I need a cam now!

[Jakepaul94]

Any input? L99 with Magnuson running 10lbs of boost (Cogged) with ZL1 pump and ADM controller.

I'd love a thumpy radical sounding cam but I realize this isn't really doable with the blower and wanting to stay with a stock converter as well.

I was looking at the BTR or cam Motion stage 2 PDS blower cams.

Anyone else have any input?

[CamaroCracka]

The short story is PD blower cams usually run an LSA around 115ish, less than that could sacrifice a couple horsepower and give you more lope.

The idea of higher LSA is so there is less overlap, i.e. less fresh air/fuel charge pushing straight to the exhaust at the end of the compression stroke, but Richard Holdener says all cams are for boost and has done a bazillion dyno runs to make his point. I think he is adamant about this because he feels people think they have to have a special cam for boost when they don't. In other words, any cam will work, but one designed for a PD blower will be optimal for your build. Since you are already settled on buying a cam, you should think about one with an LSA around 115ish, but I would hit up Andrew Cammer of GPI. He helps people make these decisions for a living and is quite good.

I run a turbo cam with 122+4 degree LSA and it sounds pretty radical, so it's doable. My vert has a 115 LSA and has a pretty good lope, but it did have more lope with an ASA cam (110 LSA). The more aggressive the cam, the more radical it will sound even with higher LSA, but do you really want to pick a cam based on the sound it makes or do you want every last horsepower. Your call.

FWIW, the vert is NA and the smoothest driving vehicle I own. People have complemented me on how it sounds, but it is not a quiet car. A lot of the sound aspect comes from the exhaust. The vert has Borla and the turbo car has SLP. The turbo car is pretty loud. You can see my cam specs below.

[racesloth]

Do yourself a favor and watch the below video and see the differences with cams before you make a choice. Brian talks a lot about the PD blower guys. To be easier on your valve train you don't need to go over .600 lift on the exhaust side (the video explains it).

Forced Induction (Part 8): Cam Shaft and Heads Selection with Brian Tooley:

[1JEWLDSSRS]

Originally Posted by CamaroCracka

The short story is PD blower cams usually run an LSA around 115ish, less than that could sacrifice a couple horsepower and give you more lope.

The idea of higher LSA is so there is less overlap, i.e. less fresh air/fuel charge pushing straight to the exhaust at the end of the compression stroke, but Richard Holdener says all cams are for boost and has done a bazillion dyno runs to make his point. I think he is adamant about this because he feels people think they have to have a special cam for boost when they don't. In other words, any cam will work, but one designed for a PD blower will be optimal for your build. Since you are already settled on buying a cam, you should think about one with an LSA around 115ish, but I would hit up Andrew Cammer of GPI. He helps people make these decisions for a living and is quite good.

I run a turbo cam with 122+4 degree LSA and it sounds pretty radical, so it's doable. My vert has a 115 LSA and has a pretty good lope, but it did have more lope with an ASA cam (110 LSA). The more aggressive the cam, the more radical it will sound even with higher LSA, but do you really want to pick a cam based on the sound it makes or do you want every last horsepower. Your call.

FWIW, the vert is NA and the smoothest driving vehicle I own. People have complemented me on how it sounds, but it is not a quiet car. A lot of the sound aspect comes from the exhaust. The vert has Borla and the turbo car has SLP. The turbo car is pretty loud. You can see my cam specs below.

Great info there sir!!

[1JEWLDSSRS]

Originally Posted by racesloth

Do yourself a favor and watch the below video and see the differences with cams before you make a choice. Brian talks a lot about the PD blower guys. To be easier on your valve train you don't need to go over .600 lift on the exhaust side (the video explains it).

Forced Induction (Part 8): Cam Shaft and Heads Selection with Brian Tooley:

Cool and informative vid sir!

[acammer]

You guys will have to learn that LSA does not equal overlap. Overlap is what determines the idle characteristics and driveability. Overlap is the result of LSA AND duration. So you can't just make a blanket statement like "A 112 LSA will give you a lumpy idle". You could have a 215/230 112+4 that has negative overlap and idles just about like stock, and then have a 244/268 117+4 that has tones of overlap, and that big aggressive idle everybody loves.

