Supercharger vs. Turbo

I just wanted to get some ideas for the set-up on my car. What do you think.....should i get a superchager or a turbo? From the research i have done they will cost about the same. Also, i want to take into consideration, wear and tear on my motor, ie: a supercharger will be on all of the time, i haven't heard of alot of mustangs with turbos although i have sen a few. If anyone has experience with turbos on a V8, and would like to comment please do. Last thing, if you do recommend a turbo what brand, size, etc. should i consider. Thanx for the feedback.

P.S. if i did go turbo, would a single or twin turbo set-up be more efficient? Thanx again.

We need info! What motor, what are your power goals, etc. Have you driven a turbocharger and a supercharged car? What do you prefer? unless you're going for 100% track vehicle looking for max HP, this makes a big difference. A supercharger will simply make the engine 'feel' like a larger displacement engine... The torque/hp curves will be pretty much the same shape, just higher up. A turbo is completely different. Its more of a slight 'lag' before the turbos spool, and WHAM you're gone. I personally like turbos much better, I like the lag. Its fun for me. It entertains me to leave off idle so the guy next to you think he has you since they leap ahead off the line, then you whip past them 50 feet down the track. More dramatic than slowly pulling away :). I am currently turbocharging the 351c in my 1969 mustang coupe, right now I'm building the motor to take 15psi boost. Should give me around 700ft/lbs of torque and 675-700hp at the flywheel, revving it to 6500rpm. The nice thing about turbos is, the torque curve should be pretty flat (on my engine, from 3000-6500).. Engine Analyzer(like desktop dyno but better, imho) predicts 697 peak torque at 4000rpm, 653tq at 3000, 627 at 5500.. From there the exhaust turbines on my turbos get a bit restrictive(when I bought them they were sized for 5500rpm not 6500), so torque drops to 544 at 6500. Thats where peak HP is made, 673hp. Someday I'll get better sized housings to get the top end up. A supercharger wouldn't be able to give ~650ft/lbs at 3000rpm, hell it'd barely be making boost at that point. The turbos are giving the full 15lbs by 3000rpm. If you have a 5.0L, I'd suggest two .42/.48 A/R Garrett T3's if you plan on revving it to 5500-6000.. If you go higher, look for a bigger exhaust turbine. I'm running .60/.63's on my 351c, and I think they'll be a tiny bit restrictive on the top end, not as much as EA predicts though. It should be completed in a few week, I'll be sure to put a post up on this forum of how it goes... I'll probably be heading to the dyno first thing after the motor is broken in.

Single is always more efficient.
Properly matched, a turbo will not have lag in the sense that you are thinking of. On a 1.6L Civic, maybe, but not on a V8. If you get a big ass turbo to make huge power, then you will. The Hot Rod arcticle on the subject pretty much declaired the turbo a complete winner.

I was planning on getting a Pro Turbo Kits setup with a T-66. It's really your choice on what brand, they're all good. For twins, I was going to go with a Indution Concepts setup, with two 60-1 Hi-Fi's. www.inductionconcepts.com (http://www.inductionconcepts.com) is a good site to check out, with lots of info.

Why would single be more efficient? I'm not saying you're wrong, I'm just curious, as I've done more than considerable research on turbos, and have never heard one way or the other which is more efficient. If there is a difference, I would be willing to bet it'd be negligable, as in 5hp out of 500.
Any and all turbos will have 'lag'. All turbos require a certain ammount of exhaust flow to get it going, and unless you have a severely undersized turbo on your motor, it will be noticeable. It won't be nearly as noticeable as a 4banger, since a v8 won't have to rev as high to make power so you can size your turbos smaller. V8s will have gobs of torque down low anyways, so its not much of a sacrifice in the first place. Its not like on a 4cyl where at 2500rpm you're making 90ft/lbs, even N/A you can easily coax 300ft/lbs out by 2500rpm of a v8. But for both engines, the efficiency range of the turbo will be about the same... So if you take two similar designed turbos, one sized for a high revving 4banger, one sized for a high revvin v8, they'll provide boost in about the same range. I do know what your saying though.. I mean, if you have a manual or an auto with a decent stall(2500-3000) and if you size your turbo(s) properly, you can launch on full boost. I have a 3500stall in my mustang, so I could definately launch under full boost if I wanted to. But launching off idle or somewhere below your turbo's spool RPM could be beneficial - I've heard from many people running turbos that if they leave off idle, they'll run quicker, since they can launch without being in danger of breaking the tires loose, then a split second later boost kicks in while they're already moving. I suppose if boost hit very hard it could break the tires free after you're moving, but I can definately see how it'd be easier to control and be more consistent launching off idle.

