2500HD LQ9 SS2 cam
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Teching In
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2500HD LQ9 SS2 cam I did some research and found myself watching Holdener's cam videos where he concludes that the SS2 cam makes more power "everywhere" than the stock cam. My gut tells me that 228/230 @ .050 is a lot for a big, heavy 2500HD. My truck is an '01 2500HD extended cam long bed 2WD with a stock LQ4. I have a big open filter in place of the stock air box and plan to install long tubes and a Flo Pro 2505 muffler. I ordered the SS2 and PAC 1219 springs, but I'm wondering if that cam will be too much. I have a stock 4L80E and don't plan on installing a converter anytime soon. I do tow and haul with it, so I'm a little worried about giving up too much low end torque with this cam even though it supposedly doesn't sacrifice any.
My thought was that even if it did sacrifice some torque down low, it would be nice to downshift into third pulling a hill at around 4k on the highway while towing and have significantly more power there. Does this logic work or am I going to have too much trouble getting any load moving from a stop? On Holdener's dyno chart it does make more power at 2500 than the stock cam. The stock stall is like 1800, so it would only be tough for about 700 RPM I suppose, which perhaps a converter would completely rectify... I'm new to the LS engines. I hear they love more cam so I thought maybe this would work. Any wisdom is greatly appreciated! Thank you
My thought was that even if it did sacrifice some torque down low, it would be nice to downshift into third pulling a hill at around 4k on the highway while towing and have significantly more power there. Does this logic work or am I going to have too much trouble getting any load moving from a stop? On Holdener's dyno chart it does make more power at 2500 than the stock cam. The stock stall is like 1800, so it would only be tough for about 700 RPM I suppose, which perhaps a converter would completely rectify... I'm new to the LS engines. I hear they love more cam so I thought maybe this would work. Any wisdom is greatly appreciated! Thank you
Last edited by 69GTOby; May 11, 2021 at 05:21 AM.
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From: South Carolina
So it's not the original engine? LQ9's only came in the Silverado SS, GMC Vortec MAX and the Escalade all other 6.0L were LQ4's. That said before I upgraded to aftermarket heads and a larger camshaft I ran the SS2 in my LQ9 with 317's heads, headers and dual exhaust. It worked well but my truck is the lighter regular cab short bed 1500. I also have the 4L60 3200 stall and 4.10's. The sloppy likes compression and the specs say 10.5 minimum but the 10.2 LQ9 is close... the LQ4 not so much. You're gonna need more converter and gears to be happy with the SS2 in that heavier truck... so your concerns are valid.
Throttle to the floor no brakes burnout in my previous setup with the SS2
Throttle to the floor no brakes burnout in my previous setup with the SS2
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Teching In
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Oops! Yesterday was a long day, I meant LQ4! Is there a way to edit my thread title? I edited the body of my original post. It is the lower compression LQ4, and I think it should have the 317 heads. They are definitely cathedral ports. I got the grind from a cheap brand on Amazon. It didn't say anything about compression in the description, but I believe you, it looks like it needs 10+ CR on paper. I'm running the stock tire size and it has the 4.10s, so I have that going for me at least. The same cam on Jegs advertises a 2500-6500 operating range.
I looked closer at Holdener's dyno chart comparing SS2 to stock and realized he didn't show power or torque below 3k for the SS2. So, it does make more than the stock cam everywhere, starting at 3k... I'm guessing below 3k the stock cam makes more. He uses an LY6 with an LQ4 cam, and the LY6 is pretty comparable to the LQ4 other than the rec port heads. I'm not sure if my cathedral port heads would help it down low in the RPM compared to the rec port or not.
Maybe since it's a 6.0L rather than a 5.3 or 4.8, with a small tire and 4.10 gear, it won't be too bad? I wish the 4L80 had a deeper first gear... I don't know, what do you guys think? Is this a bad idea? I suppose I could try it and change it out later if it's too bad, or fix it by swapping in a NV4500 like it should have anyway, haha.
