[gmcvt]

Would appreciate ya'lls input on this. I have had several cammed GM cars in the past. (5th gen Camaro, GTO etc..). They were all M6's and LS2/LS3 cars. What I am looking for is feedback on the tradeoff of driveability and tip in throttle response/low rpm torque once you have moved from stock exhaust manifolds and stock camshaft.

The LT1 is a slightly different beast with the VVT (if retained). The deal is this: I am very happy with the crispness/responsiveness of the engine at lower rpm's in normal driving scenarios (stock). But the hotrodder in me of course wants to make some changes and I know that there is a modest amount of hp potential left in it. What I dont want to do is lose that crisp torquey response of the engine in the lower rpm and I know that typically, with a cam especially, that is usually sacrificed for upper rpm horsepower. Heck, my experience has been that with headers alone, pending primary size, you can lose that.

But again, I dont know with the LT1 and VVT if that has changed a bit. And of coarse there are clearly variables to this, such as the size of cam that you choose. Its a decent financial investment to do cam and headers, not to mention a little time and while I make the occasional trips to the drag strip, the real world use of my SS is not WOT. I dont want to kill the 95% for th 5%. So just curious to get your feedback on your experiences with the LT1. Thank you!

[Redlinez]

I have a manual, so things are a little different. I did longtubes with cats, ported stock intake, ported ZL1 throttle body, and E85 with a tune. Sounds crazy, but something told me from "hotrodding" my many other cars (LS1's and Mustangs) that it might change it in a way I don't love. The trade off always seems to be a loss of bottom end and adding some herky jerky throttle response, which is what I have felt. I will I'm sure enjoy it the next time I do a HPDE event or drag myself to the dragstrip. My feelings will probably change then. I don't even love the sound, it has that clapping/whatever it's called sound when you go WOT and get up in the revs, just like my 2015 Mustang GT did with catted longtubes. As long as I stay below 3000 rpms, it sounds cool. Even my wife said, what happened to how good your LT1 cars from the 90's sounded? I kept the stock NPP exhaust.
Going cam/heads in these cars is so much more money than my LS1 cars, but the gain and baseline to begin with are so much higher. Granted I had to much cam in my daily driver 99 Z28, so the surge was my own fault for listening to Futral Motorsports. Then you could debate the drop in piston and rod combo and go Procharger.

[Zboy136]

I cant speak for everyone, and I'm no technician, and I can only speak from my own experience. I went with a stage 2 Texas Speed cam for every day use if need be. And literally the only issue I had was the tuner set my throttle to being overly touchy, which was an easy fix. The car still drives well, there can be some cam surge as it approaches 1k rpms. But you kinda learn to compensate for that. The amount of fun it added through the sound and speed, is totally worth it.

[oldman]

Originally Posted by Redlinez

Sounds crazy, but something told me from "hotrodding" my many other cars (LS1's and Mustangs) that it might change it in a way I don't love. The trade off always seems to be a loss of bottom end and adding some herky jerky throttle response, which is what I have felt.... I don't even love the sound, it has that clapping/whatever it's called sound when you go WOT and get up in the revs, just like my 2015 Mustang GT did with catted longtubes. As long as I stay below 3000 rpms, it sounds cool. Even my wife said, what happened to how good your LT1 cars from the 90's sounded? I kept the stock NPP exhaust.

I too have a M6, there are issues with PTB, 103mm TB, LT with no cats, CA front cat deletes. Some / most combinations of these on a M6 lead to the sound and conditions you describe. Including myself (I suck) I have had 4 tuners work on my car to get it where it is today. No combination that I have tried so far fixes some sort of sort of resonance issue with the above. Today I will be installing a Borla 60608 twin resonator and one or maybe two stainless steel double braided flex pipes in the exhaust system just to make the car sound and pull correctly under all street conditions.

The ZL1 forum with M6 guys also have issues with LT or primary cat deletes and sound or resonation or whatever you want to call it.