Hello,

I have a 1995 Stang with a 3.8L. I believe they make turbos for them. I heard the 6-bangers have crappy heads, wouldn't a turbo blow the lid off? Any thoughts?

I have a 4.6L V8 GT, i am interested in increasing my "top speed" (i hate being passed by hyundai's and subaru's on the highway), but i would love to have excellent 1/4 mile potential. What do you suggest?

Just about the only way to increase top speed and acceleration together is to increase horsepower. Using a lower gear ratio will increase acceleration but decrease top speed. Using a higher gear will increase top speed but will decrease acceleration. So you'll have to find an intermediate gear which gives both a little bit. Otherwise you can use a larger diameter tire which will also increase top speed, but once again you will loose some acceleration due to rotating mass. There's always a give and take situation, you cant get one thing without sacrifing another, lol.

Yeah, thats kinda what i have been told by other people. Do you know if turbos take away from top end, or do they help both, 1/4 mile time and highway?

Your gears will determine "redline" top speed, but most Mustangs will start flying before that. I figure with the gearing on mine, I *could* get over 200mph, but there's no way my car could make even close to that.

I don't remember exactly why one turbo is more efficient, but I know that it is. Having two smaller turbos will however kill turbo lag, so they are good for the street, just way more expensive.

I would go with twins if I had the money, they're more like a roots s-charger. A big one is more like a centrfrugal s-charger. The differances are much smaller though.

Turbos add power, so they won't just take away from any thing. Acceleration will be helped, and top speed won't.

They won't add as much power at top end, but they'll still add a whole bunch. I mean, 544lb/ft at 6500rpm from a 355ci engine is still better than most engine builders could get n/a.. Sure is a hell of a lot more than I could get! I'd be damn pleased with 450lb/ft from that sized engine N/A. Like any compressor, they have a peak efficiency... at a certain point they'll work best, and at all other points they wont work as well. You could size your turbo to give purely top end power, but you'll have significantly more lag and less useable powerband. I sized mine so they kick in early and just start losing their oomph by redline.
A turbo or supercharger combined with lower ratio gears will give you a higher top speed. Just lower ratio gears will get you a higher top speed, but it'll hurt accelleration, and if your motor doesnt have the power in the first place, you wont go any faster. The top speed on my car should be around 150mph, but I'm sure if I put an O/D tranny or lower ratio gears in it, it'll go faster.

1/4 mile = charger
long haul = turbo. there is something called a spoon controller to decrease the lag on turbos but maximum hp is compromised. also a charger i reckon is more beneficial because it is constant where as the turbo truly shines within cars with high compression motors (High RPM cars such as the honda s2000). Good Luck, either way ya gona have some really really crappy gas mileage.