I looked closer at Holdener's dyno chart comparing SS2 to stock and realized he didn't show power or torque below 3k for the SS2. So, it does make more than the stock cam everywhere, starting at 3k... I'm guessing below 3k the stock cam makes more. He uses an LY6 with an LQ4 cam, and the LY6 is pretty comparable to the LQ4 other than the rec port heads. I'm not sure if my cathedral port heads would help it down low in the RPM compared to the rec port or not.
Maybe since it's a 6.0L rather than a 5.3 or 4.8, with a small tire and 4.10 gear, it won't be too bad? I wish the 4L80 had a deeper first gear... I don't know, what do you guys think? Is this a bad idea? I suppose I could try it and change it out later if it's too bad, or fix it by swapping in a NV4500 like it should have anyway, haha.
You've got the perfect platform to hotrod. 6.0L engine, bullet proof trans, bullet proof rear rend. You've got the cam and springs, put them in. These big GM pickups are so detuned from the factory, a pretty basic tune will amaze you. Do the mods you talked about. Add the cam, tune, you'll love it. Don't over think this, mod it. send it. Beat on it like it wrote you a bad check.
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Teching In
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That's what I wanted to hear, thank you! I'm amazed at how tough these new small blocks are from what I'm hearing. I'm late to the scene. I'm used to the old school stuff. Lately I've been playing with my 400 Pontiac. Over the summer I spun three rod bearings. That's what ported heads, a mild cam, single plane, a big Holley, and a broken tach will do to an old school engine with a weak bottom end LOL. I'm excited to start playing with the 6.0 in this truck. I already removed like 60% of TM, enable power enrichment, added like a couple degrees of timing across the board, and some other stuff I can't remember. Can I remove TM 100% in the trans and engine since it's the 4L80E? Also, will I be able to tune it in close enough with the new cam without a dyno? I'm sure I can figure out the idle pretty quickly just by raising it and changing the airflow settings. I looked at the HP Tuners repository but didn't find a tune for the setup. Thanks for the help!
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From: South Carolina
will I be able to tune it in close enough with the new cam without a dyno? I'm sure I can figure out the idle pretty quickly just by raising it and changing the airflow settings. I looked at the HP Tuners repository but didn't find a tune for the setup. Thanks for the help!
Kyle has some great tuning tutorials
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On The Tree
Joined: May 2008
Posts: 160
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From: Michigan
Darth is right. You dont even need headers, no intake to worry about, and completely stock reliability. But fuel mileage will take a dump.
I think the SS2 is way too big for an lq4, especially in a truck. Not enough compression. I think it's the end of that video where he tests some summit cams as well and a smaller cam actually made more torque under the curve, same hp. I think it was a 218/227. That would be way more snappy off the line and not bleed off so much compression.
Now if you wanted to switch to 706 heads, the ss2 might not be a bad choice. Keep the cam duration and ports as small as you can to reach desired hp and you have a faster engine with better mpg and response.
I think the SS2 is way too big for an lq4, especially in a truck. Not enough compression. I think it's the end of that video where he tests some summit cams as well and a smaller cam actually made more torque under the curve, same hp. I think it was a 218/227. That would be way more snappy off the line and not bleed off so much compression.
Now if you wanted to switch to 706 heads, the ss2 might not be a bad choice. Keep the cam duration and ports as small as you can to reach desired hp and you have a faster engine with better mpg and response.
Teching In
Joined: Apr 2020
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Not trying to steal your post but maybe easier to ask here.
Im setting up a similar truck, new to the ls game.
To run a ss2 cam besides getting hp tuners and a af gauge
what is needed to get it running good enough for a road trip.
do i need to change injectors to get it drivable,if so whats a decent one to get.
throttle body, etc?
eventually i will be learning to tune it to get max hp and just have fun frying the tires but still use it as a truck.
thanks.
Im setting up a similar truck, new to the ls game.
To run a ss2 cam besides getting hp tuners and a af gauge
what is needed to get it running good enough for a road trip.
do i need to change injectors to get it drivable,if so whats a decent one to get.
throttle body, etc?
eventually i will be learning to tune it to get max hp and just have fun frying the tires but still use it as a truck.
thanks.
TECH Senior Member
Joined: Jun 2016
Posts: 22,295
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From: Central Cal.
Not trying to steal your post but maybe easier to ask here.
