Joined
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Again, jrp of LS2.com and LS1tech.com was kind enough to let me borrow these.
Additional credit id given where due.
Preface:
The LS1 like any other engine works as a system, treat is as one, you want to get as much air in and out as you can. The plethora of mods out there will allow you to do that. Things to consider before you start on your modding process:
1) There is no "best" part when it comes to mods.
2) When you want to start modding your car come up with a tangible plan.
3) Do not go into modding blindly; you will end up wasting money, time, and effort.
4) Do your research before you buy mods.
5) Find out your states/counties emissions requirements before choosing mods
6) Be realistic on what your going to do with your car
7) Usable power under the curve is what you want to shoot for, do not just look at peak gains
8) Work within your budget
9) If your are still under warranty Contact your own dealership and discuss your warranty and modding issues.
10) Work on matching your parts well, meaning:
- do not buy 2500+ stage 3 heads that flow [email protected] if you have a stock cam or very low duration/lift cam (i.e tr220)
- LSX intake and 90mm TB for a basic bolt on car
- dont run 230+ cams on stock manifolds or shorties
- dont run a big cam and a small stall (i.e tsp231 and a vig 2200)
- dont over/under gear your car (i.e tr230, a4, 2.73's)
(Credit given where applicable. Info/pics taken from personal experience, around the Internet, and ls1tech/ls2.com.) Special thanks to the guys on ls1tech (J-Rod, JMX, ect) :worship:
A. Cams
What they are:
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What they do: Cams are the ?brain? of your engine and dictate how your engine will perform; power, idle quality, valve events, ect.
What to look for:
- Get a basic understanding of cams before purchasing. It?ll also help you understand the info/advice that is given on the boards.
- ALL gains are relative to your own setup
1) For example if you installed S2 heads and a tsp231 cam and only put down 390rwhp tuned don?t fret if you started with a base of 290rwhp.
- When researching cams look at the average gains. Don?t look at the highest gains you see (395rwhp with say and ls6 cam) and expect to get the same results when the average is 360-380rwhp depending on setup
- Can a cam be your first mod; yes. Should a cam be your first mod; no.
1) Cams need to breath, that means a complete intake and exhaust setup. The bigger the cam the more prevalent those mods become.
2) A4 guys; match your stall and cam appropriately
- Don?t be afraid of older or smaller cams (T1/B1, tr220, comps 218, ect). They might not use the latest and greatest lobe technology or break speed records but they are proven cams and are great for the guys looking for 400 > * rwhp cam only.
- Take Internet reviews of cams with a grain of salt and use them as reference only. Contact your local fbody club or ask around your local regional forum and find as many guys who have cams as you can. Hear and drive/ride along with as many different cam setups as you can. The reason for this is everyone has there own idea of what streetable is since that is a RELATIVE term. Decide on your own what streetable is to you
- Don?t let someone talk you into a cam if it doesn?t meet your requirements and fit your specific applications and goals.
- Keep in mind there is more then one way to make the same amount of power
- If you have the sniffer for emissions either go with the cam of your choice and pray you find a good enough tuner and have luck on your side or keep the duration 226 and under on a 114 and a decent tune and you should be fine.
- When buying a used cam ask for the cam card and/or serial numbers. Take that serial number and email or PM the company or board representative with that serial number. They will be able to tell you if in fact it is one of there grinds and if it?s the one you had planned on purchasing. That is the only way short of having the cam spec?d on a cam doctor to know exactly what cam you are buying. Here's the serial number from my old TR230.
- Don?t get caught up in peak HP. These are ls1 boards not Honda boards
. Under the curve power is where it?s at.
- To make things easier most sponsors offer cams as a package deal that includes all that you?ll need for an installation. Here was my old cam kit.
I. Cam Overview:
-
![]()
- Your starting point:
Stock 98-00 trans am cam
[email protected] 198.86 intake 209.25 exhaust
Lift .498 intake .497 exhausts
LSA 119.45
Stock 01-02 trans am cam
[email protected] 196.37 intake 208.72 exhaust
Lift .464 intake .479 exhausts
LSA 115.92
When buying a cam it comes with a cam card. This card gives you the exact specs of the cam. Here is an MTI/Lunati B1 cam card and a LGM G5X2 cam card.
A. Duration:
- The amount of time (in degrees) that lift is generated is called the duration of the lobe. Camshafts operate at half engine speed. This is easy to see because the gear that turns the camshaft is twice the diameter of the crank gear that drives it. That means that the cam spins at half engine speed. Because of this, camshaft duration is always expressed in crankshaft degrees. This makes it easy when it comes time to degree the cam to ensure it is positioned accurately in the engine.
