if you're going to do a cam, do a correct maf conversation

 

Those are speed density cams

 

The stock cam isn't horrible with the right supporting components, there's a thread on here for stock cam combos. I ran SD on my 86 just so I could run the vic jr. and 4 hole throttle body.

 

ok enjoy

 

Those are excellent heads for what you are doing.

 

My best SD cam was comp XE270HR14

Made 320 rwhp with tfs 170s

 

What intake were you using?

 

I've not gone past basic bolt ons with speed density. I do understand the SD system is not a forgiving as a MAF. However, wouldn't a tune solve most/any cam related issues?

 

I don't know of any tuners who tune SD mustang ecus. They aren't common, that's for sure.

 

I ran the stock cam because I was using older TW heads on a stock 86 shortblock so had to work with piston/valve clearance issues. With good heads, intake, and exhaust it still made around 335/335 at the wheels, and ran 7.1X@94.XX. I have it set up to run either speed density or mass air, just by swapping processors, and plugging or connecting vacuum to BAP/MAP sensor. I used to run speed density with the B-cam and just tuned it, but for overall driveability it's hard to beat mass air. I think a conversion kit is $50, just have to scare up a processor for it.
What's the code on your speed density processor?

 

I ran the stock cam because I was using older TW heads on a stock 86 shortblock so had to work with piston/valve clearance issues. With good heads, intake, and exhaust it still made around 335/335 at the wheels, and ran 7.1X@94.XX. I have it set up to run either speed density or mass air, just by swapping processors, and plugging or connecting vacuum to BAP/MAP sensor. I used to run speed density with the B-cam and just tuned it, but for overall driveability it's hard to beat mass air. I think a conversion kit is $50, just have to scare up a processor for it.
What's the code on your speed density processor?

I need to check what code it it but I was thinking of running MSPNP later down the line when the funds became available for the dyno time and tuning

 

When I converter my SD car to MAF... it LOST almost 20rwhp... and 2 tenths..

SD timing curve in the computer makes more power than MAF/A9L... needless to say I went back to SD.
If you're just running H/C/I 24# injectors...stay SD.

Ultimately ran H/C/I 24s, and 150 shot and ran low 11s for years on SD... back when 11 second cars were fast!

 

Off the top of my head I think the WOT spark is similar, can check when I get home, but the SD are richer, and if you're mass air meter is some kind of restriction it'll make a difference too.

 

With what's available today I'd either throw an aftermarket EFI on it or carb it. The fox SD stuff is pretty good but it comes up quick where it's limitations are. Look at the options carefully before blowing $250 on a MAF and $200-300 for an ECU. You're half way to a Holley TermX territory. The cost to pay someone to tune an SD computer would be insane, chip, burn, time, ect.

 

Yeah I was thinking of going with a stand-alone MSPNP computer

 

Yeah, I dropped base to 10* and had added 100 octane gas.

This was before I knew how to read plugs.. but the motor is still running strong with the new owner like 10 yrs later now.

My biggest problem was splitting T5s

 

I have a PIMPXS in my turbo Fox, it's still a speed density system. I like it, the support forum is really helpful. The MSPNP is a speed density system too, I've heard its similar to the PIMP and I have also heard the forums are pretty good. If you already have a standalone system in mind, I'd get the nastiest cam that you can get, considering there will be engine management at some point, and a cam swap is basically tearing the engine half apart.

Speed density system is very forgiving. The people that hate on it ain't ever rocked with it. My 85 Marquis has the most preliminary EEC-IV speed density ECM which runs two injectors on a throttle body unit. Everyone on the Marquis forums said that ECM would never handle a head swap or an intake swap or exhaust mods, and we've done all of those things, daily driving still. I'd say just throw what you got at it.

 

Dude what kinda numbers was your SD Marquis making HP wise? Also did you run one of those high LSA cams to keep the speed density happy?

 

I'm running SD via PIMPXS on a boosted stock bottom end and cam. The heads and intake are aftermarket. I've ran both MAF and SD on various cars and they both work fine to me. Once it's tuned correctly; I think you'd be hard pressed to see a big difference. Pick your poison and enjoy.

 

Tuning pimpxs is not the same thing as tuning a stock SD ECU. There are very few tuners who will even touch the Ford SD computers.

 

Yes; I know. I'm just sharing another option.

 

Yeah there are lots of SD aftermarket options.. other than pro-m, are there any commonly used aftermarket ECUs that use a MAF?

MS, Pimpxs, fitech and Holley are probably the most common and all of them are SD.

 

Yeah there are lots of SD aftermarket options.. other than pro-m, are there any commonly used aftermarket ECUs that use a MAF?

MS, Pimpxs, fitech and Holley are probably the most common and all of them are SD.

Not that I know of. Even Ford has stopped using MAF's as much. My F150 and Taurus SHO are SD.

 

It's not really SD vs MAF is the question, it's that the SD computer in the fox is ungodly expensive to tune. MS stuff is great too.

 

I think most of it is lack of support for the SD ecus from Ford. I'm sure you could make changes using a QH but unless someone has already broke out the tune definition, it's going to take a lot of work to disassemble and locate all the info to tune it properly.

 

Quarterhorse has the base tune, and a guy named Sailor bob sells a def for $25 lets you datalog with more parameters than the base one that comes with QH.

It's not really SD vs MAF is the question, it's that the SD computer in the fox is ungodly expensive to tune. MS stuff is great too.

Not hard, just time consuming, Leech, and Decipha do it commercially, I'm thinking Pops racing does as well as long as you've got datalogs you can send them.

 

With SD.. put a wideband on the car.. tune it with fuel pressure and timing.

Tune for WOT afr and spark.
Let idle and drive fall where they may...it'll run harder than most expect.

 

haltech will run either. but noone buys an aftermarket ecu to run maf. unless you are a pro-m fan.

 

Knowing how much air is going into an engine seems like a no brainer to me but I also have no real experience with tuning SD setups. My friend is making about 1300 to the wheels with a MAF in a turbo yote. I dont understand why they get so much hate, they work.

 

i wasnt taking a dig at maf.. an ecu can also know how much air is going into the motor based on rpm, tps, iat and map. volumetric tuning isnt the same thing as injection time or fuel flow rate. sd gets the hate if u ask me..

 

some of the biggest HP small block ford motors ive ever delt with were SD... 1000+

 

my maf would not run a cam with vacuum at 16, nor my sd lol...........well it would for a few seconds but as it dropped, it died, but all other rpms actually ran pretty good, i just had to idle at around 900 to keep it from dying at a light, or dying when put in gear so out came the custom ground........as well as maf, waste of money

 

I’ve ran stand alone sd with a car that pulls 4inhg at idle. Damn near anything will run an engine that pulls 16.

 

Vacuum doesn't affect the maf. Sounds like you just needed to work on the tune. Specifically dashpot.

 

my maf wouldn't do it for some reason, NLOC guys were stumped too.
but it was a custom ground from cam research that had 32* of overlap and was ground to be run on speed density, im sure I could have got pimpx to make it run but i wasn't throwing anymore money at it. so the cam sits on my toolbox, and i guess i'll make a mailbox stand out of it one day

 

Amazing how low of timing they put in the ECU, I always forget they had it tuned to run piss for fuel.

 

Right, they don't get to full advance until 5K RPM too.

 

Another vote for PimpXS. Not much more than a MAF swap and soooo much more you can do with an aftermarket ECU. Nearly limitless.