mod confusion
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Joined: Jul 2002
Posts: 59
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From: Canada
Hi Ken
Here is what I can share with you from the dyno testing I read. A stock Lightning (3" upper and 7.5" lower) delivered 9.3psi and made 348hp at 5400 rpm. Changing the lower pulley to a 9" increased the boost to 13.4 and the power rose to 396hp. This would have the blower spinning 16200 and showing a nice power gain. At this point they decided to try and raise the boost one more time so the upper pulley was swapped out in favor of a 2.75". This brought the blower speed up to 17700 and less than a pound of boost was gained. Power output stayed almost the same. However, all this testing was done with a stock air box. The final test with the stock Eaton blower used a cone filter and an Accufab throttle body. Still spinning the 2.75" on the top and the 9" on the bottom the power rose to 415hp. Looks to me like a Harley could use a pulley larger than 9" and pick up some useable boost and power since we are running the blower slower with the 3.25" pulley on top. A 10" lower would put the blower at about 16600 at 5400. What size is an 8# pulley-around 10"? I am thinking of trying an 8# in place of my 6#. From the looks of this thread a 6# and a chip are not to hard to sell.
Here is what I can share with you from the dyno testing I read. A stock Lightning (3" upper and 7.5" lower) delivered 9.3psi and made 348hp at 5400 rpm. Changing the lower pulley to a 9" increased the boost to 13.4 and the power rose to 396hp. This would have the blower spinning 16200 and showing a nice power gain. At this point they decided to try and raise the boost one more time so the upper pulley was swapped out in favor of a 2.75". This brought the blower speed up to 17700 and less than a pound of boost was gained. Power output stayed almost the same. However, all this testing was done with a stock air box. The final test with the stock Eaton blower used a cone filter and an Accufab throttle body. Still spinning the 2.75" on the top and the 9" on the bottom the power rose to 415hp. Looks to me like a Harley could use a pulley larger than 9" and pick up some useable boost and power since we are running the blower slower with the 3.25" pulley on top. A 10" lower would put the blower at about 16600 at 5400. What size is an 8# pulley-around 10"? I am thinking of trying an 8# in place of my 6#. From the looks of this thread a 6# and a chip are not to hard to sell.
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Joined: Oct 2002
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From: Atlanta, GA
More speculation:
It appears that with the 3lb lower L pully that the HD SC is turning about the same RPMs as the stock L. In a perfect world, simply adding the L's 3 lb lower should give the HD an L engine. Similarly, the 6 lb L lower pully in the HD could provide the performance of a stock L plus a 3 lb lower. I don't think however this is the case as that would mean that the 6 lb L pully alone would provide something like 50 HP and 50 TQ gains to the HD.
Something else has to be at work here that makes our engines less efficient than the L engine. I have read rumors that: the HD computer is not the same as the L - but almost as much speculation that its the same, that the HD has a different compression ratio than the L, and that the HD has less airflow through to the intercooler. The last one seems to be the most important to me based on what I have read on many different forums and also based on the design of the L and HD bumpers - no one is contradicting it and the science backs it up. An increase in compression should help us produce power as long as detonation can be tamed and as ken indicated previously, the stock computer seems capable of taming that problem.
So then, if a 10 degree increase in air temperature provides a 1% decrease in HP, then the HD intercooler would only need to lose little efficiency to create some big losses. This article http://www.timskelton.com/lightning/...ted/page_5.htm indicates that the SC air output near 300 degress which the L intercooler dropped to around 100. We can estimate that the L intercooler is cutting the temperature at least as much as 60%. Assume that the HD provides only a 50% drop - thats 17+ HP loss immediately. Adding the missing 2 lbs of boost back to the HD and then increasing the intercooler cooling and its very reasonable to expect +30 HP on the HD. (I'll almost bet that taking the HD front license plate off will increase your engines HP output by increasing airflow to the intercooler.)
