ABK

I need some opinions about what's better s/c or turbo. I though turbo should make more hp, but s/c would be cheaper and it doesn't have lag. What you guys think. VOTE TOO

Jeff92se

iTrader: (82)

The particular sc we have does have "lag"

ABK

DAMN why is that. It still shouldn't be as bad as a turbo isn't it?

mtcookson

iTrader: (2)

the s/c the 4th gens use apparently don't reach peak boost until nearly redline whereas a turbo reaches peak boost around 3000-4000 rpm depending on the size of turbo you get. i'd choose a turbo myself but that's because i like the feeling of lag and it was an easier setup in my 3rd gen. there are also more reasons but too many to type.

Jeff92se

iTrader: (82)

Because of the type of SC. You can't really say it's better/worse than a turbo because there are many types of turbos that can be used.

I suggest you read all the threads in this section before posting this type of question.

I'd say for your current level of knowledge, I'd get one of the used SCs that are for sale. They are much cheaper and everything needed for the install is there. Also the set up is safer from a temptation(boost) standpoint

DA-MAX

iTrader: (10)

turbo lag is overrated...I hate when people complain about it. plus it can be easily remidied with proper sizing or a small nitrous shot.

mtcookson

iTrader: (2)

turbo lag is fun as hell. i love the feeling of it just all of the sudden throwing you in the seat. i also don't know why people complain of the lag.

if you mod your engine well, like getting a lightened crank pulley and flywheel so the engine revs quicker, you shouldn't have to worry about turbo lag since the engine will rev pretty quickly.

JAY25

iTrader: (38)

They compare our cars with supras with giant turbos !

Whats turbo lag? look at Hals T3/T4 set up, look at my setup, T4/T4 we post videos. We keep up with fast cars or if not beat them. We also made a video of turbo maxima boosting quick. Here Fck that term watch this video and it should answer all your questions. I am in the SCed maxima with the video camera vs a turbo maxima @ 9.5PSI. I am a better driver then the white maxima driver and a bonus my MEVI was working while his was broken and he still owned my Supercharged max. See thats what hes telling you up there. SCer doesnt lag it just takes longer to get to peak boost unlike the turbo which hits instant peak boost.


10PSI SCed max VS 9.5 t4/t04e turbo max draw your facts at the end

http://www.turbofedmax.com/videos/10....5PFITurbo.wmv

Phatmax98

iTrader: (2)

Very Nice Video!

bruteMax

Jay25:

thanks for the vid man - awesome! First time I've ever seen a turbo or sc'd maxima.

JAY25

iTrader: (38)

anytime. There are more on this particular section. Move on to the next page. Myself and Hal post them here.

ABK

I know that turbo is a great for drag racing, but for the turing sc would be better for turing wouldn't it?

mtcookson

iTrader: (2)

both of them can be used for both styles of racing. most fast drag racers use huge blowers but i've also seen some 7 second turbo cars as well. for autox a sc will help you in the low end but if you're racing properly you should be in the upper rpms so therefor a turbo would do well too.

you also have to take into account turbo size. for drag racing you'll want a larger turbo than for autocross so you can have higher power but with the cost of lag (in drag racing that doesn't really matter since they can get the turbo spooled while on the line anyways). for autocross you would want a smaller turbo so it could spool quicker incase you do drop to lower rpm's. a t3/t4 on our cars should be the best of both worlds unless you're wanting to have an all out racer. if you did, you'd have to find the right size of turbo for the style of racing you're doing.

crewchief264

I feel that for more power and sort bursts of power the turbo is the way to go, however I feel that for road racing and auto cross the sc is the way to go to from a maintance stand point although the turbo does make more power.

ejj

iTrader: (5)

No they don't...

Yes, you build boost as you go higher in the RPM range...but if I'm cruising at 3k RPM in vacuum, and punch it, boost is instant. No lag to speak of.

