Supercharger / To have or not to Have?

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USMC-716

USMC-716

SGT. MARIN
Messages
412
Location
Miami, Florida
Hey guys, got a question. My buddy just got a supercharged put on his Savege X 4.6. It makes a world of difference in speed but i'm wondering if there's any drawbacks? Pros/Cons? If any of you have one i'd appreciate your feedback or even if you've read some articles or know someone who has one. I'd like to get one but before i dump the money i want to make sure it's not going to cause a ton of headaches.. Thanks guys!!

Any and all feedback will be greatly appreciated!

happy Veteran's day to all veterans and Happy late Marine Corp birthday to all you Devil Dogs!
 
Yea all it does is lean out the motor which is very bad.

If you value your motor don't do it. Same applys to the nos kits.
 
from what i've heard it leans out your mill like crazy and makes holding a tune next to impossible since air flow changes continuously
 
who all has actually run a supercharger on their mill? ive never even seen one in person or in a thread here. maybe i'll surf youtube a bit.
 
Sad to say I had on never used it. Got it from a buddy of mine who tried it on his maxx. Destroyed his 2.5. I sold it to a guy at the track for a buck and a soda. Used the buck to buy a burger. I think I got the better end of that deal.
 
frddyj said:
who all has actually run a supercharger on their mill? ive never even seen one in person or in a thread here. maybe i'll surf youtube a bit.
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when i first joined in 2007 a couple people had posted they had tried it and one said they loved it and alot of other people said it doesnt make alot of difference other then shortening the life of your engine.. would be interested to hear robin's thoughts on superchargers for nitro engines..........
 
save your motor.......just get a mod done by Robin at Extreme and beat lots of unecessary booty.........
 
Made a huge difference because it wasnt tuned right beffore. I have tried that POS from RB and I can tell you first hand that it is a waste of money.

First the charger has no way of being calibrated for different engines, or timming specs. its just an impeller driven by a rubberband.

When you lean your engine normally, you get to the sweet spot. You could lean more, but theres not enough fuel. So, how does the s/c add more fuel to compensate for the lean condition that it causes by forcing more air? Answer, you do by fattening the needles. Only problem with that is now your engine is rich and runs like crap at any speed other than WOT.

Ive made this comparison beffor, adding the RB S/C is like strapping a leaf blower to your 1:1 car and expecting a performance increase.

This argument has been brought up several times and been shot down by people a lot smarter than me. We don't even want to start the "can you supercharge a two stroke" argument. By the way, I still have not seen a supercharged two stroke engine. Turocharging is completely different.
 
Well all the answers have been given, there is no proper way to set them up and grumpy explained why. I happened to hook up with an old bud who had gotten into RC, he was set on getting a SC because a couple of the guys he ran with had them. I told him he should let me mod his engine instead and if he could not smoke them I would give back his money. He ran circles around those guys even with a smaller engine, they chased their tune and ran extremely hot and could not touch my bud. Funny thing was, the mod was much cheaper then the SC to begin with. Take the cost of the SC, add the cost of your current engine, take that and buy a better mill, that's money well spent.
 
Purenitro said:
Well all the answers have been given, there is no proper way to set them up and grumpy explained why. I happened to hook up with an old bud who had gotten into RC, he was set on getting a SC because a couple of the guys he ran with had them. I told him he should let me mod his engine instead and if he could not smoke them I would give back his money. He ran circles around those guys even with a smaller engine, they chased their tune and ran extremely hot and could not touch my bud. Funny thing was, the mod was much cheaper then the SC to begin with. Take the cost of the SC, add the cost of your current engine, take that and buy a better mill, that's money well spent.
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well said!!!
 
USMC-716 said:
hey do you have any info on the shop you're talking about? Thanks!
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SURE! http://www.extremercmods.com/ his phone number is on his website. coolest guy you will ever meet and he has done globs of trucks here on HPISF and i haven't heard a dissatisfied customer yet. plus...a lot cheaper than a charger. Robin is his name.....power is his game and you WILL have plenty of it. he has done work for me and i am very happy with the work. After my 1:1 tank is finished....he will have ALL my work.....everything i get will be modded by him.
 
soulja55 said:
SURE! http://www.extremercmods.com/ his phone number is on his website. coolest guy you will ever meet and he has done globs of trucks here on HPISF and i haven't heard a dissatisfied customer yet. plus...a lot cheaper than a charger. Robin is his name.....power is his game and you WILL have plenty of it. he has done work for me and i am very happy with the work. After my 1:1 tank is finished....he will have ALL my work.....everything i get will be modded by him.
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Thanks i'll call him shortly!
 
