Supercharger or Turbo? - Dodge Dakota Forum

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Ron Dodge Dakota JOIN HERE 1/03/2005 20:20:14	Subject: Supercharger or Turbo? IP: Logged Message: Does anyone out there have a supercharger or turbo setup of any kind on a Dakota with a 4.7? Looking for something for mine but the only 'charger kit I can find is a centrifugal Paxton and I would much rather have the twin screw design.
ed Dodge Dakota JOIN HERE 1/03/2005 21:17:44	RE: Supercharger or Turbo? IP: Logged Message: twin screw create alot of heat
dkota_rt Dodge Dakota JOIN HERE 1/03/2005 21:49:02	RE: Supercharger or Turbo? IP: Logged Message: I live in Florida with high heat and humidity so I think "ed's" comment has no merit. I recommend the Kenne Bell twin screw. I am not sure about heat on the 4.7, however, I do know that heat is not a problem on my 5.9. The install is fairly simple and straight forward. The turbo will require more work and I doubt you will get the same performance unless you do other mods.
ed Dodge Dakota JOIN HERE 1/03/2005 23:23:48	RE: Supercharger or Turbo? IP: Logged Message: a friend of mine has the b&m 144 or equivalent and his temp ran at 165 before the charger and 195 when he installed the charger. Dispute that, nothing else changed.
LEAN Dodge Dakota JOIN HERE 1/04/2005 03:44:31	RE: Supercharger or Turbo? IP: Logged Message: Did he adjust the fuel curve, timing, plug gap and use a better ignition and bigger injectors,,, or did he just poke the blower on and wonder why it's running hot?
hybrid Dodge Dakota JOIN HERE 1/04/2005 17:12:47	RE: Supercharger or Turbo? IP: Logged Message: dkota_rt, In most cases a turbo will outperform a supercharger. Unless your injecting water,n20, or using a centrifial supercharger with an aftercooler, the turbo will pump less heat into the engine. They are very verstile, and are more efficient then most superchargers.For a street set-up a turbo is the wqy to go, hands down.
Ron Dodge Dakota JOIN HERE 1/04/2005 20:22:16	RE: Supercharger or Turbo? IP: Logged Message: Well does anyone have any ideas on a turbo setup that will work and how about someone who can do custom PCM flashs? Thanks for the help '04 CC 4.7 2wd 5spd.
fastyz400 Dodge Dakota JOIN HERE 1/04/2005 22:56:51	RE: Supercharger or Turbo? IP: Logged Message: hybrid, Yes, turbos are much better for street applications. Typically, superchargers are great for the strip, however, when it comes to street use, turbos are much better. Think about it like this. Supercharger runs off the crank. Thus, there is pressure all the time, no matter if the throtle is closed or open. Thus, is very inefficent. Robbing gas mileage. Turbos are ran off the exhaust gases. The exhaust velocity is much higher. Think of it like this, hot gases like boiling water flows much faster than a cold glass of water. Now, put a fan blade in the flow of that gas, it will spin very fast. The other side is the intake. Thus, creating pressure. When your on the throttle, very high exhaust gases, then when your off the throtle, there is very little pressure. Thus, more effiencient. Bottom line, if you are looking for a street setup, go with a turbo. STS turbos makes kits for all different types of vehicles. I was gonna get that setup for my 96 Camaro SS. But, with 3 kids, no money left for that. Their website: www.ststurbo.com
hybrid Dodge Dakota JOIN HERE 1/05/2005 00:40:14	RE: Supercharger or Turbo? IP: Logged Message: fastyz400, nothing like using expanding and cooling gasses to create more power. I've been bitten by the turbo bug, and don't ever plan to make additional power any other way. I believe vortec uses a bypass valve to allow the pressure to bypass the intake at idle. thats also a centrifical supercharger though. i'll stick with my turbo's for additional power... I hear you about the money issue's I only have one daughter, but between her, the morgage, truck payment, and bills that doesn't leave me much money for my toys anymore.
MetalJim Dodge Dakota JOIN HERE 1/05/2005 04:55:51	RE: Supercharger or Turbo? IP: Logged Message: Don't bother with a centrifical supercharger - ever. A turbo is much more tunable and just as efficient. I'll admit that I don't know much about positive displacement blowers. I've always wanted one. But I do know that turbos and centrifical superchargers are essentially the same beast - except that the supercharger is tied to a pulley and the turbo is tied to the exhaust. If you size the compressor right and you just want to install it and go and never change the boost level then it really doesn't matter. But if there's ANY possibility that you want to turn the boost up a bit down the road then a turbo is definately the way to go. Lemme put it this way. With a supercharger you have a certain boost level and require a certain octane to make sure you run detonation free. With a turbo you can have a 89octane setting, a 94 octane setting, a 114 octane setting and a few in between like max power and safe for each of your octane settings - all without changing hardware. Its a matter of flexability I suppose. I can get 94 around where I live. If you travel cross country though - you can't. Also, I like to run a little safer on the street then on the track - so even just having a street setting and a strip setting works out to be more flexible with a turbo. And I'll stress this again for clarity - if you size the compressor appropriately then there is absolutely no difference "performancewise" between a centrifical supercharger and a turbo. So 100% of the time a turbo is more flexible than the supercharger when contemplating how to boost in that situation.
