Limits to stock truck intake on this application
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Limits to stock truck intake on this application I'm building a 434 4.155 bore 4.000 stroke darton sleeved gen 4 block for a 2500hd its going to be naturally aspirated using afr 245 cathedrals how much would the lm7 intake limit me? I wouldn't want to pay 1k for a fast for only 20hp and I need to keep egr where I live
Last edited by EmeraldFlame; Oct 26, 2020 at 05:34 AM.
I got away with deleted egr for years, and I'm supposed to have it where I am too.
The fast manifold should give you well more than 20 in your application. I would guess quite a bit more over 5000 or so rpm
The lm7 intake is pretty bad, the newer truck cathedral intakes are much better, but I don't think they used egr on those
The fast manifold should give you well more than 20 in your application. I would guess quite a bit more over 5000 or so rpm
The lm7 intake is pretty bad, the newer truck cathedral intakes are much better, but I don't think they used egr on those
Thread Starter
Teching In
Joined: Feb 2016
Posts: 48
Likes: 4
I got away with deleted egr for years, and I'm supposed to have it where I am too.
The fast manifold should give you well more than 20 in your application. I would guess quite a bit more over 5000 or so rpm
The lm7 intake is pretty bad, the newer truck cathedral intakes are much better, but I don't think they used egr on those
The fast manifold should give you well more than 20 in your application. I would guess quite a bit more over 5000 or so rpm
The lm7 intake is pretty bad, the newer truck cathedral intakes are much better, but I don't think they used egr on those
Not sure what Utah laws are like, but here in Dallas Texas we do emissions and safety inspections. On the emissions side guys are supposed to make sure that all emissions equipment is there. At all the shops I've worked at the inspectors didn't even know what a EGR valve was much less how to identify them and they really just plug in the machine and if the machine see's no codes then it passes. So if they don't catch it on a visual inspection it will pass. If you disable the EGR in the tune and tune out any fault codes the machine they plug in won't know that there was originally a EGR on the vehicle, it will essentially think it was one that didn't come with it. Well, it won't think anything, it just knows what it's told. If the PCM in the vehicle is set to where the EGR is disabled and tuned out, it is now setup like it is a non egr vehicle and no machine will ever know what it used to be. A person would have to look into it deeply to figure it out and the chances of coming across an inspector that puts all that together is very unlikely.
I passed for years with no EGR, no cats, no rear 02 sensors, no AIR injection and nobody ever knew because they weren't familiar with did and didn't come on the car. It was too low to look under to see if it had cats, which wouldn't matter, because nobody ever even tried to look anyway. They look at the tires and lights and plug it in to the machine, if the machine sees no check engine light, no faults, no not ready's, it passes. When you tune all that stuff out it stays in the "ready" state and never goes "not ready". One of the things the emissions machine looks for is readiness status.
Thread Starter
Teching In
Joined: Feb 2016
Posts: 48
Likes: 4
Not sure what Utah laws are like, but here in Dallas Texas we do emissions and safety inspections. On the emissions side guys are supposed to make sure that all emissions equipment is there. At all the shops I've worked at the inspectors didn't even know what a EGR valve was much less how to identify them and they really just plug in the machine and if the machine see's no codes then it passes. So if they don't catch it on a visual inspection it will pass. If you disable the EGR in the tune and tune out any fault codes the machine they plug in won't know that there was originally a EGR on the vehicle, it will essentially think it was one that didn't come with it. Well, it won't think anything, it just knows what it's told. If the PCM in the vehicle is set to where the EGR is disabled and tuned out, it is now setup like it is a non egr vehicle and no machine will ever know what it used to be. A person would have to look into it deeply to figure it out and the chances of coming across an inspector that puts all that together is very unlikely.
I passed for years with no EGR, no cats, no rear 02 sensors, no AIR injection and nobody ever knew because they weren't familiar with did and didn't come on the car. It was too low to look under to see if it had cats, which wouldn't matter, because nobody ever even tried to look anyway. They look at the tires and lights and plug it in to the machine, if the machine sees no check engine light, no faults, no not ready's, it passes. When you tune all that stuff out it stays in the "ready" state and never goes "not ready". One of the things the emissions machine looks for is readiness status.
I passed for years with no EGR, no cats, no rear 02 sensors, no AIR injection and nobody ever knew because they weren't familiar with did and didn't come on the car. It was too low to look under to see if it had cats, which wouldn't matter, because nobody ever even tried to look anyway. They look at the tires and lights and plug it in to the machine, if the machine sees no check engine light, no faults, no not ready's, it passes. When you tune all that stuff out it stays in the "ready" state and never goes "not ready". One of the things the emissions machine looks for is readiness status.
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Okay sniffers are a little more tricky.
The problem there is the EGR is gonna be one of the least of your issues.
I used to have a car that had to get sniffer tests, back before OBD2 was out, and it didn't have a catalytic converter but I could tweak the distributor (the ignition timing) just right to get it to pass.
They measure HC's which is unburned fuel, if you have a cam it's gonna be nearly impossible to pass the sniffer.
