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Discussion Starter #1
I'm restoring an 88gt aod car and got a paxton sn2000 older ball bearing supercharger with an upgraded impeller. Im thinking this kit will only push 5-6psi tops. I have a few questions.
I've read up on Supercharging an SD fox and know about the check valve and hole before the map.
The most im going to do to this car is full exhaust, supercharger, and thinking about an Explorer top end. Staying with the stock cam.

Now I know I need an adjustable fpr, but will the 19lbs injectors support it? Do I need an fmu? Do I need to get the msd box that pulls timing with boost? Just wondering if this will work with the speed density. If had to step up the injector size, will the stock ecu still work?

If I do convert to mass air, would I still need an fmu or just a meter and matching injectors?

Not looking for a radical huge power car. I would just like to make it a nice little daily with a little bit of power. Would this combo get it in the 280rwhp range or close?

Thanks for any help.
 

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Easiest & cheapest way would be 12:1 FMU, keep the 19's and stock FP regulator, and lock out the timing at 20-22 degrees. Make sure your fuel pump is up to the task. Bigger injectors would need a tune with SD.

Converting to mass air and larger injectors with matched meter would work too. You could dump the FMU then.

No tune in either case leaves some HP on the table. With the AOD, probably looking at 260 RWHP.
 

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I'm running about 7 lbs. of boost on my 88 LX with stock injectors and an FMU with no issues. The other upgrades that I have are an Anderson Power Pipe, Ford Racing 65mm throttle body, Magnaflow cat bac, a BBK 255 lph high pressure high volume fuel pump, a Summit Racing ignition coil and a 180 degree thermostat with an aluminum radiator.

Go one heat range colder on the plugs and narrow the gap. I am running a .028 gap on mine currently and could probably go wider since I have an upgraded coil, but I haven't fiddled with that. I also set my base timing by starting at stock and slowly moving up until I heard detonation in a high gear and flooring the gas and backed it down until it was gone. I think I am at 12 degrees of base timing right now. You just have to experiment with spark plug gaps and timing, but be careful as getting too aggressive and you can blow head gaskets or worse.

I'm sure I am leaving some hp on the table, but it's just a street car and I just wanted a little more power. It is plenty fast enough for me and it will roast the tires off all the way through first, most of the way through second and chirp when shifting to third. I was able to run it at the strip last Summer and it ran the quarter in low to mid 13's at 104 mph on street tires, which is pretty good for a convertible. I also have 3.55:1 gears and my car is a 5 speed.

You can easily do Upper and lower intakes plus headers on speed density and those will yield some nice gains as well. Those will most likely be my next upgrades as my valve cover gaskets are leaking a little oil and while I am half way there I may as well upgrade. My previous Mustang had a stock extrude honed upper and lower intake and it made a huge difference.
 

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I'm running about 7 lbs. of boast on my 88 LX with stock injectors and an FMU with no issues. The other upgrades that I have are an Anderson Power Pipe, Ford Racing 65mm throttle body, Magnaflow cat bac, a BBK 255 lph high pressure high volume fuel pump, a Summit Racing ignition coil and a 180 degree thermostat with an aluminum radiator.

Go one heat range colder on the plugs and narrow the gap. I am running a .028 gap on mine currently and could probably go wider since I have an upgraded coil, but I haven't fiddled with that. I also set my base timing by starting at stock and slowly moving up until I heard detonation in a high gear and flooring the gas and backed it down until it was gone. I think I am at 12 degrees of base timing right now. You just have to experiment with spark plug gaps and timing, but be careful as getting too aggressive and you can blow head gaskets or worse.

I'm sure I am leaving some hp on the table, but it's just a street car and I just wanted a little more power. It is plenty fast enough for me and it will roast the tires off all the way through first, most of the way through second and chirp when shifting to third. I was able to run it at the strip last Summer and it ran the quarter in low to mid 13's at 104 mph on street tires, which is pretty good for a convertible. I also have 3.55:1 gears and my car is a 5 speed.

You can easily do Upper and lower intakes plus headers on speed density and those will yield some nice gains as well. Those will most likely be my next upgrades as my valve cover gaskets are leaking a little oil and while I am half way there I may as well upgrade. My previous Mustang had a stock extrude honed upper and lower intake and it made a huge difference.


So you are on the stock MAF and injectors with just an FMU? No tuning besides some timing adjustment?

Did you leave the spout out after setting it to 12*?
 

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Discussion Starter #6
I was wondering if he was still on speed density or had converted to mass air. I think you can get away with timing and fuel pressure adjustments as long as your not making a ton of boost, from what Ive read anyhow. It's no replacement for a tune, but I would think as long as your afr is in check, it would be ok.
 

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No MAF as it is still speed density. The FMU makes the mix rich under boost and my A/F meter shows the mix as being proper during normal driving. No tune, just the stock computer.
 

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Discussion Starter #8
No MAF as it is still speed density. The FMU makes the mix rich under boost and my A/F meter shows the mix as being proper during normal driving. No tune, just the stock computer.
Where did you get your check valve from and did you put the hole in the line before the map? Is it a 12:1 fmu? Any tampering with the fuel pressure or no?
 

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The check valve kit came from Vortech. I think you can still order the kit from their web-site. The FMU came with a set of discs and I used the one for 19 lb/hr injectors, which I believe is 12:1.

I am running the stock fuel pressure regulator. I did have an adjustable one on my last supercharged Mustang, but that car was much more modified than my current one and it was a mass air car. The main thing is to remember that all engines are different because of age, wear and etc...so you have to tinker with the timing, fuel pressure and etc...to find what works best for your motor. I'm not going to do too much else to this car right now because I am buying a Jaguar XJR in the next week or so.
 
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