Um, I have a supercharger, my tune stay's intact, and I can pull a four door sedan.......and the motor is still in great shape. It depends on your applicaiton, what type of driving you do(bashing,racing, sprints) and if you can tune for the supercharger. I love mine, I live the power it produce's, and you don't have to set your tune on kill to kick some butt.
 
IncedibleHULK said:
Um, I have a supercharger, my tune stay's intact, and I can pull a four door sedan.......and the motor is still in great shape. It depends on your applicaiton, what type of driving you do(bashing,racing, sprints) and if you can tune for the supercharger. I love mine, I live the power it produce's, and you don't have to set your tune on kill to kick some butt.
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A pulling truck might be a good application for a supercharger due to the lower RPM requirements of truck. When running a .50 your RPM window is small which makes your tuning window much bigger, this will help with tuning in a SC. 1.8 HP @ 16K kind of proves my point, practical RPM of up to 30K is a little far fetched as that is an additional 14K after peak HP??? They don't mention torque but I'm sure it's a healthy number which is what your looking for I'm sure. I am curious as to how much "boost" the SC produces, 50-200% makes me ask the question "how can you add a positive pressure to a normally aspirated carburetor and not push the fuel back to the tank?" and "if you did have that much pressure in the fuel system, would it not just push the filler cap open and vent to atmosphere?" These questions aren't directed at you, they are just questions I have. My other question is "who would sell paper vent filters for 1:1 cars as nitro engine air filters?" Over the many years people have come to realize that they are just bling and are NOT designed to filter fine dust particles and will ruin your engine! Yet they still sell them?

For most applications (bashing/racing) we deal with substantially more RPM and HP which in turn closes the tuning window with a SC drastically, making them finicky and a pita to tune.

8.0 specs

Displacement: 8.19 cc. / 0.500 cu. in.
Bore: 22.5 mm. / 0.886 in.
Stroke: 20.6 mm. / 0.811 in.
Practical RPM: 2,000 ~ 30,000
Output: 1.80 BHP / 16,000 RPM
Weight: 465 g. wo/muffler / 16.41 oz.
 
Yeah the pulling trucks are alittle easier to pit the sc on and get your tune. That's why I always mention that it depends on your application,and how to tune for your driving style. My SC on the HULK has a 50% overdrive pulley and I have the aux. line that goes from the sc and t's off to the exhaust and goes to the tank, which when the sc is making the boost depending on how much boost your making, not 100% of the charge is being used to to the fact that their are no valves, also the boost that isn't used goes to thru the aux. line and goes back to the tank to add more fuel pressure to meet the demands of the sc as it forces more air in the cylinder it increases the fuel pressure, which to me tells me more fuel + more air = more power. From my experience with my sc, I've liked what I've seen, but the sc aren't for every person or application. I did contact associated and spoke to their engine tech, he told me the bhp and then told me that the bhp converted to hp came out to 5.25hp. They've got crazy power, I had a mgt 8.0 and was shocked of the power it has. Thanks for your info, have you done motor work to an 8.0 yet? Just wandering, I may send these off to have work done, figured I'd see what you had to offer. Thanks again.
 
