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1996 ImpalaSS WX3
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Discussion Starter #1
Since there are no aftermarket intake manifolds for the LT1 that are legal here in Califucdia (if there is PLEASE let me know) is anyone out there port matching or doing any porting of the intake manifolds runners, or doing the same port matching and porting of the intake and polishing of the exhaust on iron heads ?
3 angle valve seats, etc...
Since I can’t install the LT4 Air Gap Manifold on my car in Cali. I’m going to have to do internal mods that are undetectable to smog techs.
I want to keep the iron heads as they tend to outlive and outlast aluminum heads...
And can take more heat without warping or cracking.
Any and all advice is appreciated.
Thank you for your time...
 

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Advance Induction, Lloyd Elliot, any number of other head porting shops offer manifold port matching as well.

-Brian
 

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Discussion Starter #3
I’ll look into what Lloyd Elliot’s offered services are, I recognize the name from engine builds.
Advance Induction as well
I place a high value in word of mouth recommendations, more than what a search engine or website says.
Such as those from members of this forum.
Thank You for the advice.
I appreciate it !
 

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Is that a new development?
This is still on their sight .

News and Updates:

February - March 2019

Like most years, we spend Dec-Feb working our backlog down, and CNC'ing as many cores & new castings as we can fit in to get ahead for the busy spring-summer season. Right now we've got the backlog down to 3-4wk. Thank you guys so much for working with us, and keeping us so busy over the years!



    • Current Backlog for most types of heads is 3-4 weeks.
    • We are preparing to do a group of old school LT's this spring - get your heads inbound if you want in, please.
    • Manifold porting & cams are an option only when we're also doing a set of heads for you at the same time.
 

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Would a CARB inspector even notice a different intake? Headers, cold air, no cats... sure. Grind off any name tag, should be fine.
 

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Discussion Starter #7
I appreciate the time you’ve taken to respond jayoldschool, but I don’t think you’re completely aware of Cali’s smog certification protocols.
You can’t grind anything off, and if installed, there has to be the manifold associated CARB sticker displayed on the radiators upper support bracket.
There’s only 1 aftermarket intake manifold for the LT1/LT4 that I’m aware of, it’s the Edelbrock Air Gap, and even with all the proper smog apparatus attachment points and EGR attachment location machined in, it’s still not CARB approved.
And yes, any smog tech out here in California will visually recognize it as a non-stock, aftermarket, non CARB approved intake manifold.
So any modifications I want to do, would have to be done internally to the stock manifold, and the heads at the same time.
If anyone is aware of any other CARB approved aftermarket intake manifolds out there, please let me know.
Otherwise I’m limited to having my heads and intake ported and port matched, along with porting and polishing of the exhaust to match my exhaust manifold or headers.
I may look to Golan Engine builders also as another alternative.
Thank you 95Wagon and jayoldschool for the responses and relevant information.
I do appreciate your advice, information, and time.
 

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Then no Kalephony-an would ever be able to get away with the First Fuel Injection Intake Manifold …

Asking this question because I GENUINELY do NOT KNOW …
Would it be CARB smog legal to 'AirGap' our own intake manifolds?
 

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The Extrude Hone process was popular in the Ford 5.0 era when no aftermarket manifolds were available yet. Might want to see if it's still around.
 

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I am aware of the CA inspection. If the home plate was on... ?

I appreciate the time you’ve taken to respond jayoldschool, but I don’t think you’re completely aware of Cali’s smog certification protocols.
You can’t grind anything off, and if installed, there has to be the manifold associated CARB sticker displayed on the radiators upper support bracket.
There’s only 1 aftermarket intake manifold for the LT1/LT4 that I’m aware of, it’s the Edelbrock Air Gap, and even with all the proper smog apparatus attachment points and EGR attachment location machined in, it’s still not CARB approved.
And yes, any smog tech out here in California will visually recognize it as a non-stock, aftermarket, non CARB approved intake manifold.
So any modifications I want to do, would have to be done internally to the stock manifold, and the heads at the same time.
If anyone is aware of any other CARB approved aftermarket intake manifolds out there, please let me know.
Otherwise I’m limited to having my heads and intake ported and port matched, along with porting and polishing of the exhaust to match my exhaust manifold or headers.
I may look to Golan Engine builders also as another alternative.
Thank you 95Wagon and jayoldschool for the responses and relevant information.
I do appreciate your advice, information, and time.
 