Now, setting LSA and Richard Holdener aside, there are unique airflow demands to various types of power adders. That doesn't mean you HAVE to have a PD cam with a PD blower - it will run and drive with whatever cam is in there, but a camshaft optimized for a specific combination will always perform the best. Generally speaking, PD blowers tend to make strong boost down low and trail off on the top end. So a PD blower cam will typically have mild to moderate amounts of overlap, with a moderate intake duration with a later intake valve close (because we have constant manifold pressure we can continue filling the cylinder later into the compression stroke), and then a generous exhaust duration opening the exhaust valve fairly early to allow ample time to clear the cylinder for the next cycle.

Naturally aspirated, centrifugal supercharger, turbocharging, nitrous, they all have specific things they like as well.

Jakepaul94 - you're right, your stock converter, PD blower setup is not going to end up with a lumpy cam that idles like a sprint car. Mostly because you'd finding driving that around with the stock converter would be miserable. BUT - there are some cam options out there that will give you much more of an aggressive performance idle, provide a well matched increase in power for your PD blower, and still work with your stock converter. Feel free to shoot me an email at andrew@gwatneyperformance.com if I can help get you squared away with what's right for you.

[JANNETTYRACING]

Originally Posted by Jakepaul94

Any input? L99 with Magnuson running 10lbs of boost (Cogged) with ZL1 pump and ADM controller.

I'd love a thumpy radical sounding cam but I realize this isn't really doable with the blower and wanting to stay with a stock converter as well.

I was looking at the BTR or cam Motion stage 2 PDS blower cams.

Anyone else have any input?

The JRE rough Idle blower cam fits the bill perfectly.

https://jannettyracing.com/products/...ose-your-grind

https://jannettyracing.com/products/...2015-camaro-ss

[EasternPine]

Originally Posted by acammer

You guys will have to learn that LSA does not equal overlap. Overlap is what determines the idle characteristics and driveability. Overlap is the result of LSA AND duration. So you can't just make a blanket statement like "A 112 LSA will give you a lumpy idle". You could have a 215/230 112+4 that has negative overlap and idles just about like stock, and then have a 244/268 117+4 that has tones of overlap, and that big aggressive idle everybody loves.

Originally Posted by acammer

Now, setting LSA and Richard Holdener aside, there are unique airflow demands to various types of power adders. That doesn't mean you HAVE to have a PD cam with a PD blower - it will run and drive with whatever cam is in there, but a camshaft optimized for a specific combination will always perform the best. Generally speaking, PD blowers tend to make strong boost down low and trail off on the top end. So a PD blower cam will typically have mild to moderate amounts of overlap, with a moderate intake duration with a later intake valve close (because we have constant manifold pressure we can continue filling the cylinder later into the compression stroke), and then a generous exhaust duration opening the exhaust valve fairly early to allow ample time to clear the cylinder for the next cycle.

Naturally aspirated, centrifugal supercharger, turbocharging, nitrous, they all have specific things they like as well.

Jakepaul94 - you're right, your stock converter, PD blower setup is not going to end up with a lumpy cam that idles like a sprint car. Mostly because you'd finding driving that around with the stock converter would be miserable. BUT - there are some cam options out there that will give you much more of an aggressive performance idle, provide a well matched increase in power for your PD blower, and still work with your stock converter. Feel free to shoot me an email at andrew@gwatneyperformance.com if I can help get you squared away with what's right for you.

Given your experience with customers with a wide arrangement of builds and this threads topic I would like to pick your brain on the feasibility of using this cam I have sitting on the shelf and eager to pop in.

It's Katechs LS3 Track Day grind. I get the impression from various sources on the web including this site that FI with 113+4@ 9.1 degrees of overlap is already a disadvantage in the event I choose to run a LSA or Whipple but how bad would it be seeing the grind was meant for a N/A car.

I have watched a few of Rich's videos and understand it can be made to work decently but I don't have any basis of what exactly would be the challenges I'd face or things I need to do as insurance for it to work.

I have attached the full cam card that was sent to me if nothing else as a visual aid in demonstrating your point.



Side question: I noticed a lot of items in GPI's L99 to LS3 conversion kit are on back order. I've had to go elsewhere for my chosen valley cover but mainly interested in getting pushrods and lifters from you guys. My problem is I cant afford to have the car down for longer than absolutely required to measure lifter and pushrod sizes for say link-bar Johnson's as it's my daily driver and I have a 160 mile round trip commute 5 days a week (It pays for this hobby so I don't complain). I live on a hill with a steep incline so doing fluid drains is a very arduous and dangerous task if I have to do it multiple times. Are the Manton pushrods and link-bars true drop-ins as far as GPI is concerned?