Now if I change anything like put stock TB on and all four factory cats the car runs and drives great, perfect throttle response, perfect sound under all conditions all the way from idle to WOT 7200 shifts.

I do note the stock exhaust has two small flex joints just before the X pipe and with my setup these seem to be overwhelmed. The whole system does a whole lot of shaking on my car. Hence it my thinking of adding in one or two double braided stainless flex joints will break up this harmonic. Also LT or CA type CAT deletes remove the twin exhaust bracket from trans to exhaust. This is the ONLY bracket for the entire front of the exhaust system, same same for most aftermarket header back systems (anything that removes the front cats where the bracket is attached to.

Long story short, I'll probably fab a new front bracket, install twin resonators and one or two flex pipes and hope any resonance issue goes away.

It is NOT a huge problem IMO, but I'm picky as this car is my toy and I want it to sound and run correctly under all conditions.

[oldman]

Originally Posted by gmcvt

Would appreciate ya'lls input on this. I have had several cammed GM cars in the past. (5th gen Camaro, GTO etc..). They were all M6's and LS2/LS3 cars. What I am looking for is feedback on the tradeoff of driveability and tip in throttle response/low rpm torque once you have moved from stock exhaust manifolds and stock camshaft.

The LT1 is a slightly different beast with the VVT (if retained). The deal is this: I am very happy with the crispness/responsiveness of the engine at lower rpm's in normal driving scenarios (stock). But the hotrodder in me of course wants to make some changes and I know that there is a modest amount of hp potential left in it. What I dont want to do is lose that crisp torquey response of the engine in the lower rpm and I know that typically, with a cam especially, that is usually sacrificed for upper rpm horsepower. Heck, my experience has been that with headers alone, pending primary size, you can lose that.

The factory header is excellent, that said the front cat goes down to something like 1.9" ID at the 02, depending on your powerlevel removing this restriction would be a major step forward in power without any loss at part-throttle or tip in. There are issues with resonance, especially on a M6 with no primary cats.

I went with 1 and 7/8 headers with no cats (and yes 2" will yield more WOT power over the entire band we beat that horse to DEATH). The headers were great under all conditions and driving, in fact, I felt that midrange power was even better vs stock header + CA front cat deletes. I had two tuners work on this combination and the problem of low speed resonance, bucking, sound or whatever was never solved. Putting cats in was the second best mod I ever did to the car (the Hurst shifter being the first). I would say NA FBO 1 and 7/8 with cats would satisfy 95% of the people, maybe 99%. Low speed 1200 RPM part throttle just general driving was NOT as good as stock, meaning you have to leave it in 4th at say 45 MPH, 5th upto 58 MPH with the LT and cats, no big deal, but just note that is ain't exactly like stock.

My first cam was a Pray spec cam for centriblower, call it stage 1. It had a 22 degree VVT restrictor. TxSpeed the guys that make the cam claim the 22 degrees does add a whole lot of flexibility to the driving experience. Most tuners do NOT use it though. That said the stage 1 cam and heads was really pretty drivable with primary cats, near stock but once you pass the 3500 RPM slight sag (I have a MSD also) very perky. Note on a M6 shifts put you at 5000 RPM so there is never any issue with WOT power or runs, we are only talking about part throttle tip in, low speed issues. Probably not a problem at all on a auto as the converter just slips or the trans kicks down.
Once again small cam LT with cats works fine, WOT power through the gears is exceptional and there is basically no difference in 0-100 times on street tires with a FBO+ heads + cam vs what I have now. i.e. the combo can put out all the power that can be hooked to the ground with PS4P tires, OK maybe a blower would get you on a perfect launch and run through the gears a .3 second edge 0-100, it would take a lot of skill. Of course, the auto guys already have at least a .5 advantage here anyway.


I broke my new engine in NA, with large cam, headers, cats, heads, FBO, the car had excellent midrange response, power easily exceeded what street tires can put to the ground, at this point NA, I no longer do WOT no-lift shifts into 3rd as the car can completely blow the tires away and that ain't so "fun" at 80 MPH. WOT in 1st and 2nd need to be carefully applied, hope that answers your question about loss of mid-range.