MardiGrasMax

iTrader: (14)

This is correct!

stephenlc

iTrader: (1)

I have a turbo sitting in front of me at my desk, so a turbo!

Stephen Max

iTrader: (59)

Ditto.

And if you have a turbo sized to give you minimum lag, then you sacrifice power at top end. Turbo systems can maximize power at low to mid rpm or mid to high rpm, but not both. Centrifugal superchargers maximize high rpm power only, but like Eric, says, if you punch it you get instant boost.

Quicksilver

iTrader: (1)

Incorrect...turbo sizing is only part of the reason turbos spool in whatever given time. There are huge turbos that spool instantly...

Also, VATN technology should not be overlooked for the most overall flexibility.

Stephen Max

iTrader: (59)

Yeah, VATN is definitely the future of turbos. But other than VATN, I'm having trouble thinking of how a huge turbo could spool instantly. Have they reduced impeller inertia to nothing?

Jeff92se

iTrader: (82)

If you punch an turbo equipped car with a small turbo, it should have near instant boost also at 3,000 rpm?

What about 1,000 rpm? How does it feel there? I was just saying this type of SC is not the same as some of the other types like the Roots that feature almost full boost from almost any rpm.

Stephen Max

iTrader: (59)

Yes, small turbos produce near-instant boost. Not instantaneously like a SC, but they will build boost much faster than a SC. They also run out of breath at high rpm where the SC boost continues to climb, so there is a tradeoff, like all boosted systems on the market today.

If you punch it at 1000 rpm you are in 1st gear and you break your wheels loose instantly. Punching it at 1000 rpm in other gears is bad for the engine, but since the question is most likely rhetorical, yeah you get boost even at that low rpm because the blower pumps more air than the engine can swallow even at low rpm. But not enough to register much on the boost gauge until you build up some engine speed.

The problem with roots blowers is poor thermal efficiency. So, yeah, you get lots of boost at low rpm, but the air is going to be hot.

It's too bad Craig Mack's car got totalled before he had a chance to work out all the bugs and dyno it. That was truly an interesting development.

Quicksilver

iTrader: (1)

Pitch of impellar blades, number of blades (a way to reduce mass...10 vs. 11 blades saves a slight bit of weight), material makeup of the impellar (composite materials, titanium...), bearings and what material they are made of...

There are also systems that somehow start the turbo spinning before a certain RPM (I guess they're electric motors) to completely get rid of any perceivable lag.

And the relatively inexpensive N2O shot to cool the intake charge and spin up the turbo quicker...

Jeff92se

iTrader: (82)

Most of that spooling aids aren't really commonly available. The antilag stuff done on Ralley cars is really tough on the manifolds etc...
VATN is a very interesting invention but damned expensive right now.

I think the best inventions so far was the sequential turbos off the late Supra TT and RX-7TT.

Quicksilver

iTrader: (1)

Actually, all of those features are readily available if you order your turbo custom in stead of buying an "off the shelf" unit...

It does cost more, but not that much more really (at least not much more to me).

And IMHO, and most others who have done work on sequential turbo cars, the Supra/RX7 setup was very wasteful and inefficient. A single, purpose built performance turbo has been shown to superceed every single performance advantage that the sequential turbos were supposed to have...


A true twin turbo setup (GT-R, Audi S4, and others) also slightly wasteful performance wise (but it looks and sounds cool as hell).

I guess everyone has a different idea on what turbo sytem works for the performance needs they require...

Jeff92se

iTrader: (82)

Yeah, I get ya. I don't really research that type of stuff too much as I have an high compression engine anyway and can't really use a big turbo anyway. So lag and big turbos aren't really a too big of a concern. The VATNs really are interesting though. Their simplicity and their lack of needing additional aids to be able to spool and flow interest me. You can even mount them sideways etc.. because they use their own oil source.

mtcookson

iTrader: (2)

if i'm cruising down the highway in 5th gear i'll be at around 2000-2500 rpm maybe and if i step on the gas i get full boost really quickly. i believe it hits full boost before i even hit 3000 rpm's and my car is turbo. granted it has a small turbo but it still spools the same way you guys are saying the s/c would.

