wheelman Posted January 7, 2004 Share Posted January 7, 2004 This may seem like a duh question but I'm going to ask it anyway. I've searched the site for information regarding the removal of the smog stuff from the GEN II chevy engines (LT1, L99) and how it affects performance and come up with basically nothing. I haven't looked on any LT1 specific sites yet so forgive me if this is a no brainer. Here goes. In the past we always removed the smog stuff from engines because it was a drag on performance. In the last couple weeks I've seen a few posts here that make me wonder if this is true for the newer engines. One post in particular was basically an advertisement for the new John's Cars LS1 kit where it was stated that removing the EGR prevents the computer from being able to retard or advance the spark like it's supposed to. I don't remember exactly what the other post was but the opinion being expressed was that there's no benefit to removing the smog equipment from the new computer controlled engines and it makes them run dirtier, idle rougher, harder to start and have less HP. I have a 95 LT1 from a Caprice cop car that I'm putting in a 73 240Z so I'm exempt from smog inspections and besides WA state doesn't have state wide inspections, only certain areas. Anyway I plan on removing all the smog equipment (air pump, EGR, evap canister) and then re-programming the PCM. Before I do this though I want to be sure that it will improve performance. I have the complete donor car so I could salvage the evap canister but I really don't want to have to deal with it. So what's the true story here? Will removing the smog stuff and reprogramming the computer increase, decrease or not change the performance. Ken W. Quote Link to comment Share on other sites More sharing options...
mas28O Posted January 7, 2004 Share Posted January 7, 2004 Washington State I just got back from there, bad snow storm. On my Lt1 I took of all of the smog parts and then I put in a new program in the ecu. No problems yet. Mike Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 7, 2004 Share Posted January 7, 2004 93 lt-1 no smog or egr suff, runs great for years. Quote Link to comment Share on other sites More sharing options...
gvincent Posted May 24, 2007 Share Posted May 24, 2007 So what all can be removed and what did you have to plug up? I am removing the drive train in the next week and will start prepping the motor soon. Shopping list: EGR block off plates? what about the air pump? anything else that can be removed? going with one of those cold air/K&N kits on Ebay for intake Thanks, Greg Quote Link to comment Share on other sites More sharing options...
deja Posted May 25, 2007 Share Posted May 25, 2007 So what all can be removed and what did you have to plug up? I am removing the drive train in the next week and will start prepping the motor soon.Shopping list: EGR block off plates? what about the air pump? anything else that can be removed? going with one of those cold air/K&N kits on Ebay for intake Thanks, Greg Before you spend money on that EGR block-off plate its just two pieces of metal, some aluminum, some steel, nothing special. You can make them yourself for 1/10 the cost. And on a LT1 nobody will really be able to see them so they don't have to be all that purdy. I removed the EGR and its vacuum solenoid, the air pump and the canister. I just got the stuff to make my K&N cold air. Trial fitted it tonight. Still have to hard mount the MassAir and make a suport for the K&N. Quote Link to comment Share on other sites More sharing options...
piston Posted May 25, 2007 Share Posted May 25, 2007 nice pic deja...reminds me of my engine...anyways, i have my egrs blocked off with some 3/8 plates. took off the smog pump+brackets. and also that evap solenoid thing on the intake manifold. im sure it has to gain a little since alot of the stuff isnt being used meaning more power to the motor. i have everyting capped off on the manifold and runing it as plain as possible. but unfortanantly, my computers not tuned, my crank bolt broke into the crank, and no harmonic balancer so engine sits at the moment...new crank and internals going in. and this time, a 3.75 crank is probably going in with 5.7 h beam rods and hyper pistons going in with ported aluminum heads. not going to be running for a while but oh well, at least i got the chance to drive it!!! Quote Link to comment Share on other sites More sharing options...
deja Posted May 25, 2007 Share Posted May 25, 2007 nice pic deja...reminds me of my engine...anyways, i have my egrs blocked off with some 3/8 plates. took off the smog pump+brackets. and also that evap solenoid thing on the intake manifold. im sure it has to gain a little since alot of the stuff isnt being used meaning more power to the motor. i have everyting capped off on the manifold and runing it as plain as possible. but unfortanantly, my computers not tuned, my crank bolt broke into the crank, and no harmonic balancer so engine sits at the moment...new crank and internals going in. and this time, a 3.75 crank is probably going in with 5.7 h beam rods and hyper pistons going in with ported aluminum heads. not going to be running for a while but oh well, at least i got the chance to drive it!!! Bummer about the crank bolt, that was just weird. If ya gotta tear it dwn ya might as well put in sone goodies. Are you going to chnage the cam too? Quote Link to comment Share on other sites More sharing options...
piston Posted May 25, 2007 Share Posted May 25, 2007 im just going to put the stroker in it and try find me a set of aluminums with the lt4 kit. same lt4 cam...i might boost the thing, so the lt4 is enough for now and not too much over lap for boost. Quote Link to comment Share on other sites More sharing options...
bodie Posted May 26, 2007 Share Posted May 26, 2007 rule of thumb if you think you gona need it to pass emission in your state keep it on, emission part on late models motors dont effect the performance of a vehicle, and most like the egr only come on at part throttle. the air pump on a lt1 is electric soe it dont matter. but if your not running catalyc converters you dont need to run and air pump. Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 27, 2007 Author Share Posted May 27, 2007 I removed the air pump, evap canister, EGR and the solenoid. Been running that way now for about 1 1/2 years. Made 274HP at the rear wheels on a dyno last month. I did retune the PCM to remove the requirement for the EGR otherwise it will throw a code. Piston, I did the same thing on my engine, over torqued the bolt and snapped it off. Fortunately enough of it was sticking out that I was able to work it out with out resorting to an ez-out. I eventually had to redrill and tap the crank and insert a heli-coil to get it put together (don't ask, it's a long story I'd rather not remember). Anyway it is possible to salvage that crank. Wheelman Quote Link to comment Share on other sites More sharing options...
