I'm giving up on my quest for a 3800SC swap and asking instead for ideas and feedback on possible 'Ghost' mods to my stock 2.8L engine. Nothing must be obviously different for a Visual Inspection at the annual Smog Test AND the Ghost mods must not degrade smog performance 'too much' and so arouse suspicion. This is a list I pulled from the Forum that look like potential options:
1) Semi-roller rockers, 1.6 ratio 2) Port & polish intakes 3) Dawg-type mod to intake and Darrel Morse-type larger bore throttle body 4) Ported exhaust logs 5) Ported Y-pipe 6) Rodney's power pulley 7) The 3.4L push rod short-block (but this is a fairly expensive one) 8) A bit higher CR pistons? Which ones? (i.e. best guess is the 3.4L DOHC at this point.) 9) Mild cam? Which one? 10) Camaro 17# injectors (to feed all of above)? 11) ??
What do you think; are mods 7-10 too aggressive for smog? Are there any other Ghost mods you can think of?
The 3.4 TDC pistons won't fit in the 2.8 block, only the 3.4. You probably know that already, but I want to make sure.
If you use 1.6 rockers plus a performance camshaft, you'll need aftermarket valve springs. The stock valve springs can handle 1.6 rockers OR a mild performance cam, but not both.
Aside from that, your list looks pretty good. Although you may not need the 17 lb injectors.
The sad part is that you can spend a ton of money on the 2.8 and you'll never know what will happen until the car is being tested. You know that here in California they try to screw people over with everything. Basically anything you do to the 2.8 at this point is a complete gamble.
I think it would be possible to drill and tap the "neck" area of the intake manifold for an N2O/fuel fogger nozzle. The nozzle should be black (no shiny bling), and facing the firewall.
You know when people "cut the trunk" on their Fieros, removing the bottom portion and making a raised flat floor? You could build a false floor in the trunk, and stick the N2O bottle there.
Worst case, you could undo the system in a short amount of time for inspections.
I have an 85 SE V6...Since new; 19 years ago I swapped in a 3.4 F-body Long block...Although this only gives approx' 20 more horses, it also gives you 30 more Lb/Ft of torque....More importantly, all of this power comes in at a lower RPM......Peak torques at 2600 and peak HP at 4500....This is like going to a better gear ratio in the "Rear end"....My 0-60 went from 7.5 to 6.5 and my 1/4 went from 15.3 down to 14.8......It is a very noticeable difference in performance. Also, you can basically stay in one gear most of the time because the power curve is so flat. (Talking about ripping winding roads here!)
Now the most important part of this notice; I have passed smog with this 3.4/ Fiero 2.8 induction at least 9 times......I will admit that slow speed driveability is not perfect (kind of hair-trigger throttle) and I have replaced the cat a couple of times. It looks absolutely stock (Minor differences on the block, if you lay under the car and really look)...
IN a parking lot Gymkana the car is basically unbeatable.....Anything with more power could not get it down. Driven flat out the engine just rips...0-30 is less than 2 seconds. You can find one of these 3.4 engines in a Camaro or Firebird from 1993 to 95...Also, GM may still be selling a long block as a replacement- even for the 2.8....You do have to drill the block for the starter (Rodney Dickman makes a jig for this)
I have an 85 SE V6...Since new; 19 years ago I swapped in a 3.4 F-body Long block...Although this only gives approx' 20 more horses, it also gives you 30 more Lb/Ft of torque....More importantly, all of this power comes in at a lower RPM......Peak torques at 2600 and peak HP at 4500....This is like going to a better gear ratio in the "Rear end"....My 0-60 went from 7.5 to 6.5 and my 1/4 went from 15.3 down to 14.8......It is a very noticeable difference in performance. Also, you can basically stay in one gear most of the time because the power curve is so flat. (Talking about ripping winding roads here!)
