Chase85

I have been wondering how much of a pain it is do upgrage a 1988 5.0, I have heard that the speed density system makes it harder to upgrade. I have seen items like a bbk speed density-> mass air conversion http://www.lmperformance.com/6532/60.html Does this only give you the ability to to install a CAI or does it solve all the problems with the speed density?
Think I have also read somewhere that the mass air system on 89s and later, detects changes in intake And exhaust(the reason the mass airs are sposed to be better) does this mean that changes in the exhause or intake will turn on the engine light if the computer isnt manually ajusted?

Any info would be great. This is all because(and I posted on another forum) I havent decided between a 88 hatch and a 89 vert(I am not fond of verts, but if its to much of a hassle to upgrade the 88 I could live with it)

GreyStang

Yes mass air adjusts to engine mods better than speed density, which basically uses a fixed calculation to determine fuel requirement. You can still mod a speed density equipped car somewhat.. what are your mod plans for the car?

Chase85

My plans for soon after I got it would be, BBK CAI, BBK headers, Magnaflor xpipe with cats and magnaflow exhaust, and a SCT Superchip. (all this stuff is at americanmuscle.com and its all stainless steal) along with come toher cosmetic changes.
And then maybe down the road like a lower psi supercharger.

07_427R

I had a 88 Lx with Speed density years ago. That system limits you on mods but works fine with a mild build-up. I was close to upgrading to mass air before I sold it but I would recommend 89+ with mass air if you going to tinker with the car. Speed density has its limits. This link covers the basics for speed density and mas air.

http://www.carcraft.com/techarticles...uel_injection/

Chase85

From what I read on that site, the Speed Density systems only flaw seems to be that if you change anythgin that affects teh VE(the manifold vacume) the computer is unable to properly compensate.Yes it does have other sensors but accordign to that site the only major one is the ve, the O2 i would assume you would want the o2 exhaust sensor to be the same (for effiency) So could you just not upgrade the intake and still see the gains from an exhaust sytem.
The only reason im trying so hard to find a loop in the 88 is cause teh 89 im alos looking at is a vert, and im worried about such things as theft, and the hassles of leaks from a vert.

07_427R

Speed density has trouble reading changes in air flow, hense different heads, cams, supercharging etc gives it fits. There is no loop except as I recall from memory you might be able to have a new computer program burned to reflect engine mods for a speed density system but if you go to that trouble why not by a mass air system?. The best thing about mass air is it reads air flow . That allows for many engine mods and the mass air figures it out as you go. Its been 10+ years since I've delt with both systems so I'm not up on modern day 'secrets' but mass air would be the ticket if you did more then headers/rockers/H-pipe/cat backs and maybe a mild E-303 cam and a new intake/throttlebody. Otherwise you may have driveability isses with speed density. If I ever dove into another older model stang, it would have to have mass air!!! IMHO

Chris


[IMG]local://upfiles/64453/0E9B563170CA4016A2C07EF6FFA0F84B.jpg[/IMG]