Low Boost

[Enemy]

So my 03 L has a cone air filter with maf adapter, and no muffler, cats are still in place. I've noticed that it's pushing between 6.5 and 7lbs of boost and then during the top end it picks up and goes to 7.5 but not the stock 8. Could this be due to the no muffler? It's been happening since before I changed from the air box to the filter Any thoughts?
L has 54k on the clock, no other performance mods

Thanks in advance

 

[san-man]

Are you looking at the stock boost guage or a aftermarket?


The stocker is junk.

 

[Enemy]

stock and I also have an aftermarket gauge

 

[san-man]

With the aftermarket guage you could try to adjust the boost actuator. To see if that helps get back the full 8lbs of boost.


There are a couple of ways to adjust the actuator in the HOW TO section.

 

[tallfreak]

I have a 4lb lower and my factory one only shows about 9 lol. The stock one is junk. If you have an Autometer boost gauge it might not be so accurate either. I am on my third one and I bought the truck May 2008.

 

[Enemy]

I have a crappy glowshift boost gauge. Probably gonna check the lines to the gauge and the T under the dash for any leaks. What should my vacuum be at at idle? Im seeing between 20-25. Also could it have anything to do with me not having a muffler?

 

[tallfreak]

It is possible that it could be because of the muffler. An increase in flow before the blower makes boost go up a little, and increase in flow after the blower (exhaust) decreases boost a little. This doesn't mean that you are losing power, it just means that you are moving more air through the engine than before. You probably gained some power by ditching the muffler.

Your vacuum sounds good. If I were you, I wouldn't worry about it too much. Remember that lower boost pressure doesn't always mean less power. Air temperature can even cause boost pressure to change a little.

 

[Enemy]

It is possible that it could be because of the muffler. An increase in flow before the blower makes boost go up a little, and increase in flow after the blower (exhaust) decreases boost a little. This doesn't mean that you are losing power, it just means that you are moving more air through the engine than before. You probably gained some power by ditching the muffler.

Your vacuum sounds good. If I were you, I wouldn't worry about it too much. Remember that lower boost pressure doesn't always mean less power. Air temperature can even cause boost pressure to change a little.

cool, thanks for the info

 

[Mondo1]

Very true. The boost read on your guage is boost that is read before it enters the engine. That is to say that it is unused boost. After my long tube install I dropped almost 2 lbs. yet I picked up power on the dyno. After adding a 6 lb pulley I still only picked up 4 more lbs on the guage , but my numbers went through the roof! Want to see more of a drop?? Get a set of ported heads!! I love boost drops!!

 

[STRK BY]

54,000 mles...is that on the belt also..?

Belt slip possibly....try a New Ford OEM belt or a new Gates drive belt.......

 

[DjKush]

If you have some time and if you still have your stock intake try and switch them for testing purposes lol see if it might be your aftermarket intAke (which I doubt). But it wouldn't hurt to try it. Good luck

 

[Enemy]

If you have some time and if you still have your stock intake try and switch them for testing purposes lol see if it might be your aftermarket intAke (which I doubt). But it wouldn't hurt to try it. Good luck

I just switched the intakes yesterday. This issue has been happening for over a month already

 

[Enemy]

Ok, so last night while doing some WOT driving on an empty road I again noticed that both gauges start at 6psi and slowly as Im going throught the gears I will hit 7 and almost 8. When I turn the truck off the gauges are a little under "0" Is this normal?

 

[Enemy]

ttt

 

[jeffthagiraffe]

yeah kind of sounds like u lost some numbers cus the no exhaust...why did u take the mufflers off i did that once and the sound just gets annoying cus its right under the truck. here in tx would get plenty of tickets but if u live in NM its probably ok

 

[Parkin Lot Pmpn]

under the hood there is a little L shaped rubber thing that is on your vacume line....dont knwo how else to describe it but every 6 months mine cracks and leaks....try that it costs 2 bucks at pep boys

 

[Enemy]

yeah kind of sounds like u lost some numbers cus the no exhaust...why did u take the mufflers off i did that once and the sound just gets annoying cus its right under the truck. here in tx would get plenty of tickets but if u live in NM its probably ok

Haven't gotten stopped yet and have had it for about 7 months. Took it off to get a cheap sounding exhaust :-D

under the hood there is a little L shaped rubber thing that is on your vacume line....dont knwo how else to describe it but every 6 months mine cracks and leaks....try that it costs 2 bucks at pep boys

Can you take a pic and show me where it;s located?

 

[Parkin Lot Pmpn]

i cant take a pic but pop the hood look to the right of the supercharger towards the firewall it sits pretty close to the spark plugs furthest towards the firewall.....take a look real and see if you find it