Now the most important part of this notice; I have passed smog with this 3.4/ Fiero 2.8 induction at least 9 times......I will admit that slow speed driveability is not perfect (kind of hair-trigger throttle) and I have replaced the cat a couple of times. It looks absolutely stock (Minor differences on the block, if you lay under the car and really look)...
IN a parking lot Gymkana the car is basically unbeatable.....Anything with more power could not get it down. Driven flat out the engine just rips...0-30 is less than 2 seconds. You can find one of these 3.4 engines in a Camaro or Firebird from 1993 to 95...Also, GM may still be selling a long block as a replacement- even for the 2.8....You do have to drill the block for the starter (Rodney Dickman makes a jig for this)
I agree with this, if you want more power and look totally stock. I don't recommend doing modifications to the long block because the Fiero intake system is the limiting factor. Basically it is to restrictive to feed an all out modified 3.4 long block.
So as i read this car has to be 35 years or older 2. pass smog check and fuel pressure test 3. they will not open the hood or decklid for a visual test 4. be identified as a classic car - much interpretation here. 5. proof of classic car insurance.
Originally posted by Blacktree: The 3.4 TDC pistons won't fit in the 2.8 block, only the 3.4. You probably know that already, but I want to make sure.
If you use 1.6 rockers plus a performance camshaft, you'll need aftermarket valve springs. The stock valve springs can handle 1.6 rockers OR a mild performance cam, but not both.
Aside from that, your list looks pretty good. Although you may not need the 17 lb injectors.
Thx for checking re: the pistons and block. I should have made that clear. Wouldn't have realized about the springs so adding them to the list. How would I tell if the stock Fiero injectors weren't getting the job done?
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Originally posted by IMSA GT: The sad part is that you can spend a ton of money on the 2.8 and you'll never know what will happen until the car is being tested. You know that here in California they try to screw people over with everything. Basically anything you do to the 2.8 at this point is a complete gamble.
This will not be run past a Smog ref, just the biannual Smog test station tech. The engine will look in all respects 'stock' so I don't see how that can fail. However, I am concerned with how the Ghost Mods will affect the Emissions. Since this is just a machine reading I don't see how I would be at risk there, if the Mods don't degrade the Emission profile too much.
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Originally posted by pmbrunelle: I think it would be possible to drill and tap the "neck" area of the intake manifold for an N2O/fuel fogger nozzle. The nozzle should be black (no shiny bling), and facing the firewall. You know when people "cut the trunk" on their Fieros, removing the bottom portion and making a raised flat floor? You could build a false floor in the trunk, and stick the N2O bottle there. Worst case, you could undo the system in a short amount of time for inspections.
I will add this to a separate list ('Mods That I Am Willing to Undo Every 2 Years') ... seems doable, except that I know nothing about what wiring/ECM-type changes would be required.
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Originally posted by cvxjet: I have an 85 SE V6...Since new; 19 years ago I swapped in a 3.4 F-body Long block ... I have passed smog with this 3.4/ Fiero 2.8 induction at least 9 times...
Now this is Hard Evidence, which is very encouraging. I would ask if there are any Emissions metrics close to failing? In my very simple view of Engine Reality my thought is that the 3.4 would pump out 20% more exhaust but that the composition of the exhaust wouldn't change. Anyone know?
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Originally posted by Rickady88GT: I agree with this, if you want more power and look totally stock. I don't recommend doing modifications to the long block because the Fiero intake system is the limiting factor. Basically it is to restrictive to feed an all out modified 3.4 long block.
Are you thinking the higher CR pistons and the mild cam would be wasted? What if I was willing to tap into my 'What I am Willing to Undo Every 2 Years' list and, let's say, have a Trueleo intake that I used all the time except for smog testing? That does't seem like too big a hassle to undo every two years, unless there are ECM-related changes required that I haven't looked into.
So as i read this car has to be 35 years or older 2. pass smog check and fuel pressure test 3. they will not open the hood or decklid for a visual test 4. be identified as a classic car - much interpretation here. 5. proof of classic car insurance.