IncedibleHULK said:
Yeah the pulling trucks are alittle easier to pit the sc on and get your tune. That's why I always mention that it depends on your application,and how to tune for your driving style. My SC on the HULK has a 50% overdrive pulley and I have the aux. line that goes from the sc and t's off to the exhaust and goes to the tank, which when the sc is making the boost depending on how much boost your making, not 100% of the charge is being used to to the fact that their are no valves, also the boost that isn't used goes to thru the aux. line and goes back to the tank to add more fuel pressure to meet the demands of the sc as it forces more air in the cylinder it increases the fuel pressure, which to me tells me more fuel + more air = more power. From my experience with my sc, I've liked what I've seen, but the sc aren't for every person or application. I did contact associated and spoke to their engine tech, he told me the bhp and then told me that the bhp converted to hp came out to 5.25hp. They've got crazy power, I had a mgt 8.0 and was shocked of the power it has. Thanks for your info, have you done motor work to an 8.0 yet? Just wandering, I may send these off to have work done, figured I'd see what you had to offer. Thanks again.
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I have not modified one but I do know there is power and rpm to be gained and that's the problem. For normal bashing, increasing the rpm too much in a large displacement engine usually ends in failure, you simply can't stroke a piston almost twice the size of the .28's at the same rpm, it will get torn up. Now with pulling things would be different as you have much more control over your rpm limits with gearing, clutching, drive line, and tires. Those engines could really benefit from a good modding. BoBo has a 5.9 that I did for him, he could tell you if I made a beast out of a turd, I haven't heard myself yet.

You mention using the aux tap to feed your fuel tank, but it says that it T's off to the exhaust as well. Would this not have a constant loss of boost leaking into the exhaust especially at higher rpm when the SC is making the most boost yet the pipe has the least amount of pressure in it. Most would assume the pipe has the most internal pressure at top rpm, in fact it is the opposite, the highest internal pressure in a pipe is made at low rpm and drops off as rpm is increased. This is the reason why high rpm engines have issues with pipes that have bigger stingers (10mm) the better 8mm stinger provides enough back pressure at high rpm so the engine doesn't lean out. Just something to think about.

As for the engine tech, I believe he told you they make 5+HP, this is not an argument more of an ongoing debate. BHP is a reading taken right from the shaft of the engine, no losses from gearing or drive line. HP is typically taken from the wheel and will be lower then the BHP due to losses. How these company's think they can fool us noobs with "power increasing" gears, bearings etc is pitiful to say the least. I'm sure he told you that under duress due to the fact the box probably says 5+ as well. In reality the numbers I posted are probably more accurate, I hate telling the truth sometimes :(.

1.8 X 5252 / 16,000 = .59 foot pounds = 113.28 in oz Reasonable expectation.

5.25 X 5252 / 16,000 = 1.72 foot pounds = 330.24 in oz The most powerful engine in the RC world.
 
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IncedibleHULK said:
Um, I have a supercharger, my tune stay's intact, and I can pull a four door sedan.......and the motor is still in great shape. It depends on your applicaiton, what type of driving you do(bashing,racing, sprints) and if you can tune for the supercharger. I love mine, I live the power it produce's, and you don't have to set your tune on kill to kick some butt.
Click to expand...


can you put up some pics of how its installed & maybe a vid clip of how it runs? ive never seen one. :peace:
 
Purenitro said:
I have not modified one but I do know there is power and rpm to be gained and that's the problem. For normal bashing, increasing the rpm too much in a large displacement engine usually ends in failure, you simply can't stroke a piston almost twice the size of the .28's at the same rpm, it will get torn up. Now with pulling things would be different as you have much more control over your rpm limits with gearing, clutching, drive line, and tires. Those engines could really benefit from a good modding. BoBo has a 5.9 that I did for him, he could tell you if I made a beast out of a turd, I haven't heard myself yet.

You mention using the aux tap to feed your fuel tank, but it says that it T's off to the exhaust as well. Would this not have a constant loss of boost leaking into the exhaust especially at higher rpm when the SC is making the most boost yet the pipe has the least amount of pressure in it. Most would assume the pipe has the most internal pressure at top rpm, in fact it is the opposite, the highest internal pressure in a pipe is made at low rpm and drops off as rpm is increased. This is the reason why high rpm engines have issues with pipes that have bigger stingers (10mm) the better 8mm stinger provides enough back pressure at high rpm so the engine doesn't lean out. Just something to think about.

As for the engine tech, I believe he told you they make 5+HP, this is not an argument more of an ongoing debate. BHP is a reading taken right from the shaft of the engine, no losses from gearing or drive line. HP is typically taken from the wheel and will be lower then the BHP due to losses. How these company's think they can fool us noobs with "power increasing" gears, bearings etc is pitiful to say the least. I'm sure he told you that under duress due to the fact the box probably says 5+ as well. In reality the numbers I posted are probably more accurate, I hate telling the truth sometimes :(.

