Under hood temps and dynoing with the hood up explained

[SID297]

I understand your side of this according to the IATs, but what about the simple fact that the filter is going to get much more airflow without the hood covering it up?? Thats always what I was wondering. Take the lid off the stock airbox, add a K&N filter to it and whats that do over stock? I cant see why people would debate the temp thing, as you proved. But the fact that the airflow is much better with the hood open is what I always wondered??

That would be fun to try for shits and giggles. You'd have to duct tape the filter to the lid though. If you want to come out to Arrington we can give it a try, with any hood position you want. I should be back there at the end of the month.:beer:

 

[me32]

So you are saying the stock air box has the advantage because it benifits from the ram air effect of a sealed system?

It does at high speeds. It was a how ford designed it.

 

[Tucker]

Go figure, the same people who mud up the track threads are trying to mud up this thread. :bored:

The fact is IAT's are not HOT as some say and the CAI makes cars faster no matter how it's tested.
Ford designed the stock box special?
Really, what proof of this do you have? Please explain in detail who from Ford you spoke with and show us the diagrams.

The stock box breaths air from a small 2.5 x 6.5" hole, that's it. That hole is blocked from direct air flow behind the fog light. So how is that a "good" design. That's no different than the airbox design from 1996 and intakes make power on that too.

Even with the JLT and stock box benifiting from the air coming in from this inlet at speed, the JLT has 360* of breathing ability in it's filter design, not a small section of the box.
It doesn't take much to truely understand how it works and that it makes cense that the stock box is a restriction.

4.5 x 9" filter 360 degrees of airflow Vs a 2.5 x 6.5" hole in a sealed airbox?:rollseyes

It's easy to prove inlet air temps, it's easy to prove track times and it's easy to prove dyno gains, so far what's been hard to prove is your point of view that the stock box is better in anyway shape or form.

Even on an engine dyno the JLT picks up power, just like on the chassis dyno and the track.
Comp Cams did some flow bench testing and show here that the stock box only flows 772 CFM and the throttle body flows 957.
Boom, restriction!

Were never going to convince the haters and that's fine, but all we can do it give info and proof. Then the customer can take that data and make a choise on what they should do.

Facts:
IAT's are at or near ambient
Stock box CFM is lower than the throttle bodys and a restriction
HP is made on the chassis dyno
HP is made on the engine dyno
Cars are faster in the 1/4
Cars are faster at the Texas mile

These are facts, not guesses or opinions, facts. The haters will test and test until they get that needle in a hay stack run where the stock box come out on top and then jump for joy and spread the word like it's gospal.
Intakes have been used and proven for 50 years, they just don't stop working.

Now, back on track, we dyno with the hood up becasue we want equal temps and airflow to the filter.

 

[ViciousJay]

Not sure if this helps but back when installed the JLT, BBr tune, H pipe and gt500 mufflers (musclefan21 was there as well) we did 2 runs hood open and 4 pulls, 6 total all back to back, only to stop and close the hood. There was a difference in ambient temps but 2hp difference.

It was done on a dyno dynamic (aka the heartbreaker, reads the lowest out of any dyno)

 

[Tucker]

Not sure if this helps but back when installed the JLT, BBr tune, H pipe and gt500 mufflers (musclefan21 was there as well) we did 2 runs hood open and 4 pulls, 6 total all back to back, only to stop and close the hood. There was a difference in ambient temps but 2hp difference.

It was done on a dyno dynamic (aka the heartbreaker, reads the lowest out of any dyno)

Good info and I'm surprised only 2 HP lose, I've scene more, but every test is different.

Thanks
Jay

 

[mikestoyz]

Im trying to figure out where TheCPE is coming from. I know he thinks it makes no difference with power, but was wondering what was the technical reason for it not to make as much power.
My suggestion above was that the stock box(because of its sealed nature from inlet behind the grill to the throttle body) was sealed and provided a forced pressure that overcame the advantage the conical filter on the JLT(or any CAI) provided. However, that is a different thread, although I love getting into the technical aspects of it all.

If indeed there is a forced pressure of some sort, you could never dyno the stock box/filter correctly unless you had one of those expensive dyno rooms you spoke of....but of course, the same thing applies to the JLT. The JLT does show an increase on the dyno. I guess hes wondering if sucking through the stock inlet behind the grill still allows enough airflow for the JLT to make the gains on the dyno.

 

[TheCPE]

If indeed there is a forced pressure of some sort, you could never dyno the stock box/filter correctly unless you had one of those expensive dyno rooms you spoke of....

Exactly.

It comes down to trying to replicate the real world environment while performing the dyno and if you can't than you aren't going to get an apples to apples comparison.

Three independent tests have been done that have shown that the claims of 15hp are not there in the real world that are on the dyno. So the question becomes why?