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Discussion Starter #11
Then no Kalephony-an would ever be able to get away with the First Fuel Injection Intake Manifold …

Asking this question because I GENUINELY do NOT KNOW …
Would it be CARB smog legal to 'AirGap' our own intake manifolds?
Website says...
“The FIRST®TPI is currently available in the Standard 6 bolt, 86-91 F-body, Vortec and LT1 base configurations. It is the customers responsibility to order the correct base. We can help you figure this out as well! The FIRST Tpi does NOT have EGR provisions. There are ways to introduce an egr system externally if needed”.

So I don’t believe it would be CARB legal in California.

But the thought of Air Gapping the stock manifold hmmmm ?????
Do you think it’s actually possible?
 

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"But the thought of Air Gapping the stock manifold hmmmm ?????
Do you think it’s actually possible?"

If you have a mill and a tig welder sure,,,,
BUT look at the intake, the first this that would disappear would be the EGR and Idle air passages.
That would be a "bit" of a problem with your test.

That said, everything I have read on the LT1 air gap intake, while a good idea, the actual numbers were never great.

The production 94-96 intakes were pretty good, albeit a little short for low, midrange.
Note there are two manifolds , early and late.
My early production 95 had larger runners at the head, more suited to a ported head,
The later 95, 96 the smaller port more closely matched the stock unported head.
Least that is what I saw first hand.
The casting numbers are different, I would have to look.

Speaking of heat, I believe the EGR roasting the bottom of the intake is an issue.
People will say " it only works at part throttle"
Yeah, most of the time, just before WOT, you are,at part throttle roasting the bottom of the intake.
"For off road " 😉 many people do not run EGR.
I didnt.

In closing, if it was me, I would work with one person or company to put together the cam, factory ported intake, aluminum head package and paint the heads black
 

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Discussion Starter #14
Thank you for the response and information 95wagon.
I had already resigned myself to having the heads and intake both done together if/when the time comes, using the stock components.
I will definitely consult/have a reputable well known builder do the work, and design the complete cam/valve train specs to match the porting flow rates.
There are tuning parameters that I can set for “off road” applications to keep the EGR temps at bay...
Marky’s been very helpful with getting me started.
My hope is that before too long I’ll be ready to better understand the parameters of doing advanced fine tuning,
Thanks again everyone for your advice and responses.
 

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Since you're in Cali, I wouldn't worry so much about performance. HP per dollar on an LT platform just isn't worth it in the land of the leftists. Just my opinion of course.

If I were in Cali (never), I would spend my car money on appearance mods, gears, stall, and suspension. If you really need more power, nitrous is your best friend. 150+ additional HP without affecting emissions? Yes please. I'm not sure if a car would fail visual inspection there if a nitrous kit was installed, but it's not too complicated to hide lines, wiring, and solenoids. You could also remove it for inspection if necessary and then put it right back on.

Don't worry about not being able to use the LT4 air gap intake. I have one and I like the looks of it, but it's not a performance benefit over the stock unit anyway so no harm here. Lloyd Elliot will port your intake for around $250. I haven't seen any before and after dyno tests, but Lloyd told me it was worth 10 RWHP and he has a lot of credibility with the LTx crowd.
 

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… Speaking of heat, the EGR roasting the bottom of the intake is an issue.
People will say " it only works at part throttle". Yeah, most of the time, just before WOT, you are at part throttle, roasting the bottom of the intake.
"For off road " 😉 many people do not run EGR. I didn't.
Diesel engines (sorry, couldn't say which specifically) have been cooling their EGR pathways since the early noughties
Chilled EGR doesn't seem like a good idea for any petrol engine old enough to legally rent a car in all 50 states, though - especially our engines.

I've always suggested and always will suggest at least disabling the EGR Valve in the tune. Disabling it PLUS blocking the EGR pathways with hidden plates is even better - just don't get caught.
(If your state lets you get away with deleting the EGR altogether, I'm jealous.)
 

