Kenne Bell or Centrifugal?

[FastDriver]

I couldn't agree more. I just don't understand why "drivability" is the point of contention with regard to low-end power.... that just is not drivability. Drivability is affected by things like a lopey cam, or a poor tune, or a cooling system that is not up to par, or a car without power steering. These are things that actually affect your ability to drive the car on the street. The fact that a car makes more power anywhere in the RPM band does not make it more driveable than a honda accord.

We got into the "drivability" argument a while back when Brian was saying turbos have poor drivability by comparison to blowers. In that case, I think he's actually got that one bassackwards.

Chris

 

[1991notchbackLX]

I'm not sure where drivability came into the equation either. Where in the power band a car makes power doesnt have much to do with the drivability. Defined as the "street manners" of a particular vehicle, drivability is a function of the valvetrain (camshaft) in my eyes, as long as all other vital systems are up to par. As far as drivability is concerned, my roots blown 4V drove like a completely mild-mannered stock GT when out of boost.

 

[N8Dogg98]

No reason to compare pushrods to ohc engines in this case, bottom line the 4.6 has room for an intercooler and the pushrod doesn't.

Exactly, my point was that with a 4.6 car you almost NEED to have a PD blower because the low-mid range power just isn't there. The 4.6 cars come on strong from 3000-4000 RPM's, and with a centri it's difficult to pass people or do well in a stoplight drag race d/t the lack of torque in the bottom half of the tach, unless you downshift and let her rip to redline.

On the other hand, the 5.0 pushrod engine doesn't need as much help in the low-mid RPM's because it already provides a reasonable amount of torque anyways. I also was unaware that the 5.0 KB kits didn't have intercoolers, and that would really be irritating. Will (Sneaky98) has a non-intercooled FRPP SVO blower on his '98 and he said that damn thing gets heat soaked like a mother. The general concensus is that for a street car a PD blower is best suited for a 4.6 car while a centri is best suited for a 5.0.

 

[bentley429isBAC]

KB Is junk on a pushrod motor. There is no fight with this, I believe there is 1 KB pushrod car that just touches 9's. They are junk. A damn novi 1000 will go 9's. On a mod motor, turbo or PD is the way to go.

My car has no problem playing "stay between the lines" rolling into it at 60 with 28x10 slicks, and imagine that there is a centrifugal under the hood.

 

[wythors]

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[Boosted92LX]

 

[strtrcr50]

Question for the PD guys. Are you running around on the street on slicks? Hard enough to hook up good on the streets without having a gazillion foot pounds of torque immediately off idle on drag radials IMHO.

 

[1991notchbackLX]

Question for the PD guys. Are you running around on the street on slicks? Hard enough to hook up good on the streets without having a gazillion foot pounds of torque immediately off idle on drag radials IMHO.

My car was fully set up for a straight line. It was on 335 M&H drag radials. Yes, it hooked HARD on the street. That car was the exception to the rule though.

 

[strtrcr50]

What a presumptuous statement. All of the owners in this video look like they’re having all kinds of fun.

YouTube - ‪Kenne Bell 5.0 Compilation‬‏

This seems to reinforce my question. I see that it's great for burnouts, but as far as drivability goes, wouldn't you say it's easier to deal with a centri on the streets?

 

[1991notchbackLX]

It all depends on whether or not you can drive. These cars in stock form will get sideways on someone who doesn't know how to handle them. The question is way too vague and subjective, honestly. I'm not defending either type, centri or PD, they're two different animals as far as I'm concerned, and I'd take either one.

 

[Boosted92LX]

It's interesting to hear all of the different replies, I appreciate EVERYBODY'S feed back! Thank you !! It's given me a good feel for what I think I need. The thing that gets me is I've read it stated here at least once that 450rwhp out of a screw type is all you'll ever see, but on KB's web page (see link below) It clearly states that with the gt40 intake and the flowzilla inlet it's capable of 675 rwhp. 785 if you upgrade rotors! Am I missing something? SEE LINK !!! VVV









Blowzilla Supercharger / Flowzilla Manifold

 

[2000xp8]

It's interesting to hear all of the different replies, I appreciate EVERYBODY'S feed back! Thank you !! It's given me a good feel for what I think I need. The thing that gets me is I've read it stated here at least once that 450rwhp out of a screw type is all you'll ever see, but on KB's web page (see link below) It clearly states that with the gt40 intake and the flowzilla inlet it's capable of 675 rwhp. 785 if you upgrade rotors! Am I missing something? SEE LINK !!! VVV

Blowzilla Supercharger / Flowzilla Manifold

Yea, you may get 675rwhp if you test your car on an outdoor dyno in alaska during the ice road truckers season with race gas meth injection, nitrious and any other add on you can find.

