671 vs 871 blowers...

[1974dodgecharger]

Minus the size what is the main advantage or differences if the prices are the same brand new?

My friend has a 871 blower kit for a 440 in box he thought he was gonna use, but decided not too.

[John_Kunkel]

You can turn the 8-71 slower and get the same amount of air as the 6-71 turning faster.

[1974dodgecharger]

You can turn the 8-71 slower and get the same amount of air as the 6-71 turning faster.

so that means less heat...which in turn is good.  I was reading somewhere 871 is more for fuel injected, but at the same price I would rather pick up the 871 then.

[Chryco Psycho]

Makes sense to me , the 6/71, 8/71, 10/71 is the rotor & case length , at a given RPM you start to create more turbulence than pressure so turning the blower slower with longer rotors makes the blower more efficient & cooler .
PSI / screw blowers are better yet over the roots type as the pressure under the rotors cannot put pressure on the rotors trying to turn them backwards

[metalstorm440]

The bigger blower is useualy the better choice.check the rotor to case clearence,rotor to rotor with a feeler gauge.[.010/.015 in general]And let me say the carbs size you pick will make a huge difference also.

[1974dodgecharger]

Whats idea price or fair price for a 671 or 871 for daily driver status blower?

[Chryco Psycho]

new 4k , used 1/2 that but it depends what you get with it , just the blower is not all that expensive but you need the crank hub , drive pullies , belts , idler pully & brackets , intake , carbs , fuel lines & throttle brackets & linkage

[metalstorm440]

You can save some $ by going through a dealer and not direct from a blower Co. like BDS or The Blower Shop or a used dealer like RBS or Good vibrations to name a few.I have not looked at pricing so i cant realy give an idea but if you want me to guess i can.

[1974dodgecharger]

You can save some $ by going through a dealer and not direct from a blower Co. like BDS or The Blower Shop or a used dealer like RBS or Good vibrations to name a few.I have not looked at pricing so i cant realy give an idea but if you want me to guess i can.

well I been talking to superchargerusa.com the person who has been emailing me has been very helpful. I want it anodized black also and they can do that for 700 bucks extra the whol setup kit.  If you think I could get it cheaper than what they quote on their website give me a PM.

seems to me though after reading and googling for many weeks now a 671 will be fine and a 871 is better, but not truely needed unless I want 900hp plus of HP and that will require more money on the engine itself.

[surmanajaja]

if you want 900hp I would not use and old-school blower at all. turbo is way easier and cheaper to make real power and screw-style is cooler and fits under the hood.

anyway for a driver 6/71 is enough, but bigger looks better so go with 8/71 if you can.

[Ghoste]

But a turbo doesn't give you that cool blower whine and the screw type doesn't give you the cool look of it poking out of the hood.  Some old school things are good. 

[Cooter]

Centrifugal Superchargers also offer intercoolers. Kinda hard to get an intercooler between the intake and blower with an 8 71.

Water/methanol injection is nice, but gimme something that actually does produce what it appear to produce, without the engine damage.

[Ghoste]

Performance mods without the risk of engine damage?  Thats a short pile.

[Cooter]

Performance mods without the risk of engine damage?  Thats a short pile.

Wow Ghoste, you on your game today taking things out of context and jumping right on the bandwagon. That has to be some kinda record. Even for you.

[Ghoste]

It was meant to be humorous but to be truthful, I had absolutely no idea whatsoever that I was even slightly taking it out of context.  Ordinarily I guess I would plead for an explanation but since it wasn't meant as a point of debate I'm not that worried about it.  You have my deepest apologies for both not understanding what you meant and for making what is now obviously a bad joke of it.

[1974dodgecharger]

if you want 900hp I would not use and old-school blower at all. turbo is way easier and cheaper to make real power and screw-style is cooler and fits under the hood.

anyway for a driver 6/71 is enough, but bigger looks better so go with 8/71 if you can.

there is a 400 dollar difference between the 671 vs 871 setup. I figure the 400 dollars I can save to get it anodized black so 671 will do then I need some money for a cam change among other things for the blower setup. 

[Chryco Psycho]

personally I would spent the $400

[surmanajaja]

But a turbo doesn't give you that cool blower whine and the screw type doesn't give you the cool look of it poking out of the hood.  Some old school things are good. 

yes I agree and thats why I said also "bigger is better". I have loved the sound of blower ever since watching Mad Max, and would definitely put one on my car too.

