Road race cam for LS3
#1
Teching In
Thread Starter
Join Date: Aug 2018
Location: Phoenix, AZ
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
Road race cam for LS3
Hope I'm in the right place. I am building a road racer. Won't be used for anything else but road racing and occasional autox for ***** and giggles. I've looked at a lot of similar posts and seen a lot of conflicting answers. But, i thought I'd lay down my specs and roll the dice here because man, am i confused. Here's my car at a glance:
-2850lbs with me inside
-LS3 w/tr6060, stock bottom, ram air w/tb spacer, pcv delete, egr delete, 1 7/8 long tube headers to x pipe to straight exhaust
-I'll probably want to be shifting around 6300rpm. Gonna probably leave redline at 6600rpm
-4.10 rear
-315/30-18 rear slicks
I called BTR and they told me to use their ls3 stage 3. Tick and comp cams gave me similar specd cam. Cam motion gave me a lower duration than the rest but all 4 of them gave me pretty high lift cams. Well this is the road race forum so somebody here must be pretty knowledgeable and be able to steer me in the right direction, hopefully. Lol
-2850lbs with me inside
-LS3 w/tr6060, stock bottom, ram air w/tb spacer, pcv delete, egr delete, 1 7/8 long tube headers to x pipe to straight exhaust
-I'll probably want to be shifting around 6300rpm. Gonna probably leave redline at 6600rpm
-4.10 rear
-315/30-18 rear slicks
I called BTR and they told me to use their ls3 stage 3. Tick and comp cams gave me similar specd cam. Cam motion gave me a lower duration than the rest but all 4 of them gave me pretty high lift cams. Well this is the road race forum so somebody here must be pretty knowledgeable and be able to steer me in the right direction, hopefully. Lol
#2
TECH Senior Member
This is the Gen IV internal forum, not the road race forum. But you're OK here. Cam Motion gave you a lower duration because they believe you need the flexibility it would give you coming out of a slow curve. Too many times I see too radical a cam that will do great on the straights, but go weak-knee'd where more low end would be nice.
#3
Teching In
Thread Starter
Join Date: Aug 2018
Location: Phoenix, AZ
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
This is the Gen IV internal forum, not the road race forum. But you're OK here. Cam Motion gave you a lower duration because they believe you need the flexibility it would give you coming out of a slow curve. Too many times I see too radical a cam that will do great on the straights, but go weak-knee'd where more low end would be nice.
What do you think? Is there a certain guy on this forum I should ask?
#4
TECH Senior Member
Looks to me to be a potent cam. Plenty of lift, which may be one reason Cam Motion went back a bit on the duration, unless the others had the same or more lift.
#5
LS1Tech Sponsor
Join Date: Jan 2008
Location: Ohio, Georgia, Nevada, Texas
Posts: 1,947
Received 1,118 Likes
on
616 Posts
We backed up the intake closing point on our Summit Pro LS Stage 3 LS3 (p/n SUM-8710) cam (from our SUM-8711 Stage 4 LS3 cam) to build more torque where most people find it useful. For where you are shifting and setting redline, it will be a good match and easy to tune. Specs are 230/242 113+3. 5 I/O, 45 I/C, 56 E/O, and 5 E/C. with .625/.605 lift and the lobes carry well up top. When you need it, you can hang at higher rpm without shifting to keep from disturbing the car mid-corner and pull out nicely with overhead to spare.
The cam has .081/.103 clearance as measured on our stock LS3. The Heads could be milled about .020 in. (after you confirm measurements on your engine). The bump in compression will make it stronger across the board and still run fine with the fuel you will be running. Double spring part number TFS-2500287 would be a good match. We also have the SUM-8707 Stage 2 cam (226/238 113+3 .600/.600), but at your weight and gear - you can be more aggressive.
The cam has .081/.103 clearance as measured on our stock LS3. The Heads could be milled about .020 in. (after you confirm measurements on your engine). The bump in compression will make it stronger across the board and still run fine with the fuel you will be running. Double spring part number TFS-2500287 would be a good match. We also have the SUM-8707 Stage 2 cam (226/238 113+3 .600/.600), but at your weight and gear - you can be more aggressive.
Last edited by Summitracing; 08-28-2018 at 03:43 PM.