Finally LT, cat and cam, I thought I was finished, but the car became too loud from startup idle to WOT. Some might actually like it. The exhaust sound was FAR higher than the engine sound (which I like).

Originally Posted by gmcvt

But again, I dont know with the LT1 and VVT if that has changed a bit.

Nutshell this is a high CR V8 and it is going to be hard to over cam over header this car. If you really want strong mid-range dropping the LSA to 112 will fix that. Note I'd still pick 1and 7/8 headers and 222 / 232 ish cam for a daily driver, yep probably leave 20 to 40 peak HP on the table but it will be a more "livable" DD. This combo may even be MORE drivable than stock. I would not toy with a 22 degree VVT, but it may be the future, dunno, I don't like over-complication for what I view as a non-issue.

Originally Posted by gmcvt

And of coarse there are clearly variables to this, such as the size of cam that you choose. Its a decent financial investment to do cam and headers, not to mention a little time and while I make the occasional trips to the drag strip, the real world use of my SS is not WOT. I dont want to kill the 95% for th 5%. So just curious to get your feedback on your experiences with the LT1. Thank you!

To cam or not to cam that has been the question since Hamlet.

The general consensus (well supported) is:
1)pull and port the heads (need to change out the DoD lifters)
2)run a valve train that can support the lift and this can range from bone stock and a GM HotCam to you need to change every part of the valvetrain out including the valves.

A FAR more controversial subject would be just installing a DoD compatible camshaft and retain stock or near-stock valve train. GM did this on the LT2. I've already gone down my rabbit hole selecting #2 above and adding in a mild ramp sub .600 lift cam and call it done for as long as I'm able to still drive.

If I was tabula rasa, I'd probably do a DoD comp cam, the weakest PAC beehive spring, factory headers with CA front cat delete, FBO, and not pull the heads.
or
GM Hotcam or smallest Cam Motion cam (both are DoD delete), Pray ported heads, LT with cats. midrange beehive spring, LS7 lifter, change trunion bearings/ FBO with a smaller header and cats.
CM is 218/ 228 114LSA +4 installed
or
leave the factory cam and valvetrain alone and do: FBO, pray ported heads. We know this is going to be 100% stock reliable right?

any of the above 3 setup would give you 95% and leave the 5% on the table which will require $$$$

No matter what choice you make go with a tuner that will work with you and your needs. Pray and Ryne Cunningham have been great, many sponsors here have a huge following too.

[gmcvt]

Originally Posted by Redlinez

I have a manual, so things are a little different. I did longtubes with cats, ported stock intake, ported ZL1 throttle body, and E85 with a tune. Sounds crazy, but something told me from "hotrodding" my many other cars (LS1's and Mustangs) that it might change it in a way I don't love. The trade off always seems to be a loss of bottom end and adding some herky jerky throttle response, which is what I have felt. I will I'm sure enjoy it the next time I do a HPDE event or drag myself to the dragstrip. My feelings will probably change then. I don't even love the sound, it has that clapping/whatever it's called sound when you go WOT and get up in the revs, just like my 2015 Mustang GT did with catted longtubes. As long as I stay below 3000 rpms, it sounds cool. Even my wife said, what happened to how good your LT1 cars from the 90's sounded? I kept the stock NPP exhaust.
Going cam/heads in these cars is so much more money than my LS1 cars, but the gain and baseline to begin with are so much higher. Granted I had to much cam in my daily driver 99 Z28, so the surge was my own fault for listening to Futral Motorsports. Then you could debate the drop in piston and rod combo and go Procharger.

Ha! Thats funny, I had a Futral cam in my GTO. Which was also a poor match for its intended purpose. Your are right on so many points...thank you for the persepctive.

[Jaxcam02]

I literally have no desire to do any major mods to this car like I have on my others besides deleting the sound tube and maybe a new intake. The SS is just to perfect right now.

