No aftermarket tune, I just set timing and tweaked fuel pressure to get those numbers... Other than a occasional moderate surge at cruse it really had no major issues, though it did stall once in awhile when dropped into gear... Setting idle at 900 in gear fixed that(also had to reset TPS voltage to .9v as it was too high with that much opening of the throttle body, anything much over 1v will cause approx 2K RPM idle)... Cam mostly dictates the stall speed, the 2600 would be perfect for a stock HO cam... As long as the lockup feature is retained, stall speed has no bearing when in O/D... I really feel with a bit less cam it would have been OK, I've driven it from home to WV, western OH(almost Indiana), plus five trips to Carlisle so I'm real familiar with it's traits... Depending on what you want to spend, maybe consider a stock HO cam with 1.7 roller rockers, those will even work OK on the speed densety systems... Had a '86(the lousy head year)5 speed, 5.0, 2.73 gear Stang that ran 14.51@96 on that setup with horrid 2.2 60ft times(no traction)... BTW that 2600 converter vs stock lowered best ET from 14.08 to 13.56(both at 101), the 2.5" exhaust system and fresh plugs dropped it to the 13.11... I probably had the P/S bypassed on that run, can't remember for sure but was worth approx .075 in the 1/4...
You are correct with that statement. The A9P is the automatic version of those 2 calibrations. The difference is the hardware for the A9P uses a 12V input on pin 30 from the neutral switch. The A9L uses signal return which is an internal ground. If you don't use that pin it makes no difference, if you do and get them backward, you fry a PCM. I've been running a relatively stock EFI system on mine since 1999 and have put 40,000+ miles on it without hardly doing anything other than changing the oil. I get 20-21 mpg in Atlanta traffic and 25+mpg on the hwy. The only time it left me stranded was when I left my lights on and no one was around to jump it off. You probably will have to use shorty headers. Most of the long tube headers I tried either didn't fit the car or hit the transmission( I originally tried an AOD). I ended up changing it to a T5 but I had one at the time so it was no big deal, because I was persistent in wanting long tube headers.
You guys with 20+ mpg must have some speedos off or just calculating hiway mileage without even factoring the on ramps. I daily drive a stock 93 mustang and have mild 5.0 in my maverick. Neither are getting close to 20mpg in any kind of combined city/hiway driving. New the 1993 Mustang was rated at 15 city 19 hiway. You say you can add 100 hp and gain 2-3 mpg? please show me your trick because I cant figure it out. Ive replaced and tuned everything on my mustang to make it run perfect. Now back to 71Mavrk. A maverick or old ford floor shifter will work. Just need to bolt it up and make some bends to the linkage until it goes around the trans more and gives full throw to the trans linkage. Also you CAN us long tube headers. I had Hedman 1 5/8" on my car. The collector tip almost touched the trans pan. So we heated up the headers tubes and the 90 degree bend before they want into the collector. We used a rose bud tip on an oxy/ace torch. stuck a jack handle in the collector and pulled them out a couple inches. Made for a straight exahust mid pipe also after that.
Perfect! What you have is exactly what I am shooting for, good numbers and little grief. What motor specs do you have and what if anything would you change? Any mods to the computer? What did you do about the shock tower brace? These guys sell one but could not tell me if it would clear the FI intake: http://www.mmsacc-stainless.com/html/FordBraces.htm If you have some detailed pictures, I would appreciate a copy.
I have the Maverick floor shifter and trans hump to do an OEM retrofit (actually have two now). I thought I read there was something about the linkage inside the trans that needed to be rotated to make the shifter work. As far as the headers, I thought the main problem was clearance for the power steering and not the trans. I will be adding PS with the motor upgrade. Any issues with ground clearance? One last thought on headers, where did you weld in the bung for the O2 sensor?
I should clarify that, that number is right if I go with the full motor mods. I can get the EFI motor up and going now with just the wire kit and a fuel pump.
There's no "screwing with a used carb" if you choose wisely. I've bought 3 or 4 barely used Holleys in the past ten years and all have given me service equal to a new carb, and this includes the 3x2 setup on my 331. I built the motor 8 years ago and setup the carbs then and other than a single jet change after adding spacers under the carbs, I've yet to touch them. The 570 I had on my V8 ranger was another. It took me awhile to get one(570's seem to be fairly rare to find used) at the price I paid ($150) but other than changing the power valve, it's just as it was out of the shipping box, I bolted it on, adjusted the mixture and idle and left it alone afterwards for two years til I sold the truck. Now, if you buy a Holley that looks old, chances are you will have problems with it. That 570 ran so well on the motor it was feeding (Explorer 5.0), that you would have sworn it was an EFI setup. I'm like you too, in that I'm also getting to the age where I'd rather drive em than work on em, but I just can't see spending the time and money to convert an old car to EFI and the problems that can entail. But , hey, it's your money, time and your car.