- As you can see in the 2 cam cards there is duration @ .050 and duration @ .006. Duration @.050 is pretty much industry standard and that?s what you?ll see when looking at cam specs from the various sponsors and what most people are talking about when discussing duration
- Duration @.050 and Duration @.006 is a way you can determine the difference between two or more cams with the same given duration at .050. For example a TR224, TSP 224, and Comps 224. The lower the duration @.006 the more aggressive the ramp rate. The more aggressive the ramp rate the more overall and under the curve power.
- If you know the advertised duration (.006) of a cam you can calculate the ramp rate. To do this you take the duration @.006 and subtract it from the duration @ .050. A number of 53 or higher denotes an XE lobe or other mild lobe and a number of 49 or lower denotes an XE-R lobe or other aggressive lobe (Beast and 99 Black Bird T/A )
- Using the B1 and G5X2 as examples is as follows:
B1: 281 (.006) ? 221 (.050) = 59
G5X2: Intake 281 (.006) ? 232 (.050) = 49
Exhaust 289 (.006) ? 240 (0.50) = 49
- Most cam companies use Comp lobes; either an XE or XE-R, the later being the more aggressive of the two. TR uses its own proprietary lobe and FMS uses Cam Motion lobes.
- Intake opening (IO) usually occurs before top dead center (BTDC), while intake closing (IC) happens after bottom dead center (ABDC). For the exhaust side, exhaust opening (EO) occurs before bottom dead center (BBDC) and exhaust closing (EC) after top dead center (ATDC). These data points are listed on the cam card that comes with each new cam.
- Traditional Splits refers to more exhaust duration and lift then intake (tsp231/237, g5x2 232/450, ect). Reverse split refers to more intake duration and lift then exhaust (TR 230/224, X1 230/227). Single patterns are defined as having both the same intake, exhaust duration, and lift. (TR224, TR220, FM4 226/226). Which cam is better depends on your application.
- GREAT technical discussion on cams started by J-Rod from ls1tech: here
- Valve Events (VE) calculator can be found here
- Other good technical shit can be found here and here and here
B. Lift:
- Lift is defined as the difference in height between the radius of the circle and the height of the eccentric. This is called lobe lift.
- When viewing cam specs the lift portion is the gross lift, meaning its calculated with the 1.7 stock rockers.
- To get the lobe lift you take the advertised (gross) lift and divide it by 1.7. If you follow the B1/X2 cam card you?ll see that they list both lobe lift and gross lift.
- If you want to add higher ratio rockers and want to know your new lift you do the following using the B1 as an example:
.559 / 1.7 = ~.329, you then take that lobe lift and multiply it by whatever rocker ratio you want. With SLP 1.85 rockers your new lift specs become .329 X 1.85 = ~ .609
Additional credit id given where due.
Preface:
The LS1 like any other engine works as a system, treat is as one, you want to get as much air in and out as you can. The plethora of mods out there will allow you to do that. Things to consider before you start on your modding process:
1) There is no "best" part when it comes to mods.
2) When you want to start modding your car come up with a tangible plan.
3) Do not go into modding blindly; you will end up wasting money, time, and effort.
4) Do your research before you buy mods.
5) Find out your states/counties emissions requirements before choosing mods
6) Be realistic on what your going to do with your car
7) Usable power under the curve is what you want to shoot for, do not just look at peak gains
8) Work within your budget
9) If your are still under warranty Contact your own dealership and discuss your warranty and modding issues.
10) Work on matching your parts well, meaning:
- do not buy 2500+ stage 3 heads that flow [email protected] if you have a stock cam or very low duration/lift cam (i.e tr220)
- LSX intake and 90mm TB for a basic bolt on car
- dont run 230+ cams on stock manifolds or shorties
- dont run a big cam and a small stall (i.e tsp231 and a vig 2200)
- dont over/under gear your car (i.e tr230, a4, 2.73's)
(Credit given where applicable. Info/pics taken from personal experience, around the Internet, and ls1tech/ls2.com.) Special thanks to the guys on ls1tech (J-Rod, JMX, ect) :worship:
A. Cams
What they are:
What they do: Cams are the ?brain? of your engine and dictate how your engine will perform; power, idle quality, valve events, ect.
What to look for:
- Get a basic understanding of cams before purchasing. It?ll also help you understand the info/advice that is given on the boards.
- ALL gains are relative to your own setup
1) For example if you installed S2 heads and a tsp231 cam and only put down 390rwhp tuned don?t fret if you started with a base of 290rwhp.
- When researching cams look at the average gains. Don?t look at the highest gains you see (395rwhp with say and ls6 cam) and expect to get the same results when the average is 360-380rwhp depending on setup
- Can a cam be your first mod; yes. Should a cam be your first mod; no.
1) Cams need to breath, that means a complete intake and exhaust setup. The bigger the cam the more prevalent those mods become.
2) A4 guys; match your stall and cam appropriately
- Don?t be afraid of older or smaller cams (T1/B1, tr220, comps 218, ect). They might not use the latest and greatest lobe technology or break speed records but they are proven cams and are great for the guys looking for 400 > * rwhp cam only.