[Challenger340]

871 case advantages to boost vrs rpm are a plus....
my question I guess...relates more to targeted power levels and Boost you are seeking ?
What are you planning ?

[1974dodgecharger]

871 case advantages to boost vrs rpm are a plus....
my question I guess...relates more to targeted power levels and Boost you are seeking ?
What are you planning ?

Im looking for streetability with the looks being more important than the actual performance. I be happy with 500hp with the blower setup. No racing whatsoever, but I do plan on rev engines at stop lights 

[metalstorm440]

You could go with a single big carb and still have all that you want.

[Ghoste]

But he also wants the visual wow factor and some blower whine.

[Cooter]

Im looking for streetability with the looks being more important than the actual performance. I be happy with 500hp with the blower setup. No racing whatsoever, but I do plan on rev engines at stop lights  

This is what leads to engine getting grenaded IMO. Sure 500 Hp blown 440 sounds nice till all that 10 second look gets your ass handed to you by a Turbo'd Nissan 240, then you wanna turn up the wick, then BOOM! "No racing whatsoever"? Nice try..Nobody spens $4K on a blower and just "Cruises it"......

[1974dodgecharger]

 

I still want the whine and 'look' of the blower 

Im looking for streetability with the looks being more important than the actual performance. I be happy with 500hp with the blower setup. No racing whatsoever, but I do plan on rev engines at stop lights  

This is what leads to engine getting grenaded IMO. Sure 500 Hp blown 440 sounds nice till all that 10 second look gets your ass handed to you by a Turbo'd Nissan 240, then you wanna turn up the wick, then BOOM! "No racing whatsoever"? Nice try..Nobody spens $4K on a blower and just "Cruises it"......

[Cooter]

Not much for the  "Vin Diesel" look myself..Cost that much, it better haul ass and prove it to me IMO.

[Ghoste]

I always wanted a blown car when I was younger so I get it completely.  The pro street look burned me out on seeing them possibly in my own case but I totally understand the appeal.

[Blown68Coronet]

Im looking for streetability with the looks being more important than the actual performance. I be happy with 500hp with the blower setup. No racing whatsoever, but I do plan on rev engines at stop lights  

This is what leads to engine getting grenaded IMO. Sure 500 Hp blown 440 sounds nice till all that 10 second look gets your ass handed to you by a Turbo'd Nissan 240, then you wanna turn up the wick, then BOOM! "No racing whatsoever"? Nice try..Nobody spens $4K on a blower and just "Cruises it"......

Well, I never had my ass handed to me by a Turbo'd Nissan then again i built mine to handle the boost.Also they do have coolers for roots blowers that go between the intake & blower. Back to the OP's question i'd go with the 8/71 so you'd be prepared in the future for upgrades.Trust me your going to want to go bigger after you get use to it.. It's a viscous cycle,lol.
On another note you can run the blower underdriven to keep boost down also they don't make boost all the time it's only when it is under load.ANother option if you just want the whine...... go with a gear drive.

[Cooter]

Im looking for streetability with the looks being more important than the actual performance. I be happy with 500hp with the blower setup. No racing whatsoever, but I do plan on rev engines at stop lights  

This is what leads to engine getting grenaded IMO. Sure 500 Hp blown 440 sounds nice till all that 10 second look gets your ass handed to you by a Turbo'd Nissan 240, then you wanna turn up the wick, then BOOM! "No racing whatsoever"? Nice try..Nobody spens $4K on a blower and just "Cruises it"......

Well, I never had my ass handed to me by a Turbo'd Nissan then again i built mine to handle the boost.Also they do have coolers for roots blowers that go between the intake & blower. Back to the OP's question i'd go with the 8/71 so you'd be prepared in the future for upgrades.Trust me your going to want to go bigger after you get use to it.. It's a viscous cycle,lol.
On another note you can run the blower underdriven to keep boost down also they don't make boost all the time it's only when it is under load.ANother option if you just want the whine...... go with a gear drive.

http://www.dodgecharger.com/forum/index.php/topic,96865.msg1115469.html#new

[Ghoste]

I think turbo'd Nissans probably grenade once in a while as well.

[Cooter]

I think turbo'd Nissans probably grenade once in a while as well.