It is obvious to me that the stock box is a hindrance when the car is stationary and hood open compared to an open filter in that same environment. However, when hood is closed and traveling down the road the stock box is no longer a hindrance vs the open filter.

but of course, the same thing applies to the JLT. The JLT does show an increase on the dyno. I guess hes wondering if sucking through the stock inlet behind the grill still allows enough airflow for the JLT to make the gains on the dyno.

With the hood open it probably is sucking very little air from the grille and mostly from all around the filter.


Also, some have suggested performing a test where you take the lid off the stock box. You'd have to duct tape the filter to the "lid" because the lid is what goes to the TB. Then you would have to rotate the tubing 180 degrees otherwise the filter is still being jammed into the box.

 

[ViciousJay]

Good info and I'm surprised only 2 HP lose, I've scene more, but every test is different.

Thanks
Jay

i can call the shop or i can give you the info and you can call them and see if you can get the dyno sheet from them. Pretty sure they save them all, also the temps in the room were 72* low humidity, and all pulls were back to back, NO COOL DOWN, as stated just enough time to drop the hood on the last few pulls which resulted in a 2hp loss

 

[TheCPE]

It doesn't take much to truely understand how it works and that it makes cense that the stock box is a restriction.

When the vehicle is stationary on a dyno that is correct it is a restriction.

so far what's been hard to prove is your point of view that the stock box is better in anyway shape or form.

I don't think anyone has said that the stock box is better. All I've said is that based on the testing of three different people there doesn't appear to be much of a discernible hp difference definitely not the claimed 15hp difference.

Comp Cams did some flow bench testing and show here that the stock box only flows 772 CFM and the throttle body flows 957.
Boom, restriction!

If the 5 liter engine can't use all of the CFMs than it isn't a restriction.

Were never going to convince the haters and that's fine, but all we can do it give info and proof. Then the customer can take that data and make a choise on what they should do.

Aside from dynos (which don't provide a realistic environment) no one has produced any data that proves 15hp is made over the stock box with the CAI. Instead data has been provided that shows very little discernible gain from the CAI over the stock box, on the order of ~5 hp.

 

[Tucker]

The typical intake makes 12-15 more RWHP than a stock box.

In theory that equals about .1-.15.

Giving the stock box a "guessed" benifit you can cut that .1-.15 down a little.

WBT gained .069 over the stock box. .03 or 3 thousandths off from a theory of .1 = GAIN
Mike went from a stock box run of 12.58 to a JLT run of 12.04 for a .54 gain. Granted he says he was having a bad night, but he has now gone a personal best of 11.90's still with the JLT. = GAIN
That guy at the Texas mile had his fastest run with the JLT = GAIN

So, if you want to be .069 - .15 faster than a guy with the stock box a JLT or any other brand intake is for you.
If you want to say I ran xxx withthe stock box, great, keep it.

Every test done by people here have shown gains with the JLT over the stockbox.

Keep testing and showing these gains, it's great.

Oh and to say the 5.0 can't use that added CFM is a joke. If that were the case the engine dyno wouldn't show a 17 HP gain now would it?

Were not taking about HUGE gains here fellas, were talking about a tenth or so. That's very easy to prove on the dyno, but hard to prove exactly with out a margin of error at the track. What we do know is it's harder to prove it doesn't work and that's proof enough.

Thanks
Jay

 

[TheCPE]

The typical intake makes 12-15 more RWHP than a stock box. In theory that equals about .1-.15.

I would agree that if a CAI is legitimately making 12-15hp you would see about a .15 et drop in the ¼ mile and should see a trap pickup of 1-1.5 mph.

Giving the stock box a "guessed" benifit you can cut that .1-.15 down a little.

I don’t understand what you are saying here.

WBT gained .069 over the stock box. .03 or 3 thousandths off from a theory of .1 = GAIN

wbt’s test showed a .069 et decrease with the jlt. For starters that is 3 HUNDREDTHS different from .1 not thousandths. And in reality that means it is less than half of what the decrease should have been for a legitimate 15hp (.15 - .069 = .081). When you do the math using the numbers from his timeslips you get an approximate 5hp differential. This is less than half of the 12-15 that is claimed.

Mike went from a stock box run of 12.58 to a JLT run of 12.04 for a .54 gain. Granted he says he was having a bad night, but he has now gone a personal best of 11.90's still with the JLT. = GAIN

He was never able to produce back to back consistent runs so you can’t make any claims about his runs.

That guy at the Texas mile had his fastest run with the JLT = GAIN

If you averaged his JLT runs that isn’t true. You can’t just pick one run, you have to do multiple runs and then calculate an average with and without.

Every test done by people here have shown gains with the JLT over the stockbox.

My GPS test showed a .5hp gain, which is statistically in the noise. But like you say, if people want that extra .5hp than they should definitely get a CAI.

Oh and to say the 5.0 can't use that added CFM is a joke. If that were the case the engine dyno wouldn't show a 17 HP gain now would it?

