Ok...which Super Charger?

[David Morton]

Now do you feel better for having said that?

We cool. For the longest time I wanted to grow up and be just like you, until I found there was a turbocharger available, and thoughts of my old love were rekindled. But you will always be special. I know someday you will find somebody new.

[BillyGman]

AAHHHH, A wise guy!!! NYUK..NYUK..NYUK...

[David Morton]

I believe you're correct and that after 4,000 RPM's there isn't any power/acceleration advantage that the roots type blower offers over and above a centrifugal. Certainly NOT above 4,000 RPM's. That's where the centrifugal begins to shine.

However, I also want to address a misconception that some people have on here (NOT meaning you Dave) that entertains the notion that a roots supercharger actually doesn't give you any power increase above 4,000 RPM's over and above a NON-supercharged engine, and some even seem to think that a roots supercharger even decreases the power output of an engine above 5,000 RPM's and that's simply an old wives' tale. Even with the 4.56 gears in my Marauder, my car has a very noticeable acceleration increase OVER the 100 MPH mark. So I fully agree with the comparisant that you've made, however, I just wanted to clear up that misconception that some others seem to have.

Preachin' to the choir there bruddah.

And I'm sure you know I'm talkin' 'bout turbochargers and not centrifugal superchargers which still have the parasitic torque loss of a belt and are like a middle of the road between Trilogys roots type and the turbocharger. More top-end torque than the Trilogy but not nearly as much as the turbocharger is capable of.

I don't know anybody dumb enough to think any forced air induction system is actually gonna lose power over normally aspirated. Must be one of those wanna-be Crown Vic owners.

Just kidding guys. Anybody that dumb has to be a Chevy man. (just kidding TTA)

['03BlkMM]

I also frequent a Mustang/Cobra board quite often, and I think that the only reason that you don't see nearly as many supercharger debates on those boards among Mustang & Cobra owners is simply because of the fact that they have a TWIN-SCREW supercharger option which we as Marauder owners do NOT have, and it's a well known and well established fact that the TWIN-SCREW supercharger is superior to both the centrifugal and the Roots type superchargers since it offers the best of both worlds.

Had it not been for atleast two different twin-screw supercharger kits being presently available for the Mustangs and for the Cobras, I'm sure that they would be having many more roots vs. centrifugal debates than they do just as we sometimes do over here. But for them, that debate has been rendered obsolete since most of the Cobra owners all reach for the twin-screw design, and their spectacular quartermile ET's prove that they're making the right choice. So there's no romm for debate in their camp.\

if you look closely at the SVT board for instance, you'll see that there have been some major knock down drag out verbal brawls over which TWIN-SCREW supercharger kit is better (Whipple vs. Kenne Belle). So it's only human nature amongst those of us who are passionate about High performance & HP.

The 96-98 Cobra's only had 2 kits available for them(back in 97-98 timeframe). I saw a few of the KB kits at the local Mustang dyno tune days which I used to frequent. Even with the KB avail for those older models the Vortech was the preferred SC kit. Even after dyno tuning, on the 96-98 models the non-IC'd KB kits made slightly less RWHP than the non-IC'd Vortechs at the same boost level. I saw this more than once. Of course that could have been due to KB's intake design on those models. On the current model Cobra's the reason you don't see many centrifugal kits is that they came SC'd. The KB is a bolt-on kit for them that will replace the stock Eaton compressor and still utilize the original intake. So it just makes sense to use the easiest/cheapest path to higher HP.
But, I owned a GT so I was running with the 2V forum crowd for the most part. The 96-up GT's only had a twin screw kit available approx 2 yrs ago when Saleen followed by KB came out with their kits. Why KB took so long to come out with a kit for the SOHC still baffles me. The Saleen was quickly found out to be a dog due to their highly restrictive intake design and once the dyno numbers started rolling in everyone quit buying them. KB came out with a well designed kit and it makes great HP. But, Even with the twin screw being available for the GT the centrifugal kits are still used quite often. The reason being that properly tuned they offer approx as much RWHP as the KB twin screw kit for less $$$. The nice thing about Vortech/ATI is that they use dealers to sell their products and dealers will discount their products. KB sells directly and does not discount. So from my perspective its still far from a cut and dry subject over there as both kits are still used.
Now, I wasn't saying that heated disagreements never happen on the mustang board, just that it didn't happen everytime. I mean when you have the moderator of the board jump into the start of SC discussions and begin warning people you know something is wrong....Of course, this thread has managed to remain civil so far so I guess I can't say that over here now!

