m112 questions (porting, silencers, stripping rotors)

BigEag205

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In the process of m112 swapping my 01 cobra and am strongly debating taking the time to port the blower/plenum and possibly fill the silencer holes. I'm just now starting to really look into this so any advice/pointers are greatly appreciated (especially first hand experience). The car will get whippled later down the road so with that in mind, I'm really not looking to pay a couple hundred for a port job. The car is rarely driven at that.

Also, I want the blower to scream as much as possible. The more i look the more i realize neither POSI or Steig seal the "silencer ports". Is it even worth it (leaning towards no). I've seen people JB Weld the silencer holes shut but something about JB Weld scared me. Would if be possibly to weld them shut and grind them down smooth for clearance without warping the casing?

What is this "stripped rotors" I'm seeing? What's it do? What're the advantages?

Again, any advice helps and if you don't have anything helpful to say, don't bother cluttering the thread please.
 
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BigEag205

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I did see a couple years ago I believe it was steig that had a thread for home porters but closed it and deleted all the pictures rendering it pretty useless =(. I understand why as I'm sure it was taking from his own business but I bet that thread was nice while it lasted.
 

07COBRAVENOM

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That was actually POSI who was helping people port their own blowers btw.

The silencer holes on my old Harley davidson were JB welded closed. Think of it this way, the JB weld would have to come loose, somehow be pushed upwards into the rotors as the rotors push air down, and also the JB weld would have to make it through the intercooler to actually cause any damage. Welding the case can actually warp it due to the soft aluminum and the heat transfer from the welding process. I will say first hand that I didn't gain any boost when my slencer holes were JBwelded but it did make it louder. If you want it to scream do a 2.76 pulley and JB weld the silencer ports
 

01yellercobra

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That was actually POSI who was helping people port their own blowers btw.

The silencer holes on my old Harley davidson were JB welded closed. Think of it this way, the JB weld would have to come loose, somehow be pushed upwards into the rotors as the rotors push air down, and also the JB weld would have to make it through the intercooler to actually cause any damage. Welding the case can actually warp it due to the soft aluminum and the heat transfer from the welding process. I will say first hand that I didn't gain any boost when my slencer holes were JBwelded but it did make it louder. If you want it to scream do a 2.76 pulley and JB weld the silencer ports

The JB weld won't just get pushed down and stay there. This happened to a buddy of mine. The person that ported his blower JB welded the ports closed. The JB weld came loose and bounced around making some bad noises. It nicked up the blowers pretty good.
 

FinnCobra

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I searched forum, and didn't find more recent topic. I have M112 and I was thinking should I leave it stock or not. I found dyno curves comparing ported vs stock. Fully ported blower losed power under 4500 rpm. My car use is street and random track days. I have 3.55 gears and TR3650. If I lose power in smaller rpms, I think I lose seconds in track too. I'll have more boost from pulleys, should I do some to help building boost and maybe have cooler charge?
 

01yellercobra

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If the blowers lost power something was up with the tune. It's really hard to add boost and lose power. If you're only going to stick with the eaton then porting is an option. If you'll ever want more than 550hp invest in a 2.3 blower.

If it's a road course set up I would hit the cooling options first. Make it last before adding power.
 

FinnCobra

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I had 302 before, Mishimoto radiator and no problems. Same radiator fits now. I don't have heat exchanger yet, I'm looking for good deal.
Article with dyno curves, engine lost power in low rpms with smaller pulley: Blower Porting by Stiegemeier
 

9397SVTs

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dyno.gif

dyno_table.gif


Where exactly did it lose power?
 

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