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Supercharging a 944 - Why so hard?

Old 11-27-2017, 03:20 PM
  #61  
Tom M'Guinn
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Not trying to be a wise guy, but how about a nice NOS kit? It installs in hours (not years), is priced more in line with the value of a typical 944 n/a, and can go from mild to wild depending on your risk appetite.

https://www.summitracing.com/parts/NEX-ML2000/
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Old 11-27-2017, 03:56 PM
  #62  
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A SC can install in hours also. Its the optimization afterwards that can take a while.
I think to make a 944 NOS motor long-term reliable you would need to:
1. Upgrade the fuel system
2. Standalone ECU.
3. Water/meth injection if using stock compression ratio.

Now its no longer a few hours anymore.... :-)

But I thought about it.
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Old 11-27-2017, 04:19 PM
  #63  
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Why would you need those things with N2O? The fuel pump, sure, if it cannot deliver the goods but the stock 944 pump seems pretty stout.
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Old 11-27-2017, 04:33 PM
  #64  
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You need to inject more fuel to compensate the extra O2 you are getting from the NOS or you will be running destructively lean. The stock ECU and AFM does not know there is more O2 in the cylinders. You can inject fuel separately with the N2O but that is a very coarse approach because the system does not know what the MAF rate when you hit the bottle.

NOS is basically chemically supercharging. Still need to do it right either way or you kill your engine. Its easier to do it wrong with NOS in my opinion.

BTW I make N2O power rocket motors in my other hobby
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Old 11-27-2017, 05:52 PM
  #65  
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I've run a lot of N2O, you can add fuel a couple different ways and it's not that difficult or dangerous as long as you have an adequate fuel system and a fuel pressure safety switch.
The WOT maps are not that sophisticated anyway and the 944 has no MAF, only an AFM. It'd be no big deal IMO to even run a dry kit for an old 5.0 Mustang on the 944.
Since you are not expecting to use more atmospheric O2 the temperature, pressure and humidity of the extra "air" is not a problem, it is a known quantity. Thus you just add a proportional amount of fuel. All you need is money! And extra bottles.
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Old 11-27-2017, 06:18 PM
  #66  
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Originally Posted by Jfrahm View Post
I've run a lot of N2O, you can add fuel a couple different ways and it's not that difficult or dangerous as long as you have an adequate fuel system and a fuel pressure safety switch.
The WOT maps are not that sophisticated anyway and the 944 has no MAF, only an AFM. It'd be no big deal IMO to even run a dry kit for an old 5.0 Mustang on the 944.
Since you are not expecting to use more atmospheric O2 the temperature, pressure and humidity of the extra "air" is not a problem, it is a known quantity. Thus you just add a proportional amount of fuel. All you need is money! And extra bottles.
Cool, well you have much more experience that me on auto NOS, you alot, me zero. Perhaps we can start another different thread on NOS versus SC versus whatever on a 944. I'd like if possible to keep this thread on the topic of SC as that is what I want to learn more about.

Edit: Also I know that there is no MAF "sensor" on a 944, I was refering to Mass Air Flow rate in my post, abbreviated MAF rate. I think a dry NOS system on a 944 would burn the rings in short order. Especially on a later engine with high CR. But what do I know?
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Old 11-27-2017, 06:29 PM
  #67  
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My setup used an Eaton M90 from a 1990 Ford Thunderbird SC. It fit very nicely and lined up well with the stock pullies. Don't forget to run a bypass so the SC can freewheel when not inder load, helps with fuel economy. I was running 5.5 psi of boost and the car was fantastic. Loads of power from idle on. I never got it dynoed but I estimate it was making 180rwhp. I used Rogue's NA tune and the tunibility was amazing. I ran a front mount IC.
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Old 11-27-2017, 06:32 PM
  #68  
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Top view of where the SC was fit.
Attached Files
File Type: mov
944 supercharger whine.MOV (2.76 MB, 23 views)
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Old 11-27-2017, 06:33 PM
  #69  
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View from under the car of the SC pulley location.
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Old 11-27-2017, 06:40 PM
  #70  
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What did you use for the bypass valve? Is that it spliced in the intake pipe? How was it actuated?
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Old 11-27-2017, 06:43 PM
  #71  
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I used the factory Bosch valve from the 944 turbo, it worked well. It's actuated when the motor is running in vacuum(cruising). That is it spliced into the intake.
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Old 11-27-2017, 06:52 PM
  #72  
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What the thing in the intake with the wires running to it?
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Old 11-28-2017, 04:47 AM
  #73  
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Old 11-28-2017, 09:56 AM
  #74  
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Originally Posted by jderimig View Post
I just read your thread. Very nice! That SC unit looks very easy (relatively) to package. Can you elaborate more on your thoughts about the Eaton?
Eaton is not very thermally efficient (high temp), prone to heat soak and does not have a good top end. Ok for a street cruiser, bad for track use. Not really in keeping with the character of a Porsche in my view.
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Old 11-28-2017, 10:37 AM
  #75  
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If you are tuned correctly, I think nitrous is more than doable. I forgot where I saw the video but a dude ran a 13 something in an otherwise mechanically stock 84 with a ton of nos. I would just be worried about the trans after the tuning is accounted for.
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