I'm kind of deadset on the use of link-bars as I am a "pay once, cry once" type of person and need to ensure the longevity of whatever is put in will last even if it may be considered overkill.

[acammer]

Originally Posted by EasternPine

Given your experience with customers with a wide arrangement of builds and this threads topic I would like to pick your brain on the feasibility of using this cam I have sitting on the shelf and eager to pop in.

It's Katechs LS3 Track Day grind. I get the impression from various sources on the web including this site that FI with 113+4@ 9.1 degrees of overlap is already a disadvantage in the event I choose to run a LSA or Whipple but how bad would it be seeing the grind was meant for a N/A car.

I have watched a few of Rich's videos and understand it can be made to work decently but I don't have any basis of what exactly would be the challenges I'd face or things I need to do as insurance for it to work.

I have attached the full cam card that was sent to me if nothing else as a visual aid in demonstrating your point.



Side question: I noticed a lot of items in GPI's L99 to LS3 conversion kit are on back order. I've had to go elsewhere for my chosen valley cover but mainly interested in getting pushrods and lifters from you guys. My problem is I cant afford to have the car down for longer than absolutely required to measure lifter and pushrod sizes for say link-bar Johnson's as it's my daily driver and I have a 160 mile round trip commute 5 days a week (It pays for this hobby so I don't complain). I live on a hill with a steep incline so doing fluid drains is a very arduous and dangerous task if I have to do it multiple times. Are the Manton pushrods and link-bars true drop-ins as far as GPI is concerned?

I'm kind of deadset on the use of link-bars as I am a "pay once, cry once" type of person and need to ensure the longevity of whatever is put in will last even if it may be considered overkill.

So - this cam (228/242 .628/.621 113+4) is what I would consider a moderate naturally aspirated. It's pretty similar in valve events to our SS2 - street strip, stage 2 camshaft. I can't really say that its right for you, because you didn't share anything about what you're looking for from the cam swap. What I can tell you is that it'll have only mild/moderate driveability impacts that won't be too noticeable with an appropriate converter (3600rpm stall), it'll have a nice cammed idle to it, and it should make pretty broad power, being strong from 3500-6500, peaking somewhere around 6000-6200rpm and shifting by like 6700rpm.

Could you add a PD blower to this - absolutely. Are there better cams more suited to a PD blower - absolutely. Everything I mentioned before applies here. This cam has a little more overlap that we'd typically use on a modest PD blower cam, and the intake valve close point is earlier than we'd like, and the exhaust valve open point later than we'd like. We would have a little more split in the cam (meaning a great difference in intake/exhaust duration) and then we'd decrease the overlap a bit. This cam vs. our SS2-SC cam has pretty similiar duration, but we're negative 5.5* of overlap vs. the positive 9* this cam has. The result is going to be a narrower power curve, and less top end. It certainly doesn't mean you can't use it - and if you're not chasing max effort and just wanna make some additional power the blower is certainly gonna get you there!

Regarding your side question - it's always very difficult to answer inventory timeline questions with any degree of certainty. When covid hit, every supply chain was shattered, and they've never recovered to those pre-covid days where you always had your inventory orders fulfilled on time, and if you needed something you didn't carry in inventory you could get it in a week. All that to say, I'd love to work with you, but I can't make promises timelines for out of stock items. GENERALLY speaking more GM/OEM type parts are 2-4wks, and most aftermarket parts (like Manton pushrods or Johnson lifters) are around 3-6wks. Sometimes they can take longer, especially the less common, higher quality stuff like high end lifters, cranks, rods, etc.

If you need something you can depend on, I'd say order what you need from somewhere you can find what you want in stock. There are several different types of Johnson link bar lifters, and you need to consider that they are all different from stock in terms of pushrod cup height, and almost always require a longer than stock pushrod. They have a narrow preload range, and if you're looking to be "on the money" with the preload you'll often need a custom set of pushrods. I don't think link bars are a bad idea, although I do think they probably are overkill in setups that won't be seeing over 7500rpm or over 450lbs of open spring pressure.

If you work out which lifters you know you want to target I can try to give you an idea on pushrod length - but understand anything I (or anyone else) gives you is just a guess, and it has to be measured for at installation. You may be better off going with a "drop in" lifter like a Chevrolet Performance - Racing lifter (aka Caddy, GMPP) and going with a pretty standard pushrod length that should get you back together with a quality setup that's not so picky and time consuming to get sourced and together.