1.8 X 5252 / 16,000 = .59 foot pounds = 113.28 in oz Reasonable expectation.

5.25 X 5252 / 16,000 = 1.72 foot pounds = 330.24 in oz The most powerful engine in the RC world.
Click to expand...


Alright, You can mod these motors and get more power and rpm out of them, your statement on getting a 8.0 to spin the same rpm as a .28, cannot be done, they are two totally different motors with two totally different powerbands, I already knew that. Increasing the rpm on a large displacement motor will lead to motor failure? That previous statement has nothing to do with modding a motor, that is all in owner's responsibility to not over rev. the motor. As far as pulling goes, it's about horsepower and torque.Your examples that your using go for any r/c vehicle, not just pulling. As far as making a beast out of a turd, the 5.9 is already a great motor that puts our great power already, if they didn't, they wouldn't sell. Engine modding helps out alot, and depending on what stage you do depends on the purpose of the motor and vehicle.

The boost from the supercharger also goes thru the aux. port and travels down to the T fitting, the T fitting joins the boost line, the exhaust pressure return line, and the return line to the tank. The boost is going to go to the tank and not out the exhaust, you have two lines at a T, one line(exhaust) has pressure coming from the pipe and traveling to the tank, the other line(tank) is drawing vacuum, the boost is going straight to the tank line because there is no resistance, the exhaust line has return pressure, the boost will take the path of less or no resistance therefore adding more fuel pressure to the tank to meet the demands of the supercharger.

High rpm engine's run poorly do to pipes that have bigger stingers than others? That's a huge blanket statement. What determines back pressure is not the size of the stinger, it's the lenght of the pipe, circumference of the pipe, the shape of the pipe, and most importantly, the inside construction of the pipe, not just how big a stinger is. These manufacture's create many pipes for many application's, it's up to the buyer to determine what kind of driving they intend to pursue, what motor they want to run, and what pipe they intend to use for low,mid,top,all around power. The construction of the pipe and the internal construction of the pipe is going to determine the amount of back pressure and where it comes in at, not just the size of the stinger!

And as for the engine tech that I spoke to, he told me what the BHP was, and then told me what the calculation from BHP to HP was. BHP in this conversation is Brake Horse Power, and that is how much power the motor makes at a certain rpm range with a load on it, what is not inclosed is the % of load that was put on the motor. HP is the obvious Horse Power, and that is how much power the motor puts out without load on it. BHP is signifigantly less that free HP, and with the converstion from BHP to HP will tell you what the motor makes. Now, if you call a manufacture that builds the motors and speak to the engine tech that help create the engine, your going to find out what the correct power output is of that motor. The 8.0 puts out 5.2HP, this information comes from the company who built,designed,and tested this motor, they know what they have. Your comment at the end about "I hate telling the truth sometimes", I don't think that's the message your customers wanna read before they send you their motor. Oh, and the breakdown you provided, here it is:

5.25 x5252/16,000= 1.72 foot pounds = 330.24oz The most powerful r/c engine in the world....well times that by 2, cause that's what I have and it is fact!
 
Alright, You can mod these motors and get more power and rpm out of them, your statement on getting a 8.0 to spin the same rpm as a .28, cannot be done, they are two totally different motors with two totally different powerbands, I already knew that. Increasing the rpm on a large displacement motor will lead to motor failure? That previous statement has nothing to do with modding a motor, that is all in owner's responsibility to not over rev. the motor. As far as pulling goes, it's about horsepower and torque.Your examples that your using go for any r/c vehicle, not just pulling. As far as making a beast out of a turd, the 5.9 is already a great motor that puts our great power already, if they didn't, they wouldn't sell. Engine modding helps out alot, and depending on what stage you do depends on the purpose of the motor and vehicle.

I wasn't very clear, I was referring to increased rpm through modification will cause failure which is a given, if the engine is abused. Doubling the rpm on the .50 wasn't meant as a doable statement either, my bad. I have done one and only one 5.9, stock this engine falls very short of great! You can't take a .28 engine and hog out the block and just use a bigger piston and sleeve and expect it to be a performer. It has the same crank, bearings, rod and block porting, which limits your port size in the sleeve to what the .28 had? In comparison the 5.9 has tiny ports that aren't even shaped or aimed in the right direction (imo), I know as I had to change all that. Why do so many blow up? maybe because the crank was kind of balanced for the weight of the .28 piston, now that it has a substantially bigger piston what was done to counteract this additional mass....... nothing. Look around the sites and you will find that most people will agree with there own experiences.