Best of all, a 6 lb pully and a new heat exchanger still would seem to fit within the stock program. An air intake and chip could add more power later. (I believe that the stock air intake with a better filter is reliable on the L to +4 lb of boost. As the HD with a 6 lb L lower pully = an L with +3 lbs, the stock box should be fine on the HD.)
A nice upgrade path might be: intercooler, pully, chip+intake.
Enough for tonight.
It appears that with the 3lb lower L pully that the HD SC is turning about the same RPMs as the stock L. In a perfect world, simply adding the L's 3 lb lower should give the HD an L engine. Similarly, the 6 lb L lower pully in the HD could provide the performance of a stock L plus a 3 lb lower. I don't think however this is the case as that would mean that the 6 lb L pully alone would provide something like 50 HP and 50 TQ gains to the HD.
Something else has to be at work here that makes our engines less efficient than the L engine. I have read rumors that: the HD computer is not the same as the L - but almost as much speculation that its the same, that the HD has a different compression ratio than the L, and that the HD has less airflow through to the intercooler. The last one seems to be the most important to me based on what I have read on many different forums and also based on the design of the L and HD bumpers - no one is contradicting it and the science backs it up. An increase in compression should help us produce power as long as detonation can be tamed and as ken indicated previously, the stock computer seems capable of taming that problem.
So then, if a 10 degree increase in air temperature provides a 1% decrease in HP, then the HD intercooler would only need to lose little efficiency to create some big losses. This article http://www.timskelton.com/lightning/...ted/page_5.htm indicates that the SC air output near 300 degress which the L intercooler dropped to around 100. We can estimate that the L intercooler is cutting the temperature at least as much as 60%. Assume that the HD provides only a 50% drop - thats 17+ HP loss immediately. Adding the missing 2 lbs of boost back to the HD and then increasing the intercooler cooling and its very reasonable to expect +30 HP on the HD. (I'll almost bet that taking the HD front license plate off will increase your engines HP output by increasing airflow to the intercooler.)
Best of all, a 6 lb pully and a new heat exchanger still would seem to fit within the stock program. An air intake and chip could add more power later. (I believe that the stock air intake with a better filter is reliable on the L to +4 lb of boost. As the HD with a 6 lb L lower pully = an L with +3 lbs, the stock box should be fine on the HD.)
A nice upgrade path might be: intercooler, pully, chip+intake.
Enough for tonight.
Senior Member
Joined: Jun 2001
Posts: 999
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From: Houston, tx
JDM has a new heat exxhanger that will significantly increase the cooling capability on the stock setup. Since we have smaller openings in the front, it is possible that the L intercooler is performing better, but that would not explain a run on dyno on a cool motor since neither would have the wind rushing in. That being said, a set of fans on the JDM heat exchanger like the following might be worth some pretty good gains if heat is our issue:
http://www.nloc.net/forum/showthread...threadid=31550
https://www.f150online.com/forums/sh...threadid=97664
On a dyno, we are seeing 335-345 on a stock L. We are seeing 310-315 on a stock HD. That means we have 30ish horsepower to make up. A 3lb lower pulley *might* just cover that much ground...
There is all sorts of speculation that we are running different compression ratios. Roush performance swears they are the same. I still cannot get a definitive answer on that question. The manifolds are the same. I have seen an L and HD side by side with the same casting numbers stamped on both. I would assume with manifold being the same that the block and heads would be the same as well. That would leave pistons or rod length as the last two variables that might be a little different than the L. I sure wish someone would figure this one out. I might try calling a Ford dealer here in town and look up the part numbers for rods and pistons for each truck....
It is wishful thinking to believe we can get down into the same 1/4 speed as the L's. Some here have said they weighed in at 5200 and change. I weighed my truck at Houston Raceway Park and the scale will not measure over 5600 lbs and it always says the same thing when I park on top of it: "over weight" I only weigh about 160 and even when I got out of the truck it said the same thing...