[EasternPine]

Originally Posted by acammer

So - this cam (228/242 .628/.621 113+4) is what I would consider a moderate naturally aspirated. It's pretty similar in valve events to our SS2 - street strip, stage 2 camshaft. I can't really say that its right for you, because you didn't share anything about what you're looking for from the cam swap. What I can tell you is that it'll have only mild/moderate driveability impacts that won't be too noticeable with an appropriate converter (3600rpm stall), it'll have a nice cammed idle to it, and it should make pretty broad power, being strong from 3500-6500, peaking somewhere around 6000-6200rpm and shifting by like 6700rpm.

Could you add a PD blower to this - absolutely. Are there better cams more suited to a PD blower - absolutely. Everything I mentioned before applies here. This cam has a little more overlap that we'd typically use on a modest PD blower cam, and the intake valve close point is earlier than we'd like, and the exhaust valve open point later than we'd like. We would have a little more split in the cam (meaning a great difference in intake/exhaust duration) and then we'd decrease the overlap a bit. This cam vs. our SS2-SC cam has pretty similiar duration, but we're negative 5.5* of overlap vs. the positive 9* this cam has. The result is going to be a narrower power curve, and less top end. It certainly doesn't mean you can't use it - and if you're not chasing max effort and just wanna make some additional power the blower is certainly gonna get you there!

Regarding your side question - it's always very difficult to answer inventory timeline questions with any degree of certainty. When covid hit, every supply chain was shattered, and they've never recovered to those pre-covid days where you always had your inventory orders fulfilled on time, and if you needed something you didn't carry in inventory you could get it in a week. All that to say, I'd love to work with you, but I can't make promises timelines for out of stock items. GENERALLY speaking more GM/OEM type parts are 2-4wks, and most aftermarket parts (like Manton pushrods or Johnson lifters) are around 3-6wks. Sometimes they can take longer, especially the less common, higher quality stuff like high end lifters, cranks, rods, etc.

If you need something you can depend on, I'd say order what you need from somewhere you can find what you want in stock. There are several different types of Johnson link bar lifters, and you need to consider that they are all different from stock in terms of pushrod cup height, and almost always require a longer than stock pushrod. They have a narrow preload range, and if you're looking to be "on the money" with the preload you'll often need a custom set of pushrods. I don't think link bars are a bad idea, although I do think they probably are overkill in setups that won't be seeing over 7500rpm or over 450lbs of open spring pressure.

If you work out which lifters you know you want to target I can try to give you an idea on pushrod length - but understand anything I (or anyone else) gives you is just a guess, and it has to be measured for at installation. You may be better off going with a "drop in" lifter like a Chevrolet Performance - Racing lifter (aka Caddy, GMPP) and going with a pretty standard pushrod length that should get you back together with a quality setup that's not so picky and time consuming to get sourced and together.

Appreciate the time you took for the honest assessment!

Frankly, the description you gave fits what I'm looking for as powerband predictions go.

The folks at Katech informed me that as 3200 minimum stall speed was highly recommended but their suggestion that a 3600-4000 was optimal. With your explanation I feel a bit more confident going forward with a 3600, I'm relatively new regarding TCs and I'm hoping that high of a stall isn't insufferable in stop and go traffic as manuals can be.

Regarding lifters, you've got me considering the GMPP set with Mantons, but certainly not above the GPI pushrod sets on account 7K rev limit is about as high I feel safe with on the SBE and likely won't get close to that at this current point in time.

As for the goals, it's mainly to make it viable for events at Road Atlanta, Tail of the Dragon, and for the occasional visit to the local drag strip once in a blue moon. That being said my intent is to not exceed 700-750 WHP with an eventual blower for a multitude of reasons chiefly I'm seeking to be able to push the car to its limit reliably without blowing the engine up due to mechanical failure. After the conversion is finished I plan on having the Strange S60 IRS differential installed as the stock 3.27 is actively dying on me, the order isn't finalized yet and the only thing I feel sure on is going with 3.73 gears. The differential is a harder choice since the Strange S-Trac and Eaton's Truetrac both receive praise.

