Supercharger Vs Cam

[Ddeitchler]

I have a 2007 2500 6.0l 4x4 silverado. I have a dilemma. I really want a whiple twinscrew supercharger. I talked to a mechanic he said i can get nearly the same power out of a cam with new springs. I dont know that much about engines, but I do know if you want easy bolt on power you buy a s/c. I know the ultimate is to do both. I cant afford that. I like the idea of spending 4k less which he quoted me 2k for the cam w springs and labor vs. 7k w s/c. I really just want the raw power w being able to tow a moderately heavy load. I'm not interested in 1/4 mile times. I just hate the stock delay. I have done k&n air intake and superchips performance tune. Not impressed! Although the tune woke the engine up I just dont have the power I crave when I hit the gas pedal. I can't stand the delay. Help please I dont want to spend 2k on the cam and not get the power I want. To clear things up I want the power RIGHT NOW! when I hit the gas but I dont want it to dog out top end. I want my cake and eat it too. HELP!!!!!!!

[Doug_Scott]

You won't get the same power from just a cam that you get from a supercharger. You can save the labour charge for the supercharger as well, they are usually quite easy to install. Note that just because something takes 8 hours to install, does not mean it is hard to do. I am looking very hard at the ProCharger HO Intercooled system right now. Lists for about $5700 ($6100k for the 6 and 6.2 litre) and they claim 50-55% "power" increase.

Having owned a couple of GTPs with the supercharger, I found that they produce power from just above idle all the way up. I had a smaller pulley on my 2000 GTP, no "cammed" car would pull the way that car did from idle up to red line.

[wavery]

The 1st thing that you need to understand is that HP is not what you need for towing (although it mostly comes hand in hand). You want to have higher "torque" at lower RPM. This is best accomplished with changing the cam. At the same time, you will need to custom "Tune" your engine for the new cam (forget custom "Superchips", they're worthless). You would get the "snap" and some increased "pulling power".

 

The Supercharger will give you more HP, but mostly at higher RPM and the torque curve will change the opposite way than what you want for towing. The Supercharger will beat up your engine while towing because you may well find yourself in a lower gear at higher RPM. I would NEVER supercharge a vehicle for towing. Supercharging is mostly for light weight vehicles.

 

If you really want more towing power, change the cam, valves and shave & port the heads (the valve job will require removing and machining the heads). This would be quite costly and you may well be better off switching to diesel for towing. It may not have the "Snap" that you might be looking for but it sure will have the raw "Pulling power".

 

In short........ I agree with your mechanic...... best bang for your buck is a custom cam. You want one that will put max torque at around 2500-3000 RPM. Just remember that your 1/4 mile ET may suffer with the new cam......

 

Remember, a new cam won't give you more torque. It will just give you more torque at a lower RPM. In other-words, if your max torque is 300# @ 4000RPM but 200# @ 2500RPM, you won't feel comfortable with pulling a long grade @ 4000RPM. If you can achieve 300# of torque @ 2500RPM, that may keep you from having to grab a lower gear to pull the same grade and if you do have to grab a lower gear, you won't be forced to keep the RPM up so high to maintain speed.

 

The other ting to consider is switching to a lower final drive gear ratio. However, on a 4x4, that could be costly. What is your current ratio?

[Doug_Scott]

Supercharger will give you more hp at all rpms, and that means more torque. HP is nothing but a mathematical number based on torque and rpm. Supercharging tends to give more power at lower rpms. It will flatten out the torque curve. It also is only used when needed. A cam on the other hand is always used. Does not matter what you are doing, the cam is always in play. Even with no load, just cruising. A supercharger is only used when you want to use it. It is all based on where the throttle opening is at what rpm and at what load. Far more friendly on the days when you are towing.

I fail to see the downside to supercharging a towing vehicle.

[wavery]

Supercharger will give you more hp at all rpms, and that means more torque. HP is nothing but a mathematical number based on torque and rpm. Supercharging tends to give more power at lower rpms. It will flatten out the torque curve. It also is only used when needed. A cam on the other hand is always used. Does not matter what you are doing, the cam is always in play. Even with no load, just cruising. A supercharger is only used when you want to use it. It is all based on where the throttle opening is at what rpm and at what load. Far more friendly on the days when you are towing.