Ron Dodge Dakota JOIN HERE 1/06/2005 07:48:20	RE: Supercharger or Turbo? IP: Logged Message: Thanks very much for your help. That ststurbo site is pretty cool...I'm going to see if I can find myself a kit that will work.
dkota_rt Dodge Dakota JOIN HERE 1/06/2005 12:02:10	RE: Supercharger or Turbo? IP: Logged Message: I will be honest and tell you that I don't know much about Turbo performance. What I do know is that most trucks rated in the top 100 on dragtrucks.com are running superchargers. There must be a reason why these guys are choosing superchargers over turbo's......Performance!!!! www.dragtrucks.com
fastyz400 Dodge Dakota JOIN HERE 1/06/2005 14:08:42	RE: Supercharger or Turbo? IP: Logged Message: Superchargers are much better for Drag. Turbos are much better for street applications. Take for example, both superchargers and turbos have their ineffieciency. Did you know a top fuel dragster engine produces about 7,500 hp. 900 hp is used to drive the supercharger. A turbo setup, the only problem is the exhuast restriction. However, when your off the gas, your not driving the turbo, while a supercharger is always spinning cause it runs off the crank. Take this as another example: Max boost: 15 psi Engine: 3,000 RPMs 6,000 RPM redline Supercharger produces: around 7.5 psi will be constant because of the pulley off the crank, as rpm goes up, boost goes up. turbo: at the same engine speed, will depend if you are at wot or part throttle. Boost may vary. If, you are at wot, then your boost will be 15psi at 3,000 rpm, if you are at 1/4 throtle your boost may only be 3-4 psi. Turbos disadvantage at the track is due to their spool up time. However, a turbo on the street is a killer, once spooled up, superchargers can't touch them. Because, you can have full boost above usually, 2,500 rpm's. Depending on the size of turbos. So, your at 15 psi, while the supercharger is only at 5-6 psi. Both at wot.
fastyz400 Dodge Dakota JOIN HERE 1/06/2005 16:55:05	RE: Supercharger or Turbo? IP: Logged Message: Unless you plan on driving around town near redline, you will never get full boost with a supercharger. At a strip, you are always near full boost with a supercharger, because, your engine is near redline the whole time down the track.
ed Dodge Dakota JOIN HERE 1/06/2005 18:21:12	RE: Supercharger or Turbo? IP: Logged Message: I don't see why a turbo can be bad at the strip but good on the street! I say this because at the strip you are hammering the gas right? On the street you pull up to some punk in a rice rocket and hammer the gas right? Well what is the difference? It is the same principle, just different road. And if you make the argument that you do not use the stall converter on the street, I will disagree, you can use your stall converter on the street to bring the revs up to whatever your stall converter allows, which is the same as at the strip, or you can rev a manual and drop the clutch. ie the turbo and charger will be building up boost.
hybrid Dodge Dakota JOIN HERE 1/06/2005 20:55:30	RE: Supercharger or Turbo? IP: Logged Message: dkota_rt Because superchargers have always been used for drag racing, thats why there are so many of them in the top 100. While turbochargers have been around for a very long time (back to the early days of automobiles) they haven't been popular for drag racing, mainly v8's. As more and more people are expermenting with single and twin turbo set-ups on v8's they are gaining popularity. Kind of the old theory of "if something works why change it"... There are very few turbo companies (aftermarket kits) for v-8's, there are a ton of aftermarket supercharger companies. A properly sized turbo can match the power curve of any supercharger in in most cases make a lot more peak power. I havent compared a lot of v8 dyno charts but of the ones I have compared, a the turbo generally makes a little more power throughout the powerband and the gap between the supercharger and turbo (power difference between the two) gets larger as the rpm's go up (turbo making more power). Don't get me wrong, superchargers make great power and a lot of it, but when it comes to efficiency and overal power production the turbo usually wins on a street vehicle and even on a drag vehicle.
