Stage 2 Cam Capabilities?

[Leadsled]

So currently my LS3/M6 dyno'd at 454whp. w/ tsp stage2 cam (229/244) Stock heads and Intake manifold. At the time of dyno the car had the factory wheels with an oversize tire 275/45r20. and no exhaust behind my mid muffler and the car had Kooks Cats... Seems to be running rich/safe

Since then, Cats are gutted and Exhaust is complete. All the slack has been buttoned up in the rear (Rear subframe bushings, diff bushing, Tie and Toe arms) I have also installed lighter flywheel and Bo white Ported TB. On the butt dyno she feels quicker.

After I install lighter 19in Forgestar F14 I will go back for a retune.
Hopefully pick up 10-15whp?

Looking to do a Sneaky Pete Nitrous Setup (stock intake manifold with nitrous piping built into manifold) GOALS 500n/a and 650 w/spray

When I plan on doing my next step to reach 500whp. I just don't feel confident the stock ported heads will get me there. When am ready the heads might need a rebuild the heads because on the 20k-30k mile marker.
I have no interest in changing the cam. but open to AM heads

I had the PRC 255 as cast castings in mind. inputs welcome

[morepowerjoe]

Well I just got the TSP PRC 260 cnc ported heads and so far it's a pretty big difference. On engine torque on hp tuners scanner it's picked up 20+ ft lbs of torque and she's taken 3* more timing up top. So I know I've picked up power just don't know how much just yet. I think I will have it re-dynoed in January. TSP said I should expect 25-30 horsepower more. So you would be at 484 at max with their heads. Not exactly 500 whp but close.

[Leadsled]

Originally Posted by morepowerjoe

Well I just got the TSP PRC 260 cnc ported heads and so far it's a pretty big difference. On engine torque on hp tuners scanner it's picked up 20+ ft lbs of torque and she's taken 3* more timing up top. So I know I've picked up power just don't know how much just yet. I think I will have it re-dynoed in January. TSP said I should expect 25-30 horsepower more. So you would be at 484 at max with their heads. Not exactly 500 whp but close.

Do you have the same CAM? I've been debating. Stock Ported heads will get you about 20hp. which is about 1,000 bucks anywhere. then you add new valve springs etc. you're around the 1500 mark.

The PRC 255 are $2,100 and bump the compression enough that did would be really close to 500whp. at least that's what tsp recommends. I don't want them to just try to sell me something. I know there's other brands out there.
but I'm just not familiar with many brands

[morepowerjoe]

I have the GPI SS3 vvt cam that has similar specs as yours just more lift. I don’t really know the difference between a stock ported head versus a cnc ported TSP head. I just know that the TSP head had bigger intake and exhaust valves and allows you to run more timing.

[acammer]

I wouldn't expect to pick up more than a handful of horsepower with a tire swap. Unless you have a baseline dyno of the car when it was stock/near stock, it's really hard to have much of a gauge on it's actual performance just based on a dyno number, as those are incredibly variable. That said, your number doesn't look far off of expected, maybe a couple percent below "average" - whatever the internet has made that out to be at this point.

The camshaft you have will make a goal of 500whp a stretch. It could be possible with a highly optimized combination of really good heads, ported rod-mod intake, and restriction-free induction, but 95/100 people exceeding that mark are doing it with more camshaft.

We port OEM heads at GPI, and typically see a 20-30hp gain with our porting program on an engine with good bolt ons and a healthy sized cam. Aftermarket heads will typically make similar gains - we port so many factory heads because the gains are honestly very close, for substantially lower costs, so the value is much higher. Aftermarket heads do offer some advantages like decreased valve angle to increase piston to valve clearance, which in turn facilitates a smaller combustion chamber and increased compression.

