Discussion in 'Fox 5.0 Mustang Tech' started by 1killercoupe, Mar 15, 2012.
can i run speed density setup with heads cam and intake
Not with any degree of ease or comfort: it would require a custom dyno tune Every time you changed something, it would be a trip back to get the tune updated to accommodate the change.
Speed Density uses Manifold vacuum (MAP), Throttle position (TPS) and RPM, Air Temperature (ACT) & Engine Coolant (ECT) to guess how much air the engine is pulling in. Then it uses all of them to calculate the air/fuel mixture. It is dependent on steady manifold vacuum and minimal changes in airflow from the stock engine configuration to maintain the proper air/fuel ratio. Change the airflow or vacuum too much and the computer can't compensate for the changes, and does not run well. Forget about putting a supercharger, turbocharger or monster stroker crank in a Speed Density engine, because the stock computer tune won’t handle it. Every time you seriously change the airflow through the engine, you need a new custom burned chip to make the engine run at peak performance.
Mass Air uses a Mass Air Flow meter (MAF) to actually measure how much air is being pulled in and uses the inputs from the TPS, ACT, ECT, RPM and Barometric Pressure sensor (Baro) to calculate the proper air/fuel ratio. It is very tolerant of changes in airflow, and vacuum and tolerates wild cams, high flowing heads, and changes in displacement with minimal difficulties. Larger injectors can be used with an aftermarket calibrated MAF or a custom dyno tune. This makes it possible to use the stock computer with engine displacements from 302-408 cu in, and make many modifications without a custom dyno tune chip. Put a new intake manifold on your 331 stroker and the computer figures out how much more fuel to deliver without having to have a new chip burned to accommodate the extra airflow.
I ran a stroker with tfs heads and intake with a comp cams custom grind on a speed density computer for years with no problems but I did pay more for the cam than an off the shelf mass air cam. Actually when I switched to mass air my car lost a little power. The only reason I went mass air when I did was because I couldnt pass up the deal on the mass air conversion parts and a blower is in my future. I never had the car on a dyno.
im getting the edelbrock performer 5.0 heads with the performer intake manifold for my 88 notch i wont be converting to mass air is there anything i could do to help it idle better like a spacer for the iac on the throttle body i will give comp cams a call for advice on the cam
also will stock pushrods work with those heads on a stock short block i have a set of crane cam 1.7 rocker arms from the 93 cobra mustang will those work with this setup . keep in mind i need to pass 1 more ct emission test.
The cam is the critical piece to modification with a SD setup, I've done quite a few over the years BUT as you change more things the MAF conversion is a good choice.
Those rockers will work if you buy a pedestal mount head. What part number are u looking at? I still think a TFS head is a better choice. I could put a nice setup together for you that will work great. Pushrod length should always be checked, I wouldn't reuse the cheap factory pushrods
the rocker arms are crane cams p.n 44746-16 93 cobra rocker arms on edelbrock performer pn edel-60379# is the p.n the same i just ask for pedestal mount head or is ther a differnt p.n thanks for the advice i wanna do the best i can while its a part
Completely agree I have no doubt my combo would not have worked if not for the comp cams custom grind I ordered. As it was explained to me getting lift was not the problem but keeping the lobe separation near or at stock numbers was the key to the engine running well.
thanks for the input