.DOC. Dodge Dakota JOIN HERE 1/08/2005 02:16:54	RE: Supercharger or Turbo? IP: Logged Message: LONG POST I'm about to toss a cherry bomb into the toilet. By my (granted, limited) experience and research, there are two types of forced air induction systems. One is centrifugal and the other is positive displacement. Both are "superchargers", 'blowers", "huffers" or whichever cute name is in vogue at the time. Centrifugal Centrifugal superchargers have as their method of forcing air into the engine a turbine, or impeller, that looks and acts similar to the volute (rotational innards) of a water pump. It functions by the same principle. As the impeller spins, it gathers air and forces it into the engine. (The compression, BOOST, results when more air is forced into a closed area-cylinder-than there is "space" for the air). Just as a water pump's volute (innards) will circulate more water as the shaft speed increases, [engine rpm increases] boost in the centrifugal supercharger increases as impeller speed increases. The speed of the impeller on a centrifugal supercharger can easily surpass 11,000 rpm in achieving operational boost. Of the centrifugal type, there are two different methods of drive systems. One is belt driven where the crank drives the supercharger's impeller (compressor) via a belt. This drive system is used by most of the popular types like Paxton, ATI, Vorteck, Powerdyne, &tc.. It makes for a relatively simple installation (read as: inexpensive]. The other method of drive is via rerouting exhaust gasses to drive the impeller. This device is commonly known and refered to as a turbo-supercharger, or "turbo". The supercharger is suspended off the engine in the proximity of the exhaust manifold and the exhaust pipes are then routed up to the blower's input, and then from the blower's output back to the exhaust system. Better assemblies will generally utilize a waste gate to reduce, although not eliminate turbo-lag (About that in a bit). Of the two, the belt driven will generally deliver a cooler air charge than the turbo due to the heat transfer between the turbo's exhaust gas driven impeller mechanism and the air charge. (Without the use of auxillary heat exchangers). With a centrifugal type, regardless of drive method, the impeller has to 'spool-up', 'get spinning', to compress the air being force-fed into the engine. There is generally a delay between throttle action and accelleration which is called 'lag' or 'turbo-lag'. It simply takes a moment to build engine rpm and spool up the impeller to produce boost. The centrifugal type of supercharger is generally best in operation over 3,000-3,500 rpm which makes it just right for drag racing and an occassional romp on the street. Below that3-3.5k rpm engine speed there is no boost. (Phew! So much detail! Read on,...) Positive Displacement The second variety of supercharger is the positive displacement design. Into that heading fall Roots and the twin-screw sold by Kenne Bell. The drive is via crank driven belt. The air is compressed by two screws which draw in air at one end of a set of counter rotating helical screws and as the air passes between the screw's lobes, is forced into the cylinders making boost. There is absolutely no 'lag' with the positive displacement system. This method provides boost from about 1,600 rpm to 4,500 rpm, providing dramatic low end hp and tq. At 4,500-4,800 rpm, the positive displacement supercharger generally has topped out. This is generally not as much a drag racing device as one for towing or other use requiring dramatic and instant low end performance. The air charge from a positive displacement supercharger is generally much cooler than a centrifugal supercharger, resulting in a denser and more efficient air charge. Air charge temperature considerations: positive displacement superchargers will run very happily on 6psi of boost. Because the air charge is cooler (denser), there is not the need for greater boost (compression) to produce the power gains that result from a dense air charge. With a centrifugal supercharger, I understand 8psi of boost is the normal beginning point, due to the air charge being warmer and requiring more compression to produce the same levels of air charge density. (Without utilizing a heat exchanger). Bottom line: decide your purpose and buy the modification (blower, cams, timing devices,gearing, &tc. &tc. &tc.) that will achieve your goals. RESEARCH RESEARCH RESEARCH!!!! I have a '00 Dak QC with a 5.9 and need more power for towing. I spent months researching blowers and what I discovered was that, for me, the great performance of the centrifugal is lost on me as I never tow in the 3,500+ rpm range, where the centrifugal works and shines best. I chose the Kenne Bell twin scres supercharger because the power is available starting about 1,600 rpm amd the bulk avaliable at about 2,000 rpm. My Kenny Bell supercharger was delivered yesterday and will be installed Monday. (I'm hoping my mechanic will be curious enough about the performance to provide a free dyno just to see the difference between my KB and the Vorteck he installed on his 'Vette :-}) ). I'll post any results, or at least impressions of the finished product. Finaly, Do your own research. Analyze web sites on superchargers. Read between the lines. Call supliers and question them specifically on their products. I was fortunate enough to speak with some manufacturer's techs who were honest with me because I asked the right questions (beware of the salesman-only contact). Check Mfr's. dyno information. ATI Prjocharger techs are good, as appears to be their product. Eaton, Vorteck and Paxton are top-shelf. Whichever supercharger you choose, buy the best you can find. A bargin blower will become a very expensive anchor too soon. This is one item that will be worth saving another few months towards a "good one". Feel free to criticize. The preceeding is based on some limited 'old' experience, and many months of research and conversation with knowlegible individuals and might not necessarily match your own experiences. If you're going to criticize, though, I'd appreciate personal experience, not that of your 'buddy' or what you heard at the mall. I turbocharged a VW in '74 with an Air Research, and a highly modified MGA with a roots type in '69. So, this isn't my first excursion, though technology has vastly improved!! Doc