It really comes down to budget - a ported factory head is impossible to beat in terms of value. Aftermarket LS3 castings stand to maybe be 10hp ahead of a good factory head - but at double to triple the cost, those gains are definitely in the space of diminishing returns. Many of us NA junkies will accept that as just part of the cost to have a truly stout combination - as evident by the aftermarket LS7 heads on my car

In your case I would contend that even very good heads are going to struggle to bring you over the 500whp mark with the camshaft you have on board, and a more comprehensive package of cam and cylinder head changes might be suitable. Especially in light of your plan to spray a 150 shot of nitrous - something with a more generous exhaust duration would absolutely benefit exhausting all that extra combustion gas.

Originally Posted by morepowerjoe

...the TSP head had bigger intake and exhaust valves and allows you to run more timing.

The timing changes are certainly going to add power, but those are much more connect to tuning strategy differences rather than the cylinder head "allowing" for more timing. It's also entirely possible to add timing to a combination without an actual measuring stick (dyno) and feel like performance is improving (confirmation bias) without any actual gain. The power shown in the scanner is nothing more than calculated on a model, and so is not meaningful evidence, but also feeds into that idea. If you were to test on the dyno it's entirely possible that those couple degrees may not cause knock, but also may add no additional power.

That's not to say they couldn't be adding power, and it's entirely possible that a different cylinder head may like different ignition advance. What I'm saying here is that unless you're measuring those sort of changes on the dyno, it's very hard to optimize timing to squeeze that last 1-2% of total power out of a combination. When I tune on the street, I work towards known good values for a given combination, but I stay on the moderate side with advance and fueling, because without the dyno it's just not possible to fine-tune those last bits. On the dyno you can lean out the combination a bit more, and search out the truly optimal amount of advance.

I'm just thrilled your back up and running, and things are trending in a positive direction for you. I know you've wrestled with that build a bit, that's how it goes some times, but I love that you've stuck with it, made changes for the better along the way, chasing out the gremlins, to land on more power, and more enjoyment.

[Leadsled]

Originally Posted by acammer

The camshaft you have will make a goal of 500whp a stretch. It could be possible with a highly optimized combination of really good heads, ported rod-mod intake, and restriction-free induction, but 95/100 people exceeding that mark are doing it with more camshaft.

We port OEM heads at GPI, and typically see a 20-30hp gain with our porting program on an engine with good bolt ons and a healthy sized cam. Aftermarket heads will typically make similar gains - we port so many factory heads because the gains are honestly very close, for substantially lower costs, so the value is much higher. Aftermarket heads do offer some advantages like decreased valve angle to increase piston to valve clearance, which in turn facilitates a smaller combustion chamber and increased compression.

It really comes down to budget - a ported factory head is impossible to beat in terms of value. Aftermarket LS3 castings stand to maybe be 10hp ahead of a good factory head - but at double to triple the cost, those gains are definitely in the space of diminishing returns. Many of us NA junkies will accept that as just part of the cost to have a truly stout combination - as evident by the aftermarket LS7 heads on my car

In your case I would contend that even very good heads are going to struggle to bring you over the 500whp mark with the camshaft you have on board, and a more comprehensive package of cam and cylinder head changes might be suitable. Especially in light of your plan to spray a 150 shot of nitrous - something with a more generous exhaust duration would absolutely benefit exhausting all that extra combustion gas.



The timing changes are certainly going to add power, but those are much more connect to tuning strategy differences rather than the cylinder head "allowing" for more timing. It's also entirely possible to add timing to a combination without an actual measuring stick (dyno) and feel like performance is improving (confirmation bias) without any actual gain. The power shown in the scanner is nothing more than calculated on a model, and so is not meaningful evidence, but also feeds into that idea. If you were to test on the dyno it's entirely possible that those couple degrees may not cause knock, but also may add no additional power.

That's not to say they couldn't be adding power, and it's entirely possible that a different cylinder head may like different ignition advance. What I'm saying here is that unless you're measuring those sort of changes on the dyno, it's very hard to optimize timing to squeeze that last 1-2% of total power out of a combination. When I tune on the street, I work towards known good values for a given combination, but I stay on the moderate side with advance and fueling, because without the dyno it's just not possible to fine-tune those last bits. On the dyno you can lean out the combination a bit more, and search out the truly optimal amount of advance.

