Help!! Boost Drop !!

[SVPAM]

03 Cobra with KB 2.6L
3.25'' upper /4lb metco lower combo
Belt number K080797
I have a major boost drop, first of all this combo should give about 20lb+ of boost it gives only 17lb max and drop with higher rpm specially after 5000 rpm and give 9-10 psi only
With higher rpm I go with lower boost it give !
Note that I'm in a tuning period, my wideband show A/F = aprox 10
What is could be the causes of the problem ? is it a belt slip ? wrong belt number ? or due to rich so the ecu does not accept more boost ?

thanks guys

 

[Posi]

Sounds like massive belt slip. If the belt isn't a pain to put on then it's not tight enough. Also look into getting a Goodyear Gatorback belt because they are softer.

 

[SVPAM]

Do you think that it's the belt brand ?

 

[04SLOBRA1]

Probably the KB, shoulda went whipple







and yes mine is on her way :rockon:

 

[SnakeBite4487]

Sounds like massive belt slip. If the belt isn't a pain to put on then it's not tight enough. Also look into getting a Goodyear Gatorback belt because they are softer.

I agree. Do you have aftermarked tenisonor and idler? Def. sounds like major belt slip. With that much boost and the charger spinning that fast its goin to be a challenge. Im only running 12lbs and i have belt slip here and there. Get the gatorback!

 

[SVPAM]

I got the belt directly from kenne bell
they are the one who sold it to me

 

[SVPAM]

Help guys I'm getting crazy !!!!!!

 

[Posi]

^Well if that's your road test and you just hit 6th gear then you're on your own! You better keep that belt slip or loss of boost to save that motor.

If you want an exotic then get one.

Not bashin, just sayin. Just becasue KB sent you the belt they don't know what other idlers and such you have. If the belt is really easy to get off or on then it's to loose!

 

[SnakeBite4487]

^Well if that's your road test and you just hit 6th gear then you're on your own! You better keep that belt slip or loss of boost to save that motor.

If you want an exotic then get one.

Not bashin, just sayin. Just becasue KB sent you the belt they don't know what other idlers and such you have. If the belt is really easy to get off or on then it's to loose!

6th gear i agree. Save your motor a little. Still sounds like the belt is the reason. Check the tension and make sure thats the right belt. As he said if its easy to come off and on then it is wrong.

 

[About2bite]

Do you have an aux idler? How tight is your belt and did you have to notch the tensioner to get it on? That 4# lower is spinning your belt a lot faster than the stock lower so you will be more prone to belt slip. I think my belt is 82" and I have a 4# lower and 3.25 (15#) upper as well, but I did have to notch the tensioner to put it on. I think your boost should be around 19#'s opposed to 20+ but you will probably not have the exact same size belt as me.

I would definitely not go running around topping your car out like that, the next question you'll have for us will be related to a rebuild. I never pull outside of 4th gear.

Goodluck

Josh

 

[SVPAM]

Come on guys I was just checking my boost
it was only one time go to 6th just to make sure that there is a drop in each gear
Actually I don't know about aux. I just got Metco 4lb lower kit with some other pulleys
and 3.25 upper
Finally, Do I have to notch the tensioner ? Or it's only a belt size
I bought (77.25'' and 78'' )
the one in is 79.75''
KB sent to me (74.5'' ) with the upper and I told him that I have lower
What is the right size to install ?! or notch is must ?
If it's must please send me some links to show me the right way to do it.

thanks again

 

[About2bite]

You may want to get an aux idler since it'll give you more belt wrap around the blower pulley.

This pic shows the pulley that will help:
http://www.billetflow.com/DSCF0024.JPG

Here is another link:
http://www.billetflow.com/IdlerBracket.htm

 

[SVPAM]

doesn't it come with the Metco kit ?
Also, where to locate the pulley in the front cover ? upper location or lower location
it's written in the instructions that if you go for smaller upper s/c pulley then put it in the upper location
if it's stock upper s/c pulley then put it in the lower location. But in the fig it shows that lower is for #4 and #2 , upper is for #6 and #8

What does it mean ?

 

[Posi]

^You need an auxiliary idler for no slip. Then 1/2" smaller belt can make all the difference in the world! That's how tight I get mine.

 

[jm@ReischePerf]

Holy belt slip Batman! You can actually hear the blower losing rpm in the video, did you guys notice that?

Anyway listen to what they are saying, you need an aux idler and a tighter belt and you'll have to notch your tensioner. This thread will give you an idea of what you're trying to accomplish as far as tension:

http://www.svtperformance.com/forums/showthread.php?t=485098

 

[About2bite]

Holy belt slip Batman! You can actually hear the blower losing rpm in the video, did you guys notice that?

Yep sure did

 

[jm@ReischePerf]

Also, where to locate the pulley in the front cover ? upper location or lower location

I honestly think they gave you two locations to help with belt sizing, the belt is not going to slip on the lower pulley no matter where the idler is. Somebody correct me if I'm wrong here.

 

[boston03cobra]

jm's right belt slip,you can hear it,look for dust on the pullys and coolant x-over pipe.

 

[SVPAM]

Yuuuppppeeeeeeeeee
I replaced the belt to 1.75'' tighter and it's work no drop
But It gave me 20lb only not as KB and Metco said (22lb ) !!!

Again my combo is 3.25''/4lb with ( C16 Mix ) ( Let's say 104+ )
I put ( 70% pump gas , 30% Leaded Vp racing C16 )
Do I have to replace the upper to 2.75'' , I have one , But my tuner told me that it will be too much boost on stock motor it will not handle 2.75/4lb even with race gas !!!!
And he is one of the best tuners for 03/04
BTW my mods are : LT headers, O/R prochamber, 3'' Cat back, 60lb injec, Ford GT dual pumps, NGK TR6, Clutch, 2.6 kb, LFP s/c water tank, Afco dual pass H.E, Race gas
Not daily use

thanks alot guys

 

[SVPAM]

helllooooooooooooooooooo