But I stand by my original suggestion, BUY A TURBO...

[SergntMac]

[

So if it is better, why hasn't anyone ventured into a complete twin screw kit for the MM?

Actually, converting a MM to the Kenne Bell twin screw isn't that hard to do. If you do your homework and gather together all the required parts, it could be up and running in about 12 hours. However, this effort upsets so much of the stock MM, the folks who own them won't like the changes one must accept in order to complete the transition, not even a decent hood to consider at this time. Guess you could say that your typical MM owner, myself included, doesn't want to explore such radical change for what is essentially a beautiful car all by itself. Billy says it well too.

thirdly might be that because it's a big heavy family sedan, my guess is that there's a greater percentage of MM owners who are simply satisfied with their cars being bone stock than there are Cobra owners, and who aren't going to even consider a $6K or $7K price tag to supercharge their vehicles. Bottom line is, there isn't nearly as big of a market for go fast parts for Marauders as there is for Mustangs or Cobras. just look at how many aftermarket places even make long tube headers for Marauders. Up until just a month ago or so there was only one place (Kooks) and that was it. now there's been a second place. but that's far from how it is with Mustangs and Cobras.

I fully agree. MM owners are a focused group themselves, and it would take a very hard core racer to cut up a MM enough to make it competitive among the drag racing masses. Maybe in another year or two, we'll see heavy cars at the track again, but they'll be recut and restitched, the days of "gassers" may return.

BTW, Billy, do you consider Kook's a "full length" header kit? It's my impression they are mid length, or, 3/4s. The offering from Stainless Works are much longer, and have 3" collectors, just wondering if you have looked into them. There are serious advantages to a complete 3" exhaust system, if you are pushing the boost into double digits.

I also want to address a misconception that some people have on here that entertains the notion that a roots supercharger actually doesn't give you any power increase above 4,000 RPM's over and above a NON-supercharged engine, and some even seem to think that a roots supercharger even decreases the power output of an engine above 5,000 RPM's and that's simply an old wives' tale.

Sorry, I can't agree here. I do a lot of reading here, almost everyday. I miss stuff, but I don't think I would have missed such a wild misconception. I've never heard (or read) anyone suppose anything close to this, and if I had, I'd be all over it. Where did you see this posted, Billy? I'd love to trade some mail on it, maybe whoop "wifey" back in line?

We all have our opinions on what's better and why, and for me the argument has been rather minor. In the face of "best low end torque comes from a Roots blower", I say yes, agreed. A Roots does produce more torque in the lower RPMs. However, the end result difference isn't that great, and I believe the proof of this has been posted time and time again. A dyno curve isn't proof of performance, it's a prescription from the doctor.

While Billy (and other Roots cars) can produce a 1.6x (or better) 60' time, so has Zack, and I've seen 1.7x 60' times with my blow through Vortech centrifugal. My position is (and always has been) that while there is a difference in performance under 3500 RPM, it's not as significant as suggested, and surely not different enough to support a "best because" foundation. Owning the torque is half the battle, exploiting it is the other half.

There may be many good reasons one chooses a Roots system over a centrifugal, but this particular difference isn't remarkable, at least by the numbers produced at the track, and should not be the leading rationale for decision. Buy what you want, but know the specs first. Besides, both styles pale in performance to turbocharging done right.

