IrocManiac

Which one is faster and which one is better as far as reliability is concerned. I have heard that Speed Density is better from the factory but MAF is better if you are going to mod your car and it is also more realiable. What makes the Speed Density cars run stronger than the MAF cars???

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TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

redmet91z

I think most would agree the speed density cars are faster in stock form. As far as reliability the speed density cars do not have a maf sensor or the burn off relay and things associated with the maf. The speed density uses a map sensor which is way cheaper than a maf sensor. The maf sensor can make adjustments for increased flow but that doesn't mean that the speed density car will be slower with mods because it calculates airflow according to data in the prom. It is a rumor that speed density can't handle mods that well. However in either case if you wanted to take full advantage of your combo a custom chip will do the job.

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1991 5.7L Z28 - gutted air boxes, K&Ns, airfoil, ported plenum, relocated MAT, accel TPI base, accel 300+ ignition, accel cap&rotor, homemade AFPR, derale fan switch, vette servo ,flowmaster exhaust, torque conv. lock-up switch, and fresh 255/50/16 Dunlop sp800s. More to come!

TRAXION

Speed Density is better from a reliability standpoint due to not having the MAF and its relays.

MAF is better from a mod perspective until you get enough cubic inches that that MAF becomes too small. There is definitely a benefit to having a MAF due to the fact that it is actually measuring the amount of air entering the engine.

My theory is this...

If you're going to burn your own PROMs OR if you go with a 400+ cubic inch engine then go speed density. If you are not going to burn your own PROMs and you will stay at 383 or lower cubes then MAF is AOK.

Generally speaking - the SD cars do appear to be faster stock. Whether this is REALLY true or not still remains to be seen/proved. But, I have observed enough that I am leaning in that direction.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.587 @ 107.97mph (1.710 60ftr) on the long runner setup.
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels. Stock Wheels. No Weight Reduction.
Gunning for NA 11's with the MiniRam II and Hooker LT Headers.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org