For the record, i asked the guys today at my buddies shop about the dyno runs they have done at their shop with KB's on pushrod engines, and pretty much the answer was 400rwhp was around the max they felt safe with, they said if they spun it much more than 10lbs (on hci car) it made so much heat they had to pull all the timing.


Just look at that guys post here that did that wild intercooler setup, beautiful car, great work, but it only made somewhere around 450rwhp.
Pouring your time energy and money into a KB and to come up short of what you can do with an SC trim with a pulley sucks.


Buy the vortech, use the money you save over the KB to get some good aluminum heads, so you don't have to run 20lbs of boost to make the power, thus you don't blow head gaskets.

 

[Boosted92LX]

Point made. Thanks!

 

[Gearbanger 101]

This seems to reinforce my question. I see that it's great for burnouts, but as far as drivability goes, wouldn't you say it's easier to deal with a centri on the streets?

The main difference here is that these guys are char broiling the tires because they "choose" to. Not because they have no other option.

When I made reference to the term drivability, I guess I should have said “controllability”? PD power can come on as smooth, or violently as you want it to and is 100% completely construable by how fast you press the accelerator.

I could pull away from a stop and all the way up to top speed without making any boost at all, or whack the throttle and see 10psi before the tach hit 2,500RPM. I like the idea of having grunt a lower RPM. As was mentioned before….when you’re racing, when are you ever below 4,000RPM? Good point. But on the flip side….where are you at 99% of the rest of the time you drive your car? Right in that sweet spot below all of that WOT action where the Kenne Bell shines brightest.

That's the MAJOR advantage of owning a PD blow car. The option to have complete control over your power band isn't there with ANY other power adder. Centrifugal, Turbo, Nitrous....nothing!!!

Like I said earlier…if you’re adding displacement to the engine, then all that additional low end torque isn’t going to be so necessary and the centrifugal huffer would probably be the all round better choice

….but you guys comparing the 5.0L to the 4.6L in the low end torque department talk as though that 1,000RPM lower power band the 5.0L has over the 4.6L is an astronomical difference!?! The low RPM 4.6L 2V torque levels are lacking for certain, but come on….the 5.0L puts out mediocre low end torque in stock trim at best. It’s not like there’s no room for serious improvement with both engines?

 

[Gearbanger 101]

It's interesting to hear all of the different replies, I appreciate EVERYBODY'S feed back! Thank you !! It's given me a good feel for what I think I need. The thing that gets me is I've read it stated here at least once that 450rwhp out of a screw type is all you'll ever see, but on KB's web page (see link below) It clearly states that with the gt40 intake and the flowzilla inlet it's capable of 675 rwhp. 785 if you upgrade rotors! Am I missing something?

What isn't mentioned when someone claims seeing "only" 450rwhp out of a Kenne Bell, is that torque levels are up near 550-bs ft markers at these levels.

So true...a centrifugal may make 450hp far easier than the Kenne Bell does, but their torque output at these horsepower levels isn't anywhere remotely close. Off by 100lbs/ft in many cases. That's A LOT!!!

On the other hand...don't put too much stock in the Kenne Bell horsepower capability claims. They have a habit of inflating their figures and dynoing their cars with astronomical amounts of timing and tanks full of race gas. Not to mention that 600hp+ capable rating is with a big displacement 351W based stroker....not your run of the mill 302ci V8

 

[FastDriver]

Yeah, really... You can make 450 with a premium H/C/I (AFRs or TWs) and a centri with less than 10psi on a conservative tune easy. That's not pushing anything hard except stock internals and the block, but considering the conservative as hell tune, RPM (keep it under 6k), and boost level, everything should hold together no problem. This is such a simple, cheap and easy combo that if I had everything to do over again, or if I built another fox it's how I'd go. God, you could find a nice Vortech or Procharger setup with intercooler in the classifieds for around $1k, and the H/C/I for another 1,500 or so. Add pipes, rockers, MAF, TB, injectors, Fuel pump, a tune, and other minor parts and you'd have a rockin' reliable setup for about $5k that will blow the doors off of just about any production car on the road. With that kind of power though, you're going to need to address the drivetrain. In short order you're going to need tires, a trans w/ clutch, probably a shifter, and axles at least - another $2500 or so. Things sure do add up fast, don't they? Wait, you haven't addressed the suspension or chassis, yet. I hope you have most of this stuff.... just wanted to make sure you were thinking about all of the incidentals that go along with a car that has this much power.

