Prc 225 heads running on factory tune?!?
#1
Prc 225 heads running on factory tune?!?
First off let me start by saying, yes im aware that the full potential of any mods like heads, cam etc benefit highly from a custom tune and is needed for the car to run properly, hell bone stock a car benefits from a tune. This is my scenerio though and i need some input hopefully someone has good advice.
The car in question is a 02 trans am ws6, ls1, prc 225 as cast heads, torquer v2 cam and a fast 92/92, lt headers and dyno tuned, 475 rwhp.
My issue now is i live in California
And before anyone says just move out of California, its easier said than done and yes i know California smog laws are ridiculous.
Which brings me to this, being that my car is a 2002 it will not pass smog for obvious reasons visually it wont and now they check for factory tunes which wont pass. To pass smog on a 2000+ vehicle in California all they are checking is monior readiness and visual inspection, so no they do not run it on the dyno for the sniffer. So now ive come to the realization that i dont want to deal with it anymore and just conform go back to stock or stockish.
Ive been throwing the idea around of doing a "stealth build" meaning putting back my stock exhaust manifolds, cats, air injection, factory tune, but leaving my prc heads on, putting a ls6 cam or comp cams even has a carb approved cam and sanding down my fast 92 intake manifold smooth and painting all black and putting the stock tb.
Now the real question in mind how will the car run on a factory tune with said mods??
-heads prc 225, 62 cc combustion chambers, 2.065 intake valves and 1.600 exhaust. Pac 660 dual valve springs
-The cam im looking into is a carb approved cam which is a 210/218 118 lsa intake/exhaust duration 270.
- fast 92mm intake
- stock exhaust
- stock tune
There is also a set of afr heads that are carb approved in which they claim you need no tune to run them and theyare smog legal but are like 3k.
the real issue here is the tune, it has to be a factory tune.
all that i need is for it to visually look factory which i think can be achieved pretty easily, have all the emissions monitors completed and have a factory tune on the pcm and id be golden. Any input helps alot! If not id just go back full 100% stock 😒
The car in question is a 02 trans am ws6, ls1, prc 225 as cast heads, torquer v2 cam and a fast 92/92, lt headers and dyno tuned, 475 rwhp.
My issue now is i live in California
And before anyone says just move out of California, its easier said than done and yes i know California smog laws are ridiculous.
Which brings me to this, being that my car is a 2002 it will not pass smog for obvious reasons visually it wont and now they check for factory tunes which wont pass. To pass smog on a 2000+ vehicle in California all they are checking is monior readiness and visual inspection, so no they do not run it on the dyno for the sniffer. So now ive come to the realization that i dont want to deal with it anymore and just conform go back to stock or stockish.
Ive been throwing the idea around of doing a "stealth build" meaning putting back my stock exhaust manifolds, cats, air injection, factory tune, but leaving my prc heads on, putting a ls6 cam or comp cams even has a carb approved cam and sanding down my fast 92 intake manifold smooth and painting all black and putting the stock tb.
Now the real question in mind how will the car run on a factory tune with said mods??
-heads prc 225, 62 cc combustion chambers, 2.065 intake valves and 1.600 exhaust. Pac 660 dual valve springs
-The cam im looking into is a carb approved cam which is a 210/218 118 lsa intake/exhaust duration 270.
- fast 92mm intake
- stock exhaust
- stock tune
There is also a set of afr heads that are carb approved in which they claim you need no tune to run them and theyare smog legal but are like 3k.
the real issue here is the tune, it has to be a factory tune.
all that i need is for it to visually look factory which i think can be achieved pretty easily, have all the emissions monitors completed and have a factory tune on the pcm and id be golden. Any input helps alot! If not id just go back full 100% stock 😒
#2
First off let me start by saying, yes im aware that the full potential of any mods like heads, cam etc benefit highly from a custom tune and is needed for the car to run properly, hell bone stock a car benefits from a tune. This is my scenerio though and i need some input hopefully someone has good advice.
The car in question is a 02 trans am ws6, ls1, prc 225 as cast heads, torquer v2 cam and a fast 92/92, lt headers and dyno tuned, 475 rwhp.
My issue now is i live in California
And before anyone says just move out of California, its easier said than done and yes i know California smog laws are ridiculous.
The car in question is a 02 trans am ws6, ls1, prc 225 as cast heads, torquer v2 cam and a fast 92/92, lt headers and dyno tuned, 475 rwhp.
My issue now is i live in California
And before anyone says just move out of California, its easier said than done and yes i know California smog laws are ridiculous.
That mostly means two things....OEM injectors (that is what the stock tune is designed for) and a cam small enough to idle at the stock tune's idle speed target.
Your current cam wont do that.....none of the other stuff matters as much if the guy looking over the car is a friendly. But it cant throw a check engine code when its plugged in and a big cam wont idle well at 600 - 650 RPM
You have to reduce the overlap.....a cam in the low 220's on like a 114 LSA would probably work.
