NEPTUNEBILL

I am still curious as to wether the IC mag could maintain 5# on a large CI motor--it would be nice to know before investing in a FAST intake, TPIS TB and having them port matched and mounted (probably 2K) for another 5K or so I may be able to add 100rwhp and tq instead of 30rwhp--I don't think I want to use anymore cent blowers and TT is a lot of money and a lot of plumbing etc--if the IC mag can manage 10+lb on a 346ci I was thinking it might manage 1/2 that on a 436ci--I know they are just out and no numbers are in I though maybe you more tech guys would have some thoughts on it.---BTW the Vinci's were able to maintain 4#'s on a 415ci iron block with the older version of the mag which leads me to believe that 5 or better is possible with the IC version---


[Modified by NEPTUNEBILL, 8:05 PM 1/8/2004]

runamuk

It's only a matter of time before someone gives it a shot :cheers:

JakeL

I am certain that somebody will probably try it, but I don't believe it's going to be an ideal solution. For the magnusson supercharger - that is, the actual Eaton supercharger that bolts to the car, the limitation seems to me to be more the flow capability of the blower itself, rather than the intercooling ability.

I belive the highest boost we've seen from a Magnusson is about 7psi with the smallest (3"?) pulley, correct? If, with that pulley, folks are already spinning the blower near its redline, then I think 7psi is as much as we'll see. With the same pulley, if you add an intercooler, your boost pressure will go down slightly, not up. (resistance to flow ohms law and all that).

My understanding is that the limit on boost pressure hadn't been an air-charge heat issue, but a blower speed issue.

Every compressor used in hot rodding cars has some upper limit on how much air it can move, just by virtue of its design. I can't find the link anymore, but I seem to recall reading that the MP119 blower has a limit of about 900cfm, which is in the neighborhood of 600hp, or around 520whp.

You can spin the thing as fast as you want, but I don't think it'll be able to move a heckuva lot more air all that well, since it just isn't made to feed big motors, that already flow a lot of cfm on their own.

As an example, which may not be very helpful, I'll compare two turbochargers. The stock turbo on an Eclipse is called a T25. It's about the size of your fists put together. You can spin the thing as fast as you want - wire the wastegate shut, and it still won't generate more than about 18 pounds of boost. (this is on a 122cid engine, mind you). The compressor is just very small, and can't move a lot of air. You can intercool the bejeesus out of it, but you still won't get any more boost pressure or much appreciable horsepower.

By comparison, a larger turbo will have lots of room to go far beyond that, simply because it's a larger compressor that can move more air. Think of a ATI P1-SC versus the F1's.

Do I think the intercooled maggie will make more power on 346's? Absolutely! But, I think that there is an upper limit of how much airflow the MP119 will support, and I think that on a 382 stroker, you'll hit that limit very quickly, since even the 500whp nonintercooled Magnusson guys are spinning that sucker about as fast as it will go.

My $0.02, based on no real world experience with the blower, and just looking at the numbers. I'm sure folks will be proving all of us bench-racers wrong in short order! ;)

Just to tighten the noose a bit further, :D I'll make a small prediction: I would be surprised if folks get to to 600whp, or much past ~550 with a 100% decked out heads/cam/headers/intercooled magnusson car.

Any of the experts want to weigh in, now that it's been ameteur hour? :rolleyes: :skep: :crazy: :D
-Jake

Shinobi'sZ

Bill,
Please for you sanity let somebody else do it first. Don't be the first one! You already have endured enough...or have you????

We have to see if the I/C Mag even makes 10lbs of boost on a H&C 346cid first....then you can probably estimate 5-7lbs on a big bore..or should I say huge bore. :jester

QuickSilver2002

Just an opinion, but I would not mess with it. Your motor does not sound boost friendly at all. You can actually disrupt some very beneficial pressure waves with a tiny blower on a big motor and end up with a loss in power.

It could work out OK, but I would not do it unless you were prepared to tear it off if things were not so great.

