How to read boost numbers

[Bmaughan]

I’ve just recently started dataloging and I’m trying to decipher my boost numbers. I seem to only be making around 8.5 lbs until the moment of peak rpm/throttle release and then it spikes up to about 9.5lbs.
Is a quick boost spike normal upon throttle release? If so, would I be right in saying I’m running 8.5lbs or would the peak 9.5 number be more accurate?

Hopefully that makes sense haha

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[Jay-rod427]

8.5 is right. There is always a tiny spike when the throttle body closes, before the bypass valve opens.

 

[Bmaughan]

Ok that’s kind of what I was thinking... but now makes me think of another question.

Just to be clear I’m running a p1sc..
I was getting about 7.5lbs on a 4” pulley... I went down to a 3.7” and now I’m only seeing 8.5.
I thought each 10th of an inch is worth about a pound.
Am I wrong? Does this seem right?

I don’t think I have any leaks/slipping. I could be missing something obviously.

 

[Cory S]

Post the .CSV log

 

[Bmaughan]

Post the .CSV log

is there a trick to uploading a .csv files? It keeps telling me the file doesn't have the correct extension. Do you post spreadsheets or actual .csv files?

 

[Cory S]

is there a trick to uploading a .csv files? It keeps telling me the file doesn't have the correct extension. Do you post spreadsheets or actual .csv files?

What about an Excel file?

 

[Bartly]

is there a trick to uploading a .csv files? It keeps telling me the file doesn't have the correct extension. Do you post spreadsheets or actual .csv files?

change the file extension to .txt and it will upload. Then whoever wants to open it has to change it back to .cvs to open it.

 

[Bmaughan]

Got it.
So log 11 is super long but it’s the only one that has the car on e85 and the 4”pulley.
Log 12 is e85 with the 3.7”

 

[SolarFlare]

1 tenth per psi is a good rule of thumb but the coyote is a very efficient motor and the P1sc is a small blower. I usually trend airflow by load, mf hz or maf lbs per min.

 

[Bmaughan]

1 tenth per psi is a good rule of thumb but the coyote is a very efficient motor and the P1sc is a small blower. I usually trend airflow by load, mf hz or maf lbs per min.

Ok so would you say, going from 4” to 3.7” and only seeing a 1 pound increase seems normal?

 

[SolarFlare]

Ok so would you say, going from 4” to 3.7” and only seeing a 1 pound increase seems normal?

Id say tell me what load, mf hz and maf lbs did

 

[Bmaughan]

Id say tell me what load, mf hz and maf lbs did

At peak rpm :
Load 1.627, Mf lbs 82.8, mf hz 9.9-10

 

[SolarFlare]

At peak rpm :
Load 1.627, Mf lbs 82.8, mf hz 9.9-10

It bad probably around mid 600s. Did you log it on previous pulley? What were numbers?

 

[Cory S]

At peak rpm :
Load 1.627, Mf lbs 82.8, mf hz 9.9-10

I’d say 687-693whp

 

[Bmaughan]

Other log is having a hard time loading for some reason… Once I get it I’ll post up the info.
So how are you determining horsepower from those numbers?
I’d love to learn how to do that!

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