JAIMECBR900

Most of the S/C setups here are centrifugal type. Meaning that there is going to be a small "lag" when coming off idle WOT into full boost simply because the S/C'rs impeller has to spin at certain RPM's before coming into full boost. This is similar to what happens on turbos. The difference is that our S/C, as are all s/c, are belt powered and not exhaust powered. The belt can "spool" the s/c quicker than exhaust will. Always factoring in parasitic loss too.

As someone mentioned, there is an exeption to that rule. When cruising off boost but on vaccum, you will get almost instantaneous boost when you gun it. The main reason is because of the belt drive explained above. It's always going to spool it up quicker than exhaust.

The big advantage of turbos is total power output. The S/C is going to be limited due to physical size and engine layout. Most of our S/C units are capable of 20 psi, but you will tap out there. Turbos are physically smaller since they have no shaft and go on the exhaust system and therefore most of the time have plenty of room to work with (there are exeptions so don't go crazy flaming). The turbo can usually be spun to much higher speeds because it is more efficient when it comes to spinning than a S/C (think about a pinwheel you had when you were a kid. You had to puff pretty hard to get it spinning, but once it got started you didn't have to blow hard at all to keep it spinning). The S/C is going to be limited by the engine speed as to how much input shaft speed it gets. A physically smaller turbo can produce the same if not more power (optimally) than a bigger sized S/C.

The only way to up boost in either application is to spin the impeller faster. The S/C does so thru a shaft connected to the belt on the engine; the turbo does it thru the exhaust gasses exiting the engine (basically).

The only S/C that have instant boost off idle are roots type of chargers. They use a different way of making boost and don't have "impellers" like centrifugal or turbos do. They are very inefficient, as someone already mentioned, and have a very low limit (usually) in the amount of boost they can efficiently produce. They work well in drag applications where you are trying to get mass moving in one direction from a stand still. Once you have "spooled" up both a turbo and a s/c....they both boost based on the same time frames. In other words, a bigger turbo gives more power but has more lag, a smaller has no lag but less power because of the time that it takes either one to get to their designed RPM band.

Stephen Max

iTrader: (59)

Oy vey. Where to begin?

abradic

iTrader: (1)

Hey Jay. First, great videos. It just makes me salivate more and more. On the vids with the weak Mustang letting off, and I believe there was a 350Z, Supra, and GS 400's, were you in a SC Max or TC Max for all of those races?

abradic

iTrader: (1)

An excellent example. You can also think of it as flying in an airplane. When you throttle up for take off, you literally hear the engines spool up. As you go down the runway, you feel more and more torque until the engines are fully spooled and you keep accelerating. Think of airplane engines as the biggest TC or SC you have ever seen. A TC and centrifugal SC is the EXACT same thing...on a smaller scale of course. You are spinning the impellar, and the faster it spins, the more air volume it takes in to compress. A TC is even more related because both are using exhaust gases to turn the impellar (or compressor if you want to call it that). I think either system is fully safe as long as you don't boost too much for your engine. I hope to have the V2 running at around 11 psi. I think the VQ should be able to hold that judging by the posts on here.

Craig Mack

I proved that the Eaton Roots Setup can be done, and for $3000 (including blower). If it wasn't for my accident, I would be tuned by now, and showing everyone what torquey off idle power really looks like. It felt awesome the brief amount of time I had it though.

I don't know why everyone here is soo scared to pursue a Roots setup. I proved that it can be done. If you are sick of the Vortech kits, and don't want a Turbo, the Roots is the way to go. It delivers a very unique sound at WOT, which IMO is by far the best sounding, and makes full boost almost off idle.

Quicksilver

iTrader: (1)

That's actually a very poor comparison. Only the basic principal of compressing air is the same between the two...