NEPTUNEBILL

Jake--your impression is the same way I am thinking--I would do something with CR and go TT before I went back to the cent blower and deal with belts and most of the power hitting at the top---

Kevin--don't worry I will not be the first to try this-I have already spent enough money for an LPE 427TT with all the options and sure you can relate--I am hoping to be perfectly satisfied with the stroker and not mess with any FI as I don't think anyone can beef up our drive trains to handle the stroker power much less the power the guys like you and Steve are putting out, I may even sell the CCW drag package and think more about road courses where I will not be leaving tranny and rear end parts all over the ground--

Thanks for the input its pretty much what I feel as well and I agree that unless you are prepared to pull it off don't even try it---

STAGED

Hey NeptuneBill,
When I went from 350cid to 381cid (bored 0.020" over) on my LT1, I think I lost only approx. 1-1.5 psi peak all else kept constant including the pullies.

One should use a 2.8" upper pulley on the intercooled 382cid Mag setup. On stock longblock/no IC a 2.8" pulley should make about 8 psi peak at sea level. Add the IC and boost should drop to about 7 psi (MY GUESS). Stroke it out and add blower cam/free flowing heads and boost should drop to 5.5 to maybe 6 psi.

Intercooled albeit rather inefficient 6 psi would do well with 10.2 to 10.3:1 CR. The beauty of adding cubes and IC to a blown setup even with boost drop is the ability to raise CR and/or add timing. More engine cubes and freer flowing heads also allow the blower to discharge more air for given rpms (as indicated by boost drop for given rpms). One also needs to use the appropriate cam. I spoke at length with someone at CompCams who's familiar with Mags and LS1s. He recommended for a 382cid 0.595"/0.605" 232/238 @ 0.050" lift and 114 lobe sep. for 16-17" Hg idle vaccum for good drivability while making the power.

Raising CR and using the appropriate blower cam is critical or else one won't see the worthwhile gains over stock cubes. If we see 502 rwhp for a 21st Century built Z06 with blower cam/stock motor otherwise/slightly more aggressive pulley/no IC; then I predict good gains on an IC'd 382cid with appropriate CR and cam. Just on cubes alone (not even considering timing advance with cooler charge air temps of IC), I think 1 hp/cid gain or 36hp is possible and absolutely huge WOT gains of mid-range torque.

So far that's the justification on paper. Now this hypothesis has to be tested by a willing owner out there.


[Modified by STAGED, 3:11 PM 1/9/2004]

NEPTUNEBILL

Thanks Eric if your numbers remain consistent with cubes than I should loose about 3 times the psi that you did so if the mag could do 9 or 10 to a 346 with the IC than I should be able to get 5psi to my 436, I am still going to let a richer guy than me prove it first--

99SlowC5

Being I'm new to the C5 and to the forum, yet old to the EATON blowers. I'm going to try to see if any of my 3800 M90 thoughts work with the C5 and the magnuson M112.
Jake, You were talking about the M112 only being able to run at 7PSI (safely) From running an M90 on my Grand prix, we have takin those SCers up to 17-18 PSI, The efficiency has gone down considerable at this point but the blower is definately capable on producing more than 7 PSI. One company makes a kit to take a M90 SC and replace it with a MP112. This MP112 is capable of making upwards of 15 PSI( once again not very efficienantly but still capable of making that about. Adding an intercooler only helps. I made an INTERCOOLER for my Grand prix and dropped 2 PSI, was able to drop to smaller pulleys and currently running 12 psi. I gained approx. 1/2 sec in the 1/4 mile. I dont know if any of this correlates to the MAG M112 and a C5 but I'd like to believe som of it does. Hopefully someone will be able to help me understand what i might not about the Mag setup.

JEFF


[Modified by 99SlowC5, 1:16 AM 1/10/2004]


[Modified by 99SlowC5, 7:18 PM 1/9/2004]

JakeL

I'll start by saying that my assumptions about the size limitations of the mag blower could be wrong - it may have more left in it than I've been led to believe from reading.

Cliffs notes of the below post: you're on the right track regarding airflow and such, I think.

There we go, MP112. I couldn't remember the right model name for the blower.


Yes, but that's on a much smaller motor that (from what I hear) doesn't breathe anywhere near as well as a LS1. My best experience/example is with a DSM: We put T28 turbos fairly commonly on those cars, and they top out right around 22psi or so. There is no way you'd ever get even remotely that much boost from it on an LS1 - maybe 7psi if you were lucky. Boost is somewhat a measurement of the resistance to airflow in the intake tract. a big V8 has much more breathing capability than a little 2.0L, and similarly, the LS1 is able to ingest a lot more air than the 3.8L six on your Prix.