#6
Teching In
Thread Starter
Join Date: Aug 2018
Location: Phoenix, AZ
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
We backed up the intake closing point on our Summit Pro LS Stage 3 LS3 (p/n SUM-8710) cam (from our SUM-8711 Stage 4 LS3 cam) to build more torque where most people find it useful. For where you are shifting and setting redline, it will be a good match and easy to tune. Specs are 230/242 113+3. 5 I/O, 45 I/C, 56 E/O, and 5 E/C. with .625/.605 lift and the lobes carry well up top. When you need it, you can hang at higher rpm without shifting to keep from disturbing the car mid-corner and pull out nicely with overhead to spare.
The cam has .081/.103 clearance as measured on our stock LS3. The Heads could be milled about .020 in. (after you confirm measurements on your engine). The bump in compression will make it stronger across the board and still run fine with the fuel you will be running. Double spring part number TFS-2500287 would be a good match. We also have the SUM-8707 Stage 2 cam (226/238 113+3 .600/.600), but at your weight and gear - you can be more aggressive.
The cam has .081/.103 clearance as measured on our stock LS3. The Heads could be milled about .020 in. (after you confirm measurements on your engine). The bump in compression will make it stronger across the board and still run fine with the fuel you will be running. Double spring part number TFS-2500287 would be a good match. We also have the SUM-8707 Stage 2 cam (226/238 113+3 .600/.600), but at your weight and gear - you can be more aggressive.
#7
TECH Senior Member
iTrader: (4)
Darrin Morgan at Reher- Morrison, Vengeance Racing, Brian Tooley, Martin Smallwood, Bret @ Land Speed, Pat G or Mike Jones would be on my list of folks to talk with about a road race cam.
This thread has some interesting comments about road race cams in LS3 by Martin. Good stuff on push rods, lobe ramp & exhaust lift.
https://ls1tech.com/forums/generatio...s3-driver.html
My personal opinion go for the fat torque curve, fast throttle response. Darrin Morgan spec'd out an excellent cam for my 416 that has an excellent broad fat torque curve from 3,000 rpm to 6,000 rpm. The curve for the cam looks ideal for the rpm range the OP described. I'm sure Darrin has a stock cube LS3 version of the cam.
This thread has some interesting comments about road race cams in LS3 by Martin. Good stuff on push rods, lobe ramp & exhaust lift.
https://ls1tech.com/forums/generatio...s3-driver.html
My personal opinion go for the fat torque curve, fast throttle response. Darrin Morgan spec'd out an excellent cam for my 416 that has an excellent broad fat torque curve from 3,000 rpm to 6,000 rpm. The curve for the cam looks ideal for the rpm range the OP described. I'm sure Darrin has a stock cube LS3 version of the cam.
Trending Topics
#8
Teching In
Thread Starter
Join Date: Aug 2018
Location: Phoenix, AZ
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
Darrin Morgan at Reher- Morrison, Vengeance Racing, Brian Tooley, Martin Smallwood, Bret @ Land Speed, Pat G or Mike Jones would be on my list of folks to talk with about a road race cam.
This thread has some interesting comments about road race cams in LS3 by Martin. Good stuff on push rods, lobe ramp & exhaust lift.
https://ls1tech.com/forums/generatio...s3-driver.html
My personal opinion go for the fat torque curve, fast throttle response. Darrin Morgan spec'd out an excellent cam for my 416 that has an excellent broad fat torque curve from 3,000 rpm to 6,000 rpm. The curve for the cam looks ideal for the rpm range the OP described. I'm sure Darrin has a stock cube LS3 version of the cam.
This thread has some interesting comments about road race cams in LS3 by Martin. Good stuff on push rods, lobe ramp & exhaust lift.
https://ls1tech.com/forums/generatio...s3-driver.html
My personal opinion go for the fat torque curve, fast throttle response. Darrin Morgan spec'd out an excellent cam for my 416 that has an excellent broad fat torque curve from 3,000 rpm to 6,000 rpm. The curve for the cam looks ideal for the rpm range the OP described. I'm sure Darrin has a stock cube LS3 version of the cam.
#9
LS1Tech Sponsor
Join Date: Jan 2008
Location: Ohio, Georgia, Nevada, Texas
Posts: 1,947
Received 1,118 Likes
on
616 Posts
Wide and flat and happy from 3200-7000 with LS3 valves and the recommended springs. Power with the Summit Pro LS stage 3 will be withing a couple percent either way of 485/445 as measured on a Dynojet with a side-exit exhaust and the gold heat wrap and venting you would typically use in a roadrace car. Also a typical roadrace tune and 10% pulley without fuel additives/vacuum etc. Much of this will depend on your tuner, but this would be pretty typical. E85 will bump it of course, but not recommended for your application as you have other consumables with better bang for the buck.