I fail to see the downside to supercharging a towing vehicle.

This is basically true, except for the part, "HP is nothing but a mathematical number based on torque and rpm"......it is much more complicated than that. If that was true, one would not be able to change the torque curve by changing the lift and duration of the cam. Torque curve involves bore, stroke, "breathing" (and everything that involves) etc. However, one must take into consideration that anything that you do to increase HP over the spectrum will increase the punishment to the moving parts beyond the manufacturers specs. This will surely decrease the engines life, particularly when towing.

 

HP = heat. The increased heat must be dissipated when used and this will change everything in the engine (not just the radiator). This isn't critical in light weight vehicles or even trucks that are not used for towing. However, when towing, one is pushing the cooling system to the max when the engine is stock. Adding a supercharger will increase the HP without the necessary capacity to dissipate the extra heat. The punishment on the moving parts is increased exponentially.

 

Changing the cam to change the torque curve to a lower RPM will not increase HP or torque (thus not increase heat production). It will just manipulate where that torque is available.

[GMstrong]

get a cam first then see where you stand

[bilesZ71]

see i'm stuck in the same position with my truck, i'm not towing a whole lot. but its lifted so i would like more power back sense the tires are stealing from engine output.

[Black02Silverado]

I would go with a cam designed for towing. Call up several cam manufactures and talk to the tech line. Explain to them what you have and what you want and let them suggest the proper cam. You will need to tell them what you tow, and all about your vehicle like gears, tire size transmission and of course the engine. Then when you have the new cam installed get in touch with Justin at Black Bear Performance. Explain to him what you did to your truck and what you are going to be doing and let him work his magic. I think you will be surprised at the results.

 

Just a BB tune in it's self is a nice wakeup call to a stock setup.

[wavery]

I would go with a cam designed for towing. Call up several cam manufactures and talk to the tech line. Explain to them what you have and what you want and let them suggest the proper cam. You will need to tell them what you tow, and all about your vehicle like gears, tire size transmission and of course the engine. Then when you have the new cam installed get in touch with Justin at Black Bear Performance. Explain to him what you did to your truck and what you are going to be doing and let him work his magic. I think you will be surprised at the results.

 

Just a BB tune in it's self is a nice wakeup call to a stock setup.

[wavery]

see i'm stuck in the same position with my truck, i'm not towing a whole lot. but its lifted so i would like more power back sense the tires are stealing from engine output.

In your case, you would be better off changing your ring & pinion to a lower gear ratio. THEN........ if you want more power, the supercharger may be the way to go.

 

The reason the cam is better for towing is because you can change your torque curve to a lower RPM...... After that, you will feel a noticeable change in acceleration from 2500RPM up. My gut tells me, that may not be what you are after.

[bilesZ71]

When i am towing its just the boat and that truck has no issues really with that. Would just like more power, i notice it sometimes when i'm goin up hill against a hard head wind that it feels like is lacking that extra bit. would just like more power in general.

[GPSilverado]

When i am towing its just the boat and that truck has no issues really with that. Would just like more power, i notice it sometimes when i'm goin up hill against a hard head wind that it feels like is lacking that extra bit. would just like more power in general.

 

 

Lifted trucks with larger tires really benefit from going to a lower gear ratio. If you have 3.42 now, depending on size of tires, you would probably benefit from 4.56 or 4.88 gears. I realize that a 6 speed trans is different from the 4 speed, but even without mine being 4wd or having larger tires, I went to a 4.10 gear, and it made a huge difference in towing.