[gmcvt]

Originally Posted by oldman

The factory header is excellent, that said the front cat goes down to something like 1.9" ID at the 02, depending on your powerlevel removing this restriction would be a major step forward in power without any loss at part-throttle or tip in. There are issues with resonance, especially on a M6 with no primary cats.

I went with 1 and 7/8 headers with no cats (and yes 2" will yield more WOT power over the entire band we beat that horse to DEATH). The headers were great under all conditions and driving, in fact, I felt that midrange power was even better vs stock header + CA front cat deletes. I had two tuners work on this combination and the problem of low speed resonance, bucking, sound or whatever was never solved. Putting cats in was the second best mod I ever did to the car (the Hurst shifter being the first). I would say NA FBO 1 and 7/8 with cats would satisfy 95% of the people, maybe 99%. Low speed 1200 RPM part throttle just general driving was NOT as good as stock, meaning you have to leave it in 4th at say 45 MPH, 5th upto 58 MPH with the LT and cats, no big deal, but just note that is ain't exactly like stock.

My first cam was a Pray spec cam for centriblower, call it stage 1. It had a 22 degree VVT restrictor. TxSpeed the guys that make the cam claim the 22 degrees does add a whole lot of flexibility to the driving experience. Most tuners do NOT use it though. That said the stage 1 cam and heads was really pretty drivable with primary cats, near stock but once you pass the 3500 RPM slight sag (I have a MSD also) very perky. Note on a M6 shifts put you at 5000 RPM so there is never any issue with WOT power or runs, we are only talking about part throttle tip in, low speed issues. Probably not a problem at all on a auto as the converter just slips or the trans kicks down.
Once again small cam LT with cats works fine, WOT power through the gears is exceptional and there is basically no difference in 0-100 times on street tires with a FBO+ heads + cam vs what I have now. i.e. the combo can put out all the power that can be hooked to the ground with PS4P tires, OK maybe a blower would get you on a perfect launch and run through the gears a .3 second edge 0-100, it would take a lot of skill. Of course, the auto guys already have at least a .5 advantage here anyway.


I broke my new engine in NA, with large cam, headers, cats, heads, FBO, the car had excellent midrange response, power easily exceeded what street tires can put to the ground, at this point NA, I no longer do WOT no-lift shifts into 3rd as the car can completely blow the tires away and that ain't so "fun" at 80 MPH. WOT in 1st and 2nd need to be carefully applied, hope that answers your question about loss of mid-range.

Finally LT, cat and cam, I thought I was finished, but the car became too loud from startup idle to WOT. Some might actually like it. The exhaust sound was FAR higher than the engine sound (which I like).




Nutshell this is a high CR V8 and it is going to be hard to over cam over header this car. If you really want strong mid-range dropping the LSA to 112 will fix that. Note I'd still pick 1and 7/8 headers and 222 / 232 ish cam for a daily driver, yep probably leave 20 to 40 peak HP on the table but it will be a more "livable" DD. This combo may even be MORE drivable than stock. I would not toy with a 22 degree VVT, but it may be the future, dunno, I don't like over-complication for what I view as a non-issue.



To cam or not to cam that has been the question since Hamlet.

The general consensus (well supported) is:
1)pull and port the heads (need to change out the DoD lifters)
2)run a valve train that can support the lift and this can range from bone stock and a GM HotCam to you need to change every part of the valvetrain out including the valves.

A FAR more controversial subject would be just installing a DoD compatible camshaft and retain stock or near-stock valve train. GM did this on the LT2. I've already gone down my rabbit hole selecting #2 above and adding in a mild ramp sub .600 lift cam and call it done for as long as I'm able to still drive.

