hypersurf1

Great job Jon, nice to know the SD can handle the 30's. Let us know if you run it at the track or make any changes.

JPJP

Great clip mustangjon. It's great you have done what people say can't be done. I once had an LSC which got me back into Mustangs again, thus my '86.

I am running a MSD-6A ignition box with my plugs gapped at .038". I hear most supercharged 5.0's like around .035" gap.

cougar john

Have you had any more luck?
I'm installing a Paxton self contained unit on my '88 Cougar XR7.
It's speed density with a cobra type upper/lower intake, 70 mil tb, MSD, headers, no cats.
Let me know if you have had any issues. I think we have basically the same motor and electronics as FOMOCO treated Lincoln and Mercury as bastards when it came to performance.
John

mustangjon

Well My car has been down and out with my tremec swap.... long story short pieced together everything with new and used parts and A+B dont equal C so for 3 weeks its been sitting at my buddies shop with us only getting a few hours one day a week to put it on his rack. I rebuilt the fmu so should now be fine on the top end with fuel, also calibrated it to the 30lb injectors. Your setup should be similar to mine, i guess you still have e7 heads tho, you need to put a check valve to your MAP sensor and a small bleed hole after the check valve in the hose to vent any boost that gets through. MAP sensors do not like positive pressure. My motor was the exact same as the speed density mustang hipo. Not sure if the xr7 was the hipo, but with the intake changes and such not much difference. Im guessing your paxton is the 1220... the 5-6lb unit will be more friendly. Actually with the 30lb injectors in mine... it doesnt start going lean till a few lbs into boost when the fmu wasnt functioing

2tonterror

I just installed a Crower 15511 and ported E7's on my 88 speed density LSC. The stock 19lb injectors worked fine. Anybody else do a cam swap??

kelly3027

Hey Guys, I'm brand new to the forum and to 'modern' muscle cars. My last one was a 70 Camaro, in the late 70's. I don't know jack about FI systems. I bought an 87 lx recently and am desperate for information. Most everything I read says trash the SD system. This thread gives me hope. I may end up getting rid of it, but I'd like to at least keep it until I understand how it works. I'm still in the process of fixing a buttload of stuff that I inherited with the used car. You ought to see the brake drums! Anyway, thanks for the information, Kelly.

rbonella

I don't get it? New to the forum, but not new to fords (mustangs specifically) I'm reading threads about people porting gt40p's, different cams, 24-30lbs injectors, going back to 19's, adding 10lbs of vortech boost, plugging this, opening that, whay are you guys not converting to mass air? You have the money to put superchargers on, but you're retaining sd? Why? You're pulling off heads, porting e7's, porting gt40's, doing all this work with old speed density crap! Don't get me wrong, I had an 88 highway patrol car that was sd and I was able to successfully make a e303 work someone ok, gt40 tubular upper and lower, shorties, hpipe, yada yada, it eventually went 12.70's @ 105 with a 28x10 slick and 4:10's, but conversions are not difficult to do, not too expensive either. My point is...if you're spending all this time and $$$ (vortech sc) why wouldn't you make the most of your investment and run mass air? 9AL is a wayyy better cu which will adapt to your modifications much better. Someone enlighten me

markus2

Joined so I can try to learn a few things from the pony owners on here.
This is a great thread and I too am running 24 lb injectors with no tune and its SD with the stock computer of course ON MY LINCOLN MARK VII.
I have idle issues and some flat spots-but dont think its due to the injectors in there-First few weeks after putting them in-the thing ran fine-so I dont think its the injector size on my car configured for 19's.

Car failed emissions of course horribly-seems to be bit rich-gotta be the injectors.

But this thread gives me hope....

There is in fact others out there running larger injectors with SD non tuned set ups.

I just wanna know what the downside is-and how it is the car runs when everybody claims:

"YA GOTTA Change the computer-it wont run-u need mass air with correct calibration for injector size"

I guess that statement might not be totally true.
I DONT KNOW THAT MUCH AND AM HERE TO TRY TO UNDERSTAND MORE ABOUT ALL THIS.

jayh88gt

rbonnela- i cant answer that question, the sd runs good, i have had a few of them. Ive got heads intake 1.7's full exhaust and 11-12psi boost, car runs goood. I guees Im cheap and lazy I only have maybe 3500 onto the car and it runs good, I'd end up spending $500 and the car wouldnt be any faster or run any better?? why bother??

Joel5.0

How far can you take speed density?.... it really depends on how far you want to take it. Just look at this GT40 headed '88 with an AOD transmission at idle and the specifications of the custom cam installed..... 24# injectors and a 65mm TB (70mm to be tested and compared) on an Edelbrock Performer, no tuner....yet.... as you can see A/C is mandatory in our neck of the woods.



Here's the setup idling in Park.......

http://www.youtube.com/watch?v=FQUDAvhNodQ