The good 'ol Peoples Republic of California (now sporting a 2/3 Super-majority in both houses of gov BTW) requires Classic Cars to only be driven to shows, not to Starbucks or the Beach, etc. I don't see a way around that. It is really a pity that Insurance Companies recognize that Classic Car owners want to drive their cars at other times (they allow 5,000 miles/yr I think?) but that the State Gov does not.
My 3.4 conversion passes very well within the set standards...In CA.......One thing I have going for me is that the long block is younger than the original age of the car...Basically 24 vs 34 years...Also, I apparently got a very good used engine with only 35,000 miles on it...I bought it from a guy in So CA who had already drilled it and included a set of gaskets and instructions.....I mounted it and the new Getrag trany on the subframe and then did a compression check just to be sure.
The parameters for smog testing do take into account that the engine is aging......So, the set of standards a 1985 Fiero 2.8 had to pass in say 1990 would be stricter than what they have to pass in 2019.
And I was going to say that the "Classic car" designation is no good for someone who wants to actually DRIVE the car daily; They have a statement you must sign "Primarily used for exhibitions, car club events, etc" and "Not used as primary transportation"
Originally posted by cvxjet:And I was going to say that the "Classic car" designation is no good for someone who wants to actually DRIVE the car daily; They have a statement you must sign "Primarily used for exhibitions, car club events, etc" and "Not used as primary transportation"
Not necessarily. I have classic car insurance on my 1967 Fleetwood, and while I did have to sign an agreement to get that insurance, my agreement includes being able to drive it to work up to three days a week and 5,000 annual miles. There is no restriction about "primarily driven to shows or events." The only restriction is "cannot be used for running personal errands," or something to that effect. Basically, I can't take it to the mall. But work, out to dinner, cruising the foothills are all explicitly ok. Oh - crap - the other restriction is that it must be stored in a locked garage. No car port, no driveway, etc. Locked garage. That would definitely put a damper on my insuring other cars I own that way.
If you want a no-hassle engine swap the 3.4pr is the obvious answer. Mine passes easily. As others noted the 3.4l long block is what GM sells as the replacement for the 2.8l, so I'm betting that even if the smog shop knew it was a 3.4 and not a 2.8, I could somehow produce documentation to support it. Same deal as the GM e-rod motor - you can put that in ANY OBD1 car legally in California. Period.
But any OBD1 swap should be generally hassle free - TDC, Quad4 - there are options. I know of at least a couple TDC swaps with BAR stickers. it's definitely doable. It's only when you get into OBDII swaps that things get dicey. Not impossible, but dicey. But I think any high-value V6 is an easy target, and the 200+ hp those engines make seems... adequate.
From what I read, the Insurance companies cut you much more slack than the DMV....The DMV registration was where the stricter driving guidelines apply.
Although I can sometimes be frustrated with CA smog laws, I have to give some credit; Years ago I swapped in a 5.0 FI engine into my 73 mach 1.....It had to have the computer and all the sensors and no codes, etc.....But they actually did NOT require a cat! "The car was not designed for a catalytic converter and so does not have a heat shield. Possibility of fire must be avoided"....I was pleasantly surprised by that display of intelligence.
A stock 3.4L P/R engine swap and a suitable cat should make it through emission testing without a problem. If you start modifying the 2.8L with a higher lift cam, high lift rockers or high compression pistons, I would venture to say that it would not pass California emissions testing. For a bit more power I would port the intake and exhaust manifolds, and add an MSD ignition. You can hide the box under the fender lineres and it can be attached or detached with the MSD quick harness.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Originally posted by mmeyer86gt/gtp: new law So as i read this car has to be 35 years or older 2. pass smog check and fuel pressure test 3. they will not open the hood or decklid for a visual test 4. be identified as a classic car - much interpretation here. 5. proof of classic car insurance.
