23 replies to this topic

[JessZ]

Hey Hybridz. I live in California, the state of strict emission control. I'm looking to increase power keeping a stock appearance. Also, being that my car needs a smog every two years I need to keep my emissions under control. I'm looking to increase the performance of my Z. Would having my head, or finding another head with port work, add performance to my motor keeping the stock injectors, cam and ECU. Would head work affect the emission output of the motor. Here's a couple pics of 'baby.'

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[cockerstar]

Can you resize the pics you've attached? They're so big that I can't see a thing on a 17" screen.

Mild port work will give you more power, and the stock ECU is supposed to be able to handle it to an extent. However, it is NOT going to be a big bang for your buck in an improvement.

The stock ECU doesn't play well with aftermarket cams. From what I know about California emissions testing (which isn't much, so I hope someone else is going to chime in here too) is that if you keep it under control and pass the sniffer test, things are a-okay and CHP doesn't really care if you put in an aftermarket ECU.

With that being said, you could swap over to megasquirt and get it running on the stock engine as-is. There's improvements to be made over the stock system in both power and fuel efficiency. You could then swap in a head with some mild port work, a decent cam, and a header, and be able to fuel and support it all.


In short, swapping on a ported head while keeping "stock injectors, cam and ECU" might work to an extent, but your power gains won't be much, and the amount of money invested for the gain will be wildly inefficient. Upgrading the head is a higher-level improvement, while a header/exhaust and an intake is more of a first step. Make sense?

[JessZ]

Here's a re-size on the photos. I've more pics if you're interested. Thanks for the response. Engine management sounds like a good first step. I can do the bolt-ons no problem.

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[RB240zDET]

Clean paint. I don't think you could pay me enough money to move to Cali to have to deal with all of the emissions crap and regulations on cars...

[JessZ]

I know, it's a pain in the butt for sure. I had '71Z before this, which I installed the '83et setup on after reading through dozens of posts on Hybridz. I sold the car because I was ready for something nicer. This '77 is a reall marshmallow. She drives so nice, no rattles, sounds solid rolling over rough roads and all the weather stripping is perfect, so at 90 m.p.h she's solid as a rock. I'm just just missing the torque. But I'm also really conscience about ruining the car by fooling around with mods but a nice 3.0 Rebello with tripples would be so fine if I could afford it. Any thoughts on modifying such a nice Z?

[JessZ]

Will only bolting on a header and exhaust do much for power improvements without up grading the cam, injectors and ECU? Any 'seat of the pants' difference?

[NewZed]

This thread is popular and covers many of the common engine upgrades and how the L6 engine responds to them. Examples: the exhaust system is well-designed as-is, and the ECU control is limited since it is not easily modified.

http://forums.hybrid...dvice-and-tips/

[JessZ]

Hey thanks for that.

This thread is popular and covers many of the common engine upgrades and how the L6 engine responds to them. Examples: the exhaust system is well-designed as-is, and the ECU control is limited since it is not easily modified.

http://forums.hybrid...dvice-and-tips/

[luseboy]

Man it's a shame that car isn't pre 75, that thing looks so clean! I assume you know that california doesn't like exhaust modding, however, as long as you keep a cat, and it's not too loud, they usually don't make too much of a fuss. That said though, they don't like headers at all, so make sure if you put one in that it isn't all polished or pretty. I don't know how it is for cars of this era, but I know for newer cars anyways, they not only do the sniffer test, but also a visual, so basically you want to keep it looking as stock as possible under the hood to not raise any suspicion. Now you can swap in a newer engine, possibly even an L28et, so long as it's a nissan/datsun engine, and you keep all the emissions stuff from that engine. I don't know what they'd think of adding a turbo motor over a N/A motor, but I imagine they wouldn't like that very much. I'm almost positive they wouldn't like you putting in a carbureted engine.

[RB240zDET]

Step 1: move to Ga, no emissions on classic cars, step 2: Remove the L series engine, step 3: replace with whatever you want... I can not believe they are so strict on emissions and modifying a forty year old car.

[Gollum]

Since we don't have some concrete CA Smog input, I'll give what I can and Ray will probably chime in if he sees this thread. My brother is a smog tech no, and my best friend is a smog tech who's worked for state refs and has been offered ref positions on more than one occasion, so there's my accolades to qualify that I'm not just some idiot. I don't claim to know everything smog related and the laws change every year, but here's the gist.


