Magneson supercharger on a 2.5 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

So I just purchased a used Magneson SC that was removed from a 2.5l and its on its way to me. It comes with the mounting brackets, piping but no instructions (its a custom kit from what I can tell - Magneson make SCs for American cars), belt or engine mods like injectors. It also doesn't come with an add-on engine management system that other kits seem to come with. Other posts suggest that my engine life is going to be directly proportional to how well I tune the thing after instal. So I need to know if anyone has any recommendations on tuning. If the recommendation is to get it to a dino and have it tuned, does anyone recommend one in the Toledo, OH area? Thanks

This is the one off eBay correct? Out of curiousity, how much did he let it go for?

You have seen it I guess? I finally bid $1400 and he accepted.

Does anyone have any instructions manual for any supercharger kit sold for a boxster. The Magneson SC I ordered is here sans instructions. Although the instructions written by ohioboxster ( http://986forum.com/forums/performance-technical-chat/7067-supercharger-installation-4.html ) are excellent, I have a few questions that Im hoping the manual may resolve.

it's not custom, it's a kit by tpc (check the sc build thread on this site). if everything you get is in the pictures then it's missing one of the mounting brackets; tpc can fabricate you a new one. also, it's designed to work with a 7th injector which means you need a piggyback computer to operate it. tpc may be able to provide you one. if you want to do a tune instead you'll have to remove the 7th injector and put larger injectors in the stock positions. softronic should be able to do the tune for you. if you seach this site you'll also find that brad roberts has dealt with a lot of these as apparently the mounting position starves the sc of oil; regardless, you should send the unit out to be refurbished. you'll probably also want to put in the latest edition of the aos in your car, as the unit draws vacuum from before the sc. so failing aos will send a whole lot of oil through the sc. you'll also want to think about fabbing a heat shield or wrapping/coating your headers, as the sc sits right close to them. if you want your engine to last you might also want to think about fitting an intercooler in there someplace, otherwise you're slamming hot air into an engine with poor air/fuel control given the 7th injector design - boom.

Thanks radium So TPC just buys magneson SCs and then sell them on as a kit for the boxster I take it. I'm a bit confused on a few points. What is the extra bracket for? I have found the spot where the SC will sit and I've tried to imagine how it will all fit together. The 7th injector you mention has me at a loss. I've heard of this configuration being used before but I can't get my head round it. If there is one injector per cylinder where does the 7th go? I assume the mixture needs more fuel than the stock injectors can cope with? But this injector is not injecting into a cylinder right? The next question i have for you is about the oil. You mentioned a vacuum failure that would send oil to the SC. I'm not sure how as it's a sealed unit. Did I misinterpret and you are referring to a catastrophic oil failure? As you can probably tell I'll feeling like I've bitten off more than I can chew here but I'm willing to see this through, at least at this point. So whats your connection with radium if you don't mind me asking?