And like I said....OEM injectors or the fueling will be way off
Its a suckfest in CA with this emissions crap....thankfully its two years apart so you get a chance to play for a bit before having to meet the smog man again
You could always install an OE cam for the smog test and swap it a week later. Its alot of work but you get to play with the car properly modded two years before dealing with it again (or moving!! )
-Tony
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www.mamomotorsports.com
Tony@MamoMotorsports.com
Anything worth doing is worth doing well. Build it right the first time....its alot cheaper than building it twice!!
www.mamomotorsports.com
Tony@MamoMotorsports.com
Anything worth doing is worth doing well. Build it right the first time....its alot cheaper than building it twice!!
Last edited by Tony @ Mamo Motorsports; 02-23-2023 at 04:51 AM.
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grubinski (02-24-2023)
#3
TECH Addict
iTrader: (1)
Hi, Tony. IDK if you'll agree, but I think with this California situation, wouldn't the OP, and other California residents with mods also benefit from a handheld tuner? That way, you could store the stock tune, and could also store the mod tune?
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G Atsma (02-23-2023)
#5
TECH Addict
iTrader: (1)
Oh, I completely agree. The other side of the coin is you can't run a stock tune if the OP goes to the trouble of changing back to the performance cam. Just thought it might save him paying for another tune for the performance cam. Personally, and I know moving is nobody's idea of fun, but I'd get the Hell outta there with the performance cam and tune, so I could leave California ASAP!!! People in California may be surprised how far their net $$$$$$ from the sale of their house will go in a different state. Changing cams, pipes, tunes, and whatever else is needed every 2 years would be all the incentive I'd need...
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G Atsma (02-23-2023)
#7
TECH Senior Member
By plugging into the OBDII port and checking the bitsum in the tune. ANY kind of change is a callout.
All that is involved to smog a 96-up car is to plug into the OBDII port and do a visual for illicit aftermarket parts like non-exempt headers and/or cold air intakes.
All that is involved to smog a 96-up car is to plug into the OBDII port and do a visual for illicit aftermarket parts like non-exempt headers and/or cold air intakes.
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88_thirdgen (02-23-2023)
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#8
10 Second Club
iTrader: (26)
I tune and understand a checksum and flashing/reading a vehicle. I'm asking specifically the level of detail the testing site is going to. Does that mean they have the OEM calibrations for every vehicle ever made that is under the smog requirement? Or do they pull the stock tune from the vehicle the first time it's been smogged. I.E. why can't the "stock tune" be the 475whp dyno tuned version of the tune file. Then in 2 years it will be the same file.
The following 2 users liked this post by RonSSNova:
88_thirdgen (02-23-2023), G Atsma (02-23-2023)
#10
Here is the deal.....you just have to pass the test with the OEM tune.....don't even think you get the sniffer test but it has to idle and run on the stock tune (and not throw a code)
That mostly means two things....OEM injectors (that is what the stock tune is designed for) and a cam small enough to idle at the stock tune's idle speed target.
Your current cam wont do that.....none of the other stuff matters as much if the guy looking over the car is a friendly. But it cant throw a check engine code when its plugged in and a big cam wont idle well at 600 - 650 RPM
You have to reduce the overlap.....a cam in the low 220's on like a 114 LSA would probably work.
And like I said....OEM injectors or the fueling will be way off
Its a suckfest in CA with this emissions crap....thankfully its two years apart so you get a chance to play for a bit before having to meet the smog man again
You could always install an OE cam for the smog test and swap it a week later. Its alot of work but you get to play with the car properly modded two years before dealing with it again (or moving!! )
-Tony
That mostly means two things....OEM injectors (that is what the stock tune is designed for) and a cam small enough to idle at the stock tune's idle speed target.
Your current cam wont do that.....none of the other stuff matters as much if the guy looking over the car is a friendly. But it cant throw a check engine code when its plugged in and a big cam wont idle well at 600 - 650 RPM
You have to reduce the overlap.....a cam in the low 220's on like a 114 LSA would probably work.
And like I said....OEM injectors or the fueling will be way off
Its a suckfest in CA with this emissions crap....thankfully its two years apart so you get a chance to play for a bit before having to meet the smog man again
You could always install an OE cam for the smog test and swap it a week later. Its alot of work but you get to play with the car properly modded two years before dealing with it again (or moving!! )
-Tony
My overall question is this, will the car compensate fuel trims for said mods, ls6 cam and or the 210 216 comps cam, the 62 cc prc heads and the fast 92mm intake, running everything else bone stock?
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88_thirdgen (02-23-2023)
#12
This is exactly what i was thinking of doing!! BUT there is down side. That being you cant mod the car past a certain point meaning it has to be modified to a point at a fine line where it will still run and operate on a factory tune with the mods without triggering a c.e.l and then switch over to custome tune designed to bring out full potential with a diablosport tuner or something along the lines.