#10
Teching In
Thread Starter
Join Date: Aug 2018
Location: Phoenix, AZ
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
Wide and flat and happy from 3200-7000 with LS3 valves and the recommended springs. Power with the Summit Pro LS stage 3 will be withing a couple percent either way of 485/445 as measured on a Dynojet with a side-exit exhaust and the gold heat wrap and venting you would typically use in a roadrace car. Also a typical roadrace tune and 10% pulley without fuel additives/vacuum etc. Much of this will depend on your tuner, but this would be pretty typical. E85 will bump it of course, but not recommended for your application as you have other consumables with better bang for the buck.
#11
TECH Apprentice
We backed up the intake closing point on our Summit Pro LS Stage 3 LS3 (p/n SUM-8710) cam (from our SUM-8711 Stage 4 LS3 cam) to build more torque where most people find it useful. For where you are shifting and setting redline, it will be a good match and easy to tune. Specs are 230/242 113+3. 5 I/O, 45 I/C, 56 E/O, and 5 E/C. with .625/.605 lift and the lobes carry well up top. When you need it, you can hang at higher rpm without shifting to keep from disturbing the car mid-corner and pull out nicely with overhead to spare.
The cam has .081/.103 clearance as measured on our stock LS3. The Heads could be milled about .020 in. (after you confirm measurements on your engine). The bump in compression will make it stronger across the board and still run fine with the fuel you will be running. Double spring part number TFS-2500287 would be a good match. We also have the SUM-8707 Stage 2 cam (226/238 113+3 .600/.600), but at your weight and gear - you can be more aggressive.
The cam has .081/.103 clearance as measured on our stock LS3. The Heads could be milled about .020 in. (after you confirm measurements on your engine). The bump in compression will make it stronger across the board and still run fine with the fuel you will be running. Double spring part number TFS-2500287 would be a good match. We also have the SUM-8707 Stage 2 cam (226/238 113+3 .600/.600), but at your weight and gear - you can be more aggressive.
Why not make it 108LSA seeing as it is for road racing not street manners? Most engine dyno tests I have seen show 108 works better when compared to anything wider, though EFI does not like much tighter than 108, carbys however do.
If stock head gaskets in there, I'd drop in some 0.036 or 040 Cometics. That'd raise compression and get quench down to a nice tight 0.030 range. They'll rpm to 7k+ at 030 with steel rods and stock pistons/clearances.
#13
LS1Tech Sponsor
Join Date: Jan 2008
Location: Ohio, Georgia, Nevada, Texas
Posts: 1,947
Received 1,118 Likes
on
616 Posts
You haven't mentioned all the details of your car, but it sounds like a Trans Am series TA3 style car? In terms of parts, you're looking at pump/injectors which is straight forward plus a flex fuel kit such as those from Dave Steck (DSX). Your tuner will have to turn on and populate the tables for varying percentages of ethanol and tuning a car for the AZ heat probably isn't the easiest task to begin with. You didn't mention the duration of the sessions, but you're going to be burning through more fuel. The weight of the fuel will affect the balance during the session. The slight horsepower gains you're going to get with a standard compression LS3 are probably not worth it, but most of it will depend on your tuner and their knowledge with road race applications.
#14
LS1Tech Sponsor
Join Date: Jan 2008
Location: Ohio, Georgia, Nevada, Texas
Posts: 1,947
Received 1,118 Likes
on
616 Posts
That sounds like a really good cam.
Why not make it 108LSA seeing as it is for road racing not street manners? Most engine dyno tests I have seen show 108 works better when compared to anything wider, though EFI does not like much tighter than 108, carbys however do.
If stock head gaskets in there, I'd drop in some 0.036 or 040 Cometics. That'd raise compression and get quench down to a nice tight 0.030 range. They'll rpm to 7k+ at 030 with steel rods and stock pistons/clearances.
Why not make it 108LSA seeing as it is for road racing not street manners? Most engine dyno tests I have seen show 108 works better when compared to anything wider, though EFI does not like much tighter than 108, carbys however do.
