kenne bells "dead" technology?

[bascosauce]

i've just been wondering for a couple weeks if a kenne bell unit is a waste of forced induction. now personally i think twin screws are incredible, that down low instant boost is CRAZY, it just seems like the KB pushrod 302s dont make as much power as other forms of forced induction. I rarely see anyone running a KB onna 5.0 anymore, speaking on terms of viewing the forums. (i will say tho that whoever is running that 347KB, major kudos bro) Im not bashing KB, or saying no one should get them, im just wondering everyones thoughts. I mean i've read they run hot and everything, and with all the power to be had in turbo's and even centrifigals (cant spell that one lol). i know they perform great power on the newer mod motors.


again, just wondering if im missing something, which i VERY well could be. thoughts, comments, anything appreciated. just intrested.

 

[Daggar]

I run a stroked a KB setup. I like it, I like it allot. If I had to do it over again though, I'd probably go turbo.... Here's why:

When I got the KB I run running a stock motor. Hands down, I still think it's the best blower for a stock block street car. I mean... 400-450 HP ontop of making 400-480 ft lbs of torque from just off idle is a damned lot of fun! The reason I'd go turbo is that NOW I'm running a Dart blocked stroker. The motor is capable of a lot more than the blower is. I'd likely have a different opinion if there were an intercooler for the KB and 5oh. Without it, it's allot more difficult to generate what the mod motors are generating with the KB.

Were I driving a modular on the street though??? Intercooled KB, all day long.

I'm sure that there are turbo guys that would disagree but from what I've seen, the KB is fire and forget. ONce it's installed and tuned, you're done. No B.S. just power. The majority of folks I know with turbos... Seems like they're always haveing to mess with SOMETHING.

Centrifugals just don't impress me a whole lot. Perhaps if I spent a butt load of time at the track, I'd be more inclined to run a centri. As far as I'm concerned, for daily driving, centris offer nice dyno peak numbers and bragging rights (relative to turbos or positive displacement superchargers).

 

[BLOWN 5.0 FOX]

347 KB what?? !! I will chime in, but will only have half of the story. I started off with a powerdyne...hated it.....went to a vortech...liked it......moved on to a 347 with kenne bell/meth injection.......hoping to LOVE it. Im still in the assembly process (of car not engine) I will find out how much there is to love this spring once its tuned .............. To be continued..........

 

[Rdrcr]

Agreed Draggar!

I will be installing a KB next summer. I've owned every type of forced induction on a variety of cars, the twin-screw/roots work the best on the street........basically they are more fun. If I was building a race car, I would install a turbo.

Mike

 

[ga94gt]

347 KB what?? !! I will chime in, but will only have half of the story. I started off with a powerdyne...hated it.....went to a vortech...liked it......moved on to a 347 with kenne bell/meth injection.......hoping to LOVE it. Im still in the assembly process (of car not engine) I will find out how much there is to love this spring once its tuned .............. To be continued..........

Man that thing is sweet man!! Talk about torque!!!

The lowend tq is why I want the KB. like Daggar said they are the way to go for a street car. I am hoping to get one when i am done with my motor.

 

[leroy93lx]

I have a question for the guys currently running KB'S, do you run blower cams with them or what? I always wondered what to do with that set up. And would a AFM natural aspiration Powerpipe be the air intake of choice? Just curious, our local speedshop has a used flowzilla sitting up there that i could get pretty reasonable.

 

[Flavadave4]

I would love to pick up a Kenne Bell, the fact that you make instant torque is enough to sell me. I know all the hardcore turbo guys will tell me to get the right size turbo and there will be no lag, and I agree but you cannot deny the neck snapping low end from a KB car. Seeing how 95% of my driving is on the street it just seems like a great setup to tool around or drive hard light to light. A few friends have turbo cars and it seems like they are always tinnkering with stuff, i think the KB blower would be more install/tune and go. Just my thoughts....

 

[FastDriver]

That's cool and all... I'm with the "turbo guys" earlier posters are referring to. With an incon twin turbo kit, I had instant torque at any RPM above 2500, where I'd see full boost (9.5 psi). Car made 420rwhp, but almost 500 rwtq. The stock cam and small turbos limited the top end power. Turbos are more complex and difficult to install. Once they're in, there's nothing that compares. More torque and more top-end. Want the instant low-end? Choose smaller turbos. What insane top-end? Choose bigger turbos.

