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Discussion Starter #1
So I am battling heat with my 2.2KB on a V10.

The TS6800 kit (6.8L motor) came with a adapter plate that bolts the SC to the OEM intake. No intercooler.

The adapter plate only has a 3/4 inch tall by 4 inch wide passageway for boosted air to pass thru to get to OEM intake.

Boost pressure just under blower outlet (I tapped this spot) at WOT ts about 9-10 psi. Boost pressure after restriction about 10 inches away is 5 psi at WOT.

THEORY:
Twin screw SC's internally compress the air. Does anyone know what psi a 2.2 compresses to before the air is released into intake tract?

If I assume 16 psi for internal compression the SC is increasing temps about 160 degrees. Once air exits SC it cools due to expansion.....hence my 10 psi boost. Once adapter expands to more volume after restriction I get 5 psi.

Once boost in a motor exceeds the assumed 16 psi internal compression, the twin screw acts like a roots 2 or 3 lobe, just packing air into motor by shear volume. Adding more boost than the SC creates internally adds more heat due to compressing air inside of manifold in addition to compressing air in SC. You do not get any cooling due to air expansion inside manifold. So ideally manifold boost would match internal SC boost.

The heat caused by compressing air to 16 psi (160 degrees ish) is always being created and that air, although cooled a little due to volume of adapter, is recirculated (some of it) thru bypass valve and very warm air is again compressed to 16 psi. By my calculations for my engine about 61% of the SC air is being recirculated back into the supercharger. Maybe a cooler for bypass air would help.

Example: cruising on a 80 degree day, heat build up from engine probably has air temp at throttle body at 100 degrees. Add the 160 degree temp from SC and just before air comes out of SC it could be as low as 260 degrees. However if you add 61% of incoming air at say 200 degrees you get a intake air temp of at least 175 degrees. After compression that air is over 300 degrees.
Once it expands it cools, but I have seen 260 degrees just prior to air going into my OEM intake. It cools more in OEM intake to about 160 while cruising.

I think a bypass valve intercooler would help cruising temps ALOT!

I moved the bypass valve vacuum line to the tap I installed just under SC. WOW what a difference, boost hits faster and harder. The valve is closing 4 psi sooner. Boost gauge after restriction reads 0 ish psi when the boost gauge under supercharger reads 4 psi.

Does anyone know the internal compression psi of a KB 2.2?

Does anyone think what I have assumed above is wrong? If so can you set me straight?

Thanks
 

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Dunno about KBs, but Whipples (Lysholms) have an internal "volume ratio" of 1.35 - so about 5 psi of internal compression. I can't imagine a KB would have triple that - they're not that different. The IATs get hot at cruise not because of the internal compression of the blower (though it's not helping), but mostly because the volume of air is relatively small at cruise, and it has to absorb all the losses and inefficiencies present. An Eaton gets super hot at cruise without a bypass.

Your idea of a cooler in the bypass is an interesting one. Before I went that route, I'd put a thermocouple in the bypass and see what the temps in there are so you have some data points. I'm sure you'll see an improvement in overall IATs; but whether or not it'll be significant, I can't say.

Quite frankly, I think the easiest and most effective thing for you to do is to inject some water/meth. Two nozzles - one before the blower (which will also raise the efficiency of the blower), and one after the blower.

What are your IATs now?
 

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Discussion Starter #3
Yes, water/meth is in the works.

Ideally it would be 100 water for its cooling effect, but I live in a cold climate and need at least 30% by mass meth.
SC is in an Excursion 8000 pound 4X4 that tows 4000 pounds.

I think enlarging the manifold adapter will allow me to re-pulley the SC to a 3" instead of the current 2.75. keeping boost at about 6 or 7 psi instead of the 10 psi before restriction and 5 psi after. This should reduce some heat too.

IAT's
In 80 degree weather under full boost the IAT in #1 manifold runner is about 180 degrees. Same pull the IATs in adapter just after SC are 260.

Cool night last night and in 45 degree weather the IAT in #1 runner under full boost was 155, and did not go higher even after 4 or 5 hard pulls.

Once winter gets here when its 20 degrees outside IATs will probably dip to under 125. Cant imagine what 20 degree water meth would do to the IATs but my Eagle talon with a turbo feels like it gets a shot of nitro when I hit 12 psi boost in -10 degree weather.

Kenne Bell shows the H series SC with a PR(pressure ratio) of 2.0 or about 15 psi. The S series has s PR of 1.4 or about 6 psi. My 2.2L outlet looks more like a H series but I am guessing at this point. See this website for this data.
kennebell.net/KBWebsite/SC_pg/H%20series/layouts/H_Series.htm

I cant post websites yet so I hope you can go to above by pasting into the search bar....sorry.

My main reason for asking about the internal boost/PR is so I do not spin my unit too slow as that would allow air to bleed past rotors, or spin it too fast and have a glorified 671 roots.

It "may" be possible that KB designed the manifold adapter with a restriction for a reason.....spinning the SC at 2.5 times engine rpm to get it in a efficient range putting 10 psi boost into adapter. Than restrict the flow to only let 5 or 6 psi into motor so it is safe. I dont know just guessing.

The bypass valve issue bugs me....I cannot figure out if at cruise the air is flowing from rear of SC to bypass valve or if air is flowing from bypass valve to rear of supercharger( in vacuum state).
 

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Interesting link. According to that, an "S" series would be better for your application. If I had to guess, "H" in some way is similar to PSI's "Hi Helix" blowers. I wouldn't necessarily think of the outlet as a restriction - it's still got to be bigger than the space between the rotors.