It's a jack of all trades car with a decent divide between road course and getting me to and from work. I know compromises are to be made solely on that basis alone and don't expect to have a shot at Victory Lane but I would at least like to hold my own against the multitude of M series BMWs, Mustangs and Audis at the events I attend.

Again, thank you for your knowledge and time!

[acammer]

Originally Posted by EasternPine

Appreciate the time you took for the honest assessment!

Frankly, the description you gave fits what I'm looking for as powerband predictions go.

The folks at Katech informed me that as 3200 minimum stall speed was highly recommended but their suggestion that a 3600-4000 was optimal. With your explanation I feel a bit more confident going forward with a 3600, I'm relatively new regarding TCs and I'm hoping that high of a stall isn't insufferable in stop and go traffic as manuals can be.

Regarding lifters, you've got me considering the GMPP set with Mantons, but certainly not above the GPI pushrod sets on account 7K rev limit is about as high I feel safe with on the SBE and likely won't get close to that at this current point in time.

As for the goals, it's mainly to make it viable for events at Road Atlanta, Tail of the Dragon, and for the occasional visit to the local drag strip once in a blue moon. That being said my intent is to not exceed 700-750 WHP with an eventual blower for a multitude of reasons chiefly I'm seeking to be able to push the car to its limit reliably without blowing the engine up due to mechanical failure. After the conversion is finished I plan on having the Strange S60 IRS differential installed as the stock 3.27 is actively dying on me, the order isn't finalized yet and the only thing I feel sure on is going with 3.73 gears. The differential is a harder choice since the Strange S-Trac and Eaton's Truetrac both receive praise.

It's a jack of all trades car with a decent divide between road course and getting me to and from work. I know compromises are to be made solely on that basis alone and don't expect to have a shot at Victory Lane but I would at least like to hold my own against the multitude of M series BMWs, Mustangs and Audis at the events I attend.

Again, thank you for your knowledge and time!

I'll add one piece of personal experience for your consideration on diffs. I've had both a TruTrac in the OEM 218mm SS rear end, and currently have an S-trac in my G-Force/Strange 9" setup. Both deliver power smoothly and strongly, with good bias ratios to help the unloaded tire from being overwhelmed. The TruTrac (at least for the OEM 218mm application) had quite a bit of lash in it - Eaton says this is normal. The S-Trac has less lash for sure. Maybe different in your S60 application, but just some things to consider.

Either way, you won't be disappointed in going to a stronger rear end than the factory junk. I wasted a lot of money on fixing and trying to strengthen those, but had several fail despite my best efforts. They just aren't up for real hard use, especially with a stick car like mine.

For gearing I think once you add boost you'll find a 3.73 is too aggressive with the torque of a PD blower. 3.45-3.55 would be a good range to consider.

[EasternPine]

Originally Posted by acammer

I'll add one piece of personal experience for your consideration on diffs. I've had both a TruTrac in the OEM 218mm SS rear end, and currently have an S-trac in my G-Force/Strange 9" setup. Both deliver power smoothly and strongly, with good bias ratios to help the unloaded tire from being overwhelmed. The TruTrac (at least for the OEM 218mm application) had quite a bit of lash in it - Eaton says this is normal. The S-Trac has less lash for sure. Maybe different in your S60 application, but just some things to consider.

Either way, you won't be disappointed in going to a stronger rear end than the factory junk. I wasted a lot of money on fixing and trying to strengthen those, but had several fail despite my best efforts. They just aren't up for real hard use, especially with a stick car like mine.

For gearing I think once you add boost you'll find a 3.73 is too aggressive with the torque of a PD blower. 3.45-3.55 would be a good range to consider.

Appreciate it. Looking more into it, the vendor allows me to get it assembled with 3.54 as a option which with the higher stall converter might be a safer bet.

[King Nothing]

Have you thought about the LS9 cam? It wouldn’t shock me to find out that it works with your stock stall and you might gain 50rwhp. It won’t have that rough idle, but it’s the best bang for buck cam.

[acammer]

Originally Posted by King Nothing

Have you thought about the LS9 cam? It wouldn’t shock me to find out that it works with your stock stall and you might gain 50rwhp. It won’t have that rough idle, but it’s the best bang for buck cam.

The LS9 cam is a nice option as a small step up from the LS3 cam, and it does gain power NA, and works very nicely with a PD. It is a nice, low cost option that will still drive/sound like stock, and add a little power. It's going to be on the order of maybe a 10whp gain, not 50whp.