TemjinX2

Hey guys,

I know there's been a lot of recent discussion about spending a small fortunate to try to eek out the last amount of power from the c32.

So instead of spending $1-2k on a upgraded intercooler system. I think it might be cheaper just to upgrade the supercharger with a larger displacement lower boost supercharger.

I mentioned kenne bell because there local to me and there a twin screw supercharger as well but its a autorotor vs lysholm sc. Looking at the comparisons, doesn't there's any real difference in performance between them.

They state the lysholm is more suited for oem applications vs autorotor which is better for racing apps.

But anyways, I was looking at the price listing for just the supercharger only for kenne bell.

On the pricing list, it saids the 2.6L sc is around $2k and the 3.6L SC is $3k. The pricing for the sc only is on page 5.

Please correct me if i'm reading it wrong.

http://www.kennebell.net/KBWebsite/P.../PriceList.pdf

I'm thinking we can just swap out the sc and just modify it to use the oem intercooler and intake manifolds.

Since our stock sc is a 1.6L, upgrading to a 2.6L should yield significant gains.

TemjinX2

I'm wondering if the ecu will throw a code if the sc clutch cabled isn't connected? Maybe we would have to wire the cable with another 12v source to fool the ecu into thinking the clutch is engaged.

TemjinX2

looking at some pics of some of the kenne bell sc's, it looks like making the stock intercooler fit on the sc would be easy. I think the challenge would be getting the stock sc adapter plate to connect to the kenne bell sc.

http://www.kennebell.net/techinfo/fo...RvsLYSHOLM.pdf

loudandheard

Making an adapter would be easy. Does increasing the size of the supercharger increase the boost? Our map sensor might not handle the increased boost.

As for the clutch, I remember the turbo srt6 guy was able to rig some thing to fool the system that it was still in use.

Did you try asking Kenne Bell if the increase in the supercharger size will increase performance. There should be an equation to show our potential gain.

I still think sourcing a 3.7 m112 would be the way to go.

jturkel

absolutely. this is why i was initially having trouble with making the supercharger on/off switch. gotta fool it to think it's still on or else it'll read errors and you'll experience some "fun" symptoms when your car figures it out.

increasing the size of the supercharger does not necessarily increase the boost. by increasing the size or displacement, it has a higher flow and therefore can provide power more efficiently without having as much heat output (b.c again, it is more efficient).




definitely interested. however, remember we will likely need to upgrade injectors and either upgrade or add another fuel pump as well.

TemjinX2

larger displacement sc will produce more power with less boost. for example with a larger displacement sc we might only need to run 10psi to equal the same amount of power as a our sc at 22psi.


the problem with the 3.7L block is sourcing the block and then you get raped on labor. I think the book time for swapping out the block and head is around 32hrs.

TemjinX2

upgrading injectors and fuel pump is the easy part. I already have walbro pump in my car.

I think the next step would be to cut off the intake runners off the stock sc and probably weld it to the engine.

I'm not worried about wiring the clutch, i just need to figure out if its a 5v source or 12v.

c32AMG-DTM

Help me understand that a moment...

Positive boost pressure is the amount of additional airflow being crammed into the cylinders. If you run 14.7 psi (1 BAR) of boost, you've doubled airflow over what the engine would've consumed N/A. You don't make double the power, because of parasitic losses due to heat generation and, for an S/C app, the power required to drive the S/C.

A larger S/C, by itself, won't gain the efficiency you claim, unless I'm missing something. Even if you kept the measured boost pressure equal (22 psi vs 22 psi), the engine would likely be making nearly equal power... depending of course on the efficiencies of the different compressor maps. The larger S/C would have more inertia (more mass), but would require lower rpms to generate the same boost. But if you slap the larger S/C on the car to only run the system at 10 psi, I would think you'd be rather disappointed in the result.

The benefit of a larger S/C, as I see it, is giving more headroom for additional power/torque, as you go past 20+ psi of boost. Who knows, with the right fueling upgrades and proper tuning, these motors might withstand 2 BAR before internals become the weak link. There's no point in pushing the stock S/C that far, because it's well outside of its operating range at that point.

c32AMG-DTM

Now a built 3.7L M112 with a slightly higher CR than the C32 (with the oem S/C), or a low CR (with a bigger aftermarket S/C) would be something. Probably too expensive to be worthwhile - but a cool concept to be sure.

c32kompressor

How would a kenne bell fit in our cars? Aren't they mainly for mustang v8s?

jturkel

a kennebell is for whatever you want. there is no specific application for using them per se, though they are frequently used on domestics like mustangs, camaros, vettes, etc

Lenin

I've see a few Ford Lightning street legal tracks with Kenne Bell SC at Atco that consistently ran 1/4 mile in 10.5 secs. Just amazing.

loudandheard

You can get a 3.7l m112 short block for around $1500-$2000. As for the work, I would think I could handle most of it myself. Essentially you would switch over most of the m112k components on to the 3.7l m112 engine and use the m113 pistons and rods. I think the job could be done for about 5k including the cost of the engine, pistons, and rods.

splinter

c32AMG-DTM’s understanding is indeed correct from my perspective.

Save for potentially improved adiabatic efficiency and/or decreased parasitic losses from fitting an aftermarket supercharger, artificial volume -and its commensurate pressure- in the intake tract is the essence of forced induction, yes? The backside of my intake valves regularly see 18+ PSI above ambient (measured from the surge tank, not the MAP sensor.)

No doubt Jim Bell is a sharp tuner and astute businessman. Previously utilized many of his hardware and software innovations on my 12-second daily driver GN Buick. No jokes from the young bucks, as that was reasonably quick ride in the '80s. As Lenin mentioned, I’ve also witnessed KenneBell-supercharged machines running remarkably fast at the local ‘strip.