Only when the "Wick" is turned up like I said earlier. "Built for boost" is relative. I don't care what type of "Building" one does, you send 20 PSI through a Stock Block 440 and you see all the pretty parts you haven't seen since it was assembled. I see Toyota's(Think Supra's) rutinely see 20 PSI.

Blowers are great, no really they are, but like Nitrous, they become addicting and sooner or later, you will blow it up...that was what I was trying to say earlier. I run Nitrous becasue it's cheap. You get outrun by a Nissan/Toyota/etc. and you have some huge Huffer sittin' up top, what are you gonna do??
Same thing I'm gonna do. Jet the Nitrous for kill next time. Your gonna go home and turn the boost up for next time.

[Blown68Coronet]

Hmmmm.....

http://www.youtube.com/watch?v=bRKAUlzYG_8

He blowed up real good!!LOL

[Cooter]

Hmmmm.....

http://www.youtube.com/watch?v=bRKAUlzYG_8

He blowed up real good!!LOL

As will you sooner or later if you actually run it. Built for it or not. And for every YT video you find of some idiots blowing up Imports, I can find just as many blowing up domestics. Proves nothing. You missed my point, and now you seem to want to "Defend" a supercharger's honor or something. I never said I didn't like them, I was just stating the obvious. NOBODY runs a blower for any length of time for looks at a pricetag of over $5K...Sooner or later, you WILL be called out if you have that big 'ol huffer sticking out of the hood. Same with the huge. stupidly wide, tires of the narrowed rear/"Pro-Street" cars. Round here anyway, it's a Pretty sad day, when you have a big ol huffer sticking through your hood that needs a parascope to drive, huge rear tires that belong on a top fuel car, and a little 8" wide tire Mustang, with a single turbo under the hood, puts you on the trailer.

But, Alas, If "Appearing" to be deep in the 10's 1/4 mile is your thing, go for it.

[Chryco Psycho]

Actually I tend to disagree , we built a 440 with an 8/71 , mild combo , underdriven , 6 PSI boost , the tune up was properly set , not lean or rich , adequate fuel supply , ran 10.0 @ 138 MPH for 10 seasons , no issues , the engine was torn down & checked regularly , it did exactly what we expected & was reliable , no bang !!
Yes you can increase the boost for more power but we didn't want to run in the 9s , too many rule changes & additions to the car to run there . More power = more stress then it could fail but kept within what it was designed to do it was fine .

[Ghoste]

More power = more stress then it could fail but kept within what it was designed to do it was fine .

And that is really the key to every engine build no matter what the power level.

[Cooter]

And Luck rides every now and then. Chryco, your a good dude, seem to know alot, but just like with the 440 11.0:1 on 91 octane, you posted Anything I've done, you've been there and done it better. Well, I'm a firm believer in NOTHING is "Realiable" until it is proven to me. Seen too many blow with superchargers, because THE WICK GETS TURNED UP, not becasue one guy got lucky for 10 seasons because he kept it "Civil".

I Have bombed over 550 Shot on a stock bottom end 302 5.0 liter. Do you really think I'm gonna get on a forum and tell someone it's "ok" and it'll live becasue I got away with it in perfect tune for over 5 years? Hell no. I'm trying to keep this guy from pissing away money here. But alas, your the expert. Whadda I know?

[Chryco Psycho]

I can't say why it work for some & not others , , the race engine I built at over 11 : ran fine on pump gas but I had a long duration cam & never loaded the engine at low rpm , ,I could make it detonate with full throttle at 1000 rpm but there was no reason to do that , this is not the only high compression pump gas engine I have been able to make work .Using full throttle above 2800 rpm never had an issue where the powerband started & it was built to work  . Fuels vary , we I was living was on top of massive oil reserves & no ethanol . There are variables .
In most cases people under build to save money & then the power becomes addictive & they want more , turn up the wick & yup it will go bang . If the guy spend the $$ on good parts & uses the engine as intended & for the power level intended & maintains it why would it go BANG ? You just have to build it smart & stay within the power range it is designed for .
You know lots & have seen lots , maybe this guy will throw away his $$ or maybe he will think things through & spend the $$ smart & keep it alive ther are cases supporting both scenerios

[1974dodgecharger]

I dont know hard to say im not a power junkie already had my thrill as a kid and was happy with it, its more of a been there done that deal and I dont need to who off in the streets anymore.

thanks cooter for the concern, but seriously if you ever met me you would understand that I would never put power down on the road.  I would run it conservative and underdrive the hell out of the blower and YES people may laugh at me and they already have, but I dont care.