If I was restricted to 1/8 mile racing, I'd be a Trilogy owner, no doubt about it, no heasitation in decision. But, it's 1/4 mile around me, with a lot of road trips in between, and if given the chance to decided today, with all we know about it now, this would be a hard call for me. All are all such good designs and all perform very well for the bucks involved.

The one thing I do notice, is how the Trilogy Roots kit appears so OEM, and that's a nice plus. However, the value of this depends on how many hoods you have looked under in recent years. Production-wise, Eaton owns it, and this is a testament of durability and ease of maintenence, both of which are strong considerations for the automobile manufacturer.

But, if I were a young and innocent mind gathering clues from popular magazines, I see more "hair dryers" in pics than "snouts", and those hair dryers have their wheels up in the air. I just paged through the last edition of MM&FF and took a quick count, 14 to 4, centrifugal over positive displacement/twin screws combined, and 20 to 1 in babes over blowers. While this proves nothing, it leads to preconception and notions of performance hard for the curious to ignore. No wonder we continue to debate?

[BillyGman]

There's enormous potential with turbos, yes. my understanding of them is that unless you want to deal with some lag down low, you need to go twin turbo, and that's going to cost about $15K if you want to do it right. Turbos are tops, but they're also tops in price too. So just like most anything else in this game, it's a matter of how much $$ you have, and how fast you want to go.


On the SVT board right now, amongst superchargers for STREET driven vehicles running pump gasoline, twin-screw superchargers are the top dogs. I'm not talking about 1998, or even two years ago. I'm talking about now. centrifugals are mentioned every now and then, but hardly ever, just as roots superchargers are hardly mentioned either. It's a board made up of plenty of Mustang owners as well as Cobra owners, and just about everyone their knows that a twin-screw supercharger can't be beat for the street. you cannot simply look at PEAK HP #'s. That tells part of the story, yes, but certainly not the whole story. And a couple years ago there were still many suercharger kits being sold w/out intercoolers. thre still are a number w/out intercoolers being sold today, but there are many more intercooled ones today than there was even two years ago. So the big treend now is intercooling and it has changed things in the way of HP #'s.

For example, if you and I have the same car, same weight, same gears,same exhaust, same tires, and you have a centrifugal making 500 HP to the wheels and I have a twin-screw making 490 to the wheels, that will not tell the whole story.The twin-screw equipped car will be faster. Because in most scenarios, with all other things being equal, the twin-screw set-up will be making more power in the low, and in the midrange RPM levels(especially at 2,500 RPM on up to 4,000 RPM and it just keeps on climbing from there just as the centrifugals do after 5,000 RPM's). The powerband will simply be wider with a twin-screw equipped engine given the same displacement.

It is no coincidence that Ford is now leaning to the twin-screw supercharger design. First it was with the GT supercar, and now it's said by Ford that the 07 GT500 will also be equipped with a twin-screw. And we don't have that choice for Marauders. And I wasn't talking about two, or four years ago. I'm talking about now. So I also stand behind my previous statements.

[BillyGman]

LOL....now we're rolling......first off, if anyone thinks that it's an "easy" task to install a KenneBelle supercharger on a Marauder, then go talk to Jeff (aka "Effster" of this board) who was the only one who has actually done it. I traded a few PM's with Jeff, and he's a great guy, and his accomplishment was fantastic. my hat's off to the man, but it was he himself who informed me that it was by no means easy. And he is a mechanic by trade, and also is co-owner of a speedshop in Long island. He told me that it was such a project for him getting everything right that he doesn't even know if it was all worth it.


Secondly, as far as the misconceptions about the roots superchargers go, you should see some of the PM's I get with people asking me questions about superchargers as well as the e-mails too from guys on THIS board who have been confused and even mislead by all the talk on here about "parasitic" loss of the roots design. I'm not saying that people have intentionally mislead others, but because of their emphasis and unbalanced commentary, they have unknowingly mislead some who are less knowledgeable and who sometimes are shy about posting questions in fear of being flamed.