piston Posted May 28, 2007 Share Posted May 28, 2007 wheelman, i did the same thing, but unfortunantly, the friggen easy out wasnt so easy to get out when it broke into the bolt itself. that thing would not drill at all. i was so pissed off, the easy broke and that was pretty much it. i welded a harden steel onto the end of the bolt and heated it and tried to turn it out, the bolt just broke little by little. i then bored the harmonic hub and slide if onto the crank itself and mig that thing on, and it looked pretty promissing since i have to take the thing out anyways, i decited to weld it onto the crank itself. i started the motor and it ran like normal, then, as soon as radiator and collant was pored in and drive out of the garage, it broke and fell off on the driveway, the weld peeled of from the crank along with little pieces off the crank. i just pushed it back into the garage and call it a day, or month you can say. i have nop choice but to replace the crank, so 383 comes to mind, i know i dont need all that hp for the car, but a lt1 383 just sounds so sick ya.... Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 29, 2007 Author Share Posted May 29, 2007 Piston, Did you even put the alternator belt on? I never even considered welding the hub on, would have been a real b*tch to change the timing chain if you ever had to, I guess it's a moot point now though. Sorry for the problems. Yeah a 383 LT1 would be fun, so is that your final plan? You'll have to keep us posted on your progress and get some dyno runs once its running. As for ez-outs, I'll never use them again. I busted one in a bolt when I was a teenager and ruined several drill bits trying to get it out before finally throwing the part away and getting a replacement from a junk yard. Wheelman Quote Link to comment Share on other sites More sharing options...
piston Posted May 31, 2007 Share Posted May 31, 2007 yeah, i had the serp belt on and ran it in the garage for a good minute. as soon as i took it out of the garage, i heard wierd idle problems, then i shut it off and the harmonic w/ hub just fell off and tore up the belt. the harmonic and hub was sitting on the street...im sure it wasnt enough to dmaged anything.. i never wanted to weld on the hub also, but i had just actually replaced the chain, and all the seals on the front cover. i had to take out the crank anyways for for a new one so i figure ill just weld on the hub for last option to see if itll work for the moment and be able to drive this thing, cranks comming out anyways right! so i welded it on. i figured if i had to take it out anyways, lwhy not try welding it and run it like that for a while. i was so close to tunning it with tunercat and got all excited too, then it leaked, had to replace seals, then crank bolt broke...now it just sits until i move out to a bigger house sometime this week before i get started again. im always updated, but i didnt even get the chance to tune the original motor to run right, so the next build would be a little longer progress... i put in over 8 hours of drilling and used over 20 high speed steel drill bits, after thinking, what a waist of time and drill bits. Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 31, 2007 Author Share Posted May 31, 2007 You have to use special left hand extra hard drill bits to remove a broken ez-out, I avoid them like the plague. BTW: Where in Sac do you live? I was stationed at McClellan AFB for 6 years back in the late 80s. Lived in Roseville for a while then in an apartment complex just off base and finally was able to move on base. The base housing was located in North Highlands close to Antelope Blvd. Wheelman Quote Link to comment Share on other sites More sharing options...
azguy Posted May 31, 2007 Share Posted May 31, 2007 I removed all the smog equipment from my LT1 - egr, air pump, evap, and put block off plates. If I had known more about emissions like I do now I wouldn't have taken it all off. If you leave everything except the air pump setup - that's just for cold start emissions lowering, you will get/keep better gas mileage at cruising speeds and the ability to run more advance with less detonation. I am looking into putting my egr back on when I do my rebuild. You do not gain anything by taking the egr off. When working properly it only opens at crusing speeds, and closes at WOT.- it doesn't affect power when you call for it with the gas pedal. Quote Link to comment Share on other sites More sharing options...
Dan B Posted August 11, 2010 Share Posted August 11, 2010 Hey all you people that removed those smog parts, Do any of you still have them? I live in california and am looking for LT1 smog parts for my engine. I need a EGR solenoid, EVAP canister and solenoid, EVAP canister, and prob some other junk so if you have any of that lying around and want to sell it let me know. Thanks Quote Link to comment Share on other sites More sharing options...
GOTHALOSISM Posted August 11, 2010 Share Posted August 11, 2010 I have a few parts like the air pump as of right now. I'll be pulling the rest off once I am able to get some headers. Quote Link to comment Share on other sites More sharing options...
Dan B Posted August 11, 2010 Share Posted August 11, 2010 Right on well send me a message whenever you get stuff off. Mainly I just need the evap canister and EGR solenoid. I have the air pump, EGR valve, and most of the plumbing Quote Link to comment Share on other sites More sharing options...
GOTHALOSISM Posted August 11, 2010 Share Posted August 11, 2010 I dont have an evap canister but will keep an eye out for one. Quote Link to comment Share on other sites More sharing options...
kellysautosport Posted August 12, 2010 Share Posted August 12, 2010 rule of thumb if you think you gona need it to pass emission in your state keep it on, emission part on late models motors dont effect the performance of a vehicle, and most like the egr only come on at part throttle. the air pump on a lt1 is electric soe it dont matter. but if your not running catalyc converters you dont need to run and air pump. i can only comment on my districts emissions rules, but in all of my LT1 cars i passed emissions without the airpump, and with the egr tubes sealed off at the exhaust. Quote Link to comment Share on other sites More sharing options...
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