I have a forged 347 with 8.5:1 compression that I planned on turbocharging. I decided not to turbocharger (for several reasons) and am now considering making my own intake manifold out of sheet aluminum for an MP112.

The intake manifold would be A LOT easier to make if I do not run an intercooler. With the lower compression and no intercooler, what kind of boost and HP numbers could I realistically expect to get on pump gas with the MP112, 317 heads, and stock Camaro cam?

 

For the love of christ, don't put a maggie on your car unless you expect disappointent.

They are terrible. Especially not intercooled

 

You will be lucky to break 500 hp to the tires.

 

I wouldn't waste your time for a non-intercooled set-up. Your IAT will sky rocket under any amount of boost.

If you have the skills to make a base manifold, then you have the skills to make one with an intercooler.

 

I expected to get flamed for this. If this was a race setup, an intercooler would be absolutely necessary to hit higher power levels. I understand that, but this is not a race setup!

Anyway, the intercooler will add a lot more complexity to the design:

1) There will be another part to mount and another surface that needs me to get/make a gasket
2) It will make my intake manifold higher, hurting hood clearance
3) It will cost more money for the parts (thin A2W IC cores are not cheap, plus I can see the little stuff adding up quickly)
4) There is a risk that if the IC fails and leaks, the water will go into the cylinders and cause some serious problems (e.g., hydrolock)
5) More weight from the IC system (I know this is a minor one, but the vehicle is already 4,000lbs)
6) Recirculation pump - another electric draw for my 102 amp alternator to feed (again, minor)
7) Another heat exchanger in front of my rad and condenser (minor)
8) More of my limited shop time

Also, I am traction-limited. My car has a 2.88 rear end, IRS, and the widest wheel I can run is 8". At some point, more HP and torque are going to yield greatly diminishing returns.

If I could hit 500rwhp, I think I would be really happy. The non-intercooled RADIX kits were supposed to yield 80rwhp on a 5.3L truck engine. My engine is a 5.7L, has a lower compression ratio (8.5:1 vs. the 5.3's 9.5:1) and a 98-99 Camaro cam which probably breathes better than the truck cam at higher RPMs. I don't know how much Magnuson left on the table when they tuned the 5.3L.

Does anybody have personal experience with this?

 

If all you want is 80-100hp over stock, then yes you'll get it. If wanting more, dont consider a roots SC without some form of intercooler. Also, if you're taleneted enough to accurately build an aluminum intake tube to mount the SC to, you're skilled enough to design an intercooler system that wont leak. Heck, if you really are scared of A2W intercoolers, flip the SC upside down or mount it remote and use a A2A FMIC

Real world experience: My M90 kit without an intercooler hit 180* IATs at idle cold. With an A2A FMIC I rarely crack 120* hot at WOT

Next, you can fit a max of 8" wheels? Thats not even 275's. The saving grace of roots/twin screw SCs are the instant torque which will annihilate any but the most sticky rear tires. Another thing, the stock LS1 cam will leave you disappointed. If anything, go for a cheap LS6 cam

 

You guys seem very confident in my fab skills! I am not great or fast at fabrication, but I take my time, pay attention to detail, and get the job done. I have very limited access to a shop, so development for me is very slow. Adding an intercooler will probably add 6 months to me getting the unit built and on the road.

An A2A intercooler would be tough to package. My engine bay and intake is setup perfectly for an LS1 intake manifold - it's a straight shot. With the MP112, it will also be very easy to package.

Wow, that's pretty high. How are you running an A2A IC with an M90? Can you post a pic of your setup?

EDIT: Okay, I thought that was you that did the DIY M90 on the F-Body. I found the thread again. That build took some ***** - I am glad someone did it! Anyway, now I can see 180* IAT at idle. The supercharger unit is sitting over one exhaust manifold (with the charge-air side facing the exhaust) and the air intake over the other exhaust manifold inside the engine bay. That's definitely going to add some heat to the air. My design will pull cold outside air from in front of the radiator and run it straight into the intake side of the MP112, staying clear from all the exhaust. That M90 build is really cool BTW.

Yea, I think I am limited to about a 255/45-17. I was hoping a little more sidewall would help. I thought the MP112 would work well with my 2.88 gears, my shallow 4L80E 2.48 1st gear ratio, and a tight converter.