Centrifugal type superchargers are the worst forced induction in my opinion. The only benefit to them is they're the most compact. If you want all out HP throughout the entire RPM range, a roots blower is the way to go. Thats more of a V8 thing though. For a driver, turbos are the way to go. they combine the efficiency of a centrifugal supercharger with reduced parasitic loss and the boost control of a wastegate to give full boost through much of the RPM range - not as wide of a range as a roots blower, but wide enough to cover the power band of most street motors. Roots blowers are the most inefficient design, however.. They take more hp to turn and heat the air charge more than centrifugal type.

what do roots blowers run?

what do they run? as in boost? they'll run whatever you set them up to. They are a positive displacement compressor, which means every revolution, no matter how fast or slow, they'll move the same volume of air. So how much boost is a function of the displacement of the blower per revolution times the gear reduction of the drive of the blower, over the displacement of the motor per crank revolution. So basically, by changing the gearing on the blower you'll get whatever boost you want. The Cobra mustangs and Lightning trucks use whipple superchargers, which are similar to roots. They're also positive displacement. There are several types of positive displacement superchargers, pistons are a positive displacement compressor, vane type superchargers are positive displacement.. there are even Wankel style superchargers(rotary engines that are spun by another engine to compress air). Positive displacement types have no 'lag' whatsoever. Roots types aren't terribly efficient, some of the others are better choices. Whipple chargers are some of the best, and I believe vane types are also very good. Wankels are decent but no one makes them anymore(they were used long ago.. like 5 decades ago..) Piston types arent very efficient and arent practical. They're almost as big as a piston engine, so whats the point? I think Roots types are used in professional drag racing because they're simple and they move huge ammounts of air for their size. And considering how big they are, you get an idea of how much power these motors make! I'm not sure where you would get a roots or any other positive displacement type supercharger for a 4cyl, most superchargers, especially roots/whipple, are focused at the v8 market, while most turbos are focused at the 4cyl market. In my opinion, the situation is very backwards.. v8s should be sporting the turbos with their ability to provide big flat torque curves, plus v8s don't really need to worry about low end torque before the turbo spools, they've got that covered... And the 4cyl will really get a benefit out of a positive displacement type blower, since it'll provide boost at any RPM, so it'll give them a boost in low end torque, but still feed them way up at 7500, 8000, or whatever RPM they'll spin to. 8cyls don't need to rev that high to make their power, they're better suited staying around 6500, and thats perfect to take advantage of a turbo's efficiency... The 4cyl needs the RPMs to make its power, and a positive displacement supercharger will both boost its power up top, and help it out down low where it isnt so strong.
I suppose if you wanted a positive displacement for a small motor, you could buy a whipple charger and gear it down a bunch. I'm not sure if it'll work too well though. The ones for the mustang and Lightning are designed for 8psi on 5.4L, so you'd have to gear it down a LOT to get it to work on a 4cyl. It might not work, and if it does, it'd probably be pretty inefficient.

1/4 mile = charger
long haul = turbo. there is something called a spoon controller to decrease the lag on turbos but maximum hp is compromised. also a charger i reckon is more beneficial because it is constant where as the turbo truly shines within cars with high compression motors (High RPM cars such as the honda s2000). Good Luck, either way ya gona have some really really crappy gas mileage.

I'm sure i will have crappy gas mileage, but if i was worried about gas mileage i would have bought a KIA. lol....But thanx for the info.