If stock head gaskets in there, I'd drop in some 0.036 or 040 Cometics. That'd raise compression and get quench down to a nice tight 0.030 range. They'll rpm to 7k+ at 030 with steel rods and stock pistons/clearances.
Compression pays dividends everywhere and the best place to get it first is a head gasket. A TFS-32694100-045 is about the thinnest (4.100 x .045) that fits the bore well and nets .038 piston to head (Leaving Bazman room to deck the block )
Next place to go looking is the head milling. Most of the biggest LS3 drop in cams will have I/O around 8 btdc with some subtle lobe design magic. The Summit Pro LS "LS3" Stage 4 (SUM-8711) has 7 I/O, 47 I/C, 60 E/O and 7 E/C and would allow for about .005 milling depending on how close you want to get the exhaust with .038 piston to head. With the lower power band requested, the LS3 Stage 3 (SUM-8710) makes sense with the intake and exhaust events a couple degrees condensed. It allows for .010 worth of milling for a bit more pop and would net a bit more exhaust clearance than the Stage 4 when (not if) mechanical over-rev occurs. Going down to the Pro LS Stage 2 (SUM-8707) cam is condensed 2 degrees further per event, but the compression gain wouldn't offset the cam timing requirements for the OP's powerband.
#15
Teching In
Thread Starter
Join Date: Aug 2018
Location: Phoenix, AZ
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
#16
Teching In
Thread Starter
Join Date: Aug 2018
Location: Phoenix, AZ
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
You haven't mentioned all the details of your car, but it sounds like a Trans Am series TA3 style car? In terms of parts, you're looking at pump/injectors which is straight forward plus a flex fuel kit such as those from Dave Steck (DSX). Your tuner will have to turn on and populate the tables for varying percentages of ethanol and tuning a car for the AZ heat probably isn't the easiest task to begin with. You didn't mention the duration of the sessions, but you're going to be burning through more fuel. The weight of the fuel will affect the balance during the session. The slight horsepower gains you're going to get with a standard compression LS3 are probably not worth it, but most of it will depend on your tuner and their knowledge with road race applications.
#17
Teching In
Thread Starter
Join Date: Aug 2018
Location: Phoenix, AZ
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
This is an interesting point and we have some cams like that. We've labeled them "single plane" to your great point about carbs. The psychology of 108 LSA can be misleading so it's better to speak in individual timing events. The OP mentioned occasional AutoX in his first post as a small tuning constraint, but ties well into the LS3's intake opening constraint to keep things from going into left field. (Flycutting is a possibility, but I'll keep this to drop-in stuff for simplicity and customer's stated powerband).
Compression pays dividends everywhere and the best place to get it first is a head gasket. A TFS-32694100-045 is about the thinnest (4.100 x .045) that fits the bore well and nets .038 piston to head (Leaving Bazman room to deck the block )
Next place to go looking is the head milling. Most of the biggest LS3 drop in cams will have I/O around 8 btdc with some subtle lobe design magic. The Summit Pro LS "LS3" Stage 4 (SUM-8711) has 7 I/O, 47 I/C, 60 E/O and 7 E/C and would allow for about .005 milling depending on how close you want to get the exhaust with .038 piston to head. With the lower power band requested, the LS3 Stage 3 (SUM-8710) makes sense with the intake and exhaust events a couple degrees condensed. It allows for .010 worth of milling for a bit more pop and would net a bit more exhaust clearance than the Stage 4 when (not if) mechanical over-rev occurs. Going down to the Pro LS Stage 2 (SUM-8707) cam is condensed 2 degrees further per event, but the compression gain wouldn't offset the cam timing requirements for the OP's powerband.
Compression pays dividends everywhere and the best place to get it first is a head gasket. A TFS-32694100-045 is about the thinnest (4.100 x .045) that fits the bore well and nets .038 piston to head (Leaving Bazman room to deck the block )
Next place to go looking is the head milling. Most of the biggest LS3 drop in cams will have I/O around 8 btdc with some subtle lobe design magic. The Summit Pro LS "LS3" Stage 4 (SUM-8711) has 7 I/O, 47 I/C, 60 E/O and 7 E/C and would allow for about .005 milling depending on how close you want to get the exhaust with .038 piston to head. With the lower power band requested, the LS3 Stage 3 (SUM-8710) makes sense with the intake and exhaust events a couple degrees condensed. It allows for .010 worth of milling for a bit more pop and would net a bit more exhaust clearance than the Stage 4 when (not if) mechanical over-rev occurs. Going down to the Pro LS Stage 2 (SUM-8707) cam is condensed 2 degrees further per event, but the compression gain wouldn't offset the cam timing requirements for the OP's powerband.