#14
I tune and understand a checksum and flashing/reading a vehicle. I'm asking specifically the level of detail the testing site is going to. Does that mean they have the OEM calibrations for every vehicle ever made that is under the smog requirement? Or do they pull the stock tune from the vehicle the first time it's been smogged. I.E. why can't the "stock tune" be the 475whp dyno tuned version of the tune file. Then in 2 years it will be the same file.
#16
TECH Senior Member
In Cali, nothing before 1975 MY is tested. Between then and 1996 it's sniff and visual. After that it's OBDII plugin and visual.
I'm going to bring up something I posted about before-
Comp has a series of 50 state legal LS cams for Gen III and IV LS engines. Some for AFM/DOD and VVT.
The spec for Gen III is 210/218, .570/.541, 118 LSA. No tuning necessary is claimed, nor is it allowed in Cali.
I would like to know how a guy pulling out his stock (191/190, .457/.466 114 LSA) 5.3 cam is NOT needing a tune for a cam that adds 19 intake degrees.
I don't see how it will be even close to running right.
I'm going to bring up something I posted about before-
Comp has a series of 50 state legal LS cams for Gen III and IV LS engines. Some for AFM/DOD and VVT.
The spec for Gen III is 210/218, .570/.541, 118 LSA. No tuning necessary is claimed, nor is it allowed in Cali.
I would like to know how a guy pulling out his stock (191/190, .457/.466 114 LSA) 5.3 cam is NOT needing a tune for a cam that adds 19 intake degrees.
I don't see how it will be even close to running right.
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88_thirdgen (02-23-2023)
#17
In Cali, nothing before 1975 MY is tested. Between then and 1996 it's sniff and visual. After that it's OBDII plugin and visual.
I'm going to bring up something I posted about before-
Comp has a series of 50 state legal LS cams for Gen III and IV LS engines. Some for AFM/DOD and VVT.
The spec for Gen III is 210/218, .570/.541, 118 LSA. No tuning necessary is claimed, nor is it allowed in Cali.
I would like to know how a guy pulling out his stock (191/190, .457/.466 114 LSA) 5.3 cam is NOT needing a tune for a cam that adds 19 intake degrees.
I don't see how it will be even close to running right.
I'm going to bring up something I posted about before-
Comp has a series of 50 state legal LS cams for Gen III and IV LS engines. Some for AFM/DOD and VVT.
The spec for Gen III is 210/218, .570/.541, 118 LSA. No tuning necessary is claimed, nor is it allowed in Cali.
I would like to know how a guy pulling out his stock (191/190, .457/.466 114 LSA) 5.3 cam is NOT needing a tune for a cam that adds 19 intake degrees.
I don't see how it will be even close to running right.
So theoretically you can build your car in California heads and cam and but running on OEM tune and be 100% compliant. BUT how will the car really run?!
#18
TECH Senior Member
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88_thirdgen (02-23-2023)
#19
TECH Senior Member
Going on the premise that going with a stock tune IS possible or even desirable with this Comp cam, I wonder which aspect of the cam spec makes this possible.
The duration and lift seem pretty middle of the road.
210/218 is only 2 degrees intake away from the old faithful 212/218 grinds. So it can't really be that.
What DOES set it apart is the relatively very wide 118 LSA.
This smoothes the idle and allows for a -22 degree overlap, but a fairly late 43 deg. ABDC intake valve closing.
That's still a lot more overlap than the stock cam's -37.5, but i guess the stock tune still thinks it's OK....
The duration and lift seem pretty middle of the road.
210/218 is only 2 degrees intake away from the old faithful 212/218 grinds. So it can't really be that.
What DOES set it apart is the relatively very wide 118 LSA.
This smoothes the idle and allows for a -22 degree overlap, but a fairly late 43 deg. ABDC intake valve closing.
That's still a lot more overlap than the stock cam's -37.5, but i guess the stock tune still thinks it's OK....
#20
Going on the premise that going with a stock tune IS possible or even desirable with this Comp cam, I wonder which aspect of the cam spec makes this possible.
The duration and lift seem pretty middle of the road.
210/218 is only 2 degrees intake away from the old faithful 212/218 grinds. So it can't really be that.
What DOES set it apart is the relatively very wide 118 LSA.
This smoothes the idle and allows for a -22 degree overlap, but a fairly late 43 deg. ABDC intake valve closing.
That's still a lot more overlap than the stock cam's -37.5, but i guess the stock tune still thinks it's OK....
The duration and lift seem pretty middle of the road.
210/218 is only 2 degrees intake away from the old faithful 212/218 grinds. So it can't really be that.
What DOES set it apart is the relatively very wide 118 LSA.
This smoothes the idle and allows for a -22 degree overlap, but a fairly late 43 deg. ABDC intake valve closing.
That's still a lot more overlap than the stock cam's -37.5, but i guess the stock tune still thinks it's OK....