CiViC KiLLeR

All this fight about turbo and superchargers. I thank that if a turbo is good for some things and a supercharger is good for other things some of us max people need to try to use both at the same time!!!! It will be a crazzzzzzzy setup but it whould be cool to see and it is cool to tell your friends that you have a turbo/super maxima!!!!!! But if I had to pick it whould be a turbo.

abradic

iTrader: (1)

Actually, it's a dead on comparison in theory...especially a turbo. A turbo uses exhaust gases to turn the turbine. As the exhaust turns the turbine, it drives the impellar (compressor) and pulls in air, just like a jet engine. You're more right with the SC though since it is different. A centrifugal SC uses a belt to drive the impellar (compressor) which makes it more unique. However, both setups are using the impellar to compress the air. The faster it spins, the more air it brings in to compress resulting in more psi. It is exactly the same setup as an aircraft engine. They both have lag due to spool up time, but once they spool up, watch out! It's just a basic similarity.

Stephen Max

iTrader: (59)

Oh, were we fighting? I thought it was a pretty civilized discussion so far.

Hey Craig, do you have more pictures of your Eaton setup? I'd like to see how you did it.

ejj

iTrader: (5)

Because (although I don't think you realized it) you proved that you _have_ to re-locate the throttle body to get the roots blower to work. That makes things a lot more complicated.

Still a good idea though.

Craig Mack

Nooooooooooot exactly, mr. Senior Citizen.

As a correction for my horrible driving issues, we ditched the BOV and ran the bypass valve. This made a SIGNIFICANT difference. It made the car much quieter, and improved driveability greatly. The car was ALMOST normal. The idle still had a teency bit of lope to it, so we set my S-AFC 30% richer from 0-1000rpm. This made the car idle normally. Problem solved. The Throttle Body was not moved.

I must say though, relocating the throttle body to the non charged side would be the ULTIMATE solution to my problems. But, my setup prior to the wreck was VERY streetable for a daily driver and almost as good as relocating the throttle body. I would still be driving the Max to this day with the TB in it's stock position.

Stephen: Here's the site to the Eaton pics: http://members9.clubphoto.com/craig5...ner-de8c.phtml There aren't that many, sorry. But I can tell you, it's a simple concept.

Basically:

1)Cut drivers side cooling fan out to make room for blower
2)move battery back right in front of the drivers side strut tower
3)Make a mounting bracket, bolt it to the spare threads in the transmission, and to the spare thread(s) in the engine block
4)run a shaft, with flex-spacer thingy (the black peice in my pics) over, make
5)Put a big pipe around the shaft to protect it
another little mounting bracket
6)mount pulley and connect to shaft
7)buy belt and strap her on
8)Bypass air, set S-AFC to 30% richer fuel from 0-1000rpm.

The time consuming part is fabricating this stuff, and making sure all measurements and cuts are PRECISE. For instance, if the shaft isn't completely straight, it will put lots of strain on the nosedrive bearings, and eventually F up the blower.

And finally...VOILA! You have an Eaton Roots Supercharger system, that delivers a whole different kind of boost. I didn't fully appriciate the quick throttle response of my Eaton blown Max until it was gone. My Cobra has muscular acceleration, but I miss the quick, responsive, torquey, "light" feel of the acceleration of the Max. It really did haul lots of @ss.

A custom positive displacement SC setup is a nice alternative to Turbocharging, for those who crave low end power like I did. The roots SC/Twin screw cannot be beaten in terms of low end power delivery. Instantaneous throttle response that even the most efficient spooling ball bearing turbo cannot touch.

Stephen Max

iTrader: (59)

Thanks a lot, Craig. So did, or can, your installer make any drawings with dimensions of the mounting brackets for people wanting to do this?

twotone

iTrader: (1)

What about this setup for 5th gen?
This setup gave you extreme low end power.. but what about high-end power?
S/C is known for its continuing top-end as opposed to turbo.. but no low-end.
This setup seems to have all the low-end but how does the top-end compare to standard Vortech setups?