#18
LS1Tech Sponsor
Join Date: Jan 2008
Location: Ohio, Georgia, Nevada, Texas
Posts: 1,947
Received 1,118 Likes
on
616 Posts
So you think I would benefit from a thinner head gasket? How much more compression will this give me? Will it compromise reliability? My #1 concern is reliability. That's the reason I'm swapping a NA v8 into a subaru instead of FI and dealing with all the cooling probs that brings. As you said, AZ heat! That's also the reason I wanted to keep the redline where it's at.
You are correct with cooling being your number one priority. Steam vent kits, 160 stat, air extractors toward the front of the hood, but especially extra oil coolers are going to be the big thing. We carry windage trays from Improved Racing and other for resistance to oil starvation. If the budget allows, dry sump kits using a mix of factory components from the Z06, 2010-13 Grand Sport, or the Z28 are popular along with ARE components. The Dailey dry sump pan etc. is a common site on Optima series cars etc. and very compact.
It's a good move your making. Plus it would be legal at the Holley LS Fest.
#19
TECH Apprentice
This is an interesting point and we have some cams like that. We've labeled them "single plane" to your great point about carbs. The psychology of 108 LSA can be misleading so it's better to speak in individual timing events. The OP mentioned occasional AutoX in his first post as a small tuning constraint, but ties well into the LS3's intake opening constraint to keep things from going into left field. (Flycutting is a possibility, but I'll keep this to drop-in stuff for simplicity and customer's stated powerband).
Compression pays dividends everywhere and the best place to get it first is a head gasket. A TFS-32694100-045 is about the thinnest (4.100 x .045) that fits the bore well and nets .038 piston to head (Leaving Bazman room to deck the block )
Next place to go looking is the head milling. Most of the biggest LS3 drop in cams will have I/O around 8 btdc with some subtle lobe design magic. The Summit Pro LS "LS3" Stage 4 (SUM-8711) has 7 I/O, 47 I/C, 60 E/O and 7 E/C and would allow for about .005 milling depending on how close you want to get the exhaust with .038 piston to head. With the lower power band requested, the LS3 Stage 3 (SUM-8710) makes sense with the intake and exhaust events a couple degrees condensed. It allows for .010 worth of milling for a bit more pop and would net a bit more exhaust clearance than the Stage 4 when (not if) mechanical over-rev occurs. Going down to the Pro LS Stage 2 (SUM-8707) cam is condensed 2 degrees further per event, but the compression gain wouldn't offset the cam timing requirements for the OP's powerband.
Compression pays dividends everywhere and the best place to get it first is a head gasket. A TFS-32694100-045 is about the thinnest (4.100 x .045) that fits the bore well and nets .038 piston to head (Leaving Bazman room to deck the block )
Next place to go looking is the head milling. Most of the biggest LS3 drop in cams will have I/O around 8 btdc with some subtle lobe design magic. The Summit Pro LS "LS3" Stage 4 (SUM-8711) has 7 I/O, 47 I/C, 60 E/O and 7 E/C and would allow for about .005 milling depending on how close you want to get the exhaust with .038 piston to head. With the lower power band requested, the LS3 Stage 3 (SUM-8710) makes sense with the intake and exhaust events a couple degrees condensed. It allows for .010 worth of milling for a bit more pop and would net a bit more exhaust clearance than the Stage 4 when (not if) mechanical over-rev occurs. Going down to the Pro LS Stage 2 (SUM-8707) cam is condensed 2 degrees further per event, but the compression gain wouldn't offset the cam timing requirements for the OP's powerband.
As a matter of interest, if the budget allowed a forged piston with valve reliefs - I'm guessing you'd recommend tighter LSA then to pick up some TQ?
#20
Teching In
Thread Starter
Join Date: Aug 2018
Location: Phoenix, AZ
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
You guys have helped but I'm still thoroughly confused. I don't wanna mess with heads right yet. I still have a lot of other stuff to do on the car. Maybe later I'll go back and do that. I need someone to bottom line the camshaft to me! Lol