what do they run? as in boost? they'll run whatever you set them up to. They are a positive displacement compressor, which means every revolution, no matter how fast or slow, they'll move the same volume of air. So how much boost is a function of the displacement of the blower per revolution times the gear reduction of the drive of the blower, over the displacement of the motor per crank revolution. So basically, by changing the gearing on the blower you'll get whatever boost you want. The Cobra mustangs and Lightning trucks use whipple superchargers, which are similar to roots. They're also positive displacement. There are several types of positive displacement superchargers, pistons are a positive displacement compressor, vane type superchargers are positive displacement.. there are even Wankel style superchargers(rotary engines that are spun by another engine to compress air). Positive displacement types have no 'lag' whatsoever. Roots types aren't terribly efficient, some of the others are better choices. Whipple chargers are some of the best, and I believe vane types are also very good. Wankels are decent but no one makes them anymore(they were used long ago.. like 5 decades ago..) Piston types arent very efficient and arent practical. They're almost as big as a piston engine, so whats the point? I think Roots types are used in professional drag racing because they're simple and they move huge ammounts of air for their size. And considering how big they are, you get an idea of how much power these motors make! I'm not sure where you would get a roots or any other positive displacement type supercharger for a 4cyl, most superchargers, especially roots/whipple, are focused at the v8 market, while most turbos are focused at the 4cyl market. In my opinion, the situation is very backwards.. v8s should be sporting the turbos with their ability to provide big flat torque curves, plus v8s don't really need to worry about low end torque before the turbo spools, they've got that covered... And the 4cyl will really get a benefit out of a positive displacement type blower, since it'll provide boost at any RPM, so it'll give them a boost in low end torque, but still feed them way up at 7500, 8000, or whatever RPM they'll spin to. 8cyls don't need to rev that high to make their power, they're better suited staying around 6500, and thats perfect to take advantage of a turbo's efficiency... The 4cyl needs the RPMs to make its power, and a positive displacement supercharger will both boost its power up top, and help it out down low where it isnt so strong.
I suppose if you wanted a positive displacement for a small motor, you could buy a whipple charger and gear it down a bunch. I'm not sure if it'll work too well though. The ones for the mustang and Lightning are designed for 8psi on 5.4L, so you'd have to gear it down a LOT to get it to work on a 4cyl. It might not work, and if it does, it'd probably be pretty inefficient.

This might be a really ignorant question but, to have roots blowers would i need to have a supercharger, sounds like i would, but i'm new to mustangs and V-8's. Also, i heard of a stock 4.6L (i'm guessing Cobra, magazine article didn't say) achieving unbelievable 1/4 mile times with only a smaller blower pulley....again, is this only with a supercharger or would my '03 GT have this as well.

First off, sorry about all the 4cyl references, I'm also a regular on the Turbo/Supercharger/NOS part of the Honda/Acura section of this forum, and forgot this post was on the Mustang part... And no, I don't own a honda/acura, let alone trying to get power out of one with a blower or NOS. I'm just big into forced induction, mainly turbos, so I go there to exercise my blower knowledge(and keep the ricers from fuckin up their mom's civic...) and to offer advice to help them in their fruitless struggle to make power from a 2 liter inline four in a front wheel drive car(after all, we need SOME competition from the ricer community!). But I really don't think any honda is gonna come close to touching the twin turbo'd 351c in my '69 stang... :)