Far be from me to dissuade you from modifying your AMG as you see fit, TemjinX2. Still anticipate you’ll soon catch up for good times at Willow Springs. Sliding through turn 8 at 110 is infinitely more invigorating than doing same along most any straightaway.

All due respect, I simply can’t justify pissing away any more discretionary funds hot rodding a $10,000 C.

TemjinX2

Larger displacement SC can move more air per revolution.

If we keep it simple we know the formula for pressure is. P = (nRT)/(V).

We know Pressure is the result of the quotient of volume. Assuming the gas constant and temperature is the same for both superchargers, we are actually lowering the pressure with the larger displacment supercharger because we are increasing the volume of air it can suck in.

Since we increased the volume, we would need more molecules of air to equal the same 14psi compared to a smaller volume supercharger.

So 22psi on a 2.6L SC is actually more air then 22psi on a 1.6L sc.

I just picked the 10psi vs 22psi as arbitrary numbers to explain the concept of making more power with less boost with a higher displacement sc.

You see this on turbos as well. For example on a 2.0L rsx engine, when people turbo it with a garrett gt28 at 6psi they get around 260-280whp but then if they take that same engine and use a garrett gt30 at 6psi they get around 300whp.

The gt30 yields more power then the gt28 because its a larger turbo and can move more air at 6psi then a gt28.

Basically what i'm suggesting is just upgrading to a larger turbo.





We know based on the EC turbo of the srt6 that the stock block can take up to 440whp on a dyno dyanmics.


Measuring the power limits of the engine by bars of boost isn't accuarate because 2BAR on a turbo and 2BAR on a supercharger would yield different hp or even 2BAR on different size superchargers would still yield different amounts of HP.

TemjinX2

Unfortunately i don't have your engine building skills and i don't really feel comfortable building my own block. I just suggested this because this is more of a bolt on affair.

But since i do have a extra block, I might got this route as well. But right now i'm throwing out ideas.

TemjinX2

here's a comparison of the lysholm design and autorotor. They look very similar to the stock c32 sc. Thats why I think it would be easy for kenne bell to adapt there sc to work with the stock adapter plate so we can reuse the oem throttle body and intercooler.



Uploaded with ImageShack.us

FrankW

MB book time is wack.

if you are doing the block and head you probably will want to pull the front off and pull the engine out to do it anyway. there's no way it takes 32hrs if you have all the parts ready to go.

you would need the 112.e37 block and heads. 113.e54 pistons and whatever else you would need and a lot of tuning.

and without making the displacement larger I don't see a need for a larger supercharger.

c32AMG-DTM

You haven't increased the volume or flow efficiency of the cylinder heads, which is where you're registering boost pressure. You've just changed twin-screw compressors which might have different efficiency maps and optimal operating ranges. I feel my prior comment that, pound-for-pound (no pun intended), the compressors would likely provide similar hp/tq figures - it's just that the larger compressor would give the owner and tuner more headroom.

Going from S/C to turbo (like EC did with the SRT-6) is a whole 'nother ballgame - you eliminate the parasitic losses of driving the S/C off of the engine (at the expense of lag). So that alone probably frees up 60+ bhp in our application.

I wasn't commenting on the power [output] limits of the engine, I was commenting on the mechanical limits of the engine. I was merely elaborating that I know of no modded (but properly tuned and fueled) M112K bending rods or holing pistons... my hypothesis is that the stock S/C is the weak link long before the stock internals. So, what boost (and/or max torque) will the internals withstand, before they need to be upgraded?

TemjinX2

it is, but thats what pshek's shop charged me. I wouldn't do it that way exactly. Since i have my extra c32 block, i would probably just bore the stock block and keep the stock stroke with custom forged pistons and rods.

So if i went that route, it would be closer to a 3.4L-3.5.

Guran

Why not use a Turbo. The stock S/C is using 60 hp to get 349 hp.
If you have 500 hp in your car the S/C is taking 100 hp off.
Thats mean that you have 600 hp if you unplug the S/C. And
let a Turbo charge the car.
Correct me if i am wrong.

/Guran

TemjinX2

I think your confusing psi with cfm. Psi is a measure of pressure or pound force unit of per square inch. CFM is a cubic unit of air per min per square foot. Larger sc will move larger amounts of CFM even with the parasitic lost.

More air into the engine with more fuel with upgraded injectors and fuel pump should create more hp.

I doubt the cylinder heads have been maxed. Considering a i4 2.0L evo can do 1000whp, a stock rsx head can flow 500whp, so i'm sure our 3.2L v6 with two heads can still probably flow 500whp.

we already know the stock head can flow at least 440whp on a dyno dynamics. That already shows there still a good amount of room from the stock head.

Unless you know the cfm numbers of the stock heads?

The power limits of a engine is more of a accurate way of stating the limits of a engine since all the engine components are used to produce that power.

But I think we both agree the stock sc is the greatest weakness of the stock engine.


But to summarize, your stating that a larger supercharger wouldn't help because the greater parasitic lost would negate any hp gains?

TemjinX2

I created this thread to discuss upgrading the sc because it would be a easier and quicker installation and we would be able reuse most of the oem hardware.

There's already a turbo thread on here and on the srt6 forums. Just look at the srt6 turbo thread, the turbo conversion required a lot of fabrication.

The limited space of our engine and the V6 lay out makes it difficult to install a turbo without custom fabricated exhaust manifolds, unless you go with a rear mount turbo.

Guran

My thoughts was a rear mount turbo. 0.3 bar or unplug the S/C and go for a
big one. Thats my next step.Rear mounted.
Sorry to bother you. Just an idé.
/Guran

TemjinX2

all good man. I welcome everyone's input. I wanted to discuss the viability to a project like this. But if you do go with the rear mount turbo, keep us updated..