Agree w/ Notorio. Not much "interpretation here" and not up to you to "be identified as a classic car." In CA and most other states, It means the car has "Classic" "History" etc Tags and Registration. Most states put requirements for these special Tags in writing in State's Rules or Codes. Many have them online at DMV and/or State Code/Laws sites. So You can apply for these Tags but State can deny the app or take them after.
The Tag and/or Insurance Co will restrict driving to club events, to be in parades, and similar low driving. Many states will not allow you to drive to work, malls/stores and other things. Some states require you to have a "daily ride" before they give one of these special tags. If a cop stops you violating the rules for these tags can have big fines, points, or much worse. If wrecked while breaking the rules then "classic car" Insurance Co can void the policy and cost you big time for years.
If you can't get the special Tags... Some states still requires you to pass E-testing and Inspection every year or two to get normal registration even for 25+ year old cars. Some now dropped E-testing for OBD1 and older but not Safety Inspection.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
...and, one more time, my last (2017) smog check on my 3.4pr Fiero ...
Getting these cars through smog is NOT a problem.
Data! that is much better than my stock 2.8 which bumps up right against one of the specs each time ... I can't remember which, will have to try to find the paper work.
Originally posted by Dennis LaGrua: A stock 3.4L P/R engine swap and a suitable cat should make it through emission testing without a problem. If you start modifying the 2.8L with a higher lift cam, high lift rockers or high compression pistons, I would venture to say that it would not pass California emissions testing ...
I'll add the ignition idea to my list. Thanks!
Your comment about the Lift and Compression really gets to the crux of the matter ... with me knowing nothing about how all the Emission Control components work together to create the emission profile, I wonder if one 'tweaks' a component 20% how much that really changes things. For example, if the cam and rockers increase Duration and Lift 20% (just a fake number for sake of argument) is the emission profile going to change dramatically? To me that would suggest that the system is balanced on the edge of a knife. I think I will try to find some reading material on this ...
The OP lives in a big brother state that has some very stringent emission requirements. This is why we see cars with a CA compliant description. IIRC even the Fiero had changes on cars sold in that state. . If you look at the products in the Summit Racing Equipment catalog., you will often see "not legal in CA". Performance cams modify a cam timing and allow a larger amount of air/fuel mix into the cylinders. That may present potential for higher emissions.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
The OP lives in a big brother state that has some very stringent emission requirements. This is why we see cars with a CA compliant description. IIRC even the Fiero had changes on cars sold in that state. . If you look at the products in the Summit Racing Equipment catalog., you will often see "not legal in CA". Performance cams modify a cam timing and allow a larger amount of air/fuel mix into the cylinders. That may present potential for higher emissions.
Some times yes, the performance parts increase emissions, but mostly, they are not tested for emissions compliance. So the lack of certification on the parts prevents them from emissions compliance.
Are you thinking the higher CR pistons and the mild cam would be wasted? What if I was willing to tap into my 'What I am Willing to Undo Every 2 Years' list and, let's say, have a Trueleo intake that I used all the time except for smog testing? That does't seem like too big a hassle to undo every two years, unless there are ECM-related changes required that I haven't looked into.
Any modification you do will impact emissions in some way. As has been said before, you are risking a smog failure and wasted time and money if it does not work out. Mixing and matching parts is like an art, and in a lot of cases requires skill and experience to get it right. If you don't have it, I would advise you to keep it simple to narrow down any issues.
Originally posted by Raydar: My cammed, built up 3.4 didn't have any trouble passing emissions as long as the EGR and cat were working properly.
To save me the trouble of looking, can you please list what your 3.4 mods are, especially the cam? Any chance you have a smog report from before and after?
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Originally posted by Rickady88GT: Some times yes, the performance parts increase emissions, but mostly, they are not tested for emissions compliance. So the lack of certification on the parts prevents them from emissions compliance.