in the small town up north where i lived there was a tug called the 'radium king' that sat at the locak museum. it was used to haul barges loaded with yellowcake uranium from great bear lake during ww2 to evenually be dropped on japan in a more condensed form. it became the name of our band and my online moniker. if you check most sc companies sell to other companies and not to end users. maggie is just a rebranded eaton, sold to tpc for their kits. if you look at the first images posted in ohioboxster's thread, you'll see one of the sc itself, and one of a pile of misc parts. in the misc parts image you'll see a black metal bracket sitting under a baggie; that's the second bracket required to secure the rear of the sc to a second pair of header bolts. note also that you'll have to get longer threaded studs w/ nuts to replace your current header bolts to attach the brackets. in the first image you posted you'll see the piping with flanged fitting designed to bolt to the intake plenum. just back from the flange you'll see a thing with a small hose attached to it - that's the 7th injector. it ties in to the fuel supply and is controlled by a little piggyback computer that takes an rpm signal from the car and a vacuum signal from the vacuum system. when the car is hauling (ie, high rpm, creating a vacuum) it adds additional fuel to the intake air. you'll need to get this controller from tpc. note that the 7th injector approach is, ihmo, half-a$$ed and destined to kill your engine fast. there's no intercooler so intake air times are way up already (contributing to detonation). your car's computer doesn't know wtf is going on and is trying to rationalise how much fuel it thinks the car is getting against what it is seeing in the exhaust and modifying itself accordingly. lord knows whether it can properly compensate timing. air/fuel ratios are imperfect to say the least, etc. a great opportunity to run lean and burn holes through pistons. poor. better to delete the 7th injector, get 6 bigger injectors, and work with softronic on the tune. there are two oil issues. one is that scs are typically self-lubricated. that is, they have a small reservoir of oil designed to keep bearings cool and happy (unlike turbos which typically use engine oil for this purpose). brad roberts has advised that the orientation used by tpc is not optimal for the maggie internal oiling system, leading to premature failure. poor. you can't fix how it is mounted, you can accept the need to repair it more often, and you should send it out to get rebuild. the other issue (and not a big one) is that the boxster is designed to have vacuum in the crankcase. it gets this vacuum from the intake of the car. the car's air oil seperator (aos) is the interface between the crankcase and the intake; it passes the vacuum from the intake to the crankcase, vents crankcase vapours into the intake to be combusted in the engine, and stops crankcase oil from slopping into the intake. the boxster aos is a known failure point; it's not a matter of if but when. later versions of the aos have been improved, but if you have a 2.5 you have an early one and should change it. on the tpc kit the aos connection to the intake is pre-sc, so an aos failure will send oil and crap into your sc. note that tpc solved this problem by using a catch can instead. that is, any car with a newr tpc turbo kit doesn't have vacuum in the crankcase (bad for the rings) and is venting the crankcase to atmosphere (bad for the environment) and catches any sloshed-up oil in a can prone to overflowing (bad for the track). poor.

This is way cool, I think you have gotten a deal, but as with any deal there is some work. First you need to get the book Street TurbochargingHP1488: design, fabrication, installation, and tuning of High-Performance street turbocharging systems. By Mark Warner. It’s a very good newbie book to help you understand how to boost your car and you can download it to Kindle. Second, replace the pos motronic computer with a MegaSquirt EMS. There is a huge DIY community with it. They are way cheap to build and easy to tune. It’s half the cost of a basic chip flash and you can retune in real time. I am surprised more Porsche owners don’t use them. Third, don’t boost your stock motor with more than 4.5 psi this will safely give you 30% more horse power. Last, the supercharger has more drag on the motor than a turbo. So install a 3rd radiator, oil cooler, ceramic ims bearing and so on. Good luck and cheers.

Thanks guys. I'm going to start with reading on the subject. Then I think I'm going to look at the large injectors and see if it's I'm willing to try myself. Any suggested retailer? Pelican can fix me up I'm guessing. I'm guessing $150-200 per injector? No small price but my motor only has 55k miles so I'm not risking the dodgy 7th injector. I'll assume at this point I can Gerry rig the kit system to not use the 7th injector. Im also not planning on going to large boost pressures. I have read that a S bumper with the extra radiator may help. Lucky for me my bumper needs replaced as of last week. First time I've been in an accident involving someone with insurance and the honesty to use it. An intercooler doesn't seem practical. If I go with the correct approach I'm assuming that the onboard compuer will be happier and will be incotrol of it's senses. Fuel mixture should be under control and less chance of a melt down. I asked earlier about the function of the 7th injector; I'm assuming now that the 7th injector would premix the air with fuel prior to injection. That even sounds like a bad idea. Yeah, boom. Radium king: the reason I'm interested in radium is that I'm a radiation therapy physics and prof in radiation physics. Radium has a lot of historical usage in therapy as it was what was available in the early 1900. Thanks for your help. I'm finally putting the pieces together.