hybrid Dodge Dakota JOIN HERE 1/08/2005 11:18:59	RE: Supercharger or Turbo? IP: Logged Message: .DOC. Great post, a lot of info there for the people just starting out. I just want to add a few thigns. With the roots type s/c they make good numbers on low boost, thats great if all your looking for is some more low-end towing power, but raise the boost (via a smaller pulley) you drastically raise the intake charge temp. With both the centrifical superchargers (exhaust driven and belt driven) you have the option to run an aftercooler/intercooler to drastically cool the charge temp. I personally wouldn't run any form of forced induction without a mothod to cool the charge temp prior to entering the engine. Thats one of the reasons why I perfer the exhaust driven turbo over the superchargers. At about $300 for an intercooler, and in most cases a 10-15% increase in power (some have upwards of 30% increase with a good design and great flowing core spearco makes a good one) You cant go wrong there. To say that turbo's usualble power is between X rpm and Y rpm isn't completely true. If one knows what they are doing, they can match a turbo to their specific desires. They are much more versatile. As an example, I built a kit for one of my cars using a small garrett air research turbo. It would spool about 1,600rpm, and have full boost (6psi) by about 2,100rpm. It was great because it provided low end power where I needed it. Plans changed and I wanted a car that makes more peak power and a broader power band. I upgraded to a considerabley larger turbo. This turbo on the same engine starts to spool about 2,000rpm. The larger turbo gave me an increase of 49whp (peak). At 2,500rpm it made 10whp more and went up from there. That was running the same boost, just different sizes of compressors. The whole point of that was to show the versatility of a turbo. You can have fast spool, but you sacrifice some power, or you can sacrifice some low end power for more power across the rpm range. You can also have several different boost settings with a turbo by using an electronic boost controller. Great for daily driving, racing on the track, or towing. Turbo's also require less power to make power. By utilizing the exhaust gasses to run the turbo. I don't mean to sound like i'm trying to talk you or anybody into a turbo over a supercharger, it all comes down to personal preference.. Those are a few of the reasons why I chose what chose. Also sorry if this post is all over the place, it's early and I'm at work trying to do sveral things at once so i'm getting lost in my thoughts....I can elaborate to clear things up if anybody needs me too. Oh just want to add. Technology has changed a lot since the days of cartridge bearing turbo's. They have full ball bearing turbo center sections that reduce spool time. With the scenero I posted above had I used a ball bearing turbo the spool of the larger turbo would probably be in the 1,800rpm area.
ed Dodge Dakota JOIN HERE 1/08/2005 15:57:18	RE: Supercharger or Turbo? IP: Logged Message: to intercool a procharger as I saw in my procharger catalogue, you add 1250 dollars, I cannot believe it costs that much though. Anyone else seen that amount?
hybrid Dodge Dakota JOIN HERE 1/08/2005 20:36:25	RE: Supercharger or Turbo? IP: Logged Message: ed, Is that a centrifical supercharger or a twin screw/ roots type? Correct me if i'm wrong in my hypothesis. But being a belt driven compressor wouldn't you loose boost pressure by adding an aftercharger/intercooler? Unlike a turbocharger where the boost is endless (so to say), you can make up the lost pressure (because of all the added piping). I supose you could always install a 8psi pulley, then the intercooler and your boost would be back down to about 6psi. How does that work with a supercharger? All intercoolers have pressure drop through them. Generally 1-2psi is acceptable. So if your supercharger is making 6psi, add the intercooler and 3-4 feet of charge piping your probably left with about 3psi? can anybody confirm my hypothesis? Actually does the aftercharger come with another pulley? (smaller one maybe?) You could always install a smaller pulley and fabricate your own intercooler set-up for a lot less then $1,250. Thats crazy IMO. I paid $265 for my intercooler and about $60 for my piping (mandrel -U- bends) So i'm sure you could fabricate an air to air set-up a lot cheaper then the procharger's price. Isn't that a air to water set-up? $500 And you can have a nice set-up with a front mount intercooler. Just my $.02
ed Dodge Dakota JOIN HERE 1/09/2005 01:03:48	RE: Supercharger or Turbo? IP: Logged Message: go to www.procharger.com and take a look, you make way more power with intercooling on this centrifugal charger. reduces air intake temp a ton apparently. and a tip on boost, an engine with restrictions may make 10lbs of boost for example.and make 450hp. however an engine with less restriction may make 600hp with 7 lbs of boost. it is complicated but the most boost does not mean you will make more power. And intercooling allows u to run more boost without detonation.
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