Guran

Mido on this Forum, my friend, is goíng for a BIG Lysholm S/C.
The car is running
Lets Midi inform you whats happyning.
Thats a big project.
Me and my SLK32 friend has tested different way to get a SLK32/SRT6
to get me to a low 11. Now with the perfekt chassi the car is a 10.9 car.
And lower. And thats without a bigger S/C. There is is so mutch power in the
car that is unleashed.

TemjinX2

yeah i was going to ask about that on his thread. But i know he's always in a different part of the world. Fortunately for you and the srt6 guys, you guys are 300-400lbs lighter so it makes 10's and 11's a lot easier..lol.

Guran

Yes. You are totally right The weight is a problem. But if you unplug the S/C
You get at least 60 hp more. With a Turbo..
And i think a C32, with my car setup , is a 11.5 sek car.
No problem.

c32AMG-DTM

Apologies in advance for the ridiculous multiquote.

No, I'm not, but that's okay. Yes, I'm familiar with both units and what they stand for. Simply stated, CFM is flow, PSI is pressure. They are not interchangeable... but they are related.

100% Correct. That "more air" will also register as "higher boost pressure" downstream of the S/C, where it is measured. If the larger S/C is only pushing 15 PSI into the heads, it will absolutely produce less power than the smaller S/C pushing 20 PSI into the same heads.

Now, assuming equal boost levels, the larger S/C will spin at a lower rpm to generate the same "more air" as the smaller S/C - but if the "more air" is constant between the two (i.e. if you drive the larger S/C at a PSI target within the operational limits of the smaller S/C), the recorded boost pressure will be equivalent. One won't be magically more or less than the other.

No, I don't know the cfm numbers of the stock heads. Even so, saying "the stock head can flow at least 440whp" is inaccurate. The head doesn't flow "horsepower" - it merely flows air.

I'd caution trying to relate our power potential capabilities by referencing a completely different system engineered and developed by other manufacturers and modded by different tuners. Does the M112K possess similar power potential to the 2JZ-GTE? They're nearly equivalent in displacement (we have a slight edge, actually), and both are 6 cylinder configurations...

Is a CAI an "engine component"? How about the exhaust? I'd maintain that "engine component" is the stock longblock.

Depends on what you're trying to achieve. If you're looking for 320-350 rwhp, the stock pullies and tuning are the greatest weaknesses, while the OEM S/C is fine. If you're looking for over 400 rwhp out of a S/C-based system, the OEM S/C bappears to become a limitation needing to be addressed.


No, I'm not stating that; it's not that simple. The S/C should be matched to the CFM requirements anticipated by the system. If you're looking to flow beyond the OEM S/C's capabilities - sure, then the larger S/C will help. If not, it won't.

Keeping the heads and exhaust constant between the two setups, what I am stating is that running a custom larger S/C at 20 PSI boost pressure on a C32 would yield approximately the same power output as running the OEM S/C at 20 PSI of boost pressure. Because the "more air" pushed into the engine would be the same approximate quantity in both examples. Parasitic losses would depend on efficiency ranges of both compressors, but my guess is that they'd be relatively similar if both are twin-screw S/C forced-induction systems.

TemjinX2

The more air part isn't the same for both sc's. The larger sc can suck in more air in the same period of time as the smaller sc so your air volumes would be different not the same. The larger one will have to suck in more air if you want both sc's to have the same psi.

Its like if you took a 12oz soda and poked a pin size hole into the can. The soda will squirt out because of the pressure is forcing out the soda into the hole.

Now if you take that same 12oz of soda and pour it into a empty 2Liter soda bottle and poke the same size hole, the soda won't squirt out as hard as it did when it was in the 12oz can because we increased the volume of the container.

You can increase the pressure by reducing the volume and squeezing the bottle and the soda will squirt out harder from the 2Liter bottle.

You can also take a full 2liter bottle poke a pin size hole and the soda is going to come out harder then the 2liter bottle that was half full. You increased the pressure because you added more soda.

You can't relate the same psi on different size sc's because the flow rates are different.

I disagree with your explanation, but the point your bringing up is, you think the stock head basically won't flow anymore air with the larger sc into the engine and that the stock sc is already blowing the max air that the head can flow into the engine?

Are you saying the that ec turbo srt6 didn't produce more power because it was flowing more air into the head but rather recovered lost power from the stock sc?

