Kenne Bell vs Eaton...Boost vs Temperature Break Point??

[Grumpy]

I hope that I can get this question right the first time, so here goes...

At what Boost Pressure can the KB S/C be run, at which it will essentially duplicate the Charge Air Temperature of an Eaton M112 running 12 lbs of Boost?

This will probably be the most boost that I'll feed my '03 as I need some decent longevity out of the life of the engine.

When making your responses please assume that the stock Intercooler remains installed.

Thanks in advance
Grumpy

 

[Shadowgray03]

I never over spun my eaton so dont have any baseline numbers to go by. Once I get my tuen dialed in for 17psi though I will log AIT 1 and AIT2 and compare them to what I logged with the stock eaton and let ya know.

 

[Shadowgray03]

I found a bit more data on reported temp differences between a twin screw and roots style blower. It looks as if a twin screw will raise inlet temps by 8.6 deg f per PSI while the roots will raise it 15-16 deg f per PSI. Not taking into account the reduced parasitic loss of the KB it looks as if you can run the KB at 14psi and still have the same inlet charge as a stock eaton.

 

[Grumpy]

Shadowgray03...

That's exactly the kind of info I was hoping to get. Thanks very much for your response.

I was hoping that I would be able to run 15 - 16 lbs of boost with the KB and have charge air temperatures essentially the same as the Eaton at 8 - 9 lbs of boost.

Thanks again for your reply.

 

[NVMYPWR]

Originally posted by Grumpy
Shadowgray03...

That's exactly the kind of info I was hoping to get. Thanks very much for your response.

I was hoping that I would be able to run 15 - 16 lbs of boost with the KB and have charge air temperatures essentially the same as the Eaton at 8 - 9 lbs of boost.

Thanks again for your reply.

So "around" how much HP/TQ would that be on a stock or slightly modded 03 Cobra( CAI, catback)?

 

[toofast4u]

Originally posted by Shadowgray03
I found a bit more data on reported temp differences between a twin screw and roots style blower. It looks as if a twin screw will raise inlet temps by 8.6 deg f per PSI while the roots will raise it 15-16 deg f per PSI. Not taking into account the reduced parasitic loss of the KB it looks as if you can run the KB at 14psi and still have the same inlet charge as a stock eaton.

So using that math if the roots raises the input temperature the conservative number 15 degrees per PSI then at 12# boost it should have raised the temperature to 180 degrees above ambient. Now if you take the 180 degrees above ambient and divide it by the screws 8.6 degrees per PSI then the KB will have the same temperature increase at ~20.93 PSI.

 

[toofast4u]

Originally posted by NVMYPWR
So "around" how much HP/TQ would that be on a stock or slightly modded 03 Cobra( CAI, catback)?

With which the KB or eaton. The KB at 15 psi, CAI, and catback I would expect to make around 550-560 rwhp depending on tune.

 

[08snake]

Someone on here dyno'd a KB 03 Cobra with the 9lb pulley, no chip and got 456rwhp, thats about what I get with 14lbs on the Eaton....

 

[toofast4u]

I think that was shadowgray03 he is running 9# with no chip currently. He is having some problems getting a good tune for his 17# pulley.

 

[Shadowgray03]

Originally posted by toofast4u
So using that math if the roots raises the input temperature the conservative number 15 degrees per PSI then at 12# boost it should have raised the temperature to 180 degrees above ambient. Now if you take the 180 degrees above ambient and divide it by the screws 8.6 degrees per PSI then the KB will have the same temperature increase at ~20.93 PSI.

Yep, I was running 9psi on the KB for a few weeks while I tried to get a tune for 17psi and put down 456rwhp, cant remember TQ numbers but they wer low because of how lean it was at lower RPM. Car is currently sitting in garage, pullied for 17psi and im awaiting a couple tunes.

Below is just a little table showing a comparison.

 

[toofast4u]

I am running 9# now without a chip and haven't gone in boost really. I am just poking around waiting on the Predator. Shadowgray03 I only have to worry about being lean at WOT right normal driving staying out of boost should be fine right.

 

[Jerryk]

Im at 465rwhp at 14lbs on the Eaton, and I saw one KB owner report almost 565rwhp at 14 lbs... for what its worth

 

[Shadowgray03]

Originally posted by toofast4u
I am running 9# now without a chip and haven't gone in boost really. I am just poking around waiting on the Predator. Shadowgray03 I only have to worry about being lean at WOT right normal driving staying out of boost should be fine right.

Under normally driving conditions the car will try and maintain a 14:1 A/F (via feedback from O2 sensors) and can adjust fuel trims by 25% (if I remember correctly) so there is quite a bit of adjusting the car can do. Its under WOT (ie open loop) operation where it results to predefined data instead of O2 feedback and this is where running lean can be dangerous. If you stay out of boost you should be fine, but with the 9psi pulley you will likely be safe even under boost, but as always it would be a good idea to verify this on a dyno before doing it

Originally posted by Jerryk
Im at 465rwhp at 14lbs on the Eaton, and I saw one KB owner report almost 565rwhp at 14 lbs... for what its worth

Yep at 1psi over the stock eaton I have tons more power. A lot of this is due to the greater efficiency(ie reduced inlet air temps) of the KB and a lot is due to the reduced parasitic loss. 565rwhp is VERY respectable for a KB with 14psi.

 

[roushraven]

All of this brings up a question that probably can't be answered here; but I wonder why Ford chose the Eaton-Roots type rather than the apparently more efficient Lyshom-Screw?

 

[Shadowgray03]

Originally posted by roushraven
All of this brings up a question that probably can't be answered here; but I wonder why Ford chose the Eaton-Roots type rather than the apparently more efficient Lyshom-Screw?

I would guess due partially to price and partially to longevity that the eaton has proven over the years. The new ford GT will be using a twin screw so there must have been some issues with it in the past.