Harley#356

Numbers speak the truth lol

Harley#356

hahaha so I got my dyno tune today, and could punch my truck from a standstill and see what my peak boost is.

Looking at that chart, a 6 lb lower with a HD upper should be 10.45 lbs of boost.

Who wants to guess how much boost I'm seeing?
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10.4 lbs!!!!



Now I do have a JLP intake which usually adds around 1.5 lbs, and I have a ported stock plenum and throttle body which usually adds around 0.5 lbs, but I also have a full exhaust which can usually drop 2 lbs of boost, which pretty much cancell each other out.


I'm really surprised though that it actually came out that dead nuts on 10.4 lbs as registered on my aeroforce today. Average conditions & temps as well.

SO glad I ordered that 6 lb'er on Monday and threw it on Wednesday. Was exactly what I was looking for boost wise!

BlairTruck

your numbers mean nothing there are to many variables in your 10.4.
needs to be stock truck. swap the pulley see what it hits

thats the best i can do for my argument right now
i bet if you put a stock pully back on you would be at 4.4

Harley#356

If somebody has a 0lb ring to let me borrow, I'll gladly put it on there and I guarantee you I'm at 6 lbs on the button. I'll even pay for shipping to/from. Any takers? Heck I've got the 4 lb ring I'll toss on to do a comparison with too.

There's actually very few variables in my combo. An intake tract mod that is very well known and documented to add 2 lbs of boost, and an exhaust tract mod that is very well known and documented to lose 2 lbs of boost. +2 and -2 = 0 net gains. Sticking me right back at the 10.4 mark.

It makes absolutely no sense whatsoever that I'd be at 4.4 lbs anyway. I have never heard of anyone pushing less than the stock 6 lbs of boost. Now if somebody had NO pullies and NO intake or filter, but did a FULL exhaust then they could potentially be at 4 lbs, but its really azz backwards to do a full exhaust and not a single intake or pulley mod. Many guys have kept the stock pullies, just did an intake, and seen 8 lbs though....that 2lb gain from just the intake setup.

Saying I'd be at 4.4 lbs on a stock pulley is saying that the 6 lb lower is worth 6 lbs of increased boost, and also saying that...

I wouldn't gain ANY boost from a ram air intake, smooth elbow, ported throttle body, and ported plenum, and I would just lose 1.6 lbs of boost from a full exhaust.

So how can you possibly argue that intake mods don't add ANY boost at all, when its been posted countless times that intakes, ported plenums, etc. all add boost by freeing up the intake path?

Doesn't make any sense, and doesn't have any supporting data behind it whatsoever

BlairTruck

graph these ball lol

Black Molly

that is one small graph

Harley#356

aww now don't get testie (no pun intended lol) because you're side of the discussion has contradicting statements and no numbers behind it

BlairTruck

all i got to say is that your with mods that change the amount of boost up and down get a number that matches your graph. Your only guessing on what your boost should be

i added the 9" pulley only and got 6 lbs with zero other mods. He numbers are more accurate

Harley#356

My very limited mods that are very well known that intakes typically add 2 lbs, and full exhaust typically drops 2 lbs. Not rocket science.

So you have a bone stock truck, with JUST a 6 lb lower. Not even a K&N drop in filter?

Even on a bone stock truck with zero mods other than a 6 lb lower that should make 10.45 lbs of boost, if its in crisp dense cold canadian air you can easily gain a pound or slightly more from cold dry temps. And analog boost gauges can easily vary by +/- 0.5 lbs when you're reading a fat needle on a tiny division gauge.


If you still want to argue you get 12 lbs net of boost with a 6 lb lower on a harley truck, then how can you possibly explain that those 12 lbs are at a much lower blower RPM than a lightning pushing 12 lbs net of boost? Since the engines, blowers, intakes, etc. are all identical, how can one possible create more boost than the other at equal blower RPM's?

BlairTruck

bone stock no filter no nothing. Before install 6lbs after install 12lbs.
That was many years ago now. but i did do the test to check

How can i argue numbers right.
You say cold air. it was the same air for the 6lbs as it was for the 12lbs

Seems between my completely stock setup, and your maybe add 2lbs here lose 2lbs there
Mine is more accurate. But you have a graph that shows no real world info all theoretical

But i guess there is no arguing with the Harley Master

here is my pie chart

jonolds72

+1
my first mod was a 8.5 lower (so called 4lber) and my increase was 4lbs total boost 10psi. no cai, nothing just a pulley and a predator.
then i went to a 9 inch lower, and i saw 12psi, still no intake or any other mods.
i see size of pulleys of net increase over stock weather it is a lightning or harley
that is my understanding (not sure if it is correct or not, but that is what makes sense to me)

havinnoj

I was under the impression that an intake- fipk - wouldn't do anything for increasing boost or power. Or is it just a negligable amount?

PS - awesome thread unfolding here!

Harley#356

so then you're stating, there's NO variables that can affect boost levels except for a pulley, that there's no way that temperatures can affect boost levels, altitude, intakes, exhaust, etc. yet SOMEHOW your harley truck is magical, and it can spin the supercharger slower, yet make MORE boost than a lightning spinning the same RPM

Are there any other remotely physics-savy people on this forum? Or are only the village idiots left?


of course it will increase boost and power. Maybe not anything huge, but you're uncapping the first restriction on the inlet system. The airbox sucking through the tiny hole in the fender and a paper filter. Been documented time and time again that guys typically gain 2 lbs from an intake system. Same thing with adding full exhaust guys typically drop 2 lbs.



On another note, anybody have any stock HD blowers for sale? I want to start buying them up and selling them to L guys since our blowers magically make more boost with less blower RPM's than the Lightning blowers do lol

havinnoj

Mannn I guess I missed that school lesson!! So typical gains at 2lb are 15hp and tq?

BlairTruck

my boost test was done the same days only hours a part
i love your typically and usually gains, its guessing

im sure graphs can be wrong sometime and maybe even you could be wrong for once