A roots blower IS a supercharger.. if thats what your asking. Usually they go on top of big v8s, with either a single or dual carbs sittin on top of that. The common GMC 6-71, 8-71, 10, 12... etc are roots blowers. These are the ones that you always see on hot rods and drag cars.
http://www.blowerdriveservice.com/pcar27.jpg
Starting from the top, you have your air scoop, it houses the filters and directs air into the carbs, which are directly below it. They are the ones with the small hard lines running around them(fuel lines, those are holley double pumper carbs). Then under those, that huge chrome thing, that is a roots supercharger. Probably a 6 or 8-71. That looks like a big block chevy to me, probably a 454. BDS(Blower Drive Service, www.blowerdriveservice.com) is the company that made that blower. That is obviously way to huge for a 4cyl. The way a positive displacement blower works, like a roots supercharger, is that on every engine revolution it moves more air than the engine displaces. Its simple ratio math.. if it displaces say 700 cubic inches of air for every time a 454ci big block chevy turns over twice(since its a four stroke like most automobile engines, each piston only intakes air every other crank revolution), it would be 700ci/454ci.. pressure ratio would be about 1.5. To figure out what that'd be in PSI, the formula is simple.. ambient air pressure times pressure ratio, minus ambient air pressure.. so 1.5 x 14.7(pressure @ sea level) - 14.7. That comes to about 7.4psi. If you put a smaller gear on the input of the supercharger, the internals of the supercharger will turn faster.. this means the blower will displace more air per engine revolution. Say you changed the gears to increase the displacement per 2 engine revolutions to 1000ci. That would increase the pressure ratio to 2.2, or 17psi. This is why putting a smaller gear on the supercharger will increase boost pressure. That is why when they put on a smaller blower pulley on a 4.6 cobra, they ran faster.. they simply increased the boost. This would only work with a supercharger, obviously. But you can get small gains(nothing near what increasing boost would get you) by installing underdrive pullies on your non-supercharged GT. What this does is make the gears on your alternator and water pump bigger, so these units don't spin as fast. As a result, it takes less effort to spin them, and when talking about engines, effort is horsepower. However, there is a compromise, since the water pump will not move as much water and the alternator won't make as much power. Generally, most auto manufacturers will overshoot on the size of the pullies, making them smaller than they need to be to provide sufficient cooling/charging. This is so they aren't in risk of either causing the motor to overheat(underdriven water pump) or incapable of maintaining the charge on the battery(underdriven alternator). So there are many aftermarket kits available to underdrive your water pump and alternator. But you have to be careful, keep an eye on your voltage guage(if you have one, if not, install one if you install underdrive pullies) and water temp guage. Water temp typically isn't a problem, but if you're driving along on a hot day(so the electric fans are going full tilt) and blasting the radio and A/C, your alternator may not be able to keep up. Your battery will lose its charge while your driving, resulting in a stalled engine and a call to the tow truck or a friend with jumper cables.
If you are looking to supercharge, obviously a GMC 6-71 or whatever roots supercharger isn't really an option, I dont know of anyone who makes a manifold for a 4.6 to fit a GMC blower(although if you really wanted one, I'm sure someone could make you one.. hell, I could make you one!). And it would require a rather large hole in your hood. Passing emissions would be a massive chore as well! However, Vortech makes a couple centrifugal supercharger kits for the 4.6(my friend has one on his 2001GT, its pretty quick! I think he runs somewhere around a 13 sec 1/4 with 8psi, but I think he should be running quicker... I think he has trouble hooking on launch). If you wanted a positive displacement supercharger, I believe Whipple makes a Lysholm type(aka whipple-type, they've really been the ones who popularized Lysholm types as of late, so their name as been stuck on as the type of compressor, even though technically its a Lysholm screw type...). I know they make one for the 4.6/5.4, since they manufacture the one in the Lightning, but I'm not sure if it'll clear a stock GT hood. Probably can be done, if not, I'm sure with a cowl hood they will. They are much lower profile than a Roots type.

One of my favorite quotes was "It's not turbo lag. It's foreplay." :ylsuper:

HAHA I've never heard that.. thats great!

If you want 1/4 or just a drag setup, go with a supercharger (roots/centi). If you want to whip rice, go with a turbo; but they're friggin massive with all the plumbing.

yeah, its a bitch to route all the turbo piping. I started off using stock cast iron exhaust manifolds with custom extensions for my twin turbo system, but right now I'm in the process of making custom headers. The turbos were originally in my fender wells with the stock exhaust setup because I had NO room up front in my '69. I've since pulled the motor in the car, relocated the radiator to in front of the radiator support(gave me about 4 inches up front), and I'm in the process of installing a remote electric water pump to get rid of that bulk up front. I'm relocating the alternator to sit further back using a serpentine pulley setup from a '94-'95 mustang gt and a custom bracket.. Then I get to install a remote oil filter to give the headers room to go foward, the battery is already in the trunk.. so after alll of this I have a bit over a foot in front of my motor to fit both turbos. I'm also going to notch my shock towers to get more room around the headers so I can use larger radius bends for better flow. Should be a nice setup, better than in the fenderwells!

I'm sure i will have crappy gas mileage, but if i was worried about gas mileage i would have bought a KIA. lol....But thanx for the info.
Correct me if I am wrong, but wouldn't a supercharger give you better gas mileage? (assuming your foot isnt in it) If you compress the air in the chamber don't you get more bang-for-your-buck in terms of detonation of the fuel because the explosion is more violent?

