S-Trim vrs KB boost comparison

final5-0

Mustang Master
Apr 6, 2003
6,817
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DFW Texas
I've been meaning to do this for some time now :D

We have seen a recent thread from 95cobraguy where he gave us his dyno
results in numerical values.

He not only provided rwhp and rwtq
but
He also included boost values as well

Since I had that data at my disposal :)

I thought it might be kinda cool if we used it to show a graphical
representation of how a Vortech and a Kenne Bell blower builds
boost in an easy to view side by side display.

We see all the time in threads the generic info of .............
Well ... a Vortech builds boost high
and
The KB comes on down low

Here is a visual way to see it ;)

Now ... you gotta understand ... I searched and searched :crazy:
For some boost info on a 5.0 based KB combo
but
None could be found :bang:

True ... using a 331 & Mod Motor for a comparison is not apples to apples :(
but
To get the point across ... IMHO ... it ain't all that far fetched :nono:

btw ... I got the info on the Mod Motored KB1700 combo here :)

http://www.alternativeauto.com/prodserv/kennebell.html

Anyway ... Here is what I came up with :D

Grady

strimvrskb.jpg
 
But isn't that only cofirming what KB has always maintained. Their units (twin screw) superchargers produce full boost from about 2200 rpm depending on the unit whereas a centrifugal delivers increasing boost only as rpm increases. Seems to me that one can have more fun on a daily basis in the 2000 to 4000 rpm range than in the 5000+ range.
 
As you stated Grady...it really isn't even close to apples to apples. This especially due to the fact that the S-trim seems to be running far lower boost than the KB car. Nonetheless, it's obvious that even with identical max boost levels there is a huge discrepancy in the rate at which boost builds up. You sure convinced me to do a KB over a centrifugal if I ever went to a blower (For my street car that is).
- Justin
 
But isn't that only cofirming what KB has always maintained. Their units (twin screw) superchargers produce full boost from about 2200 rpm depending on the unit whereas a centrifugal delivers increasing boost only as rpm increases. Seems to me that one can have more fun on a daily basis in the 2000 to 4000 rpm range than in the 5000+ range.

I posted this stuff not to say or get the board saying
which is better
this one is good
that one is bad

:nono: :nono:

Each blower has its application IMHO :nice:

The chart just shows each blowers boost curve with relation to rpm :shrug:
thus
Peeps can plainly see KB and Centri blowers do it very differently :D

Grady
 
As you stated Grady...it really isn't even close to apples to apples. This especially due to the fact that the S-trim seems to be running far lower boost than the KB car. Nonetheless, it's obvious that even with identical max boost levels there is a huge discrepancy in the rate at which boost builds up. You sure convinced me to do a KB over a centrifugal if I ever went to a blower (For my street car that is).
- Justin

Even though I could not find a 5.0 h/c/i KB combo .....

I do feel the general principle of how each blower builds boost is shown here :D

The main focus I wanted to show is :)

one is about low end rpm
and
the other high end rpm

IMHO ... The amount of boost is not all that important here :shrug:

Its just data presented in a different way ... thats all ;)

Grady
 
Another thing to think about not mentioned on that chart is the parasitic power losses of each as rpm increased. That is how much power each blower eats up to run at a given rpm.

It would be cool to see an identical combo with only the blower as the difference so we could see the boost build and also see the power curve on both cars. Because just looking at the boost isnt the whole story, when you factor in heat and parasitic losses the KB may not look as good as it does on this chart.

I know your trying Grady....:D
 
You say the KB may not look all that good

That is all about perspective IMHO :)

If you look at how the KB builds boost

You could say the KB won't build anymore boost past mid rpm range :(

So ... in that case ... the KB would not look so good
if
That kind of application is important to you :shrug:

Each is different

Different does not have to be bad ;)

Grady
 
You say the KB may not look all that good

That is all about perspective IMHO :)

If you look at how the KB builds boost

You could say the KB won't build anymore boost past mid rpm range :(

So ... in that case ... the KB would not look so good
if
That kind of application is important to you :shrug:

Each is different

Different does not have to be bad ;)

Grady

I see what ur sayin, but who needs the kb to biuld more boost past midrange if at 3200 rpms it's already got more boost than the centri does at 6000 rpms.