I am fairly new to the truck world, and I am learning quickly. But I was wondering what is the difference between the lightning and the Harley that warrants 40 hp? (Ls run 380 stock and HDs run 340 hp right?) Are they just tuned differently? I am unsure how to explain to people why the engine has less horsepower, but is the same engine (or so I am told).

Thanx in advance

 

2lbs less of boost courtesy of the upper pulley being larger than the stock L. That would only account for about 20 of the 40 difference with the remainder apparently in the tuning of the computer.

The biggest question you have to ask is what you are going to use the truck for. Pure performance? There is only one answer: The L! If you want good performance AND you need to carry people, then the L won't work for you as it has no back seat.

You are going to have to mod the hell out of your HD to get close to an L that is lightly modded just to overcome the weight issues.

Although I could be wrong, I suspect the driveline in the HD may be responsible for some of the HP losses (at the wheel anyway) as it is a 2 piece steel vs. 1 pc. aluminum in the HD.

Ken

 

The upper pulley on the HD is larger, yielding 2 pounds of boost less than the L. Also, the exhaust on the HD is longer. As far as the tuning, the computer parameters are set exactly as the L, with the exception of shift points and AC timing (I have no idea why that is). For the most part, the loss in HP is due to the decrease in boost. This is easily fixed.

 

According to Truck Trend March/April 2002:

They asked George Magro, manager of product development at Ford, "about the powertrain similarities between the Lightning and the Harley-Davidson F-150, Magro notes that the 40-hp difference (340-hp H-D F-150 versus 380-hp in the Lightning) is due to a larger pulley installed on the SuperCrew's supercharger. The result is the blower rotating at a slower rate, hence lower boost. The Harley-Davidson edition uses a full-vehicle-length exhaust, unlike the abbreviated pipes sitting in front of the rear tires on the Lightning. A slightly smaller opening in the lower front valence allows less air to flow through the intercooler, meaning that incoming air is not cooled as much as the higher-powered sport truck. The cumulative result is a modest decrease in power."

Straight from Ford - larger upper pulley, longer exhaust system and smaller opening on the front valence cause the 40 hp difference between the two.

Even if you changed these three things on your H-D you might match the horsepower, but there would still be a difference in speed because of the additional weight.

 

Don't forget the exhaust manifolds. Our Harleys use the exhaust manifolds off the old 235hp 5.4. The Lightning has a larger (better breathing) version. I suspect most of the power loss other than the 2lb lower boost is in those manifolds.

 

terry, are you sure on the manifolds? there was a thread in the L forum concerning the manifold with a couple of Ford guys swearing they were the same and one swearing they were different..



where did you get that information from? I sure would love to know for sure... If that is indeed the case, a full exhaust system from headers on back would probably benefit a great deal...

thanks

Ken

 

but did ya ever notice that the gap on the 02 HD between the top of teh bumper and the bottom of the grille shell is bigger than on a 00 or 01 f150? They did that to compensate a little. just a fyi

 

Hi Ken
I got that info from Mike at Performance Products (the Superchips distributor). Just talked to him again today and he insists the Harley has the old (lousy) small manifolds.

Terry

 

From Texan Ford parts department and from the Tommy Vaughn Ford parts department, I got the same information:

For 1999+ 5.4l engines, regardless of L, HD, or Standard F150, the part numbers are the same.

Left exh. manifold: RXL3Z-9430-GA
Right exh. manifold RXL3Z-9431-FA

Just what I could come up with... some of you guys call your local parts deparments and see if you get the same answer.

Thanks,

Ken

 

Same answer here from a couple of dealerships and some aftermarket places.

 

Ok, I went out to the truck and looked under the wheel well... Push the rubber back slightly and you can read the part numbers on your exhaust manifold with a flashlight.

Driver side:

RF-2L1E-9431 CA with a little W3B nearby

Passenger side:

RF-XL 3E -9430 DD

That's what mine read... somebody go read yours and confirm my numbers

I tried 3 more dealers including the ones online and got those numbers... They say there is no special listing for an L or Harley... Just the 5.4. If, in fact, we have garbage manifolds, why on earth would ford have done that?

Thanks

Ken

 

Ok... i have talked to another person that told me those numbers are casting numbers on the manifolds and not the actual part numbers. They can vary from truck to truck... Again, this ford dealership employee insisted that our manifolds are the same as the L which are the same as the standard F150....

Someone Please get definitive, final proof!

Ken

 

Ken, I think that Neal actually saw our manifolds compared to the L's at one of the Ford Plants, and he said that they were definitely different.

 

Thanks outnumbered,

I read that post and I am wondering if they had something on there that was different up until mass production. I don't doubt that Neal saw different manifolds. If anyone could recognize them as different, he would certainly be able to.

oh well, i guess we'll never know for sure...