I was also considering a cam. I don't want to degrade fuel economy too much, or have a rough idle. I'm not sure if the Z06 cam is a good "blower cam" or not.

 

It will never make near 500whp with a non-intercooled 112. Unless you run M1 or M5....

The highest numbers achieved on the intercooled 112's are in the 500-550 range. This is with 5.7-6l, 11:1 compression, 90mm TB, 18,000rpm blower speeds, and the right cam.

 

spray it with meth or a small shot to keep the IATs in check.

 

Dont attempt this without exceptional fab skills. This thing has to be DEAD on or you will chew endless belts. My setup was off 2 degrees and it wouldnt keep a belt at all. You have to locate this thing in space and keep it parallel to the crank axis within about 1/2 a degree and within about .025" of perfect belt alignment. Anything outside of that will be trouble

The outlet being near the exhaust has nothing to do with the IATs. Much like the heatsoak BS people cry about with alum intakes vs composite, the air isnt in the tube long enough to draw anything out. I did a test by wedging a lunchbox icepack in between the manifold and outlet then monitored the IATs. Not a single degree change

Just wait for my next build

If you baby it off the line you might keep control of it. I have a hard time keeping my 275's planted with a 2.73 rear through a 4L60E

You're worried about mileage with a M112? Anyways, the LS6 cam isnt big enough to really affect it. The ultra high IATs from a non-intercooled setup will limit how much timing you can put into it and kill mileage quite a bit. My kit dropped about 2mpg highway after all the bugs were ironed out. It wouldnt have dropped that much had I not had alot of timing pulled to cut down on flash knock

 

I'm not worried about the whole belt alignment thing, but thanks for the heads-up. .025" looks about right - I'll pay careful attention to it. I will build in some adjustment, and use shims if necessary to mock it up and test it. I have access to a mill for critical parts like the base of the intake manifold, etc.

So if it's not heat soak, how do you explain 180* IAT at idle? That's really really high! I mean I know you're pulling in warmer (than ambient) air from the engine compartment, but still? It's not 180*. Is the thing pumping while you're at idle? Are you sure your bypass valve is of adequate size, and working properly? There has to be some explanation.

Assuming the tire height is the same, you still have more final drive gear. The 4L60E is pretty low at a 3.06 or something.

I do a lot of highway driving. I still can't figure out how you're getting your IATs so high!

So when's your M112 build thread coming out?!

 

This guy knows exactly what he is talking about, the only way to go is a large single turbo on a daily driver.

 

If you would like to make the A2A intercooler people angry, you could just put on a small nitrous kit, that would never work, the turbo crowd would all be right and the old roots blower would be wrong, just wrong...

 

I don't want to make anybody angry - I just want to know how far I can take it with an MP112 on my current setup without an intercooler!

Or maybe how far I could take it with a mild cam?

I didn't expect to be hit with this much hostility!

 

He says he knows what he's talking about but hasnt posted the first bit of data to support any of his claims in any of his roots-bashing threads. Put up or shut up

You should be worried! It's the hardest part

You misunderstood. I hit 180* with no intercooler, outlet plumbed strait to the TB. The 120* was with a large FMIC hot-lapping at the track in the middle of august

Month or so when it's done, it's a M122 though. Im going to finish it before posing too much about it on this site. Too many nay sayers to rain on my parade again. Heres two for the mean time to satisfy your curiosity

http://i150.photobucket.com/albums/s...t/DSC02202.jpg
http://i150.photobucket.com/albums/s...t/DSC02254.jpg

Not very far unfortunately

 

They already have a kit for this....Search it

 

I still don't understand. What do you mean by "at idle cold" - I was just assuming that you meant a cold engine at idle?

 

Thats right

Trying to convey just how much heat the Eaton produces

 

Here's some info on the MP112 from Magnuson. It's the 4th generation, which is the one I am using.

http://www.magnusonproducts.com/mp112.htm

But who really wants to follow a link, right? Here are the pictures:





Is looks like the sweet spot for this unit is right around 10,000 RPMs. If I made the supercharger hit 10,000 RPMs and my 6,000 RPM engine redline, my IATs would be between 130-180* F, which seems manageable. I think I am reading the chart correctly?

 

The supercharger shouldn't even be pumping at idle?! Why is it pumping at idle? Maybe the temp is so high because it's pumping into a closed throttle body?