Im setting up a similar truck, new to the ls game.
To run a ss2 cam besides getting hp tuners and a af gauge
what is needed to get it running good enough for a road trip.
do i need to change injectors to get it drivable,if so whats a decent one to get.
throttle body, etc?
eventually i will be learning to tune it to get max hp and just have fun frying the tires but still use it as a truck.
thanks.
Im setting up a similar truck, new to the ls game.
To run a ss2 cam besides getting hp tuners and a af gauge
what is needed to get it running good enough for a road trip.
do i need to change injectors to get it drivable,if so whats a decent one to get.
throttle body, etc?
eventually i will be learning to tune it to get max hp and just have fun frying the tires but still use it as a truck.
thanks.
Teching In
Joined: Apr 2020
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i know its not the perfect set up and since im rebuilding the motor(rings, bearings) i may put a better converter in it while i have the motor out.
i already have the cam,just gonna stick with it.
later on i may drop it in a better project car...
mostly wanna learn how to tune with hp tuners as the next peoject is a 2wd truck wanna put a turbo on and will need to know how to set up the computer on that...
Only been tuning carbs,might aswell learn this stuff also.
On The Tree
Joined: May 2008
Posts: 160
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From: Michigan
yup seen the posts on that
i know its not the perfect set up and since im rebuilding the motor(rings, bearings) i may put a better converter in it while i have the motor out.
i already have the cam,just gonna stick with it.
later on i may drop it in a better project car...
mostly wanna learn how to tune with hp tuners as the next peoject is a 2wd truck wanna put a turbo on and will need to know how to set up the computer on that...
Only been tuning carbs,might aswell learn this stuff also.
i know its not the perfect set up and since im rebuilding the motor(rings, bearings) i may put a better converter in it while i have the motor out.
i already have the cam,just gonna stick with it.
later on i may drop it in a better project car...
mostly wanna learn how to tune with hp tuners as the next peoject is a 2wd truck wanna put a turbo on and will need to know how to set up the computer on that...
Only been tuning carbs,might aswell learn this stuff also.
As far as tuning for a road trip.....either plan on lots of reading and test drives or just take it to someone. Setting idle and wot is nothing compared to part throttle tuning and knock tuning, tip in, slight load, trans shift points......
Teching In
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I dont think the stock lq4 injectors are enough. They're only around 25 lbs/hr. Some used ls3/ls7 or flex fuel injectors would be the cheapest option probably.
As far as tuning for a road trip.....either plan on lots of reading and test drives or just take it to someone. Setting idle and wot is nothing compared to part throttle tuning and knock tuning, tip in, slight load, trans shift points......
As far as tuning for a road trip.....either plan on lots of reading and test drives or just take it to someone. Setting idle and wot is nothing compared to part throttle tuning and knock tuning, tip in, slight load, trans shift points......
no tuner close by. Im hoping to find someone who would share a base file i could use as a starting point.
I was going to say the same exact thing. I have a 2016 2500 with a 6.0, Magnuson makes an awesome blower kit for our trucks. I actually worked on a 2013 Escalade recently that had the kit and it fit and performed flawlessly, looked like it could of came from the factory like that. It also depends what you want to do with the truck, mine is more of a work truck and family hauler so I don't want to lose any torque and driveability. I have been looking into a set of longtubes and a tune to unchoke it a bit since a blower isn't in the budget.
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Teching In
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Thank you for all the feedback! I installed the cam and springs a while back, which was awesomely easy to do! I did all the tuning stuff that I found here so that it will idle and drive: https://forum.hptuners.com/showthrea...de-(w-pictures). I definitely need to do more tuning though, but am pretty lost. I understand I need a wideband. Can I get a wideband and replace one of the regular O2 sensors, and use the feedback shown on HP Tuners, or do I need to install another O2 bung, and add the wideband, and use an air/fuel gauge, like one would do with a carburetor?