Explanations aside, I just want to understand the points your trying to communicate.

c32AMG-DTM

There's really only one point I'm trying to communicate, which is that the bolded section above is inaccurate (IMHO). The S/C doesn't "have" the PSI. It creates the additional airflow that causes the positive boost pressure in the intake manifold. The intake manifold doesn't care if it's a massive S/C spinning relatively slowly to create 20 max PSI, or a smaller S/C spinning relatively quickly to create 20 max PSI - if the manifold registers the same amount of boost pressure @ a given engine rpm, it has the same approximate volume of air contained within itself for both scenarios. Different ways to get to the same place with the same (approximate) result.

Unless your new S/C greatly improves on the efficiency of the OEM unit (if both are twin-screws, I don't see much improvement), they will produce nearly equal parasitic losses and power output will be similar up to the airflow capability of the stock unit. If you are looking to boost beyond what the stock unit can efficiency provide (~23+ PSI?) on stock IM and cyl heads, you'll appreciate the headroom afforded by the larger aftermarket unit.

Make sense?

TemjinX2

A larger displacement sc would improve efficiency because it will have larger rotors and can produce more power while spinning slower. Since the rotor doesn't require to spin as much as the smaller sc, the parasitic lost is lower.

I would just read this article.

They took a 5.0L mustang engine and dynoed it with a kenne bell 2.8L supercharger and a kenne bell 3.6L supercharger.

The 2.8L sc produced 859hp at 13.1 psi with sc rpm at 15929. Then they installed a 3.6L sc produced 904hp at 13.3psi with a sc rpm at 12425.

http://www.mustang50magazine.com/tec...o_numbers.html

loudandheard

Wow, how can we produce numbers like that? It does seem like would should net more horsepower, but we may not net as much of an increase as what they do. If a 29% increase in the size of the supercharger nets 5.2% increase in horsepower, then we would see a small gain, if the math is correct. Let say we are at 350hp and a 3.6l supercharger will give us a 5.2% increase for only a total of 368hp. I think we need to increase the horsepower of the block in order to see bigger gains from a larger supercharger alone.

c32AMG-DTM

Thanks for the link. You might not see it (and that's okay), but this is in support of what I've been saying all along. You aren't going to run the larger blower system at half (or less) of the boost pressure of the OEM system and expect to make equivalent power (post #6 that I first responded to in this thread).

Going back, here's where I think you're, perhaps, thinking about this wrong:

You keep posting that volume is increased. For the purposes of what boost pressure you're using, that's incorrect. Boost pressure is registered downstream of the S/C. Internal volume of the S/C itself is irrelevant for calculating or measuring the boost pressure within your intake manifold. If the intake tract volume hasn't increased, boost will need to remain (approximately) the same for the same engine output.

Now, if you create larger aftermarket surge tanks (like NW), port your cyl heads (like AMG_Jerry did), etc. Then you have increased volume (and flow), and you can make equal power at much lower boost.


As I'd been saying, if the aftermarket S/C is more efficient than OEM, and you run it vs. OEM at the same boost, you'll gain some power from lowering parasitic losses. But, on our engine, it probably would mean netting 20 whp or so.

I wouldn't be satisfied with spending $8-10k to buy the blower and have all the custom fabrication necessary to make it work, only to wind up with 20 whp. What's the point? So, I'd be inclined to encourage my tuner to up the boost past what the OEM system was capable of... maybe 24-5 PSI, and see what sort of output was achieved. The value of a larger blower is the headroom it gives over the smaller OEM blower.

Some additional efficiency is nice, but there's no magic twin screw that will make the same power at less than half of the boost as our OEM system. Jim Bell comments that this newly engineered 3.6L blower makes the same power at 2 PSI less than their 2.8L. If you had originally said "hey, we might make the same power with the aftermarket blower at 20 PSI as our OEM blower makes at 22 PSI" - I probably wouldn't have even posted in this thread...


BTW, even though the magazine is "5.0 Mustang and Super Fords" - the engine used in the test is the GT500 engine, which IIRC is a 5.4L.

betrezra

A couple things to consider here for going to a larger blower:

1. boost is boost..... if you make 12psi with small blower @ 5000rpm, and 12psi with large blower @ 5000rpm then all things should be equal..... HOWEVER..... the larger blower will had a different efficient adiabadic map...... meaning that you may get 12psi of boost @ 5000rpm just like the small blower.... BUT with better efficiency and LESS HEAT which will make more HP.