With no cats, HC's will be high but you can tune it to be lean enough at idle to clear this, and timing can have an effect
They check for NoX and timing and egr play a huge role here. Egr's cool cylinder temps which directly relate to nox, but again the right timing can help this fall into line
You may have to play with the tune a little to make it pass.
Which you will anyway because even if you have cats and egr if the tune is off a little it's still gonna burn dirty
You need to find a friend that will run his bone stock nissan altima on the rollers and enter the info into the inspection machine for your truck. I heard from "a friend" that's the easiest way with sniffers. I also heard from a friend that if you approach the inspector at a tiny little hole in the wall place that does inspections with a 100 dollar bill before you ask for an inspection that sometimes they just take care of the inspection while you read a magazine and don't pay attention to what they're doing. Can't do that with OBD2 stuff, the machine knows what it's hooked up to..
The problem there is the EGR is gonna be one of the least of your issues.
I used to have a car that had to get sniffer tests, back before OBD2 was out, and it didn't have a catalytic converter but I could tweak the distributor (the ignition timing) just right to get it to pass.
They measure HC's which is unburned fuel, if you have a cam it's gonna be nearly impossible to pass the sniffer.
With no cats, HC's will be high but you can tune it to be lean enough at idle to clear this, and timing can have an effect
They check for NoX and timing and egr play a huge role here. Egr's cool cylinder temps which directly relate to nox, but again the right timing can help this fall into line
You may have to play with the tune a little to make it pass.
Which you will anyway because even if you have cats and egr if the tune is off a little it's still gonna burn dirty
You need to find a friend that will run his bone stock nissan altima on the rollers and enter the info into the inspection machine for your truck. I heard from "a friend" that's the easiest way with sniffers. I also heard from a friend that if you approach the inspector at a tiny little hole in the wall place that does inspections with a 100 dollar bill before you ask for an inspection that sometimes they just take care of the inspection while you read a magazine and don't pay attention to what they're doing. Can't do that with OBD2 stuff, the machine knows what it's hooked up to..
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Teching In
Joined: Feb 2016
Posts: 48
Likes: 4
Okay sniffers are a little more tricky.
The problem there is the EGR is gonna be one of the least of your issues.
I used to have a car that had to get sniffer tests, back before OBD2 was out, and it didn't have a catalytic converter but I could tweak the distributor (the ignition timing) just right to get it to pass.
They measure HC's which is unburned fuel, if you have a cam it's gonna be nearly impossible to pass the sniffer.
With no cats, HC's will be high but you can tune it to be lean enough at idle to clear this, and timing can have an effect
They check for NoX and timing and egr play a huge role here. Egr's cool cylinder temps which directly relate to nox, but again the right timing can help this fall into line
You may have to play with the tune a little to make it pass.
Which you will anyway because even if you have cats and egr if the tune is off a little it's still gonna burn dirty
You need to find a friend that will run his bone stock nissan altima on the rollers and enter the info into the inspection machine for your truck. I heard from "a friend" that's the easiest way with sniffers. I also heard from a friend that if you approach the inspector at a tiny little hole in the wall place that does inspections with a 100 dollar bill before you ask for an inspection that sometimes they just take care of the inspection while you read a magazine and don't pay attention to what they're doing. Can't do that with OBD2 stuff, the machine knows what it's hooked up to..
The problem there is the EGR is gonna be one of the least of your issues.
I used to have a car that had to get sniffer tests, back before OBD2 was out, and it didn't have a catalytic converter but I could tweak the distributor (the ignition timing) just right to get it to pass.
They measure HC's which is unburned fuel, if you have a cam it's gonna be nearly impossible to pass the sniffer.
With no cats, HC's will be high but you can tune it to be lean enough at idle to clear this, and timing can have an effect
They check for NoX and timing and egr play a huge role here. Egr's cool cylinder temps which directly relate to nox, but again the right timing can help this fall into line
You may have to play with the tune a little to make it pass.
Which you will anyway because even if you have cats and egr if the tune is off a little it's still gonna burn dirty
You need to find a friend that will run his bone stock nissan altima on the rollers and enter the info into the inspection machine for your truck. I heard from "a friend" that's the easiest way with sniffers. I also heard from a friend that if you approach the inspector at a tiny little hole in the wall place that does inspections with a 100 dollar bill before you ask for an inspection that sometimes they just take care of the inspection while you read a magazine and don't pay attention to what they're doing. Can't do that with OBD2 stuff, the machine knows what it's hooked up to..
I got away with deleted egr for years, and I'm supposed to have it where I am too.
The fast manifold should give you well more than 20 in your application. I would guess quite a bit more over 5000 or so rpm
The lm7 intake is pretty bad, the newer truck cathedral intakes are much better, but I don't think they used egr on those
The fast manifold should give you well more than 20 in your application. I would guess quite a bit more over 5000 or so rpm
The lm7 intake is pretty bad, the newer truck cathedral intakes are much better, but I don't think they used egr on those