I think that is exactly the case: the manufacturer didn't submit the part to CARB for compliance testing which is apparently quite expensive. It must be a cost-benefit thing where the manufacturer feels the potential sales are small vs the cost of getting the compliance tests done. Rodney could probably confirm this with respect to his replacement cat, which can't be sold in the PRC, to my great regret. This same issue was at work when I was looking at different handguns for sale. The one I really wanted was not allowed in CA b/c the manf had never submitted it for testing.
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Originally posted by Spadesluck: Ever thought about just moving instead?
Often, yes. We moved here 20 yrs ago from a four-season state with harsh winters for the sake of my wife's health (and happily it really did help.) Now we are pretty much stuck here.
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Originally posted by Rickady88GT: Any modification you do will impact emissions in some way. As has been said before, you are risking a smog failure and wasted time and money if it does not work out. Mixing and matching parts is like an art, and in a lot of cases requires skill and experience to get it right. If you don't have it, I would advise you to keep it simple to narrow down any issues.
Actually this is precisely why I am bouncing this off of the Forum. I figure enough wisdom will flow to point me in the right direction.
Actually this is precisely why I am bouncing this off of the Forum. I figure enough wisdom will flow to point me in the right direction.
I love the thought of a hot engine that looks stock and passes emissions. But people can give you thousands of ideas, but ultimately it is up to you to pay for it and put your time into it ,...just to hope it passes. The fewer mods you do, the fewer potential problems to diagnose. Keep it simple and enjoy the power you get from larger displacement. The engine is an air pump, the limiting factor is the intake system. No matter how much you modify the long block, the intake will only support so much power. And some modifications could acutely cost you power. I don't know how much the stock (ported) intake can flow, but my money says a stock 3.4 block is all you need, if you use the stock 2.8 intake system. Keep in mind that the Fiero exhaust system has to be used, or some type of log style header that looks stock and the cross over pipe. They are restrictive to say the least. The name of the game getting the engine to breathe.
[This message has been edited by Rickady88GT (edited 12-24-2018).]
Originally posted by Rickady88GT: I love the thought of a hot engine that looks stock and passes emissions. But people can give you thousands of ideas, but ultimately it is up to you to pay for it and put your time into it ,...just to hope it passes ...
There's no rush so I will take ideas and research them before doing anything and I really appreciate everyone chiming in. Ideally I'll be collecting parts in 2019 and make the changes during Christmas break. So far I've been reading about Compression Ratio and temperature. According to one reference NOx production increases exponentially with Temperature. Since CR raises the temperature vs stock this seems like a potential Red Flag. More reading needed ...
To save me the trouble of looking, can you please list what your 3.4 mods are, especially the cam? Any chance you have a smog report from before and after?
I don't have it any more. It was sold several years ago. It was a Grooms rebuilt 3.4. Had ported heads and a Crane 272 cam. (The cam required different springs and some machine work to accommodate those springs.) The Crane H-262 cam is "one size smaller" and will work with stock springs, as long as you keep 1.5 rockers. I had a bored lower intake and throttle body, as well as a Trueleo intake. (The closest thing available to the Trueleo is "Dawg's" intake mod.) I also had FOCOA headers and 19# Bosch injectors.
It ran rich until it warmed up and went into closed loop.
For yours? I would do maybe an H260 cam, stock ratio "Comp" roller tip rockers, ported TB and "Dawg" intake mod. Ported exhaust manifolds and Y-pipe. If you've got a few hundred to burn, have the heads ported. Retain your EGR and cat. It'll probably pass smog on stock injectors, but you may want to go larger for best WOT performance. You can go with DOHC pistons, but keep in mind that the higher the CR, the more likely it is to have high NOx readings (due to high combustion temps.) It's been my experience that if it pings at all, it ain't gonna pass.
This is just my best guess. Others will, no doubt, have equally valid suggestions.
[This message has been edited by Raydar (edited 12-24-2018).]
