me it's interesting to see what's going on in my engine. I'm not by any means an expert on this stuff but have learned a lot by doing. Some of you guys who know more than I jump in if you think I'm off track. When TGO is back online go there and read and re-read the DIY EFI stuff read TRAX's tech articles. Look at grumpy's info. These guys are the experts and are most helpful as long as you don't try to pirate or try to make money off their work.