Chris

 

[Gearbanger 101]

Good point Chris. Anyone who thinks’ they are going to strap an S-Trim, Kenne Bell...whatever to a near stock car and go run down John Force is in for a lot of disappointment.

Count on spending at least a much money and attention to the chassis and drivetrain at you will on the blower.

 

[Boosted92LX]

Yeah, really... You can make 450 with a premium H/C/I (AFRs or TWs) and a centri with less than 10psi on a conservative tune easy. That's not pushing anything hard except stock internals and the block, but considering the conservative as hell tune, RPM (keep it under 6k), and boost level, everything should hold together no problem. This is such a simple, cheap and easy combo that if I had everything to do over again, or if I built another fox it's how I'd go. God, you could find a nice Vortech or Procharger setup with intercooler in the classifieds for around $1k, and the H/C/I for another 1,500 or so. Add pipes, rockers, MAF, TB, injectors, Fuel pump, a tune, and other minor parts and you'd have a rockin' reliable setup for about $5k that will blow the doors off of just about any production car on the road. With that kind of power though, you're going to need to address the drivetrain. In short order you're going to need tires, a trans w/ clutch, probably a shifter, and axles at least - another $2500 or so. Things sure do add up fast, don't they? Wait, you haven't addressed the suspension or chassis, yet. I hope you have most of this stuff.... just wanted to make sure you were thinking about all of the incidentals that go along with a car that has this much power.

Chris

Yeah... The sad little T-5 is coming out and giving way to a tko 600 first. After that, then we'll worry about a blower. I've killed waay to many T-5's to go down that road again. Probably won't worry so much about axles, because this car will likely never see slicks. I've had 400 ish hp n/a windsor engines before and the only axle problems I had was when the slicks went on.... btw, I've got a billet flywheel, 26 spline spec clutch, bellhousing, etc, etc already. I just need the trans.

Then....

Yes, fuel system, and blower. H/C/I later.

Soon. It's coming.

 

[FastDriver]

You're all over it then, Allen!

 

[Sharad]

random thoughts:

"KenneBellCobra" from Cincinnati is the guy that had the pushrod/KB record. (I think it's still the record, but he parted out the car) I'm sure if you google or youtube him, you'll see video of him running mid nines. IIRC, it was a stroker with lots of boost and tons of meth. HUGE wheels up launches.

My dad's KB '93 GT makes ~400rwhp and his GT500 makes ~500rwhp. Both of them sit on [wide] radials and spin the tires EASILY on tip-in throttle (maybe 20% throttle) just changing lanes in traffic. It's a little too touchy if you ask me.

I really like a ProCharged car (pushrod or modular) because of their dr jekyll mr hyde personality. At part throttle/low rpms, they're just like driving a stocker around. (no twitchy throttle), but in the boost they're animals.

Regarding boost on a centrifugal, you don't have to rape the car to make boost. I mean seriously, who races at 3000rpms? If you pay close attention, when you wind out first gear, your rpms only drop 1500-2000 rpms when you shift to 2nd, 3rd, 4th. So basically, if you're in boost when you nail it in first, you're never OUT of boost with a centrifugal.

Regarding Intake Air Temperatures, my dad and I used to call each other when we drove our cars (he lived 250miles away at the time) and his KB '93 GT's IATs were consistently 100° hotter than the IATs on my ProCharger car.

Regarding the performance of a centrifugal on a fox, I ran 11.36 @ 122 on a stock 302, which is around 400rwhp. Tim Stockwell went 10.80 @ 129 on a stock 302 with an S-trim (and a truckload of meth). So you can make plenty of power even with a stock 302 and a centrifugal. In fact, as I mentioned earlier, I went 10.17 @ 132 on a stock block 306 with just heads and intake (stock cam) and a non-intercooled ProCharger. I mean, those are BASIC mods anymore...

YES, I'm biased.