No, because a supercharger creates parasitic drag on the engine, like A/C. A turbo uses the heat from exhaust gasses to spin, which is already spent anyways. Most people with turbo mustangs that I've talked to said that they got a small boost in gas milage with it, if they didn't step on it all the time.

Turbo lag is a result of torque converter selection,cubic inch,a/f raito and turbo size. Turbochargers are excelent for drag racing (espically behind an automatic.) You just have to learn how to build boost at the line (Transbrake) :evillol:

Hypsi said it. Not ALL turbos have lag. Look at my '89 Daytona. It has a 2.5 liter 4 cylinder. Zero lag with the stock tiny mitsu turbo. I mean zero. It will build 12 psi with the tranny in neutral and the wastegate unplugged!

a Garrett T-03 (same as a T-3 but built for a chrysler) with a .48 exhaust housing has very very little lag on the same motor. Most of the "fast" turbododges I know of run a 2.5 with a hybrid and .63 housings.

Single turbos driven by 8 cylinders have proven the most efficient moslty because you can spool a massive turbo with 8 cylinders and flow a lot of CFM.

Centrifugal superchargers have been used widely on 'stangs because it isn't far from a bolt-on affair. Some of them are bolt-on, the ones that don't require oil line plumbing.

The problem with running a turbo is the fact that Ford EEC electronics have no provision in them whatsoever for timing retard and fuel enrichment under boost. Yes, the pressure regulator will up the PSI, to a point, but you still need some kind of FMU and boost retard...

I like superchargers they just seem to sream muscle to me, but to each his own. Also depends on what it is going on.

Sure, if you size your turbo small enough, you can essentially eliminate lag, but your top/mid range HP will suffer horribly... its not a worthy tradeoff. If you size your turbo so you have no lag whatsoever you're giving away HP. If you select a turbo with a small enough housing to give boost around 1500rpm, you will not make power much above 4000rpm.. your exhaust pressures will be extremely high, your compressor's efficiency will be in the crapper, and your compressor might not even be able to keep the boost up. Let me put it this way... all true *performance* turbocharged engines have turbo lag. If you want a bit more passing power out of your daily driver, sure throw a small turbo on there and run 5psi. If you want to make power, put a larger turbo on. You wont regret it. You won't have as much power below 2500 or 3000rpm, but in the split second it'll take you to go from 3000 to 6500, you'll forget all about it. If the turbo on your dodge will spool 12psi in neutral, it is severely undersized. If I were turbocharging a car(and I am.. my '69) I would never ever consider a turbo anywhere near that small. The turbo shouldn't make any kind of boost without a load on the engine, certainly not 12psi.
As for what transmission, if you're drag racing, go with an auto. That way you can load up the engine and build boost on the line.. just revving it up with the clutch in will not(or rather I should say, should not!) build boost. If you're doin any kind of track racing or for a street car, I'd say go with a manual. That way its a bit easier to keep the turbo in the rpm range where it makes boost, plus you get more power to the ground. And its more fun!

I'm not saying that pathetic mitsu is good, just that it is possible to not have lag.

Anyway, properly sized twins on a V-8 doesn't produce really noticable lag since there is some low end torque present already, so that's a moot point. I think it would get along well with a twin .60/.63 setup....(turbo t-bird t-3's, I believe)