['03BlkMM]

On the SVT board right now, amongst superchargers for STREET driven vehicles running pump gasoline, twin-screw superchargers are the top dogs. I'm not talking about 1998, or even two years ago. I'm talking about now. centrifugals are mentioned every now and then, but hardly ever, just as roots superchargers are hardly mentioned either. It's a board made up of plenty of Mustang owners as well as Cobra owners, and just about everyone their knows that a twin-screw supercharger can't be beat for the street. you cannot simply look at PEAK HP #'s. That tells part of the story, yes, but certainly not the whole story. And a couple years ago there were still many suercharger kits being sold w/out intercoolers. thre still are a number w/out intercoolers being sold today, but there are many more intercooled ones today than there was even two years ago. So the big treend now is intercooling and it has changed things in the way of HP #'s.

For example, if you and I have the same car, same weight, same gears,same exhaust, same tires, and you have a centrifugal making 500 HP to the wheels and I have a twin-screw making 490 to the wheels, that will not tell the whole story.The twin-screw equipped car will be faster. Because in most scenarios, with all other things being equal, the twin-screw set-up will be making more power in the low, and in the midrange RPM levels(especially at 2,500 RPM on up to 4,000 RPM and it just keeps on climbing from there just as the centrifugals do after 5,000 RPM's). The powerband will simply be wider with a twin-screw equipped engine given the same displacement.

I think you've lost the point of my original post. Here it is.

"I've been a member on the Mustang board since '96 and have seen and participated in many a "which SC is best thread" and I don't remember any that have gotten as out of hand as quickly as the ones over here do. I'm not saying that it doesn't happen, just that it is a rare occurance."

I never said anything about "here and now" there is never an argument. My next post in response to you was to show that there was more than one kit available over the years (since '96) and that there was reason for debate on the subject.

Even if as you say a different brand of SC kit is occasionally used on the SVT forum it would still give people a reason to debate its use. Because obviously it was an attractive kit to somebody and they had a good reason for it being the best one for them to buy.

On your other point, I completely agree. For a street driven car as far as SC's are concerned a properly designed twin screw kit is the best. I say a properly designed twin screw because Saleen's foray into the SOHC twin screw came up very short of peoples expectations. Most were getting 315-325rwhp after dyno tuning and everyone was expecting >350rwhp. It was later found that the intake was more restrictive than a stock GT's. Then the KB twin screw kit comes along and is getting 400rwhp with the 9psi kit. So just because its a twin screw kit doesn't necessarily mean its going to be a good performer.

[BillyGman]

On your other point, I completely agree. For a street driven car as far as SC's are concerned a properly designed twin screw kit is the best.

And your statement above proves my point. You agree with me most likely because of the knowledge that you've obtained and have been exposed to from the mustang boards, many Mustang and Cobra guys now realize that a good Twin-screw supercharger kit cannot be beaten for STREET vehicles by a roots design nor by a centrifugal design. And that's simply because so many Mustang and Cobra owners have either been exposed to the twin-screw design from an internet board buddy of theirs, or they have had a twin-screw S/Cer on their own car.

However over here, MAC's last post where he's pitching the case about centrifugals being equal or even better than twin-screws is a typical response because less people on this board have been exposed to the use of twin-screw superchargers mostly because only one guy from this board has one on his Marauder, and he doesn't post here very much anymore, and he had quite a project on his hands which took a lot of time getting it right since there aren't any twin-screw supercharger kits for Marauders like there are for Mustangs and Cobras(although I also want to point out that he didn't have to alter the hood on hid Marauder as MAC has implied. Also note that MAC's talking about full out race cars in magazines that are centrifugal equipped that are running big time boost pressures that aren't for street use, and that are launching at 4500-5,000 RPM's with monsterous stall speeds and/or the use of trans brakes that you cannot use on the street in traffic conditions. So there ya go.