The boost from the supercharger also goes thru the aux. port and travels down to the T fitting, the T fitting joins the boost line, the exhaust pressure return line, and the return line to the tank. The boost is going to go to the tank and not out the exhaust, you have two lines at a T, one line(exhaust) has pressure coming from the pipe and traveling to the tank, the other line(tank) is drawing vacuum, the boost is going straight to the tank line because there is no resistance, the exhaust line has return pressure, the boost will take the path of less or no resistance therefore adding more fuel pressure to the tank to meet the demands of the supercharger.

Lets say you have a (T) bottom being the SC, top left being Exhaust, and top right the tank. If point S had 5psi and point E had 3psi, point T is not going to have 8psi right, it will have 5psi, which will overcome point E causing leakage of the SC/tank pressure to the exhaust. Another interesting point is the aux tap feeds the tank, once the pressure is built up in the tank it will equal the pressure being applied to the carb which would mean there is no positive fuel supply from the tank. Being an open system there is also the possibility that "if" the pipe made more pressure then the SC, it would back feed into the SC via the aux tap causing oxygen spent fumes to be re-used. Too bad they don't give more specs, but maybe they don't want to.

High rpm engine's run poorly do to pipes that have bigger stingers than others? That's a huge blanket statement. What determines back pressure is not the size of the stinger, it's the lenght of the pipe, circumference of the pipe, the shape of the pipe, and most importantly, the inside construction of the pipe, not just how big a stinger is. These manufacture's create many pipes for many application's, it's up to the buyer to determine what kind of driving they intend to pursue, what motor they want to run, and what pipe they intend to use for low,mid,top,all around power. The construction of the pipe and the internal construction of the pipe is going to determine the amount of back pressure and where it comes in at, not just the size of the stinger!

The only pipes that are internally restricted are the Buku and Cvec style pipes, the cone regulates back pressure because it has to contain pressure for it to move. Conventional pipes have big holes or sections cut off the end of the internal cone much larger then the stinger, this does not create back pressure. Exhaust pressure is regulated by the smallest opening which is the stinger, a smaller and longer stinger will reduce exhaust flow and raise back pressure even more. Exhaust pulses are influenced by internal design and length. My statement is true and been proven many times. I do know a bit about pipes as I hand made the pipe on this engine from my own design. It has an 8mm stinger and I reassure you, if I put on a 9mm stinger it would fail.
http://s99.photobucket.com/albums/l291/purenitro/?action=view&current=MOV08749.flv

And as for the engine tech that I spoke to, he told me what the BHP was, and then told me what the calculation from BHP to HP was. BHP in this conversation is Brake Horse Power, and that is how much power the motor makes at a certain rpm range with a load on it, what is not inclosed is the % of load that was put on the motor. HP is the obvious Horse Power, and that is how much power the motor puts out without load on it. BHP is signifigantly less that free HP, and with the converstion from BHP to HP will tell you what the motor makes. Now, if you call a manufacture that builds the motors and speak to the engine tech that help create the engine, your going to find out what the correct power output is of that motor. The 8.0 puts out 5.2HP, this information comes from the company who built,designed,and tested this motor, they know what they have. Your comment at the end about "I hate telling the truth sometimes", I don't think that's the message your customers wanna read before they send you their motor. Oh, and the breakdown you provided, here it is:

5.25 x5252/16,000= 1.72 foot pounds = 330.24oz The most powerful r/c engine in the world....well times that by 2, cause that's what I have and it is fact!

People who are newbs will be impressed.
People who know will smile and nod.

I don't hold back the truth from my customers just to make a buck, I have turned away piles of rtr's and sport mills. I state my honest opinion and they make their own choice, usually it's an upgrade to a better engine, no use throwing money into a sub par engine that won't last. Do I benefit from this? NO, do they? YES, am I happy in the end? VERY!

I'm not here to flame you bud, you have a sweet truck and it hauls the mail! I'm just sharing info that may benefit you, take it as you will.
 
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