Originally posted by theogre:Most states put requirements for these special Tags in writing in State's Rules or Codes. Many have them online at DMV and/or State Code/Laws sites. So You can apply for these Tags but State can deny the app or take them after.
The Tag and/or Insurance Co will restrict driving to club events, to be in parades, and similar low driving. Many states will not allow you to drive to work, malls/stores and other things. Some states require you to have a "daily ride" before they give one of these special tags. If a cop stops you violating the rules for these tags can have big fines, points, or much worse. If wrecked while breaking the rules then "classic car" Insurance Co can void the policy and cost you big time for years.
In California, the thing that makes your call a "collector car" is meeting certain criteria, and having that criteria verified by a referee. No special plates or tags. "Just" a trip to the ref.
The breakdown for us, as it applies here, is that in order for a ref to approve your ride as a collector car he will verify it is unaltered from factory specs. So, this is not the way to get your LS4-powered Fiero through smog.
In California, the thing that makes your call a "collector car" is meeting certain criteria, and having that criteria verified by a referee. No special plates or tags. "Just" a trip to the ref.
The breakdown for us, as it applies here, is that in order for a ref to approve your ride as a collector car he will verify it is unaltered from factory specs. So, this is not the way to get your LS4-powered Fiero through smog.
The only way to get an engine swap done right is to get the SB500. Otherwise, our engine swaps will have to go through a certification and biannual inspections. And those are a hassle and NO changes to the engine are allowed after the swap certificate is validated.
Here in Maryland they use V.E.I.P which is a standardized 3rd party/out sourced program. They have one bay in each station for pre ODBII vehicles. Those used to be put on a treadmill/dyno barrel for testing. But now for the most part they are idle and off idle tested. Before the test they look at the emissions sticker to see if the equipment that is stated in it is there. I can only assume that Cali does do a load test. I can tell you that on a loaded test modified equipment does produce more emissions. I only mention this due to before Maryland had their own emission stations that were run by the state. When the Feds changed the laws around( 4 gas with NOx opposed to 3 gas), it was cheaper for them to have it out sourced. Most of the operators at the V.E.I.P don't have a clue what is really going on with the way emission are handled. They rely on the ODBII readings. When there is a pre ODBII car they normally have a different operator run the test. I miss the older system. The operators were required to know. I am no longer certified, but when it was 3 gas, I was a certified emissions technician. Yeah this was about 20 years ago. On the old system, I had through them a boner. I had a 1978 LUV truck that I had a 1964 Buick 300 V8. The operator looked under the hood and said "No way". So I had him go get his manager. The manager came back and had him confirm the emissions sticker equipment. NON catalyst, A.I.R, NON EGR, Carburated. The equipment matched and worked. And passed the exhaust readings. The shop I was at had a registered gas analyzer. Drove that truck like that another 100,000 miles. DON'T TRY THAT NOW OR IN CALI. There are some things you can do to tone down the emissions during testing. Most would be done in tuning(EEprom program) Here is an area that is highly illegal in all states, to tamper with PCM programming, but there are many who do it. If you are a technician, you can be fined heavily. And I won't mention any of the ways the programming would work. Do some homework. My current configuration is running the stock program/bin for the PCM and engine that is in it, except for matching the shift patterns to the tire size. All code monitors are on. Maryland has been hinting on changing their Historic car guide lines. If/when they do, I am doing my best to make it safety and emissions legal with little changes.
The thing you'll mostly need to pass smog with significant mechanical mods is custom tuning of the stock computer... and that's getting harder and harder to come by.
CA does have a process whereby you can do a swap and have it certified smog legal. Once you get that sticker, you just have it smogged like the car the engine came out of (mid '90's Camaro for iron head 3.4). You can still do "ghost" mods to your engine at that point as well, as long as it stays within the test limits. Given the hassle of going through the certification process, do something move impressive than an iron head 3.4 if you'll go that route.
