Camshaft Recommendation

[PurpleRam]

the Cross flow nature of the hemi heads is a big part of why they
love boost, the exhaust valves draws directly on the intake,

This is exactly why big LSA works so well on blown hemis.... The above mentioned LSA's are much more suited to an LS as the valves dont face each other like the hemi does
and that is what sends the boost straight out the exhaust when you add a blower.
The factory know what they are doing with the 120+ LSA's and with boost you dont need lots of duration unless you want it to rev to the moon.
Think of it as a denser/more compacted charge rather than a bigger/longer one as if NA.
When supercharged, you are really affecting the pressure difference across the intake/exhaust.
NA is pretty much 1:1...so 1 atmosphere at intake valve vs 1 atmosphere at exhaust valve.
With a blower running 14.7psi, it is 2:1 ratio....2 atmospheres at intake vs 1 atmosphere at exhaust valve.
So you can see why the boosted intake charge wants to head straight out the lower pressure area exhaust.
So we need to delay intake open, and get the exhaust shut....there is still plenty of time to fill the cylinder as the charge is twice as dense
not twice as big.
You can make tons of power while retaining perfect street drivability/idle by making a wise blower cam choice like the cams I mentioned or similar.

Correct, 114-120 LSA is best range for positive displacement supercharger, 104-108 for Procharge/vortech types, You also need more lift and duration on the exhaust side to aid scavenging along with wider lobe separation to reduce valve overlap, long overlaps the intake charge goes out the exhaust valve, . like you mentioned , ..


It is a fine line between valve overlap and exhaust lift and duration. and those TSP cams have over the competition(at this point ) is more Exhaust lift and 5* more duration and are in the sweet spot of LSA which helps these G3s, the best Exhaust flowing ports in theses G3s is still less then 75 % intake to exhaust ratio, the 120+ LSA are great for emissions.but the G3 hemi doesn't act like a act like a Traditional Hemi(which a lot of the early G3 aftermarket cams were designed after) during the early rotation after BDC intake stroke, we don't need to close the exhaust valve as early,. .. keep in mind that a traditional G2 hemi the valve angles are Intake 35*; exhaust 23*, the G3 it's 18* for both, and the intake path is as close to a straight downward angle as you can get, point is the Intake charge is pushed down in to the chamber, and not into the exhaust valve, this allows the G3 to utilize smaller LSA's , the nature of the 18* angle draws on the incoming intake but doesn't pull on it like the older Hemis.........which is also why we need to close the Intake valve as fast as possible because of it's angle it's more prove to intake reversion.

........in four different cars,on 4 different chassis dyno's and 6 different track rentals here in the mid Atlantic, I've seen those TSP cams run 40-60hp better on the chassis dyno and on the track 3-6 tenths faster than both the Hellcat and Demon cams.........for the record I am not affiliated with TSP and you couldn't give me one of their NA cams.

[coanan]

Correct, 114-120 LSA is best range for positive displacement supercharger, 104-108 for Procharge/vortech types, You also need more lift and duration on the exhaust side to aid scavenging along with wider lobe separation to reduce valve overlap, long overlaps the intake charge goes out the exhaust valve, . like you mentioned , ..


It is a fine line between valve overlap and exhaust lift and duration. and those TSP cams have over the competition(at this point ) is more Exhaust lift and 5* more duration and are in the sweet spot of LSA which helps these G3s, the best Exhaust flowing ports in theses G3s is still less then 75 % intake to exhaust ratio, the 120+ LSA are great for emissions.but the G3 hemi doesn't act like a act like a Traditional Hemi(which a lot of the early G3 aftermarket cams were designed after) during the early rotation after BDC intake stroke, we don't need to close the exhaust valve as early,. .. keep in mind that a traditional G2 hemi the valve angles are Intake 35*; exhaust 23*, the G3 it's 18* for both, and the intake path is as close to a straight downward angle as you can get, point is the Intake charge is pushed down in to the chamber, and not into the exhaust valve, this allows the G3 to utilize smaller LSA's , the nature of the 18* angle draws on the incoming intake but doesn't pull on it like the older Hemis.........which is also why we need to close the Intake valve as fast as possible because of it's angle it's more prove to intake reversion.

........in four different cars,on 4 different chassis dyno's and 6 different track rentals here in the mid Atlantic, I've seen those TSP cams run 40-60hp better on the chassis dyno and on the track 3-6 tenths faster than both the Hellcat and Demon cams.........for the record I am not affiliated with TSP and you couldn't give me one of their NA cams.

Hey. I'd like to learn a little more about the TSP stage 4 or stage 3 cam. Best option for my setup in Sig.

[Hemituna]

Correct, 114-120 LSA is best range for positive displacement supercharger, 104-108 for Procharge/vortech types, You also need more lift and duration on the exhaust side to aid scavenging along with wider lobe separation to reduce valve overlap, long overlaps the intake charge goes out the exhaust valve, . like you mentioned , ..


It is a fine line between valve overlap and exhaust lift and duration. and those TSP cams have over the competition(at this point ) is more Exhaust lift and 5* more duration and are in the sweet spot of LSA which helps these G3s, the best Exhaust flowing ports in theses G3s is still less then 75 % intake to exhaust ratio, the 120+ LSA are great for emissions.but the G3 hemi doesn't act like a act like a Traditional Hemi(which a lot of the early G3 aftermarket cams were designed after) during the early rotation after BDC intake stroke, we don't need to close the exhaust valve as early,. .. keep in mind that a traditional G2 hemi the valve angles are Intake 35*; exhaust 23*, the G3 it's 18* for both, and the intake path is as close to a straight downward angle as you can get, point is the Intake charge is pushed down in to the chamber, and not into the exhaust valve, this allows the G3 to utilize smaller LSA's , the nature of the 18* angle draws on the incoming intake but doesn't pull on it like the older Hemis.........which is also why we need to close the Intake valve as fast as possible because of it's angle it's more prove to intake reversion.

........in four different cars,on 4 different chassis dyno's and 6 different track rentals here in the mid Atlantic, I've seen those TSP cams run 40-60hp better on the chassis dyno and on the track 3-6 tenths faster than both the Hellcat and Demon cams.........for the record I am not affiliated with TSP and you couldn't give me one of their NA cams.

I dont disagree they will make more power on a strip car but we are talking daily driver here.
You can keep your 40-60hp cos when you are making 800-1000hp, as if you can tell/need the difference on the street.
I dunno what you guys can live with everyday, I must be getting old
I'd rather put a bigger, better blower on than a bigger cam

[FstdodgeKY]

i love all the talk going on here, My personal opinion i'm not looking to for max power output for what i have but rather maximize the power i can make with my setup and still have the car behave reasonably on the street. I also would like a decent idle but not race car sound. for right now im looking at going the demon plus cam from ost. but havent ordered anything yet.

[PurpleRam]

i love all the talk going on here, My personal opinion i'm not looking to for max power output for what i have but rather maximize the power i can make with my setup and still have the car behave reasonably on the street. I also would like a decent idle but not race car sound. for right now im looking at going the demon plus cam from ost. but havent ordered anything yet.

OST cams are a good choice, and there is a lot of tuning history with those guys. What cam do you have now ?

[FstdodgeKY]

Just running stock cam but motor is at machine shop for rods and pistons.

[FstdodgeKY]

Just to keep everyone updated i have decided with the demon plus cam. After speaking with mike again at ost we believe we can make my combo work for what i'm trying to achieve, good driveability with the best power. I appreciate all the help and look forward to getting this thing running again.

[tbrtuning]

Good choice. That cam can be made to drive nice on a stock converter and will let you make good power at lower boost for 93 octane