what is the difference? im strongly considering doing the lightning swap on my 03 expy. there are 2 auctions on ebay right now with the major stuff i need, but one is for the harley, and one is for the lightning. thanks in advance. by the way, one of the auctions ends in a few hours....

 

The Lightning has a more aggressive tune 380hp/450lb/ft vs the Harley 340hp/425lb/ft.
I think both use the 4R100 tranny.

 

so, it's the same s/c, just different tunes on the pcm?

 

It's actually a different upper pulley, I think. I'm pretty sure the Harley has a larger upper pulley, therefore the SC spins slower and it makes a touch less HP. That xcan be changed pretty easily though.

 

thanks for the info

 

What bigsnag said. The Harley truck uses the same Eaton M112 supercharger as the Lightning, just with a larger pulley to produce less boost. The M112 made for the L trucks has a smaller s/c pulley so it spins faster and produces more boost, but the s/c are the same.

If you get the HD s/c and decide to swap the s/c pulley, I would advise you to get the proper tool that removes the pressed-on OEM pulley. Others have tried, with varying degrees of success, to remove the pulley without the pulley removal tool, and have either succeeded, or damaged the snout.

Bolt-on aftermarket s/c pulley's are commonly sold by vendors who specialize in selling performance parts for the L and HD.

Stewart

 

The dropped the boost on the HD trucks due to the extra weight of the SCAB and SCREW versions that the HD's come in. The Lightnings are the lightest since they are std cabs with a short Flareside bed. This was to keep detonation down from lugging around the extra weight.

 

Definitely have to have the puller tool. With it, it is pretty easy, though. Without it, well, just forget about trying to get it off without it.

 

I disagree with your opinion, because there's just too much empirical evidence that proves otherwise.

There are many Lightning owners who tow very heavy loads while still on the stock tune, on the stock pulley, with a stock engine, with zero detonation issues. Loads that include other Lightnings on a vehicle trailer, large boats on a trailer, utility work trailers full of concrete and construction materials (me, before I modified my truck) with no issues whatsoever.

Besides, in my opinion, I feel it would have been a snap for Ford engineers to revamp the fueling parameters and fuel curves in the Harley PCM, to offset the greater weight the HD has over the Lightning, if they wanted the HD to have the same boost levels of the Lightning.

Lack of detonation and lugging issues, based on the daily driving habits of many Lightning owners, has lead me to this conclusion.

Plus, don't forget, there are all the modified Lightning owners who have a 4lb or 6lb lower pulley who also tow heavy loads (me again, after I modified my L), and they have no detonation issues either. Yes, they have custom tunes, but if they can create more boost, and still tow heavy loads safely, all because of a custom tune that modifies the fuel curves of the stock program, then it really wouldn't have been difficult for Ford to produce stock HD's that put out the same amount of boost as a stock L.

One last thing, none of this even takes into account all of the modified HD's with pulley upgrades that have no detonation issues. And those HD's are producing more boost over their stock configuration, with zero weight loss to their truck.

They have the same OEM weight, but much more boost over their OEM spec, all because they have a custom tune that's tweaked their a/f ratio.

Those trucks are operating safely.

If what you contend is true, then the stock HD's wouldn't be able to haul a heavy payload or pull a heavy trailer without a custom tune to alter the a/f ratio.

Stewart

 

Throw the modified "if's, and's and butt's" out the window since we're talking about a bone stock rig. Sure, Lightnings do fine under tow, but it's not the "towed" weight that is mentioned.....it's the carried weight, from start up to shut down. A bone stock HD will have higher ACT's at the same boost/load level because of the weight of the vehicle. We can sit here and discuss pulley changes and chips all day long, but from a bone stock standpoint, that is not applicable since Ford builds and warrants their vehicles AS IS off the assembly line. Throw in the gear ratio (not sure if the L's and HD's are the same), and that'll also play a factor as well. The HD's were built/tuned around their weight and purpose.

 

Yes, I agree.

But what you pointed out has nothing to do with detonation, as LxMan1 has contended in his post, because Ford engineers could have EASILY remapped the fuel ratio and parameters to handle the same boost level, with a heavier truck.

I agree with you, it had more to do with the reliability, durability, and longevity of the Harley truck than anything.

The only reason I brought the pulley and tune (a/f ratio) into the discussion was to disprove the contention that detonation stopped Ford from offering the HD's with the same boost levels as the L's.

Lowering the boost level of the HD, when compared to the L, had nothing to do with detonation, and everything to do with Ford wanting to limit the stress and workload on the truck, which could affect the overall reliability and durability of the truck, not to mention warranty claims.

Basically, it came down to money.

Stewart

 

I guess I'll disagree with everyone. I think they lowered it in the HD truck because they didn't want it to make as much power as the L. Just like with the new Shelby Mustangs. They could easily make just as much power as the Ford GT, it basically the same engine, but they wouldn't want to have a Mustang make as much power as their flagship race car. That just wouldn't seem right. Same thing with these trucks. I have nothing to verify this, other than Ford's history of doing just that.

 

I thought of that too, but even if the HD was produced with the same power as the L, it still would not have the performance characteristics (acceleration, 1/4 mile times, etc) as the Lightning, so there would be no "threat" to Fords flagship high performance truck.

So if there was no threat to outperforming the L (or even performing as well as the L) why wouldn't Ford produce the HD's with the same boost levels as the L?

I believe it's like Matt (Blurry) intimated: Because "Ford builds and warrants their vehicles AS IS off the assembly line, Ford will make sure to stay within the reliability parameters ("zone" if you will) their engineers set forth, to minimize warrantee issues, thereby saving money.

Stewart

 

What I pointed out was the heavier truck having elevated ACT's, which has alot to do with detonation. Simply throwing more fuel at a detonation problem is not a fix.
Another thing to consider is the added stress on the transmission in a heavier vehicle with the same HP and TQ. This can cause the trans temp to rise too much, for too long, and we all know what a transmission's worst enemy is...heat.

 

Through logical reasoning, I've already proven how easy it would have been for Ford engineers to create a safe program to run the HD trucks with the same boost level they gave the L, even though the HD is a bit heavier. So if you're contending the reason they lowered the boost level of the HD truck was because of detonations issues, like LxMan1, then you're as mistaken as your fellow moderator.

Remapping the fuel parameters and fuel curves is not just adding more fuel to stave off detonation. I'm still a neophyte at custom tuning, but with my engine build about to begin, I'm trying to learn enough to be able to provide my own custom tunes, probably with the SCT racer pro package.

Stewart