Ken
http://www.nloc.net/forum/showthread...threadid=31550
https://www.f150online.com/forums/sh...threadid=97664
On a dyno, we are seeing 335-345 on a stock L. We are seeing 310-315 on a stock HD. That means we have 30ish horsepower to make up. A 3lb lower pulley *might* just cover that much ground...
There is all sorts of speculation that we are running different compression ratios. Roush performance swears they are the same. I still cannot get a definitive answer on that question. The manifolds are the same. I have seen an L and HD side by side with the same casting numbers stamped on both. I would assume with manifold being the same that the block and heads would be the same as well. That would leave pistons or rod length as the last two variables that might be a little different than the L. I sure wish someone would figure this one out. I might try calling a Ford dealer here in town and look up the part numbers for rods and pistons for each truck....
It is wishful thinking to believe we can get down into the same 1/4 speed as the L's. Some here have said they weighed in at 5200 and change. I weighed my truck at Houston Raceway Park and the scale will not measure over 5600 lbs and it always says the same thing when I park on top of it: "over weight" I only weigh about 160 and even when I got out of the truck it said the same thing...
Ken
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Joined: Oct 2002
Posts: 55
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From: San Diego
HD to L comparison
mmeyek,
Aside from the obvious weight difference between the Lightning and HD f150, the performance diff's are:
1- HD lower valance has less intercooler/ air exchange from smaller grill opening
2- HD has larger upper pulley diameter, which creates 2 psi less than L
3- HD exhaust is much more restrictive, length exiting rear of pass tire, and traveling over rear axle housing
4- PCM tuning for HD is designed for correct A/F and timing curves at lower boost level (6 psi stock)
5- HD 20" wheels reduce final drive/ gear ratio
Soo far, I have eliminated all differences between my '02 HD and my '01 L, with the exception of the 20" wheels. This includes uploading the L programing into my pcm today. I will be track testing my '02 HD today for comparison data.
Mod's include: L valance, Bassani cat-back w/side exit tips, L upper pulley, pcm programed for L.
Aside from the obvious weight difference between the Lightning and HD f150, the performance diff's are:
1- HD lower valance has less intercooler/ air exchange from smaller grill opening
2- HD has larger upper pulley diameter, which creates 2 psi less than L
3- HD exhaust is much more restrictive, length exiting rear of pass tire, and traveling over rear axle housing
4- PCM tuning for HD is designed for correct A/F and timing curves at lower boost level (6 psi stock)
5- HD 20" wheels reduce final drive/ gear ratio
Soo far, I have eliminated all differences between my '02 HD and my '01 L, with the exception of the 20" wheels. This includes uploading the L programing into my pcm today. I will be track testing my '02 HD today for comparison data.
Mod's include: L valance, Bassani cat-back w/side exit tips, L upper pulley, pcm programed for L.
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Joined: Oct 2002
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From: Atlanta, GA
Thanx all.
As background for my motivation for this thread, I am not interested in track times. I doubt I will ever take the truck to the track. I'm not a racer and instead love the deep burble of the exhuast as I pull slowly away from a light. On the other hand, safely returning my engine to the performance it has in the L (or better - 400 HP has such a nice ring to it) is my goal. The fact that my engine is a "detuned" L engine irritates me. The benefit of this effort is just gravy - I know I have more power if I need it.
Ken800 - I have never had a car dynoed so I am at a bit of a disadvantage here but I have seen video where the car on the dyno had a big fan blowing across the engine to keep it cool. Because this would more accurately recreate a real world scenario - rarely would an engine be turning 5000 rpms with no air flow across the engine - do you know if the numbers you posted are in a "static" no fan dyno vs a "fanned" dyno? In the fanned dyno the intercooler would still come into play. Am I grasping at straws trying to make my speculation real? I think thats call denial.