First impressions: the cam sounds awesome at idle, which is a plus. It's a little soft down low, maybe not any worse than a stock truck, but pulls pretty good above 3,500-4k. I know I'm leaving a lot of power on the table without doing any real tuning. I also need to uncork the exhaust side. I still have the full stock exhaust. I want to do long tubes and something about the trash can sized muffler, but I don't want ANY drone or excessive noise, so I'm kind of torn on that issue. Any tuning and exhaust suggestions would be much appreciated. It sounds like I need to upgrade to big block injectors, like yesterday. And obviously, a higher stall converter would go a long way as well, which I'll get to eventually.
Overall, my goal is a stock appearing, beat up work truck, but with a little surprise power hidden beneath the cloak of innocence. Thanks again for all the help and suggestions.
First impressions: the cam sounds awesome at idle, which is a plus. It's a little soft down low, maybe not any worse than a stock truck, but pulls pretty good above 3,500-4k. I know I'm leaving a lot of power on the table without doing any real tuning. I also need to uncork the exhaust side. I still have the full stock exhaust. I want to do long tubes and something about the trash can sized muffler, but I don't want ANY drone or excessive noise, so I'm kind of torn on that issue. Any tuning and exhaust suggestions would be much appreciated. It sounds like I need to upgrade to big block injectors, like yesterday. And obviously, a higher stall converter would go a long way as well, which I'll get to eventually.
Overall, my goal is a stock appearing, beat up work truck, but with a little surprise power hidden beneath the cloak of innocence. Thanks again for all the help and suggestions.
On The Tree
Joined: May 2008
Posts: 160
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From: Michigan
Well, you WILL lose low end torque with that cam. Stock truck cams maximize low end tq and are hard to beat. Long tube headers will gain alot back. As long as you run a full exhaust exiting out the rear, nothing should drone much in a pickup. If you go with a straight through muffler you want your collector extension to be in increments of about 18". Meaning where the primaries meet the collector, measure from there to the very end of the exhaust. 108",126", 144" etc. You can do your own research on that, but if it will help with low end tq and especially right where the converter hits. If you don't hit those numbers within inches, you can install a resonator at the correct distance. That will also kill drone. On these trucks, removing the stock muffler often kills low end tq. I suspect because GM has this exhaust tuned for pulses. Free power.
But the biggest improvement will come from a higher stall converter. Stock is 2200 I think for the LQ4, 1800 for the half tons. 2500 would be good. 3000 if you really want it to be snappy. But the higher you go, the mushier it makes the power delivery under light throttle until the converter locks up.
But the biggest improvement will come from a higher stall converter. Stock is 2200 I think for the LQ4, 1800 for the half tons. 2500 would be good. 3000 if you really want it to be snappy. But the higher you go, the mushier it makes the power delivery under light throttle until the converter locks up.
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Teching In
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I realized I wouldn't gain any low end torque with this cam, but even with a stock converter stall of 2200, I'm pretty close right out of the gate to where this cam will make more power than the stock one, so a little sacrifice of torque below 2500 rpm or so is worth a significant power gain everywhere above 3000. I just need to get this thing dialed in which is where I'm kind of lost.
I'm confused, if I don't use an air/fuel gauge and want to read the O2 voltage on HPtuners, don't I have to unplug an upstream sensor to plug in the wideband, and won't that put it in open loop?
Any recommendation on injectors to get? I see talk of 8.1 marine injectors, flex fuel injectors, stock big block injectors... I don't know, I just want whatever will work that is affordable and easy.
I logged a full throttle run to 5500 rpm and noticed a few things. At about 4k it had 27* of advance, 22* at 4500, 18* at 5k, and 15.5* at 5500. That doesn't seem right. It reads 0.0 knock retard on the list on the left, so I don't know why it would be pulling timing.
I'm confused, if I don't use an air/fuel gauge and want to read the O2 voltage on HPtuners, don't I have to unplug an upstream sensor to plug in the wideband, and won't that put it in open loop?
Any recommendation on injectors to get? I see talk of 8.1 marine injectors, flex fuel injectors, stock big block injectors... I don't know, I just want whatever will work that is affordable and easy.
I logged a full throttle run to 5500 rpm and noticed a few things. At about 4k it had 27* of advance, 22* at 4500, 18* at 5k, and 15.5* at 5500. That doesn't seem right. It reads 0.0 knock retard on the list on the left, so I don't know why it would be pulling timing.