More Bad News

[Vector]

Just for reference with no pre-filter setup I see people posting 4.75 on a 15 is about 14.5-15 psi@8k
4.63 16-16.5@8k
4.5 17.5-18@8k
4.38 19-19.5@8k

Those are the ranges I am getting.
4.88 is 12.5-13 with a pre-filter

Let me know. Your guys thoughts.

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[Tommy V]

Yea weather plays a big part,i have seen 15 psi on the 4.75 pulley in cold air.Valve timing and other things play a part too.I like to look at load to see how much stress im putting on the motor along with boost.With that 4.38 pulley i was seeing 2.72 load and probably 17 to 17.5 psi boost.That is what most likely took the head gasket out.

 

[Jay-rod427]

Yea weather plays a big part,i have seen 15 psi on the 4.75 pulley in cold air.Valve timing and other things play a part too.I like to look at load to see how much stress im putting on the motor along with boost.With that 4.38 pulley i was seeing 2.72 load and probably 17 to 17.5 psi boost.That is what most likely took the head gasket out.

DAYUM that's a lot of load. At 14 lbs at 7900-8000 I only see 1.8 or so.

 

[kcc0521]

Tommy is addicted to power and trying to chase down a slow turbo car. The first step is admitting you have a problem. The second step is listening to friends when they tell you not to run a pulley.

 

[Vector]

Ok current on a 4.88
2.31 load was my peak around 7700
Not completely sure what that references just sharing for comparison.

 

[Jay-rod427]

Tommy is addicted to power and trying to chase down a slow turbo car. The first step is admitting you have a problem. The second step is listening to friends when they tell you not to run a pulley.

 

[Tommy V]

Ok current on a 4.88
2.31 load was my peak around 7700
Not completely sure what that references just sharing for comparison.

Yup that is right around where i was on the 4.88 pulley.Load is based of maf sensor and couple other sensors.Its a good indication of how much air is being pushed into the motor.

 

[Tommy V]

Tommy is addicted to power and trying to chase down a slow turbo car. The first step is admitting you have a problem. The second step is listening to friends when they tell you not to run a pulley.

Yea that 4.38 pulley has taken a couple motors out so far.Atleast i was on e85 unlike someone eles that ran that pulley.Yea my hard head keeps causing me alot of pain,but damm that car was flying with that pulley lol!!

 

[Jay-rod427]

Yup that is right around where i was on the 4.88 pulley.Load is based of maf sensor and couple other sensors.Its a good indication of how much air is being pushed into the motor.

What's interesting and goes along with fueling requirements, how the ecu calculates load, and determines fuel needs after the MAF maxes out...

 

[Jay-rod427]

Yea that 4.38 pulley has taken a couple motors out so far.Atleast i was on e85 unlike someone eles that ran that pulley.Yea my hard head keeps causing me alot of pain,but damm that car was flying with that pulley lol!!

I just bumped to a 4.13", but on the p1x and will limit rpms to around the 15 lb mark whatever it ends up. Please don't go bewm! LOL

 

[Tommy V]

What's interesting and goes along with fueling requirements, how the ecu calculates load, and determines fuel needs after the MAF maxes out...

Yea im not 100% sure but the maf cfm maxes out but the hertz does not.Maybe thats how it still calculates it or it is just a based calculation not really sure.But the more hp your car is making the more load you will have also.

 

[Jay-rod427]

Yea im not 100% sure but the maf cfm maxes out but the hertz does not.Maybe thats how it still calculates it or it is just a based calculation not really sure.But the more hp your car is making the more load you will have also.

True. Maybe it's a background calculation on Hz. Black Magic I tell ya!

 

[Vector]

Ok that explains why I see the maf peg
I get 12.6 Hz around 7700
Stock plastic procharger blower intlet and pre-filter

Maf flat lines at 6300 86.6 or something

Probably could live a while with headstuds and the 4.3 pulley.

I was going to do them over winter and consider the 4.5. but that was just an idea.

I bet it hauled ass for a bit on the 4.3

 

[Tommy V]

Ok that explains why I see the maf peg
I get 12.6 Hz around 7700
Stock plastic procharger blower intlet and pre-filter

Maf flat lines at 6300 86.6 or something

Probably could live a while with headstuds and the 4.3 pulley.

I was going to do them over winter and consider the 4.5. but that was just an idea.

I bet it hauled ass for a bit on the 4.3

Yea it def would not hurt to put head studs in if your going to a 4.5 pulley.You.could go down to the 4.6 first.No doubt it would run a low 9 with that 4.38 pulley,but i also need fuel rails to run that pulley safely.

 

[Vector]

Yea it def would not hurt to put head studs in if your going to a 4.5 pulley.You.could go down to the 4.6 first.No doubt it would run a low 9 with that 4.38 pulley,but i also need fuel rails to run that pulley safely.

Thanks for sharing all the info, good or bad.
current fuel setup is twin 465hp pumps fore hat, -10 feed and rails, -8 return 1050x injectors

So at the moment the safe cutoff could be the 4.6 pulley

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