How bad do you think the emission will get if switch to non-EGR heads? The last time I got it inspected I was only half the allowable limit on every thing.

------------------
89 350 TPI,comp cam,edelbrock intake base,SLP headers,highflo cats,flomaster cat back,accel 300+ ign,ported plenum and runners,ported maf,auto w/shiftkit,cold air induction,AFPR,custom chip,3.23 posie best ET 14.011@98.72mph without cam/New best 13.926@98.27mph

 

It all depends on how hard your state is on emissions. The computer will throw a code saying the EGR system is not working unless you get a custom PROM to fix this. I have read a few articles saying disabling EGR has no performance benefit.

------------------
1989 Iroc-Z 5.7 350, Blue, T-Tops

Lightly Moded:
Edelbrock Headers, Rebuilt B&M 700R-4 Tranny, Higher Stall Torque Converter, Airfoil, 3.4 w\posi, K&N's, Ported & Polished Plenum
-- Blue LED Bakelite Dash & Climate Control
- I am just some 17 Year old spending every dollar I make on my car.

 

Its not that im looking for more performance, its if I get some dart iron eagles or vortec's that dont have heat risers in them.Im just wondering if I would still pass emissions.In jersey we have the test where they put the car on rollers and get it to 15mph.I can shut the EGR stuff off myself I have the prom buring equipment.

 

As I understand it, the biggest effect the EGR has on emissions is NOx. Tim (Traxion) has a fairly radical 350 with a Miniram and he was successful in getting it to pass an IM240 (dyno) test in Illinois. He had to install cats and some tweaking with the settings of the eprom, but he passed.

As long as you don't have a "visual", then you should be able to make the car pass with possibly some appropriate tuning in the eprom.

Besides NOx emissions, the EGR also helps with fuel economy and has no performance penalty. If you do have a visual inspection of the EGR, you can always look at installing something a Vette type EGR, since the Al L98 heads don't have provision for an EGR either.

 

Next spring I will be using holleys fuel injected carb manifold and it doesnt have the EGR passages.So with a little tweeking of the ecm it should pass.

 

I have a car with a 350 and a cam with no EGR (vette heads) that passes the smog test just fine without the EGR. The car does have a cat though, and the cat will lower NOx readings besides the EGR. If you have the IM test you would more than likely need either a cat or the EGR to pass. This is of course just sniffer, if its not there or isnt working properly you will fail a visual/functional check.

As for the chip/code setting issue, just yesterday I stuck in a 89 prom with only the VATS turned off on this car and it never set an EGR code. There were quite a few times the EGR duty cycle was at 100% for long periods of time, but no codes. Theres no wire in the car at all for either the EGR temp sensor nor the EGR solenoid. Take that as you wish, but I havent had a MAF car throw me an EGR code yet. I hear the SD cars arent so nice about it. And as always, your results may vary.

 

Since I replaced the cats(duel)last year it shouldnt be a problem then.Thanks

 

Interesting Max. I usually TOTALLY disable the EGR - not just the diagnostics but all by the temperature. I found that there appears to be a difference if the ECM is "trying" to run the EGR and if it is outright disabled.

Just set the EGR Enable Temp for hex FE (254) which will require an MAT reading of 150*C before the ECM even tries to enable the EGR.

I still have to respond to that "book" of an e-mail you sent me.