[Cooter]

thanks cooter for the concern, but seriously if you ever met me you would understand that I would never put power down on the road.  I would run it conservative and underdrive the hell out of the blower and YES people may laugh at me and they already have, but I dont care.

So, I'm kinda confused here...You stated in another thread that you had no idea that Cylinder heads (Indy) were so "Expensive"?
Yet, you are willing to pay over $6K(By the time you buy EVERYTHING to make it work) for a blower set up......For looks....Dang, you coulda made some SERIOUS power for a set of $6K Indy heads. Of course, HP made underneath the hood loses out to something poking through the hood I guess.

[Blown68Coronet]

Hmmmm.....

http://www.youtube.com/watch?v=bRKAUlzYG_8

He blowed up real good!!LOL

As will you sooner or later if you actually run it. Built for it or not. And for every YT video you find of some idiots blowing up Imports, I can find just as many blowing up domestics. Proves nothing. You missed my point, and now you seem to want to "Defend" a supercharger's honor or something. I never said I didn't like them, I was just stating the obvious. NOBODY runs a blower for any length of time for looks at a pricetag of over $5K...Sooner or later, you WILL be called out if you have that big 'ol huffer sticking out of the hood. Same with the huge. stupidly wide, tires of the narrowed rear/"Pro-Street" cars. Round here anyway, it's a Pretty sad day, when you have a big ol huffer sticking through your hood that needs a parascope to drive, huge rear tires that belong on a top fuel car, and a little 8" wide tire Mustang, with a single turbo under the hood, puts you on the trailer.

But, Alas, If "Appearing" to be deep in the 10's 1/4 mile is your thing, go for it.

Well Cooter you OBVIOUSLY don't know me......
I didn't build my car just for looks at car shows & cruise nights, i,ve been to a drag strip or two.My build has been somewhat like Chryco's, been running a Roots since 2000, Now switched over to an F2 with meth injection, i do my homework and  research the shit out of what i do prior to doing it. Like Chryco said as long as you don't set it on kill and have good parts it can be "reliable". And i don't go around "appearing to be", It's a reality.

[1974dodgecharger]

thanks cooter for the concern, but seriously if you ever met me you would understand that I would never put power down on the road.  I would run it conservative and underdrive the hell out of the blower and YES people may laugh at me and they already have, but I dont care.

So, I'm kinda confused here...You stated in another thread that you had no idea that Cylinder heads (Indy) were so "Expensive"?
Yet, you are willing to pay over $6K(By the time you buy EVERYTHING to make it work) for a blower set up......For looks....Dang, you coulda made some SERIOUS power for a set of $6K Indy heads. Of course, HP made underneath the hood loses out to something poking through the hood I guess.

miss you too cooter...

[Rolling_Thunder]

back to topic - its been already said -  spin a 8-71 slower to make the same boost. This cuts down heat and heat = prone to preignition....       So I would spend the $$$ for the 8-71....     spin it to 6-8lbs of boost on a mild 440 and make power.   Turbos will get you more power but realistically if you want to look of a blown engine go for the roots.   

Im putting an 8-71 on my 440 for my 64 Polara...   why?  I want the old school racer look...    then the Charger will be a pro-touring style and the Challenger will be a nice distance driver with a small block / OD auto

[Ghoste]

Good choices. 

[Lord Warlock]

Nice try..Nobody spens $4K on a blower and just "Cruises it"......

Actually some people do spend 10k on a blower and just plan on cruising it, occasional 0-60 blasts, one or two 55-120 trials, and a very small chance at running it once at a track at a show, and that's only if i'm medically capable of attending a show, that is a big question mark at this point.  
But in my case it isn't my charger, its a modern challenger, i'll get more fun out of it than the charger getting blown.  I've already laid out 8k toward the upgrade, and expect to schedule the install soon.  Having a blower isn't going to change my current driving habits much, and the car is going to be in my daily driver car, i'll just get used to extra power.  Keep in mind I gave up a blown ford to get the challenger I drive now, haven't missed it at all.  
Wish superchargers were interchangeable with other motors, like only an intake manifold change to bolt it to the old 440, but that isn't the case, and at this point don't need two fast cars, just one fast one, and one awesomely beautiful one (charger) that should be good enough for me for the small amount of road time I expect to see.