If I was tabula rasa, I'd probably do a DoD comp cam, the weakest PAC beehive spring, factory headers with CA front cat delete, FBO, and not pull the heads.
or
GM Hotcam or smallest Cam Motion cam (both are DoD delete), Pray ported heads, LT with cats. midrange beehive spring, LS7 lifter, change trunion bearings/ FBO with a smaller header and cats.
CM is 218/ 228 114LSA +4 installed
or
leave the factory cam and valvetrain alone and do: FBO, pray ported heads. We know this is going to be 100% stock reliable right?

any of the above 3 setup would give you 95% and leave the 5% on the table which will require $$$$

No matter what choice you make go with a tuner that will work with you and your needs. Pray and Ryne Cunningham have been great, many sponsors here have a huge following too.

Wow, thank you oldman. LOTS of good info in here. Gonna need to read a couple of times to soak in.

I'm going to assume that the tabula rasa option uses a DoD cam because you are not pulling the heads to get rid of the DoD lifters?

I kinda like the idea of option 3. Pray heads and FBO. (although I assume it would be a good idea to yank the DoD lifters at this time also). I think the variable for me is the A10 and how it would compensate for any loss of low end torque. I haven't really monitored where my RPM's are at on my normal drive but I just dont want to lose that crisp clean pull from low to mid rpm's.

So I would certainly be tempted to leave the cam out of it or at least go with your suggestion as far as staying around a 112LSA. The other thing is the change in exhaust volume/tone. On my 18 5.0, once I installed headers, it was nasty of coarse, so I installed a MF resonated X pipe that made a massive difference and was nice. Volume levels were near stock and didn't have the nasty rasp. I haven't looked too deep into whats available for the 6th gen Camaro in that regard when trying to tame the rasp.

Back to the header/loss of low end torque, this issue was prevelant on my 5.0. At one point I had a "CAI" and long tubes and that combo overall made a significant negative difference at low to mid rpm torque. I hated it. Yanked them both off and went back factory and was happy again. I'm sure I gave up some peak hp but it wasn't worth the real world loss where you spend the overwhelming majority of your time. Not for me anyway. Of coarse the coyote is a smaller displacement engine (and obviously very different is every way) and it may react more negatively to the larger primary header tubes than the LT1 at lower rpms. When I installed Kooks on my 10SS I dont recall experiencing a torque loss. And it was an M6.

One of the things I enjoy so much about my Camaro is the torque. and good throttle response(although I know that alot of people would argue the latter) and I dont want to lose that.

Thank you again for all that info!! Very helpful.

[gmcvt]

Originally Posted by Jaxcam02

I literally have no desire to do any major mods to this car like I have on my others besides deleting the sound tube and maybe a new intake. The SS is just to perfect right now.

I totally get that. I am more satisfied with this car than I have ever been with any car in my life. I have done mild to fairly wild and this car seems to scratch most all of the itches out of the box. BUT there is that part of me that wants to make at least some minor changes and take advantage of SOME of the potential without straying too far from the factory formula.

[oldman]

Originally Posted by gmcvt

I'm going to assume that the tabula rasa option uses a DoD cam because you are not pulling the heads to get rid of the DoD lifters?

Right, if you don't pull the heads you are limited to a DoD cam. The only dyno example of a DoD cam install was superchevy magazine. I don't know of anybody with a DoD cam, two other vendors that marketed DoD cams no longer offer them (or at least don't advertise them).

Since I do all my own work, I would do it for grins and it meets the needs of many people: fuel lobe for FI, increase duration for more power and a cam sound, pretty mild cams overall. Cons: DoD lifter failure. Pros even Chevy has gone to a bigger cam for the LT2, and I would predict this trend will continue as long as the engine remains in production. I honestly believe a workable combination will be found for FI as well as NA.

Originally Posted by gmcvt

I kinda like the idea of option 3. Pray heads and FBO. (although I assume it would be a good idea to yank the DoD lifters at this time also). I think the variable for me is the A10 and how it would compensate for any loss of low end torque. I haven't really monitored where my RPM's are at on my normal drive but I just dont want to lose that crisp clean pull from low to mid rpm's.

Good news and bad, you can't change out the DoD lifter (as of yet) to a stronger lifter. You either put in normal lifters and have a normal cam, or you are stuck with a DoD cam and DoD lifters. Sure you can put in stronger lifter on the regular lobes, but the Dod lifters are the weak point.