Yeah, I pulled my t3's from a turbo t-bird with a standard trans. The auto's had I think .60/.48 or something like that. A bit too restrictive, though those would probably work nice on a higher revving 302 running high boost. I cant wait to get my car together, it should move quite well. I'm expecting to run 10s, although I wouldn't be heartbroken with 11s. If I can manage a bit more than 15psi, and I should with all the prep I'm doing to avoid detonation(I won't get into that, it'd take pages, but pretty much anything you can think of, I'm doing.), I might be able to get into single digits(and promptly get kicked off the track!). Should keep the civics in line at the very least!
I know the mitsu isn't exactly a performance vehicle, I wasn't saying it was your fault or anything... Most manufacturers put quite undersized turbos on their cheap sports cars. Many sort of casual performance buyers don't like lag, so they put small turbos on to avoid this. But if you've ever driven a higher end production turbo cars(like the audi TT or a porsche turbo), they all have pretty noticeable lag if you try to gun it while cruising at 2000rpm(My father's TT will barely move if you do this..). But after driving the car for 15 minutes, you'll know exactly where the turbo works and where it doesn't, and shift accordingly. I must say, with the high ratio gearing and incredible handling of that car, its a blast to drive like a demon, as long as its under 65mph. After that the car's power to weight ratio gets pretty evident, but the gearing in the first three gears gets the car up to speed pretty fast.

t-3's on a 302. Kinda small for the setup I would think

Not one t3, two.. I'm running two .60/.63 T3's on my 351. I got the recommendation for these turbos from the site www.toohighpsi.com. They were used on his Budget TT 351w.

oh twins :banghead: Sorry I can't read. It's the result of a central Illinois education :bloated:

Don't feel bad Hypsi87 most of us went to public school I know I did! lol So we understand!

i have not read this whole thread.
i was just wondering if sequential turbocharching has been mentioned.

Don't think so.. Do you mean sequential as in one turbo for low RPM, one for high, or sequential as one turbo feeding another to achieve rediculous boost levels(ie two turbos, both compressing at a 2:1 ratio, one feeding the other... that gets you around 44psi... one turbo at 2:1 gives you 14.7.) If it is the first, its not an easy thing to do. The exhaust piping will get VERY large and complicated, not to mention expensive for all the valves you'd need. Something best left for the pro's... As for the second, you better have some very good gas(propane, nitro, toluene...) and a motor that is VERY good at getting rid of heat to withstand that kind of boost.. as well as a very low comp ratio! Not to mention the shortblock that would be required, and the extremely hot spark to get through all that air... Again, best left to the pros. It'd have no place on the streets anyways, who needs a 302/351/4.6 thats running 40psi on the street? That'd probably put you in the 2000hp range... Sweet.

I'd love to have that kind of horsepower in a streetcar it would be the greatest ever made.

The fastest street legal cars in the US run 6 second 1/4 miles... thats right around 2000hp!

Here's a question then:

Where would someone look for turbos on the 4v 4.6 Cobra engine(97)?

correct me if im wrong, but 03 cobras and lightnings have EATON superchargers not WHIPPLE. there is a an upgrade kit from whipple for the cobras though. (im hoping there will be a kit for the 5.0s) as for the turbo or supercharger, if you want a street car, i would opt for the supercharger (i would prefer a kenne bell twin screw) (www.kennebell.net) but if you want a full out race stang i would definitely go for a huge turbo. they are much more better for making power and gobs of torque, but with the heat they create i wouldnt want one on the street for my mustang. just my opinion though.

On further research, yes the superchargers are made by eaton.. The Ford website says 'Roots type' for the cobras, but it says 'Lysholm Type' for the GT, which must be where I heard it from, and my poor memory kinda blurred it all together.

yeah, i used to think there was a roots on the gt but my friend told me a few weeks ago that it wasnt. is Lyhsolm the brand of the s/c? cause ive never heard of a lyhsolm "type". from what i hear the brand IS actually whipple. not saying your wrong, i just want to know

I beleive it is referred to as both a screw type and lysholm type... I believe someone named Lysholm invented it, much like a rotary engine is known both as "Rotary" and "Wankel". Whipple is just a brand, but they're the big manufacturer for lysholm/screw types, so some people just refer to them as whipple superchargers. Lysholm Technologies is a brand though - although I'm not sure if they distribute to the US. Their website is http://www.lysholm.se/

oh, ok, thanks for the new knowledge