Kashmir: you have a MegaSquirt in a 986? I'm sure people here would be interested to hear about that once they get over the silly name. I certainly would. I agree the Bostronic system is way to much of a black box for those who like to tinker. but getting people to change is difficult so we need to know what that system can do for us.

I have a kit on my Boxster they work well only down fall is the squashed part of the pipe leading to the Supercharger from the intake. To tune mine properly I added a UNICHIP piggy back and disconnected the 7th Injector as the standard ones will flow enough fuel without it. What i wanted to do was work out a way to enlarge the squashed part of the pipe make up a smaller pulley for the super charger re connect the 7th injector and run more boost. But I bought the 996 Turbo so the 986 got put on hold. Any how what you need to do is buy a unichip an old one will work fine ( i bought mine from a guy on this site for 200 bucks) put it on a dyno and properly tune it. A custom ceramic coated exhaust (keep the heat away from the supercharger), a bigger throttle body and a IPD Plenum will also need to be added if you want the maximum out of it. After a lot of playing for I ended up with just under 180kw at the wheels which for the little 2.5 on 5psi of Boost is wicked, thats the same power as a 3.4lt 911 . If you want to re-fresh the super charger before you fit it you can get a rebuild bearing kit on ebay for around $100 bucks. Good luck with the build brother, they are such a brilliant car to drive up in the mountains. Cheers, Tim

Tim986, thats great that you got the system working. I'm really looking forward to installing now I've done some reading but I want to do it right. Thanks for the info on the rebuild kit. Thats a weight off my mind that i won't have to send it in for a rebuild. How many miles have you put on the 986 since the SC? Without upgraded injectors I'm a bit worried it will run lean so I'm going to price some new/remanufactured injectors first. I didnt have any luck finding a UNICHIP setup for less that $2000 USD. I'm interested in knowing if it's possible to just remap the ECU with something like the Softronic package. Since your not running (and I'm also not planning on running) the 7th injector then maybe it's possible to get away with not having a piggy back computer. Couldn't the stock ECU handle it as long it's look-up values for thing like injector pulse were modified? Also, does anyone have any recommendations for injectors used with and SC running 4-5 psi? What are the stock sizes/flow rates?

Yes Softronic or any of the other flash tuners will be able to do a tune for you on their dyno's. My 996 Turbo is flash tuned that way. I thought the UniChip would be cheap for you, Mine was an old 2nd hand model, but is good enough for my set up. Only thing to do was hot wire it in to the ECU wiring loom. No need to do injectors they will flow plenty but if your worried about fuel pressure upgrade your fuel pressure regulator to a 5psi FPR from David Green at Green Motorsports over there in the states. Tell him I sent you and you will get a good deal. If you have any questions at all I'm more than happy to share my knowledge. If you haven't done so already I would look at fitting front ant rear strut braces ant the lower brace from pedros garage on the net. Then fit adjustable sways with tarett drop links the improvement in handling it just fitting the above is worth its weight in gold. Good luck, Cheers, Tim

Further investigation into the use of the stock injectors 996 606 122 00 suggests that they should be good for 300hp since they are also used on larger engined Porsches. So now I'm thinking that it's time to contact the Softronic people and see what they can do for me. They don't mention much about using them on cars that have an SC kit installed but hopefully they have something for me.

Let me know how you go. The Main problem you will have is the flat squashed part of the super charger piping if you can have that enlarged some way i think you could make more than 300hp with a pulley change. Good luck,

Tim I know its been a while but I was wondering if you had access to the fuel map that you use. At the mo Im going with the 7 injector set-up driven by an SMT6 and I could do with a starting point. Wounldn't the extra injector have to put 1/7th of the fuel that goes to your 6 injectors?

Hi Trans atlantic Im using a UNICHIP with a custom tune By a UNICHIP they are cheap and easy to tune

when u add the unichip also add a 5 bar fuel pump regulator that will get you the fuel your injectors will need for 300hp