Under current law, almost ANYTHING you do will be illegal. By california law, anything modification you make that changes the amount or mixture of air OR fuel going into the engine needs to be certified by CARB. This means even a larger throttle body is illegal, as it will allow more air into the engine. An exhaust header is illegal as it will scavenge the cylinders DIFFERENTLY (maybe not even more or less) thus changing air and thus fuel amounts. If it increases HP in ANY level it's technically illegal if it doesn't have a CARB number.

Is that an extreme view of the law? Yes. But it gives the authorities room to move and do what they need/want to do.

Your car is pre '96 thus pre OBD-II obviously, which is great. Because if you install something like Megasquirt on a OBD-II vehicle you will automatically fail smog because you have no OBD Diagnostics Port for the machine to hook up to.

So what can you do? As much as you want to/or think you can get away with. Will a cop or smog tech go looking for your ECU to check if it's stock? Probably not. But funky wiring might tip someone off. A missing dizzy because you're running EDIS or some COP ignition might be a bit of a tip off too. Most smog techs will fail you depending on what you look like because they'll assume their license and thus job, is on the line. If they were caught, or if you were from the state then they could loose their license for life.

The REAL beauty of our laws, is that we have such good provisions for engine swaps. As long as you transfer all of the smog equipment from the engine's donor than you can swap anything from a newer vehicle as long as it's a passenger vehicle or light duty truck. They will frown on you putting a 460 from a Ford F-250 in your Z. Might not even BAR label it.

As far as passing a modified head, it's definitely doable, but I think having the stock ECU will be fighting you tooth and nail. As long as you have a good functioning EGR along with minimal carbon build up, solid compression test you'll be able to pass. Most L engines I've seen fail, fail due to very low vacuum, thus a poorly opening EGR. Most failing L motors will pass if you hook up a hand vacuum pump to the EGR valve during the test. What happens is as the engine ages and you've got low compression you have low vacuum under load as the engine is struggling to breathe well, and the EGR never gets the chance to open all the way.

What will really make it hard to pass is a radical cam, since it will dramatically change vacuum levels under light load and lower RPM that you'll be at during the test. Keep the overlap minimal and you should be okay, but that will also limit how much compression you can run before reaching knock limitations. Running a high compression motor is totally doable on the street, but getting one to pass will be almost impossible.

Your best option in my opinion, is to just pull the motor and swap something else in and BAR label it. And talk to the local Ref BEFORE you buy a motor. Tell him what you're doing and find out what will be required. In the end, he's the law you need to satisfy, so find out what he wants. Be kind, curious, and thoughtful and you'll usually be rewarded by meeting a guy who really likes cars and is willing to give you advice. And honestly, I doubt you'll spend more than you would on modifying the L motor. A decently ported head will set you back a good $1k + and other rebuild costs incurred while putting it on. I've completed swaps for less than that.

[BluDestiny]

Keep it a stock DD. headers and a shaved intake wont do anything but look cool for the most part. Maybe 10hp if your lucky(assuming you don't have a clogged rusted exhaust system already).

Also if you can pass the sniffer most smog places wont care( at least were I'm at). If you get a real **** who looks for any little thing then you get boned.

Edit: I've had to smog 2 280zx's and neither of them cared that I had some lose wiring from deleting Cruise and AC and stuff, although all the smog provisions were there( egr was hooked up). Just my .02

edit again: after I moved to FL I realized how awesome not having emission laws are.

Edited by BluDestiny, 18 January 2012 - 11:19 AM.

[Tony D]

Megasquirt came out when? 2000? 2002? I was in on the second (last) B&G Group Buy of kits for self-assembly, and at that time there was a group of guys in Long Beach with VW Vans which installed them in the stock harness and passed Smog (which it wouldn't do with the VW system due to parts issues, etc)
These same vans have been passing Smog since (what now, 5 cycles?)

Is it Legal? No

Does it pass the visual that they do at most any station? Yes.

It can be configured to do just about anything the 75-78Z EFI did, save for the fact that the MS has an O2 Sensor so yeah...they 'dumb boxed' the original 8X8 Fuel-Only Matrix ... AND IT PASSED!

It's foolish that you can legally put an LS(X) into the car easier than a different ECU and Wiring Harness but that's the way it is.
It can pass, but you have to do it yourself, and know what you have to do to get it to pass or you will be in for a miserable time of it.

Whatever you decide, good luck.

[randy 77zt]

When i first got my 77 in 1994 I did some tune up work on the stock l28.I installed some new injectors and soldered on new injector plugs.After that I built a new distributor out of 2 with a reworked timing curve.I removed the throttle body and cleaned it .then put on a slightly bigger exhaust with no cat-but i had flanges to reinstall the cat fast.the car ran very well -it would make 90 mph in a quarter mile.The stock exhaust manifilds dont flow that bad and usually dont leak.