The shifter linkage arm on the transmission must be positioned above the pivot point to work, same as a C-4. Column shift C-4's had the linkage arm pointing down or below the pivot, floor shift models had the arm on the topside of the pivot, that's how you can tell them apart from each other. If you use an aftermarket shifter (cable type) it makes no difference which linkage arm it has, you can orient the cable to work with either one.
I have a VDO electronic speedo that is within 1mph verified with my Navigation that I use on my cell phone. I get 200 miles to a tank from full to about 3/8 to 1/4 and on average, takes 10 gallons to fill up. I don't have a sump so I generally don't let it get down below 1/4 tank. I drive a combination hwy and city in traffic daily to work and back, usually with the ac on. The engine isn't internally modified at all, I deleted the EGR spacer and run an Explorer throttle body and Hooker 6901 long tubes, 3.50 gears and 25.7 in tall tires. Stock engine and on the chassis dyno with the 3.00 gears it made 215hp, 294 lb/ft torque. The shock tower braces I made out of tubing, see pics in my gallery, and most of the ones I have seen won't clear the intake. There may be more choices now. I didn't modify the computer at all, and if I changed anything, I would use a hydraulic clutch. When I decided to do this, everything I could find was for Mustangs and I didn't have the wealth of info that is available here. I am currently running 3.50 gears and only can muster right at 25mpg on the hwy, but the combination numbers of 20-21mpg are achievable. Ethanol content does however wreak havoc on fuel economy and I will get as low as 17 mpg in the city on occasion. Keep in mind that fuel quality and blends vary greatly based on region and season, and may offer some explanation for the differences. The header issue was just my experience and I wanted a manual anyway, so I didn't want to mess with modifying headers. My goal then was to use as many off the shelf parts as possible to make it easier to repair down the road if something were to break since I was doing this for the purpose of daily driving. I do sort of miss messing with the carb every now and then especially since it adds to the allure of playing with older cars. My luck has been pretty good as far as getting a good running engine with fairly low miles and with all of the electronics in almost new condition so it has been a good experience.
it can easily achieve those numbers with free flowing air cleaner/exhaust and a good computer tune. Computer tunes can be like a tune up since they pay for themselves over time. Even oil and tire choice/pressures can make a difference too. My 500 horse s10 street Blazer gets 18mpg hwy with 3.73 gears. I could easily get more.. but my current compression required premium/e-85 mix won't allow it. With a bit less compression it's probably a 23mpg truck. It's all in the tuning and torque tuning just off idle up to cruise rpm is key to light throttle gas mileage. As for the talk of factory computers.. the factory config's have a lot left on the table if you want to invest the time and cash. I wouldn't doubt that you'd get 3mpg gains from a good one. And if you do run an aftermarket cam.. you'll likely need one for sure. If you want to do it on the cheap.. then I'd stay close to stock and free up the extra potential with intake/exhaust and a good tune. Just those heads alone willl negate the use of a stock tune due to the increased airflow potential. Especially at lower lifts. Figure on the extra $600 or so to get all that stuff dialed in unless you have the means to do it yourself. And you can easily spend a grand if you want to flog that last 3 horses out of it. lol
How much total HP a engine can make has little effect on constant cruse MPG, all highway my '86 5.0 Stang could easily make 26 MPG... Even my 4300Lb, 430 RwHp, supercharged Marauder will get 22 on the highway... That's figured pump to pump, on ramps and stops at McDonalds included... Around town is of course another story, can about see the gas gauge fall when the SC is whinin'... http://www.fueleconomy.gov/feg/bymodel/1993_Ford_Mustang.shtml
What location on the firewall did you cut for the harness and where did you mount the computer? At 70 MPH, what RPM are you turning? Also, where did you insert the return line into the tank? I was looking at using the vent lines to get the fuel back to the tank. I'm still unclear if the computer needs to be modified. I see some posters saying they changed heads and intake without reprograming. Others have said the heads alone would require a reprogram. Anyone?
On the average O/D & EFI is worth around 5 mpg over a carb & three speed automatic... One of the Stang rags(MM&FF I believe) reported 7 mpg on a early five speed Fox Stang that was converted to EFI... If one has a wideband A/F gauge, there really isn't any reason that a carb could not be tweaked to give a cruse MPG close to the EFI(assuming a O/D trans)...
You hit upon my reasons to go with the EFI. While you probably could get the carb to perform close to the EFI, there would be tweaking required. Here in Reno, the summer temperatures range from 70’s to 100+. The winter could be nice in the 60s and then down to the teens. Then there is the switching of gas blends between the seasons. Also, there is no ability to adjust the carb on the fly for the elevation during a drive from Reno (5,000 ft) to the Bay Area (100 ft). Throw in the yearly smog check. I just don’t want to screw with it. Five years from now, when gas is $8-$10 a gallon and you can stretch 10-15%+ better MPG with an EFI, then the cost of the install would not take too long to recover.