2. a larger blower will require more HP all things being equal.... nothing is free...... unless your larger blower is a new more efficient type.... low friction unit... eaton has one out now.

We went through all of this with the centrifugal blowers years ago... for instance a powerdyne could effciently make up to 10psi non-intercooled. You could spin it faster and make beyond 10psi of boost, but it would actually lower HP due to getting out of the efficent map of the blower, over heat the intake charge and kill power. You could get away with this on a 1 pass with iced down intake.... but who drives a car like that on the street.

If it were me I'd do other tricks to the stock blower like port/polish the blower inlet, outlet (per specs), port polish heads gasket match to exh manis), optimize the tune, and increase boost with stock blower to edge of efficent map.

hope this rambling makes sense...

blackbenzz

One question... How are you guys going to tune it?

c32AMG-DTM

It does.

mustang281man

boost and hp have no relation to each other at all. all boost is is a restriction.

i say go for the kenne bell, i have had the thought of a kenne bell c32 in the back my my mind for the past 4 years now but i know for the cost it wouldnt meet me need for speed so i use those finances on other projects.

splinter

Know you’re a competent technician and all, but several here may disagree with your assertion.
Are you claiming that enthusiasts who’ve reported increased output via additional boost have been hoodwinked?

betrezra

Assuming same motor here:
Small Blower 1 makes 12psi of boost @ 5000rpm.
Large Blower 2 makes 12psi of boost @ 5000rpm.

HP should be similar IF the air charge is same outlet temperature meaning the supercharger compressor is still working in the efficient map.

Now rev up things to 7000rpm
Small Blower 1 makes 15psi of boost @ 7000rpm, but outlet temp of 210 deg F.
Large Blower 2 makes 15psi of boost @ 7000rpm, outlet temp still nice 170 deg F.

You'll lose HP with small blower 1 @ 7000rpm due to heat generation.... computer will pull timing.

True boost is a measure of friction through the motor. I totally agree.

Just trying to make the point above that additional boost will continue to make additional HP as long as you're in the efficient map of the blower, and you have the fuel/ignition to support it.

....

further regarding boost is not a good measure of HP.....

combo 1 - nonported heads, blower makes 12psi of boost @ 5000rpm and 400hp.
Same motor with ported heads, blower makes 8psi of boost @ 5000rpm @ 500hp.
As long as the blower can supply the air (in the map) then HP will go up even though boost dropped....... boost dropped due to the reduction in backpressure of the ported heads. Now pulley this same blower down to get back to 12psi of boost with ported heads and you'll make additional HP (if the blower has the capacity to support the add'l air flow).

I've always been a proponent of a free breathing motor (p/p heads, intake, exh) and a big blower and lower boost.......

VS a non-ported h/i with alot of boost.

msheredy

This actually isn't true because boost pressure isn't the same as airflow. Otherwise using this theory 1 supercharger would fit the needs of every engine made and that simply could not happen. Bigger engines need more airflow hence the market for large and small blowers/turbos.

c32AMG-DTM

I'm not sure what you're concluding based on my post...? Take one engine, run it N/A. Take the same engine, without modding anything else, and push 14.7 PSI (1 BAR) of forced-induction (blower or turbo, doesn't matter) through it. It isn't double the amount of airflow consumed by the engine/cylinders? I realize heat generation will cause it to not be exact; I'm speaking more theoretically.

My comment didn't have anything to do with the size of the engine (just that the same one be used), so I'm not sure how you concluded that somehow I was suggesting one supercharger would supply enough airflow for every engine ever made...?

MRAMG1

Guys, I have to jump in here as being both a former owner of a C32 and the owner of a Whipple charged stang.

C32amg is right in what he is saying about the size of the blower. That is:

1. A larger blower, say a 2.4 liter, vs the stock blower.

Both the Whipple and the stock blower on a C32 are of the Lysholm design. Please forgive my spelling. The stock one has a Teflon coated rotor in an effort to have a tighter clearance.

Now with that being said, if both blowers were on the car generating the same amount of boost, small vs large displacement, you would be VERY hard pressed to see ANY different HP on a dyno. Why you ask, its simple.

