What's the difference?>

 

20 bucks ..that;s all

 

The Steeda's are SFI approved and have the harmonic balancer built into the unit.The Mac's are not and are piggybacks.This means to have a harmonic balancer you bolt the stock balancer to the new underdrive unit.Some people say you don't need this balancer on your crank.I say that if Ford didn't think it was necessary they would have deleted it to cut costs.The Steeda parts are first class in fit and finish,but I have not used the Mac parts so they could be good also.Steeda and March UDP's also allow the use of Steeda's timing adjuster.

 

March products are tricky, many sites don't list the SFI approved crank underdrive pulley as an option to purchase. 99% of the time if you order March UDP's you will get piggy-backs.

 

well steeda it is then.


as far as harmonic balancer, cross plane v8 engines have a lot of vibrations, balancer supreses some of those vibrations, otherwise you'd be loosing torque and power. steeda's timing adjuster is gabage, btw, it's a wrong thing to use and it sux in any application, don't buy it. a proper way to adjust timing on electronic ignitions is to make modifications to timing map, either in ecc-v or use an aftermarket ignition control module.

 

Mind telling us how the timing adjuster is crap?

 

don't mind at all.


ford's waste spark ignition works by sensing crankshaft position using crank sensor. this sensor is critical in firing precise ignition and injection events. if this sensor is off, both ignition and injection is off. poor performance and efficiency is the result. you could melt down the engine if spark and fuel delivery is off by miles.


now, mapped electronic ignition's work by using a map of ignition advance values, which computer selects based on throttle position and rpm. this map has highs and lows. steeda's mechanical adjuster sends false signals to ignition [and injection] which in turn either raise or lower the entire map by a pre set number. this is bad, sense it is possible to advance timing at lower rpm and closed throttle by a few degrees before detonation, but at high rpm and open throttle timing might be too much and you could get some bad detonation. proper way to adjust timing on a mapped ignition is to modify the map, and not raise the entire map by a set value. add to this the fact the injection events don't fire when they should, and you could do some serious damage to the engine.

why people are using such timing adjusters/ that's because most people are dam, especially old car guys, who are used to be able to adjust by turning distributor. fact is, ability to modify your ignition map cost you less than their mechanical timing adjuster/ecm confuser.

think steeda's timing adjuster is the same line of devices as air temperature sensor resistor. sure people tune by confusing computer, but the results are week and unimpressive.

 

Wrong.The pulse width of the fuel injectors are controlled by the cam position sensors.The timing adjuster does advance,or retard,timing the same amount from idle to WFO but on a basically stock engine(like mine) there have been no adverse effects.I did gain +2 mpg's though.I believe that most handheld programers start modifying the timing at 2000 rpm.The Steeda part allowed me to advance the timing starting at idle.

 

Wrong.

Fuel map lists target A/F ratio based on throttle position and rpm. Rpm reading comes from crank sensor.


a) I'm a programmer.
b) I'm knee deep into electronic engine controls, and I don't mean OEM stuff.

You are hurting your engine by not providing proper sensor readings to your computer.

 

I know that Haynes manuals are not the end all be all of shop books but they say that cam position sensors control the fuel injectors.(I already knew this).They couldn't be that far off.