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OP

I am a original owner of a 96 here in CA and very aware of how mods affect smog test. I now have a 383 H/C, shorty header (Edelbrock) and T56 which still passes emissions even after BAR lowered the max HC levels this year. It is critical you don't go to big on a cam but the most critical is the tune. Ed Wright has always done my tunes. Whoever does the tune will need to address the IM "readiness" function as you are only allowed 1 to show not ready since 1/1/18 and that can be nearly impossible on H/C cars....so (cough)…"adjustments" need to be done in the tune to "fix" that problem. Now with the lower HC max you need a "cooperative" smog test shop that will run the car with as minimal of RPM possible for the 15 and especially the 25 mph roller test. These are not the "under the table" shops where a donor car is used these are regular "STAR" testing shops that know it takes more effort to get these cars, when modified, to land on a # that will pass

You MUST have a CARB sticker for anything they can see (intake, exhaust) and no doing the counterfeit ones can be a major (read impound and heavy 4 figure fine) if you get caught doing that stuff. Shops don't risk that anymore as BAR sends out spy cars set up to disable stuff discretely to see if the shop passes or fails the car as a result. They will lose their license, etc and get fined so the "pay a guy" deals are far and few between now. They are there but not like it used to be.
 

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if you are just wanting to port your stock manifold and iron heads contact Lloyd Elliott. IDK if he does iron heads but he may and if doing a cam also he is the guy. Golen is a good builder. I bought a 383 short block from him and have over 40k mi on it now
 

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Discussion Starter #19
Thank you all for the advice and information.
I had my car tested about 6 months ago and because I keep my car well maintained, and replace my secondary ignition system’s components regularly it passes with numbers well below the allowable limits.
I would never consider doing anything fraudulent with CARB stickers and such, that’s just asking for trouble.
I’ve thought of doing a nitrous power adder system. I’m not sure how STAR smog stations would react to holes drilled in the intake or throttle body for the injectors even if I removed it for the test and they were plugged...
Anyone ???
BALLSS;
I would love to hear more from you about what you’ve been able to accomplish as a Cali resident, since you have precise and direct knowledge regarding what can and cannot be legally done.
I know your time is valuable, but please, always feel free to chime in as your input in this area is priceless.
I have the ability to tune for smog testing specifically (JET’s DST) but not the knowledge of how to do so on my own just yet.
I’ve done a “READ” and saved my stock GM tune w/ AIR disabled, but haven’t flashed anything new in yet.
I do have an ISSF member helping me learn what can and cannot be done via pcm tuning, but they’re not from Cali, so they don’t always know the specifics and requirements.
I’m always open to advice and suggestions in the tuning arena as long as it’s from those who have been tuning these things and know what they’re doing.
Please,
No bench racing advice from well meaning members, who haven’t done tried and proven real tunes or adjustments themselves, as there’s little room here for error.
I may at some point soon have Ed Wright do a tune for me, just to have a baseline one done by someone of his experience, that I can flash in to try, and take a look at to get a better idea of how he goes about increasing efficiency and power.
I would love to have 6 or 7 complete tunes at my disposal that have been customized to my driving ranges specific to whether I want better mileage, performance or even ones for all 3 of the available octanes.
Lloyd Elliot has been recommended to me by several members of the forum and is probably who I will go with when it’s time (read “have the money”) to do my intake and exhaust.
I appreciate all the responses and advice.
Thank you all very much !!!
 

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Tuning is above my pay grade and I leave it up to those who specialize in it. Ed Wright, IMHO, is without a doubt the most qualified LT1 tuner out there. I believe he still will do mail order tunes but he does charge more than the others doing tunes.

For a stock motor, well maintained, even with head and intake porting there would really be no problem passing emissions. Motors with cams running more fueling, timing and lower engine temps push even motors in excellent mechanical condition like mine beyond emission levels her in CA without having to do a separate "smog tune" that will have less timing and have the fan temp on set back to stock so the motor runs hotter and the CATS light off better. In addition with H/C motors they have a bigger problem getting EGR and CAT heat IM monitors to show "ready". Driving using the GM "drive cycle" is impossible unless you own a private track as the sequence of speeds will get you or someone killed on public roads to get IM monitors to reset. Every time you clear a code or disconnect the battery the IM codes need to reset which can take some driving time

This is why you could need a tune that makes those IM functions to show ready all the time. Not something most tuners know how to do....assuming that can be done (cough)...

Bottom line is these 96-99 cars are what CARB and BAR want off the road so they are doing the slow death by lowering emission levels to where brand new they would fail.

I am likely out of CA in a few years to NV or AZ where emission testing will be a non issue. Not because of smog test, I will be moving for financial reasons as my house here is worth considerably more than something twice the size in those states and I am retired now

Back to your car. sounds like it is basically stock with some mild bolt ons. A good mail order tune will give it some more performance and it will still easily pass CA emissions. You keep it that way and you should not have a problem with emission testing. Start doing H/C/larger injectors, more fueling & timing you will need to "make adjustments" as I have to pass emission testing
 
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