I was thinking of the JDM heat exchanger when I posted. Intercooler fans are on my list of things to do. Today I took a look at the intercooler on the truck and wondered if anyone has not just built a scoop the would drop below our valance and channel more air across the intercooler. That seems like a pretty easy fix to our smaller grill opening.
Blown4DR - I'll be looking for your data. Good point on the exhuast too. I had forgotten about that. If I recall correctly, the L exhause is very close to optimum for the truck as after market systems show little gain for an L.
As background for my motivation for this thread, I am not interested in track times. I doubt I will ever take the truck to the track. I'm not a racer and instead love the deep burble of the exhuast as I pull slowly away from a light. On the other hand, safely returning my engine to the performance it has in the L (or better - 400 HP has such a nice ring to it) is my goal. The fact that my engine is a "detuned" L engine irritates me. The benefit of this effort is just gravy - I know I have more power if I need it.
Ken800 - I have never had a car dynoed so I am at a bit of a disadvantage here but I have seen video where the car on the dyno had a big fan blowing across the engine to keep it cool. Because this would more accurately recreate a real world scenario - rarely would an engine be turning 5000 rpms with no air flow across the engine - do you know if the numbers you posted are in a "static" no fan dyno vs a "fanned" dyno? In the fanned dyno the intercooler would still come into play. Am I grasping at straws trying to make my speculation real? I think thats call denial.
I was thinking of the JDM heat exchanger when I posted. Intercooler fans are on my list of things to do. Today I took a look at the intercooler on the truck and wondered if anyone has not just built a scoop the would drop below our valance and channel more air across the intercooler. That seems like a pretty easy fix to our smaller grill opening.
Blown4DR - I'll be looking for your data. Good point on the exhuast too. I had forgotten about that. If I recall correctly, the L exhause is very close to optimum for the truck as after market systems show little gain for an L.
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Joined: Jun 2001
Posts: 999
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From: Houston, tx
I would say that starting on a cooled down engine, fan or no fan, the HP will net the same on the dyno. Once heat soaked, the fan is imperative. Often, people dyno with the hood UP which means cooler outside air in the engine bay.
I certainly would not say that the intercooler ventilation doesn't have anything to do with the equation, but I would say I hightly doubt that it would have a measurable effect on a dyno. Real world street driving, the smaller ventilation might come into play though.
Just to give you my frame of reference, I have considered a JDM intercooler as well as intercooler fans so that I can "hot lap" at the track without paying as much of a price.
Are you looking for 400 RWHP or 400 at the crank? 400/500 club on this truck is going to take a lot of bolt ons...
Ken
I certainly would not say that the intercooler ventilation doesn't have anything to do with the equation, but I would say I hightly doubt that it would have a measurable effect on a dyno. Real world street driving, the smaller ventilation might come into play though.
Just to give you my frame of reference, I have considered a JDM intercooler as well as intercooler fans so that I can "hot lap" at the track without paying as much of a price.
Are you looking for 400 RWHP or 400 at the crank? 400/500 club on this truck is going to take a lot of bolt ons...
Ken
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Joined: Oct 2002
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From: Atlanta, GA
I'm only looking for the power at the crank which I think should be relatively easy to achieve and still keep the car well within the safe zone. I'm satisfied with my truck performance stock - its the annoying feeling that I am being cheated by a detuned engine that is driving my need to mod. Its like raising an underachieving child.
Good info on the intercooler and dynoing. What you say makes sense so I'll back off that option for now.
After reading a thread over at http://www.nloc.net/forum/showthread...hreadid=31269, I have become more confident that the HD will take the L 6 lb pully with no chip/filter etc. At the same time, I have read the warning and think that a good before and after check of the air ratio would be a good thing.
Good info on the intercooler and dynoing. What you say makes sense so I'll back off that option for now.
After reading a thread over at http://www.nloc.net/forum/showthread...hreadid=31269, I have become more confident that the HD will take the L 6 lb pully with no chip/filter etc. At the same time, I have read the warning and think that a good before and after check of the air ratio would be a good thing.