[JessZ]

Yeah this California smog stuff is a real bummer. I had a '69 Camaro in the late 90's. I think smog was anything post-'65 back then. I had a Performer intake and Holley 650 carb. I had to buy a stock manifold and carb to get it to pass, money and time spent I was not thrilled about. I'd then swap back and did this for two cycles. I had more energy then and that swap wasn't too hard anyway. The way I see now, I'm left with three options: 1. build a new motor and swap every cycle, 2: do a little vin swap from a junker, 3. my mom also has a '77, so if I found a cool smog guy I could have them sniff her car and couple the result to my car; I may be dreaming here? I'd be interested to hear any input on this last idea.
I did the turbo swap already to my last '71, and finding one completely intact for the '77 seems farfetched. Ideally, because the car is so clean, I'd like to increase power while keeping a stock appearance. I'm willing to stroke the motor out too, but any mod at this point is sketchy. I'll talk to the rep and see what he/she says. I'll keep you all posted.

[ctc]

Yeah this California smog stuff is a real bummer. I had a '69 Camaro in the late 90's. I think smog was anything post-'65 back then. I had a Performer intake and Holley 650 carb. I had to buy a stock manifold and carb to get it to pass, money and time spent I was not thrilled about. I'd then swap back and did this for two cycles. I had more energy then and that swap wasn't too hard anyway. The way I see now, I'm left with three options: 1. build a new motor and swap every cycle, 2: do a little vin swap from a junker, 3. my mom also has a '77, so if I found a cool smog guy I could have them sniff her car and couple the result to my car; I may be dreaming here? I'd be interested to hear any input on this last idea.
I did the turbo swap already to my last '71, and finding one completely intact for the '77 seems farfetched. Ideally, because the car is so clean, I'd like to increase power while keeping a stock appearance. I'm willing to stroke the motor out too, but any mod at this point is sketchy. I'll talk to the rep and see what he/she says. I'll keep you all posted.

A couple comments, because I went though something similar recently.

1) PITA : Not only do you need to do the swap every two years, but you need to store the motor and keep everything running. This was to much of a commitment for me.

2) Bad idea. It's one thing to cheat on a smog test, but switching VIN's will risk getting the car impounded and crushed. That's a line I wouldn't cross, but to each his own.

3)If you found a cool smog guy, pay him $200 bucks to to not sniff your car and pass it anyway. That's how most of the 240SX and RX7 guys do it. Although this is getting harder and harder.

4) L28ET is not really that hard to find. I weekly see adds on Craigslist for a non-running 280zx turbos in California. Figure about $1000 for a complete car, or a shipped engine off of ebay with all the necessary parts. Besides, you have already done it once.

If it were me, I would go the MegaSquirt route. You can use the stock wiring harness that is in the car and if you want to get really trick, the guts of a MegaSquirt will fit in the stock ECU case. Use all the stock manifold parts. Then you can modify at will and upgrade the tune each time.

Also do some research on emission and smog control devices. There is a great thread on here about emissions, just search for it. Remember, a well tuned car is a clean car. Only once you get really radical with the cam and lots of raw fuel in the exhaust do things get really out of hand. With a well tuned ECU and good fuel and igition control, you should be able to pass smog on a 35 year old car no problem.

Is your car Federal emission or California, easy way to tell is if it has a stock O2 sensor. If it is a Cali car, then all the stock components are in place that you need. How is the corner smog guy going to tell the difference between a stock 02 sensor or a wide band? Believe me, if it's close and they can pass it they will take your money.

[JessZ]

It's a Cali car, purchased in San Francisco originally.

[RB240zDET]

It just seems that there is no easy, legal and cheap way to modify your car with the current regulations put in place by California.

[Tony D]

There is.
I'm revealing as we speak.
Did you get it?

[Gollum]

There is.
I'm revealing as we speak.
Did you get it?

Ummm..... less is more? Yay weight reduction!

Honestly, our laws are the #1 reason one of my best friends got into subarus. They're the ultimate stealth smog car. AWD cars currently don't have to go on the rolling road, and due to their turbocharged nature there's lots of power to extract with very little visual change. AND you can tune the ECU with nothing but a fancy USB cable and open source software, which also allows you to removing all those fancy tip offs that the ECU would send the smog machine, making the electronic side a pass-every-time situation. Then just pass the EVAP and the sniffer, and visual and you're good.

This is how there's STI's roaming the streets that put down 500+hp that still don't need special smog hookups, yet 200hp hondas fail daily.

Is it legal? Heck no, but since when have car guys all been doing things the legal way? American graffiti anyone?