Just a few notes. CO (carbon monoxide) high levels caused by partially/incomplete brunt fuel. Most likely cause is not enough O2 to sustain combustion. HC (hydrocarbons) High levels mostly caused by something that would cause a misfire. Faulty ignition, Too much O2 (air leak), weak compression, over or under advanced timing. The converter can only handle so much before it overheats. But it is supposed to take HC and CO and turn it into H2O and CO2. Then the back part of the converter is supposed to break down whats left into more H2O and O2. When engines are cold they produce some H2SO4. That's why our exhaust systems rot out from the inside on short trip driven cars. CO2 (carbon dioxide) High levels normally due to too much CO and the converter is trying to convert it by adding O2. 1 C+1 O+ 1 O(atoms) making CO2. If the converter is not working the CO levels on a rich system are high. O2 (oxygen) OK this one is different on different type of emissions controls. Single/standard/old/early catalyst, 3 way catalyst, Air induced catalyst, Secondary air injection, ect. For the most part on a standard catalyst you want at least 1/2 the % of O2 that enters the engine. Considering that average is near 20% in ambient air, you should have around 10 % coming out of the tail pipe. The rest should have been converted into something else. An A/F O2 sensor should be reading back and forth around 1/2 of it's range considering it is reading from ambient to nothing. On a 3 way catalyst, the downstream O2s should read about 60-75% of it's range when the catalyst is working and hot. The extra O2 is the catalyst trying to clean up some of the left over CO2. NOX (nitrides of oxygen) Normally nitrogen is stable. But when you have uneven temperatures in the combustion chamber, the nitrogen gets mixed with oxygen. EGR helps this by adding an inert/already burnt gas back into the mix. Helping to even out the temps. Anything that can cause a hot or cold region (compared to the rest of the combustion chamber) will cause NOx to rise. Over advanced timing causes too early a flame front from the top. (direct injection reduces this while being able to keep timing curve up. Coolant passages too close to the chamber(careful with those porting jobs). Protruding head gasket material(bad designs,[slow air speed,reason for split port intakes] over milled heads, too high compression pistons, over boosting. Running the wrong thermostat can cause high COs and higher NOX. In the last 20 years there has been a lot of design changes in the way coolant passes through the heads to help with this.
[This message has been edited by cmechmann (edited 12-27-2018).]
Originally posted by Will: The thing you'll mostly need to pass smog with significant mechanical mods is custom tuning of the stock computer... and that's getting harder and harder to come by ...
That's a good point to consider, as long as the ECM still checks out as a stock 88 Fiero.
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Originally posted by cmechmann: Just a few notes ...
Those are a whole heap of helpful notes actually; thanks! Since I still have what appears to be the original Cat I was figuring I would replace that for sure. Since if I recall correctly that I have had 1 emission right on the failure line and the other 2 were well within the limits that the Cat was bad (I mean at least one of the three different catalysts was kaput.) But if I knew which was almost failing perhaps that would help my diagnose the system better. Searching through my records I can't find the prior smog checks. Perhaps the shop I use will be able to retrieve them ...
In Maryland on pre 3 way catalyst. Limits were HC 220 ppm and CO was 1.2. Newer the HC limits were around 120 ppm. O2 levels were determined by what equipment it had(A.I.R). As stated before, after 1995, they were relying on ODBII systems to monitor for failures. The 3 main differences in pre ODBII and ODBII was that there 3 monitors added in ODBII compliant cars. Ignition system capable of reporting misfires. Monitoring O2 post cat. And Evap system leak test. So if the system didn't show failures, it was reasonable to assume that the emissions were in spec. If I'm not mistaken, Cali also does a gas test to see if the ODBII monitors have not been disabled. If they fail gas test they might look at data stream to see if something had been turned off. The (P0420/430) are tampered with a lot on tuned cars.
That's a good point to consider, as long as the ECM still checks out as a stock 88 Fiero.