[GPSilverado]

I have a 2007 2500 6.0l 4x4 silverado. I have a dilemma. I really want a whiple twinscrew supercharger. I talked to a mechanic he said i can get nearly the same power out of a cam with new springs. I dont know that much about engines, but I do know if you want easy bolt on power you buy a s/c. I know the ultimate is to do both. I cant afford that. I like the idea of spending 4k less which he quoted me 2k for the cam w springs and labor vs. 7k w s/c. I really just want the raw power w being able to tow a moderately heavy load. I'm not interested in 1/4 mile times. I just hate the stock delay. I have done k&n air intake and superchips performance tune. Not impressed! Although the tune woke the engine up I just dont have the power I crave when I hit the gas pedal. I can't stand the delay. Help please I dont want to spend 2k on the cam and not get the power I want. To clear things up I want the power RIGHT NOW! when I hit the gas but I dont want it to dog out top end. I want my cake and eat it too. HELP!!!!!!!

 

 

If you have the bucks, I would recommend the supercharger. I would recommend a whipple or Magnacharger over a Procharger, if you are wanting the power down low for towing. The Procharger is more like a turbo in the power delivery, with the torque coming more in the mid to upper RPM range. The Magnacharger type setup will give you power from the initial hit of the throttle, and produces usable torque across the entire RPM range. A simple camshaft change will not give you the same power across the entire range, and will probably hurt mileage more in daily driving.

If you are serious about the supercharger, get in touch with Blackbear performance. They are dealers, and Justin is one of the best tuners out there. They can answer all of your questions about what works, and what doesn't. (They drive these type vehicles every day with superchargers on them)

[Ddeitchler]

3.73 ratio and 6speed towhaul transmission

[Doug_Scott]

Supercharger will give you more hp at all rpms, and that means more torque. HP is nothing but a mathematical number based on torque and rpm. Supercharging tends to give more power at lower rpms. It will flatten out the torque curve. It also is only used when needed. A cam on the other hand is always used. Does not matter what you are doing, the cam is always in play. Even with no load, just cruising. A supercharger is only used when you want to use it. It is all based on where the throttle opening is at what rpm and at what load. Far more friendly on the days when you are towing.

I fail to see the downside to supercharging a towing vehicle.

This is basically true, except for the part, "HP is nothing but a mathematical number based on torque and rpm"......it is much more complicated than that. If that was true, one would not be able to change the torque curve by changing the lift and duration of the cam. Torque curve involves bore, stroke, "breathing" (and everything that involves) etc. However, one must take into consideration that anything that you do to increase HP over the spectrum will increase the punishment to the moving parts beyond the manufacturers specs. This will surely decrease the engines life, particularly when towing.

 

HP = heat. The increased heat must be dissipated when used and this will change everything in the engine (not just the radiator). This isn't critical in light weight vehicles or even trucks that are not used for towing. However, when towing, one is pushing the cooling system to the max when the engine is stock. Adding a supercharger will increase the HP without the necessary capacity to dissipate the extra heat. The punishment on the moving parts is increased exponentially.

 

Changing the cam to change the torque curve to a lower RPM will not increase HP or torque (thus not increase heat production). It will just manipulate where that torque is available.

 

 

We need to settle on what horsepower is. It has always been defined as work done over time. Work done is torque. Horsepower is really just a number that comes from torque over time. It is purely a theoretical number. Torque is what dynos measure.

We can talk about power as being heat, but there is no need to, it only confuses people.

 

If you change the cam shaft, it will move the power band, and will also increase peak torque numbers if all other changes are made to match. Camshaft technology is a science. You can change where the powerband will be, how long it will be, what point you want the highest torque number, etc.

If you do not increase heat production, you will not increase power. In other words, you must increase the amount of heat produced in order to increase power, because heat is power.

 

To the OP, talk to supercharger manufacturers, and talk to cam grinders, both will try to sell their technology, but you can make a more informed decision this way. Generally, the route to take when wanting more pulling power, is gear swap, tune, exhaust, tune, then it gets serious. Talk to public experts (people that are publically recognized as experts) regarding cams and forced induction. Personally, I would not act on advice derived from annonymous posters in a forum (I know, I am giving advice and asking you to listen, and that goes against the very point I am trying to make). It is a major decision to make. And don't forget to mind your local laws regarding emissions.