Thanks for the input. thats really the info I was looking for ... I was told AM castings are not worth it because its so little gain over the factory port LS3. I think I will just weight out my options when that time comes around and make my mind off that. I can always sell my factory castings to help off set the price for Aftermarket options

[morepowerjoe]

Originally Posted by acammer

I wouldn't expect to pick up more than a handful of horsepower with a tire swap. Unless you have a baseline dyno of the car when it was stock/near stock, it's really hard to have much of a gauge on it's actual performance just based on a dyno number, as those are incredibly variable. That said, your number doesn't look far off of expected, maybe a couple percent below "average" - whatever the internet has made that out to be at this point.

The camshaft you have will make a goal of 500whp a stretch. It could be possible with a highly optimized combination of really good heads, ported rod-mod intake, and restriction-free induction, but 95/100 people exceeding that mark are doing it with more camshaft.

We port OEM heads at GPI, and typically see a 20-30hp gain with our porting program on an engine with good bolt ons and a healthy sized cam. Aftermarket heads will typically make similar gains - we port so many factory heads because the gains are honestly very close, for substantially lower costs, so the value is much higher. Aftermarket heads do offer some advantages like decreased valve angle to increase piston to valve clearance, which in turn facilitates a smaller combustion chamber and increased compression.

It really comes down to budget - a ported factory head is impossible to beat in terms of value. Aftermarket LS3 castings stand to maybe be 10hp ahead of a good factory head - but at double to triple the cost, those gains are definitely in the space of diminishing returns. Many of us NA junkies will accept that as just part of the cost to have a truly stout combination - as evident by the aftermarket LS7 heads on my car

In your case I would contend that even very good heads are going to struggle to bring you over the 500whp mark with the camshaft you have on board, and a more comprehensive package of cam and cylinder head changes might be suitable. Especially in light of your plan to spray a 150 shot of nitrous - something with a more generous exhaust duration would absolutely benefit exhausting all that extra combustion gas.



The timing changes are certainly going to add power, but those are much more connect to tuning strategy differences rather than the cylinder head "allowing" for more timing. It's also entirely possible to add timing to a combination without an actual measuring stick (dyno) and feel like performance is improving (confirmation bias) without any actual gain. The power shown in the scanner is nothing more than calculated on a model, and so is not meaningful evidence, but also feeds into that idea. If you were to test on the dyno it's entirely possible that those couple degrees may not cause knock, but also may add no additional power.

That's not to say they couldn't be adding power, and it's entirely possible that a different cylinder head may like different ignition advance. What I'm saying here is that unless you're measuring those sort of changes on the dyno, it's very hard to optimize timing to squeeze that last 1-2% of total power out of a combination. When I tune on the street, I work towards known good values for a given combination, but I stay on the moderate side with advance and fueling, because without the dyno it's just not possible to fine-tune those last bits. On the dyno you can lean out the combination a bit more, and search out the truly optimal amount of advance.

I'm just thrilled your back up and running, and things are trending in a positive direction for you. I know you've wrestled with that build a bit, that's how it goes some times, but I love that you've stuck with it, made changes for the better along the way, chasing out the gremlins, to land on more power, and more enjoyment.

Thanks Andrew for the kind words and wisdom.

[ss camaro-monte]

Yep, my gpi ported heads got me about 20hp over stock on a baby cam. Some say ported heads aren't worth it but imo ported heads are a bigger difference than say a stage 1 to stage 2 cam by most manufacturers. Most "stage" increase are worth only 10-15hp.

[dino2012ls3]

Why not go with LS7 heads and smack right thru that 500 mark. Than you can run bigger cam without worrying bout ptv (I know bigger isn't always better). GPI is the masters of that!!!

[acammer]

Originally Posted by dino2012ls3

Why not go with LS7 heads and smack right thru that 500 mark. Than you can run bigger cam without worrying bout ptv (I know bigger isn't always better). GPI is the masters of that!!!

My signature should give it away - I'm a big fan of that move!