Those are a whole heap of helpful notes actually; thanks! Since I still have what appears to be the original Cat I was figuring I would replace that for sure. Since if I recall correctly that I have had 1 emission right on the failure line and the other 2 were well within the limits that the Cat was bad (I mean at least one of the three different catalysts was kaput.) But if I knew which was almost failing perhaps that would help my diagnose the system better. Searching through my records I can't find the prior smog checks. Perhaps the shop I use will be able to retrieve them ...
John
Keep in mind that if you replace the cat, you have to replace it with a CA-legal replacement, which may or may not be hard to come by and WILL be expen$ive. There's only one cat in the system, so I'm not sure why you're referring to three, unless you're recalling your experience with a different car.
Also, there's a point at which it will become easier to do an engine swap. You could go to the 3900 V6 out of a Pontiac G6 with 6 speed manual transmission and have 240 HP with a stick ALTHOUGH duplicating the G6's catalyst configuration in the Fiero may or may not be difficult.
[This message has been edited by Will (edited 01-01-2019).]
Originally posted by Will: There's only one cat in the system ...
LOL. Was referring to the three measured emission gases (HC, NOx, and CO), where just one of these three (I think maybe the HC??) was one digit away from failing, similar to what someone else mentioned. Until I did a little research I didn't understand that the Cat has three catalysts in it, one to handle each gas, which apparently come to end-of-life at different rates, so it is not unusual to have one failing from a bad Cat instead of all three.
quote
Originally posted by Will: Also, there's a point at which it will become easier to do an engine swap. You could go to the 3900 V6 out of a Pontiac G6 with 6 speed manual transmission and have 240 HP with a stick ALTHOUGH duplicating the G6's catalyst configuration in the Fiero may or may not be difficult.
Yeah, that is an attractive swap. From what has been posted here by others I'd be concerned I'd get a Ref who would be a stickler on the exhaust. For my long-term plan perhaps the thing to do is make an appointment with a Ref at the paper-planning stage and walk them through everything before committing to buying parts (and then HOPE they don't retire before I do the swap.)
[This message has been edited by Notorio (edited 01-01-2019).]
Originally posted by cmechmann: If I'm not mistaken, Cali also does a gas test to see if the ODBII monitors have not been disabled. If they fail gas test they might look at data stream to see if something had been turned off. The (P0420/430) are tampered with a lot on tuned cars.
There are two tests for OBDII cars. On 1996 to 1999 cars, they are tested just like pre-OBD cars. Visual inspection, timing check, gas cap check, dyno check. For 2000+ cars, it's a visual inspection, gas cap check, and an OBDII reader to be sure "enough" (it varies by car) monitors are set. Nothing further is done.
Originally posted by Will: Keep in mind that if you replace the cat, you have to replace it with a CA-legal replacement, which may or may not be hard to come by and WILL be expen$ive. There's only one cat in the system, so I'm not sure why you're referring to three, unless you're recalling your experience with a different car.
Cats for Fieros (and indeed all pre-OBD cars) are neither difficult to come by nor particularly expensive. The one I used two years ago was a Magnaflow 36305. It's 2.25" on both ends, there is also the 36304, which is 2" on both ends. It was $140 from Summit. Took one day to get. There are plenty of options for other cats that fit the same spec at lower and higher price points. The range I found was $120 to $220.
The only cats that tend to be difficult to source in California are for older OBDII cars with unusual cats, like those integrated into an exhaust manifold etc. Sometimes there are not aftermarket options here and you end up stuck at a dealer. California legal OBDII cats do tend to be expensive - the one for my old Hyundai Santa Fe was $600. That hurt, especially when 46-state (CA, MA, WA, NY are all the same spec IIRC) cats were half that.
OTOH, how often do you replace a cat? Once every decade or two? Meh. I'm not gonna sweat it. And, these 4-state cats aren't without value. They carry a mandatory minimum five year warranty. You don't get that with the $50 cats.
