Would the KB be a waste if 91 octane is all I want to run, or do you guys know of an advantage the KB gives over the stock besides being able to boost more? In other words, if I run 14psi w/ the eaton, what advantage is 14psi w/ the kenne bell. It seems that I'll already be pushing the limits of 91 octane on the eaton? Would anyone like to convince me to change???
kenne bell worth getting if solely on 91 octane?
- Thread starter doubleblack
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i bet much less boost drop off. also the KB runs much cooler and therefore maakes more hp at the same boost.
I wont try to convince you to change, but there are characteristics of the twin-screw that are better than the stock eaton. Things like a lower outlet temperature and requiring less power to drive than the eaton at the same rpm because it's supposed to be more effecient.
does the eaton on 14psi have boost drop off issues?
QUOTE]Originally posted by Lomancobra
more hp at the same boost. [/QUOTE]
Please correct me if I'm wrong saying that supporting that additional HP at the same boost level still sounds like fueling plays a major part.
Let's say 14psi w/ the eaton making 450ish is barely being safe w/ 91 octane...
Then let's say 14psi w/ the KB will make 470ish...
That extra 20hp still needs to be supported w/ the proper fueling and since I was barely safe w/ 450hp I would be in the danger zone trying to support the 470hp at 14psi. It seems in order to be safe w/ the KB, I would have to drop my boost a few psi to get it back to 450hp (the safe 91oct HP). Is my thinking totally wrong here?
please enlighten me...just trying to decide if the KB should or shouldn't be part of the long term planning w/ my cali gas...
PSI is just pressure, whats really important is volume. The KB is a bigger blower (more displacement), that combined with it's efficiency means it will move a lot more air. You will get more air into the engine, and more HP even at LESS boost. Take it to the extreme, this is hypothetical, but you could have 20 PSI (on your gauge) and in the intake manifold, even if there was ZERO air flow, (assuming all intake valves were closed, work with me, it's just an example) or say your garden hose faucet is on , 60 psi, but the nozzle is off, so there is no flow, You need airflow, not just high pressure. The point is that all the PSI in the world means nothing without flow. Ever aired up a tire on a 10 speed bike? You can put in 50-60 PSI almost instantly, then ever aired up one on an older ATV with balloon tires? Takes 5 mintues just to get it up to 5 PSI, which tire really has "more" air in it? Not the one with the high pressure.
He's also confusing octane requirements and pre-inginition/detonation with air/fuel ratios and running lean.
If you can run 14 PSI on 91 with an Eaton, the same 14 PSI on a KB just requires more fuel to make more HP since there is more air.
The octane requirement would actually be lower since the KB is not heating up the charge as much at 14 PSI.
HP and rich/lean is not the same as boost and octane.
If you can run 14 PSI on 91 with an Eaton, the same 14 PSI on a KB just requires more fuel to make more HP since there is more air.
The octane requirement would actually be lower since the KB is not heating up the charge as much at 14 PSI.
HP and rich/lean is not the same as boost and octane.
Another good point.
From a fueling standpoint, there are two ways to combat detonation as we all know:
1. Richen the tune
2. Raise the octane
I am confident that high boost levels can be tuned by adding more fuel regardless of the octane. But there is a point where too low an octane rating at high boost needs to be accompanied w/ a super rich tune to combat the detonation. At that point, I maybe losing HP w/ the KB w/ too rich a tune to combat detonation and start to equal the output that an eaton can give at a lower boost levels.
1. Richen the tune
2. Raise the octane
I am confident that high boost levels can be tuned by adding more fuel regardless of the octane. But there is a point where too low an octane rating at high boost needs to be accompanied w/ a super rich tune to combat the detonation. At that point, I maybe losing HP w/ the KB w/ too rich a tune to combat detonation and start to equal the output that an eaton can give at a lower boost levels.
You think?? Is there THAT much difference between 91 and 93 octane? I guess the tuners would know.
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is the KB worth it... yep
I think another thing to look at here is the fact that the k/b at x amount of boost is also going to make more hp throughout the curve and not just on top which is nice to know as well.
:thumbsup:
:thumbsup:
Yeah, you guys are all correct, the KB is more efficient...I didn't realize how efficient...I posted on Modularfords and Nitrous Pete was saying 80hp more at the same boost levels of the eaton...and said 91 oct is fine...
holy cow! I didn't know it was that good a number...
holy cow! I didn't know it was that good a number...
k/b...got balls??
:beer:
:beer:
You are right, a super rich tune can prevent the detonation even with crappy gas.
Can somebody post a link on the K/B Supercharger? What is the price for it? Any help is appriciated!
Thank You
Thank You
Up to a point. An A/F ratio that rich can and will wash oil off the cylinder walls, and cause lots of carbon buildup, not good for the long term health of your motor.
If you tune for a sane (between 11:1 ~ 11.8:1) A/F ratio it is certainly possible for detonation to occur at peak torque when cylinder pressures are highest even with a cool intake charge from an efficient compressor. There is only so much that 91 octane will allow before the gas itself is the limit, no matter what else you do.
I didn't say it was good for longevity, I was just agreeing it can prevent detonation, even with low octane.
That's a very good point, which goes hand-in-hand w/ my original post. But, for my purposes, it doesn't seem I'll be pushing the limits of 91 oct w/ what I want to use the KB for. Right now 14psi sounds like a good number, although 16psi may be possible but w/ issues...
Lagtime, because I've always had a love for supra's, what's the highest HP you've seen on a 91oct supra whether double or single?
I heard a while back that some lightning's blew up a couple Kenne Bell blowers. One of the after market co.'s did it. (JLP?) I don't have the pictures any more, but how is the reliability on the kenne bell's? From what I heard they just gave out under normal use. Don't hold me to this, but I read something about it somewhere...
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