On here there's all kinds of debating due to non-exposure of twin-screw S/Cer use, while on the Mustang/Cobra boards, it's been an established fact for awhile now that Twin-screw is the way to go. Many street driven cars from the Mustang boards are into the 10 second brackets with Twin-screw set-ups, and w/out running 4500 RPM stall speeds and/or trans brakes on them which would be very impractical for the street. Some of the twin-screw kits of old were not only poorly designed, but also were NOT intercooled, and that makes a world of difference. Up until recently, twin-screw kits were very expensive to manufacture too, due to the machining process required for the rotors (which is more involved than the machining for the roots S/Cer rotors), and that helped to drive the cost of the kits up and the popularity and/or availability down. But the more recent use of CNC machining techniques have reduced manufacturing costs significanlty, and that's why you're seeing more and more twin-screw kits available now from Kenne Belle as well as Whipple. I believe twin-screw superchargers are the wave of the future for STREET driven vehicles. But unfotunately that probably doesn't include Marauders.

['03BlkMM]

And your statement above proves my point. You agree with me most likely because of the knowledge that you've obtained and have been exposed to from the mustang boards, many Mustang and Cobra guys now realize that a good Twin-screw supercharger kit cannot be beaten for STREET vehicles by a roots design nor by a centrifugal design. And that's simply because so many Mustang and Cobra owners have either been exposed to the twin-screw design from an internet board buddy of theirs, or they have had a twin-screw S/Cer on their own car.

However over here, MAC's last post where he's pitching the case about centrifugals being equal or even better than twin-screws is a typical response because less people on this board have been exposed to the use of twin-screw superchargers mostly because only one guy from this board has one on his Marauder, and he doesn't post here very much anymore, and he had quite a project on his hands which took a lot of time getting it right since there aren't any twin-screw supercharger kits for Marauders like there are for Mustangs and Cobras(although I also want to point out that he didn't have to alter the hood on hid Marauder as MAC has implied. Also note that MAC's talking about full out race cars in magazines that are centrifugal equipped that are running big time boost pressures that aren't for street use, and that are launching at 4500-5,000 RPM's with monsterous stall speeds and/or the use of trans brakes that you cannot use on the street in traffic conditions. So there ya go.

On here there's all kinds of debating due to non-exposure of twin-screw S/Cer use, while on the Mustang/Cobra boards, it's been an established fact for awhile now that Twin-screw is the way to go. Many street driven cars from the Mustang boards are into the 10 second brackets with Twin-screw set-ups, and w/out running 4500 RPM stall speeds and/or trans brakes on them which would be very impractical for the street. Some of the twin-screw kits of old were not only poorly designed, but also were NOT intercooled, and that makes a world of difference. Up until recently, twin-screw kits were very expensive to manufacture too, due to the machining process required for the rotors (which is more involved than the machining for the roots S/Cer rotors), and that helped to drive the cost of the kits up and the popularity and/or availability down. But the more recent use of CNC machining techniques have reduced manufacturing costs significanlty, and that's why you're seeing more and more twin-screw kits available now from Kenne Belle as well as Whipple. I believe twin-screw superchargers are the wave of the future for STREET driven vehicles. But unfotunately that probably doesn't include Marauders.

Yes, but as much as I like the twin screw SC I still like the turbo best. I'll take mine in a cheaper single kit please! I can live with a little bit of low end lag for what I'll gain over 3k rpms.

One other side benefit to the cheaper costs you talked about with the twin screws is more price pressure on the other SC manufacturers. That price pressure eventually helps all of us buyers out...

[BillyGman]

One other side benefit to the cheaper costs you talked about with the twin screws is more price pressure on the other SC manufacturers. That price pressure eventually helps all of us buyers out...

yes, especially the price competition that Whipple has been puting up against Kenne Belle. the more that Whipple gets involved with the aftermarket Lysholm design, the more competition it will mean for Kenne Belle's Autorotor design (both being twin-screw as I'm sure you're aware of). And the prices will continue to drop atleast to a certain point.