It has been pointed out several times now, that on a dyno with the vehicle\engine stationary the enclosed stock box is a restriction. This isn’t the case in a real world scenario however and so again you are comparing apples to oranges.

Do you understand that the restriction of the enclosed box exists on a dyno because you don’t have all the air rushing into the grille and thus the box?

Were not taking about HUGE gains here fellas, were talking about a tenth or so.

Yep, you are right we aren’t talking about huge gains I'd say between 1-5 hp. 15hp to me on a NA motor is pretty big, 5 or less isn’t.

 

[Tucker]

I would agree that if a CAI is legitimately making 12-15hp you would see about a .15 et drop in the ¼ mile and should see a trap pickup of 1-1.5 mph.


I don’t understand what you are saying here.



wbt’s test showed a .069 et decrease with the jlt. For starters that is 3 HUNDREDTHS different from .1 not thousandths. And in reality that means it is less than half of what the decrease should have been for a legitimate 15hp (.15 - .069 = .081). When you do the math using the numbers from his timeslips you get an approximate 5hp differential. This is less than half of the 12-15 that is claimed.



He was never able to produce back to back consistent runs so you can’t make any claims about his runs.



If you averaged his JLT runs that isn’t true. You can’t just pick one run, you have to do multiple runs and then calculate an average with and without.



My GPS test showed a .5hp gain, which is statistically in the noise. But like you say, if people want that extra .5hp than they should definitely get a CAI.



It has been pointed out several times now, that on a dyno with the vehicle\engine stationary the enclosed stock box is a restriction. This isn’t the case in a real world scenario however and so again you are comparing apples to oranges.

Do you understand that the restriction of the enclosed box exists on a dyno because you don’t have all the air rushing into the grille and thus the box?



Yep, you are right we aren’t talking about huge gains I'd say between 1-5 hp. 15hp to me on a NA motor is pretty big, 5 or less isn’t.

1-5, that's funny.

Now you want to average runs to get the numbers you want? That's even funnier.

 

[TheCPE]

1-5, that's funny.

Now you want to average runs to get the numbers you want? That's even funnier.

Within any scientific testing, you run multiple trials and perform statistical analysis. :shrug:

Not sure how averaging runs "gets you numbers you want"....

 

[Tucker]

Nothing your posting is proof of anything.
We post videos of IAT's
Dyno graphs of gains
3rd party dyno graphs of gains
3rd party track gains

You post up your GPS test says it's worth 1-5 HP.?

I prefer to have all the 3rd party testing show the world what works.
We can do the test too, but the best backing is from customers.

Thanks
Jay

 

[kdanner]

Some statements are wrong about a couple of cars I am involved with. Certain facts are being left out. The whole truth should be told. I'll correct.

WBT gained .069 over the stock box. .03 or 3 thousandths off from a theory of .1 = GAIN

WBT gained 0.0337 with the stock airbox over the brand J. Jay is correcting numbers, not using the actual ones. The slowest passes of the night were with the Brand J installed.

11.34 Brand J
11.35 Brand J
11.31 Stock

That guy at the Texas mile had his fastest run with the JLT = GAIN

That guy at the Texas mile never told Jay what was on his car for the 171.5 MPH run. Since the weather was much better(half the density altitude) for that one Sunday morning run where it ran 2.4 MPH faster than any other pass all weekend , it wasn't included in the comparison out of fairness. All other passes for the weekend were within 1.5 MPH of each other, and of all the afternoon runs in similar conditions, the fastest run was actually with an Airaid installed, it was not the brand J. The slowest pass of the weekend was with the Brand J installed.

 

[GeorgeInNePa]

That guy at the Texas mile had his fastest run with the JLT = GAIN



Thanks
Jay

I read the thread.

He also had his slowest run with the JLT.

Why don't you mention that?

 

[Tucker]

Oh look the "other 2" who do nothing but attack and ruin good informative threads.

So you only use "corrected numbers" when it's in your favor? Hmmm.
Every other time you guys talk about numbers you correct them and corrected he WAS FASTER, LOL

As far as fastest at the mile, Sat. your fastest run was with the JLT, FACT. I don't care if his slowest run was with it too, the FACT is the fastest run was NOT WITH THE STOCK BOX! LOL

This thread is about IAT's and dynoing with the hood up

 

[kdanner]

As far as fastest at the mile, Sat. your fastest run was with the JLT, FACT.

No, not fastest at the mile. Looking at Saturday only, the fastest and the slowest runs were with a brand J, there was a 1.2MPH spread across all runs. Then we ran on Sunday.

As far as what this thread is about Jay, it was you who mentioned me. Since you included only half truth, the responsible thing was for me to provide it all. If you don't want me in threads, don't tell half truths about me.

 

[Tucker]

Still the stock box was NOT the fastest.

I can go on and on if you want.

 

[kdanner]

Still the stock box was NOT the fastest.

That is correct. The Brand J was NOT the fastest either.