Any personal experiences????
I really wanna know how the idle will be, it's not a large cam so I'm thinking I can get away with it.
If you want to put a cam in speed density auto car i think the e303 is the way to go,b303 is more of a stick cam.
Neither one will idle well. Ford alphabet cams have poor vacuum characteristics at idle and low RPM's. Speed Density likes lots of vacuum. There are plenty of "bigger" cams that will actually work much better.
T-jet posted a chart from 50tech.com http://www.foxtbirdcougarforums.com/showthread.php?t=16085&highlight=speed+density+cam
Chances are ZERO & NONE...
Speed Densety will not like ANY cam with more than approx 212-215* @ .050 and less than 114* lobe center...
Think of SPEED DENSITY as the evil green peace overlord of hell. who's number one goal is non-performance cars, no horsepower, and no speed. you wanna live forever , drive speed density, and all the old people will fly passed you. sorry about the rant.....i'm either old school, or mass air. the speed density e.c.m. has very little room to play with your cars engine setup. sorry
um, thats why the '87-'88 stangs where faster out of the factory then the '89-'93's? I had my stock speed density '88 stang running in the 12's @104mph... Thats not fast?
I helped a friend of mine gasket port (matched the port openings to the gaskets size on the intake and exhuast) the heads on his 87 f-150. (thought it would help) truck ran great before. afterwards it ran like shiznit, wouldn't idle, fell flat on its face. no power. after lots of cusing and a few months he ponied up and bought the $700.00 kit from jegs to convert to mass air. no problems since. so after watching his bad luck unfold, i stay away from the speed density.
As long as you have more than 16/17" vac the speed densety will be happy(idle)... This isn't to say it could lean out with large enough airflow(heads, intake, exhaust, etc)...
The SD is not a bad system, it just has to be programmed for the particular engine it is operating... IF you had large cam, heads, inj etc and it was programmed for these and to idle on 12" of vac it would be great...
Your friend fvcked up then. My GT40 headed .533 lift cammed SD Bird runs fine. Probably has just as much balls as your carbed set up.
your cam works fine because of the short duration(more vacuum). if you were to bump up to a cam with more duration(less vacuum), it would run like shiznit without Mass Air.
lift isnt the only thing different on aftermarket cams.
I know. But if his friend just ported the heads and caused the SD computer to go crazy..............he had to do something else besides port match the heads. GT40Ps flow more than simple port matched E7s and I have no problems. He had to add too big of a cam or something......
I'd have to agree. I had an aftermarket cam with speed density. The previous owner of the car installed the cam. The heads and intake had work done to them too.
Something else was wrong IMHO.
Like Tom said once you start to go nuts you have to calibrate the SD for the combo. Most aftermarket computer setups are SD.
The '87 F-150 cam has the same lift as the SO cam. I've never been able to find duration #'s to compare the two, but I'll guess it has a little more duration than the SO cam due to the extra weight, E7 heads from the factory and 19 pound injectors as opposed to 14's.
I can't really see the duration being too much though, at least not enough to interfere with a simple port match job to the point where it makes it run all messed up. The cam specs on Thunderjet's cam are here: http://www.compcams.com/Technical/Search/CamDetails.asp?PartNumber=35-308-8
***With all this being said, I've had an idea floating in my head for a while that I'd like to try, but just haven't gotten around to it. It involves my current motor setup in the Cougar, a vacuum sytem and speed density. Perhaps in the springtime.....
Vac can? ;)
Per Ford Racing:
On EFI engines, performance camshafts work only with mass air induction systems.(B303, E303, F303, X303, Z303 cams)
Speed density system, airflow is "inferred".
Mass air system, airflow is measured directly. It reacts faster and more accurately to changes in airflow and improves idle quality and overall vehicle perfromance.
FYI 87-88 5.0 HO' were the fastest in bone stock trim. If you can tune it properly SD is the way to go. Problem is that it gets expensive when you start playing with longer duration cams. Mass Air is much more forgiving in stock trim (OEM-wise) and cheaper. WIth some skills you can tune it though. Once you go balls out you'll need an aftermarket ECU anyway so.....
Good job thunderjet with that speed density setup! Looks like a quick car.
Were the specs on the cams the same? Did the small mass air meters have anything to do with the later models lower power? Were the compression specs the same?
There was a change in '91. A slight one, but as far as 87-90 yes they were.
Realisticly? 5hp.
MAX In stock form anyway.
Yes. Same heads, block, pistons, rods, crank, and head gaskets. Piston change in '93 to Hypereutectic as opposed to forged. Same specs on size, comp. height, valve relief size, etc.....
****** There is hearsay that the '86 and VERY EARLY '87 cam in the HO was an ever so slightly different grind that was a little more aggresive. I've never heard confirmation or seen any hard facts or evidence to support whether this is in fact true ******EDIT the HO cam had a part # change for the 88 model year....the cam may have snuck in some late 87's.....
It's a bit quick ;)
IIRC the engine components (H/C/I) were the same (excpet for the slight chance that the 86-87 cams were a bit better). The major difference was in the computer calibration. Each successive year from 87 on the computers got a little less aggressive programs to help with emissions.
So in essence a 88 would be less agressive then a 87 and 87 less then 86...
Is an 86 HO speed density computer a decent one to run then? I found one local for a decent price.
Also, the 1986 SD HO uses 19 lb injectors right? If so, could I go grab the 19lb injectors from a 93HO (MAF Duh) Cougar I saw in the junkyard and use those without a problem?
Basically any HO computer will operate any orange top 19lb inj...
My 5 speed '86 5.0 stang used to buck like a sum bish unless I ran Amoco premium... Ran good though... Converted it to Mass Air using a '89 A9P auto EEC(was told it was a stick)... Still bucked(& lost .25 sec at the track).. Finally sold it and kept the A9P... Inst that same EEC in my Bird, it bucked... Tried a C3W1(Motorsport EEC), it bucked... Finally a '89 A9L from the flooded stang convert fixed the problem...
Yea more info than you wanted, but gives a idea how different EEC's can react...