The size, and the breathing of the motor you're putting a compressor on are very important, and the LS1 has a lot more of both. Similarly, the Cobra guys have the same blower on their cars from the factory, and they get closer to 12-13, I believe, due to the smaller and less-well-breathing motor. Boost does not equal airflow.


The smallests pulley I've seen for sale is a 3" for the magnusson. I don't know if that was a practical boost limit without the intercooler, or if folks are getting towards the blower redline.

It's also worth noting that adding an intercooler will introduce a pressure drop, so for the same pulley size, you'll see less boost. If the 3" pulley is spinning the blower at its redline at the engine redline, then folks aren't going to see any increase in boost pressure either, although the cooler charge will still make for more horsepower.

But, there's a lot if "IF"s in what I'm saying, especially without being able to find the stupid documentation on the Eaton unit. :cuss

-Jake *shrug*

99SlowC5

you could be right.. I see what your saying about the LS1 breathing better thus keeping boost levels down. So frankly I dont know :D The redline of the M112 is something we've gone over on the M90, Efficiency drops but boost increases... I dont know just trying to add something to help myself understand the switch if I add a MAG to the C5 :D

JEFF

JakeL

Here's a starter from Eaton's site:
http://www.automotive.eaton.com/prod...rols/M112.html

and another:
http://www.capa.com.au/eaton_mp112_4th.htm

Their graph stops at 14,000 RPM and only 700 cfm, which doesn't quite add up. Folks must already be spinning them faster than that for greater airflow, since it would need to be a bit higher than that to support the few 500rwhp cars we've seen here.

If we had all the pulley sizes, we could figure out the current blower RPM folks are spinning it at, and get a feel for how much headroom there might be. 3" blower pulley, what's the crank pulley diameter? I don't have my manuals handy.

-J

JakeL

While searching, I found a quote or two saying that you can spin the M90 faster, due to it's lighter, and shorter rotors. Part of the MP112's reason for existence is that it generally spins a bit slower, and tends to have longer service life because of it.

Do you know any of the blower redlines offhand? I ran across another post saying the lightning guys (5.4L, but seriously undersquare) regularly go over 14,000 on their M112's.

-Jake

99SlowC5

I dont know what the redlines are i thought i remembered 17,000 on an M90, Thats the "safe" from EATON I'm sure, The stock pulley on a 3800 M90 is a 3.8" about 8 PSI, they make 2.45" pulleys. thats upwards non-ICed of at least 20PSI, Not efficient but 20PSI. 2.45 is way past the "redline" of the M90 and by adding heads, cam, headers, and Intercooler this brings the boost levels down to probably 16-18? The redline means very little to the 3800 M90, I dont know about the M112 but there are a few guys running M112s on Grand prixs with very large cams, ported heads, and still pushing 15 PSI. I do not know though if this means anything to a MAGed C5?

JEFF

7.0sc SuperVette

Neptune,
The mustang people replace the Eaton with a higher output compressor, e.g Kenne-Bell Blowzilla. I'm curious if this blower fits directly on the manifold? Of course the snout length for the pulley drive would be different and would require some adaptation. I would be interested in something like that for my street 427, but I (Andy) will be finishing up on perfecting the ATI belt drive first. Perhaps others have info on these larger more efficient twin screw blowers?
Roy

NEPTUNEBILL

Thanks Roy it would appear that I will have to wait on an Eaton or Kenne Bell and not waste time and money with the 112, 436ci is a lot of cubes to fill for a blower setup designed for 90 less CI--

7.0sc SuperVette

Neptune,
Sometimes when I am on the fwy on ramp in 2nd w/3.90/427 zipping up to about 3500+ rpm without dipping much into boost w/ATI, I say to myself-myself I says, we don't need no stinkin' blower!
With your 436/11:1 CR and big cam I imagine your left brain might be thinking the same!
But then we can never be too rich, too thin, or have too much RWHP !:yesnod:
Good luck on you plans, I should have mine back from ANDYS' in a few days after final tuning-will post. :hurray:

NEPTUNEBILL

Even with the boost turnred down I almost never saw the boost side of the gauge and have always felt the same way, its nice to know its there but when do I use it going 35mph up and down my beach, I hope to find the stroker is more than satifactory particullarly since I am about to come to the conclusion that no one can make a drive train that can handle to power to make these drag cars--