Good news, Pray ported heads, TB and Intake will lose no torque or drivability in any conditions. Just be sure to work with him on tune and what you want. The are dynos with ported heads and stock cam with OK results. We are talking 100% stock valvetrain so it should be identical in reliability. Put in studs for the heads, it really is not that hard to pull the heads. Same as any other OHV V8 plus 8 direct injectors (no big deal).

Originally Posted by gmcvt

So I would certainly be tempted to leave the cam out of it or at least go with your suggestion as far as staying around a 112LSA. The other thing is the change in exhaust volume/tone. On my 18 5.0, once I installed headers, it was nasty of coarse, so I installed a MF resonated X pipe that made a massive difference and was nice. Volume levels were near stock and didn't have the nasty rasp. I haven't looked too deep into whats available for the 6th gen Camaro in that regard when trying to tame the rasp.

I have a M6 and the issue seems to me to be a combination of no primary cats, and not related to anything else. 1100 RPM to 1600 RPM. I actually have good news on this too (fixed by Borla twin resonator in front of the factory X). I just did that fix just yesterday.

The 112 LSA will bring up torque by a huge amount, given 22x intake duration. Just remember the lope gets strong with low LSA cams. I know it does not make sense that midrange would come way up but idle quality go way down...

I'd stick with the smaller header, but guys with the 2" report no drivability issues. I still think the 1 and 7/8 header is a good compromise, but many think 2" is the only way to go.

Originally Posted by gmcvt

Back to the header/loss of low end torque, this issue was prevelant on my 5.0.

Honestly, I did not see any issues with my Kooks 1 and 7/8 with cats. If you are worried go with CA type front cat deletes, move the 02 sensors behind the secondary cats and call it a day (assuming you have an auto).

Originally Posted by gmcvt

Of coarse the coyote is a smaller displacement engine (and obviously very different is every way) and it may react more negatively to the larger primary header tubes than the LT1 at lower rpms. When I installed Kooks on my 10SS I dont recall experiencing a torque loss. And it was an M6.

LT don't seem to be an issue on the LT1, even the 2" on stock engine.

Originally Posted by gmcvt

One of the things I enjoy so much about my Camaro is the torque. and good throttle response(although I know that alot of people would argue the latter) and I dont want to lose that.

NA, full built, large cam, MSD, 103, throttle response is excellent. Since you have an auto, I'd do a high stall converter which I love on any NA auto car built or not

[oldman]

https://www.camaro6.com/forums/showthread.php?t=493412
Here 32 WHP with ported heads. There is a slight loss of torque, you will NEVER be in that range WOT, and you would never notice it part throttle. So it is a complete win.

[DAFLab-SS-18]

Originally Posted by Jaxcam02

I literally have no desire to do any major mods to this car like I have on my others besides deleting the sound tube and maybe a new intake. The SS is just to perfect right now.

You may say that now. But gapping a stock 2nd gen CTSV by just adding a Roto-Fab and E85 is well worth it I'm my opinion.

$400 for the intake
$225 for the sensor
$300+$180 HPtuners MPVI2 and 4 credits
About an hour of installation time.
15 minutes of tuning.
45 seconds to flash the new tune.
Gapplebees.

[gmcvt]

Originally Posted by oldman

https://www.camaro6.com/forums/showthread.php?t=493412
Here 32 WHP with ported heads. There is a slight loss of torque, you will NEVER be in that range WOT, and you would never notice it part throttle. So it is a complete win.

This really does seem to be ideal scenario for me. I didn't see, in that thread anyway, if the results were any different after he addressed the head gasket issue.

[OB0001]

Originally Posted by Jaxcam02

I literally have no desire to do any major mods to this car like I have on my others besides deleting the sound tube and maybe a new intake. The SS is just to perfect right now.

I'm happy to with 455hp ,CAI and Flowmaster axel back and maybe E85 and tune.