- Take Internet reviews of cams with a grain of salt and use them as reference only. Contact your local fbody club or ask around your local regional forum and find as many guys who have cams as you can. Hear and drive/ride along with as many different cam setups as you can. The reason for this is everyone has there own idea of what streetable is since that is a RELATIVE term. Decide on your own what streetable is to you
- Don?t let someone talk you into a cam if it doesn?t meet your requirements and fit your specific applications and goals.
- Keep in mind there is more then one way to make the same amount of power
- If you have the sniffer for emissions either go with the cam of your choice and pray you find a good enough tuner and have luck on your side or keep the duration 226 and under on a 114 and a decent tune and you should be fine.
- When buying a used cam ask for the cam card and/or serial numbers. Take that serial number and email or PM the company or board representative with that serial number. They will be able to tell you if in fact it is one of there grinds and if it?s the one you had planned on purchasing. That is the only way short of having the cam spec?d on a cam doctor to know exactly what cam you are buying. Here's the serial number from my old TR230.
- Don?t get caught up in peak HP. These are ls1 boards not Honda boards
. Under the curve power is where it?s at.- To make things easier most sponsors offer cams as a package deal that includes all that you?ll need for an installation. Here was my old cam kit.
I. Cam Overview:
-
- Your starting point:
Stock 98-00 trans am cam
[email protected] 198.86 intake 209.25 exhaust
Lift .498 intake .497 exhausts
LSA 119.45
Stock 01-02 trans am cam
[email protected] 196.37 intake 208.72 exhaust
Lift .464 intake .479 exhausts
LSA 115.92
When buying a cam it comes with a cam card. This card gives you the exact specs of the cam. Here is an MTI/Lunati B1 cam card and a LGM G5X2 cam card.
A. Duration:
- The amount of time (in degrees) that lift is generated is called the duration of the lobe. Camshafts operate at half engine speed. This is easy to see because the gear that turns the camshaft is twice the diameter of the crank gear that drives it. That means that the cam spins at half engine speed. Because of this, camshaft duration is always expressed in crankshaft degrees. This makes it easy when it comes time to degree the cam to ensure it is positioned accurately in the engine.
- As you can see in the 2 cam cards there is duration @ .050 and duration @ .006. Duration @.050 is pretty much industry standard and that?s what you?ll see when looking at cam specs from the various sponsors and what most people are talking about when discussing duration
- Duration @.050 and Duration @.006 is a way you can determine the difference between two or more cams with the same given duration at .050. For example a TR224, TSP 224, and Comps 224. The lower the duration @.006 the more aggressive the ramp rate. The more aggressive the ramp rate the more overall and under the curve power.
- If you know the advertised duration (.006) of a cam you can calculate the ramp rate. To do this you take the duration @.006 and subtract it from the duration @ .050. A number of 53 or higher denotes an XE lobe or other mild lobe and a number of 49 or lower denotes an XE-R lobe or other aggressive lobe (Beast and 99 Black Bird T/A
) - Using the B1 and G5X2 as examples is as follows:
B1: 281 (.006) ? 221 (.050) = 59
G5X2: Intake 281 (.006) ? 232 (.050) = 49
Exhaust 289 (.006) ? 240 (0.50) = 49
- Most cam companies use Comp lobes; either an XE or XE-R, the later being the more aggressive of the two. TR uses its own proprietary lobe and FMS uses Cam Motion lobes.
- Intake opening (IO) usually occurs before top dead center (BTDC), while intake closing (IC) happens after bottom dead center (ABDC). For the exhaust side, exhaust opening (EO) occurs before bottom dead center (BBDC) and exhaust closing (EC) after top dead center (ATDC). These data points are listed on the cam card that comes with each new cam.
- Traditional Splits refers to more exhaust duration and lift then intake (tsp231/237, g5x2 232/450, ect). Reverse split refers to more intake duration and lift then exhaust (TR 230/224, X1 230/227). Single patterns are defined as having both the same intake, exhaust duration, and lift. (TR224, TR220, FM4 226/226). Which cam is better depends on your application.
- GREAT technical discussion on cams started by J-Rod from ls1tech: here
- Valve Events (VE) calculator can be found here
- Other good technical shit can be found here and here and here
B. Lift:
- Lift is defined as the difference in height between the radius of the circle and the height of the eccentric. This is called lobe lift.
- When viewing cam specs the lift portion is the gross lift, meaning its calculated with the 1.7 stock rockers.
- To get the lobe lift you take the advertised (gross) lift and divide it by 1.7. If you follow the B1/X2 cam card you?ll see that they list both lobe lift and gross lift.
- If you want to add higher ratio rockers and want to know your new lift you do the following using the B1 as an example:
.559 / 1.7 = ~.329, you then take that lobe lift and multiply it by whatever rocker ratio you want. With SLP 1.85 rockers your new lift specs become .329 X 1.85 = ~ .609