Do you have to tinker with them? Nope - ran mine for 10,000 miles without touching them or anything related to the engine. Then I did touch them, cranked 'em to 12 psi of boost and bent a rod - stupid me for not correctly tuning them, which is what I get for not taking my own advice. Anyway, twin-screws are damned efficient, but I haven't seen anything to indicate that they are more efficient than turbos.

Anyway, I'm sure you will like whatever you choose, but if you choose turbos you'll like 'em more

Chris

 

[bascosauce]

its people like "fastdriver" that i was reffering to. with the correct size turbo there shouldnt be too much lag and boy do they crank out power lol.

like i said in my earlier post, im just intrested to see wat everyone will say. im not bashing one or the other, it just seems like i dont hear too much about twin screwed foxes now-a-days, but turbo'd monsters. maybe its just because of their top-end abilities.

please continue posting everyone, i've enjoyed reading all the posts!

 

[bluevenom867]

One reason perhapse is the KB (refering to the 2.3L) is actualy a fairly small blower for a positive displacment supercharger.

For you turbo/centri. guys,that means the KB displace 2.3L per revolution,or 140ci. The 302 is a 90* fire four stroke engine,so only four psitons are actualy drawing in (or in this case being pressurized) at any time,witch means your engine only needs 151ci of air to actualy make a 100% VE. So,putting the KB on and driving it at the same speed as the engine,you would actualy LOSE power over a good flowing n/a set-up (at 100% VE,race engines can achieve VE as high as 130% n/a).So,in order to make an power you have to overdrive the unit (turn the blower faster than the engine RPM). The more overdrive,the more air is forced into the manifold (thats a big differance between Roots/screw blowers and turbo/centri. superchargers. The air is NOT compressed in the blower,rather compressed in the manifold.) and the more psi or "boost" is created.

So now,lets say you where to overdrive your 2.3L KB 200%,now when your engine sees 2500rpm,your blower is turing 5000rpm,and is displacing 280ci of air. Your 302 only needs 151ci of air to make its 100% VE at anyone time,so your a giving it roughly 80% more air displacment. By that,you'd be seeing about 12.5-13psi of boost and your 302 would be acting like a 540 big block operating just under 100% VE (assuming some parasitc lose and heat from compressing the air).

Old school Roots blowers,notably the 6-71, displace roughly 420ci of air per revolution and thats at engine rpm,no overdrive.So doing the math,you could see with zero overdrive,the 6-71 would put out around 26psi of boost (theorecticly of course,with perfect clearances and no pressure leakage),and turn at a lower rpm reducing parts wear. Yes its not as effecient,but when your putting out twice as much airflow,the small hit on effecientcy is far overtaken by pure displacment.

Oh,and also your little 302 would be thinking its almost 800ci

And just a little idea,but adding a couple fuel injectors befor the inlet would help cool down the inlet charge and also cool the rotors while adding more power! Or you can just use a little (or big? HAHA!) shot of nitrous.

 

[ninety15.0]

My buddy ran a 2 L kenne bell for a year on his SN95 GT. The car was insane on the streets. He had it pullied for 12 psi and all of that boost was available at 2100 rpm. The car was a torquey SOB...and pulled very well up to the stock redline. You could pull out into traffic in 2nd gear and just put the hammer down and boost would be there instantly and off you went! Quickly!

The car saw exceptional efficiency/load values (tweecer tuned) at low rpm and b/c of that it got excellent fuel economy. We got 28mpg cruising at 80 mph with 3.73's on a 300 mile highway trip. The car was a blast to drive.

At the track it ran low 13's at 114mph!!! severely traction limited...on brand new 285 street tires. If you arent going to go with turbo's....the KB is the only way to go for a street car.

That being said...im going turbo.

 

[5spd GT]

Another reason you do not see Kenne Bell's is the limited selection of intakes that are compatable with the set-up. Stock, Gt-40, and I have seen a modified Performer once.

I believe they put more strain on an engine as well, for a stock block combo.

When you are racing, anywhere above 4k, the "centri's" are going to win, generally speaking. I do not believe they are just for guys that love dynos.

Turbo is the best way to go from what I have seen around, and the sound is incredible.

I do like Kenne Bell's a lot though, especially on the newer stangs, whether SOHC or DOHC...

 

[2000xp8]

If there was room for an intercooler they'd be much more popular.

 

[StangCrazy302Gt]

this is good info, alot are leaning to a turbo... me i am looking into kb or a centri so info on then to would be great

 

[Notchbck93]

My understanding is that meth before the screws on a KB would eat the coating off of them. I believe that came from Rick Anderson.