What kind of timing do you see at 180* IATs? The direction of air flow in the bypass (in my opinion) varies under different conditions. Though many seem to disagree (we've had this discussion in an old air to air supercharger thread). After the info you've posted, I think you might be best served by finding someone with an "S" blower to trade.
 

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Discussion Starter #5
My timing sucks!

I had it professionally tuned and tunner highly recommended a water meth system.

There are a couple spots in the pull where the timing is actually negative.....like -5 degrees.

I can tune my talon but Fords have quirks That I don't know about so I had it done by someone who knows what they are doing.

Thanks for advise but I don't have a H or S series. Wish I did, I have the old TS series 2.2L SC and from what i hAve been told by KB, none of their new superchargers wI'll fit my kit.
 

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Discussion Starter #6
Sorry forgot to say the SC outlet is not the restriction. It's the adapter that the SC bolts to that is bolted to the OEM intake manifold.
 

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What does the adapter look like?
 

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Discussion Starter #8
Can't post photos yet.
But it's about 1.25 inch tall, and 18 inches long. Width varies from 8 inches where SC bolts on, to about 14 inches at rear of SC where it bolts onto OEM manifold.

Air has to flow thru a .75 inch tall by 6ish inch wide tunnel to get to OEM manifold inlet.

The adapter does widen up toward rear as does the tunnel. But the .75 inch height is constant.

As stated I get 10 ish psi just under SC, and toward rear of adapter just before OEM intake opening I get a max of 5 psi.
 

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Upload the photo to some other service and post a link here. I never attach any photos here; then only members can see it and it doesn't help as many people. Or, find a photo online and post up a link here. How much clearance do you have to the underside of the hood? It seems to me a new adapter plate is in order.
 

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Does it look anything like this:



?

If so, and you have some clearance to the hood, it looks like all you need to do is make a spacer between the two part adapter and you should see some improvement. If not, then the discharge wasn't a restriction.
 

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Here's another I found on line:



FWIW, accounting for my intercooler core, I have 6 square inches of area available in my Whipple 2.3L discharge. It's not a restriction. 4.5 inches shouldn't be cause a drop of 5 psi, IMHO, but the shape could be a contributing factor, I suppose. At what two points are you measuring boost?
 

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Discussion Starter #12
Yes that is it exactly.

I drilled and tapped a 1/8"NPT nipple in the 4"X 6" ish opening right under where the SC bolts to adapter. That is where I get 10 psi or so at WOT.

The 5 psi reading at WOT is tee'ed off of the bypass valve vacuum/boost line that feeds the fuel pressure regulator.

You can see the bypass valve bolted to adapter in 1st photo.

You can see the hole that feeds the bypass valve in second photo.

Great photos....exactly what I have.
 

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The only restriction in that system is the inlet manifold, not the outlet.
 

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The only restriction in that system is the inlet manifold, not the outlet.
Ditto, that's an awful path for air to get into the blower. If there's room under the hood, a nice project would be to upgrade to a bigger blower, say at least 2.8 for that big V10 engine. An intercooler and better plenums to/from the blower would help a ton(IAT's dropping and boost jumping).
 

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Discussion Starter #15
Sorry, maybe I am reading something wrong.

The adapter pictured is the outlet adapter. It directs boosted air to OEM intake manifold.

So I guess I'm confused. The adapter is the inlet for motor, and outlet for supercharger.

Where is the inlet restriction discussed? The adapter?
 

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You never brought up an issue or comment about the inlet to the supercharger. Your entire concern seemed to be about the outlet of the supercharger where it attaches to the intake manifold. That "adapter" outlet manifold from the supercharger is not a restriction. I was simply stating that if there is any restriction in the system, it is in the inlet to the supercharger. I think you are overthinking the system. The bypass valve needs to have a vacuum hose connected to it that attaches to the intake manifold of the engine, or at worst, the outlet manifold of the supercharger. It needs to see boost pressure. It will also see vacuum when the engine is not in boost.
 

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The part that the throttle body bolts to, that has tight turns inside it for the airflow to reach the blower. It's not under pressure, so that airflow needs to be larger in volume and with as straight a path as possible. I know it's made that way to fit the space.

Saleen414 is right in just pointing out the biggest restriction shown in the pictures. He built his own KB blower plenums, so he knows a bit about what works.
 

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I'm still a little puzzled about the two different pressure readings. OP - can you try another place to measure boost from?
 

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Discussion Starter #19
Yes I can, there is a spot where the EGR could go. My V10 did not come with a EGR so KB put a block of plate in the kit too. I can tap that.

It's in the rear part of adapter.

The bypass valve was designed to get vacuum/boost signal from the aluminum mount it's bolted to. There is a port there for it. That port sees boost and vacuum. However it's a 1" hole that that boost and vacuum has to go thru to get to port.

With dual boost/vacuum gauges one tee'ed tothe bypass valve port and one under supercharger my readings are very different.

When driving up a hill or something the boost gauge under SC will read 3 or 4 psi. The boost gauge on bypass valve pillar will read around 0 ish. Switching gauges has same outcome.

I have moved the bypass valve vacuum/boost hose to tap under supercharger and system seems much more responsive.
 

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There has been some talk that measuring boost in different parts of a manifold can cause different readings. But so far to my knowledge, no one has presented any data to confirm this can happen. I'd be interested in seeing what you read at the EGR block off. It makes sense that moving the hose to a place where boost happens sooner would make the more more responsive.
 
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