The larger blower, while spinning slower and generating less heat to the charge, has MORE mass in the rotors, hence more parasitic loss for each revolution. Meaning it would take more crank HP to simply turn this greater mass of the larger blowers rotors vs the smaller one.

Now crank up the boost to say 20 PSI, and YES the larger blower will start to shine, as the smaller stock unit is getting out of its efficiency range and would generate alot more heat.

The reason why mustangs see such a HUGE gain from a simple blower swap is from the change in blower design. That is Eaton to Whipple. Two very different rotor designs and efficiency ratings.

As the C32 already has a Whipple, that is the same Lysholm design, you will NOT see ANY huge gain from it per say. Unless you crank up the boost.

Sorry guys, there is no free lunch in the realm of physics

mustang281man

its the volume of air (cfm) not the pressure of the air (boost) that makes more power. example:

A 1.6L supercharger displaces 1.6L of air per revolution. so if your engine is turning 6000rpm with a stock crank and supercharger pulley you supercharger is turning 12600rpm and displacing 20160L of air or 712CFM. now say you put a 185mm crank pulley with the stock supercharger pulley, at 6000rpm the supercharger is turning 15000rpm and displacing 24000L of air or 847CFM.

Now take a 2.2L supercharger and here is what your numbers would be.
Stock pulleys, engine 6000RPM - 979CFM
185mm crank pulley, engine 6000RPM - 1165CFM

thats a big difference in volume of air just by going to a bigger blow with the same pulley combo. thats why porting heads lowers you boost but you make more power, its because it allows more air to flow through (CFM - up) them with less restriction(boost - down).

MORE AIRFLOW = MORE HORSEPOWER

TemjinX2

+1

thats what i've been trying to say for the last couple of posts.

The second part is true as well. I know another person with a c32 engine that has the same mods as me except he has a ported head and he makes more power but less boost.

c32AMG-DTM

Precisely.

I was hoping you saw this thread, as you have a wealth of knowledge and experience with this stuff.

Correct. And, if you leave the heads and intake manifold stock, more airflow will also equal more boost pressure. You're forcing more air into the same volume of space with the same flow capability; it has to cause a commensurate increase in PSI.

Right, because he ported the heads, allowing for more airflow than the stock intake/heads would flow. So boost drops at every given rpm with the OEM blower.

If you swap out the OEM C32 blower for the 2.6L Kenne Bell, leave the heads stock, adapt/customize the stock plenums and intake tract, and then custom fabricate a crank and S/C pulley ratio to run the whole system at 10 psi... I'd be impressed if you broke 260 rwhp.

You're welcome to prove me wrong... I've been wrong before. Anyway, if you reread the entire thread, I think I've been pretty consistent in my comments. Good luck (sincerely) if you decide to undertake this project.

TemjinX2

i dont need too, I just have to wait for mido to give us a update. He already has a autorotor sc on his car. Autorotor makes the sc's for kenne bell.

jturkel

ok.....

...so after all this debating.....who is going to do this in the states?

c32AMG-DTM

LOL. No disrespect, but he also has a completely custom built bottom-end, and no stone left unturned (or expense spared) for improving the performance and flow characteristics of his entire M112K engine. I do not recall seeing the specs, but he may have increased engine displacement and/or lowered CR with his custom Ross pistons as well. His results will only demonstrate what can be achieved if you're willing to go "whole-hog" and invest many tens of thousands of dollars into a complete build. To be clear, in no way a knock against MIDO - I'm a big fan of his project, and hope it's going well for him.

As such, I do not see the relevance of his C32T build to the discussion being had in this thread (which, I thought was "let's install a larger Kenne Bell blower in place of the OEM unit on an otherwise stock M112K motor, and run it at lower boost.") With a free-flowing engine and high boost targets, you'd need the greater CFM capability of the larger aftermarket blower. With an otherwise stock engine and a low boost target - you won't.

In any event, if you're not going to pursue this S/C swap (which I think is a good move, BTW), then there's not much reason to keep discussing it.

c32AMG-DTM

Good question.

I'd expect it's unlikely though. To make it worthwhile, you'd probably need at least $15-20k in engine and transmission/drivetrain upgrades, along with supporting mods and custom fabrication, so you could use the 2.6L S/C to its potential. Who's going to dump that kind of coin into a C32 at this point? So many better options exist, IMHO - like trading-in the C32 on a C55 and adding a Kleemann blower kit, or moving up into a stock C63.