Tvs2300 jackshaft front pulley question

[Price32]

I live in Denver, CO which is at 5800 ft above sea level...really high altitude. My current compression ratio is 10:7.1 on a forged 370. My question is how can I calculate the boost I am running with the added altitude? I currently got a 3.2 pulley on the front jackshaft and was told that I am making about 7lbs of boost, but if I want to get a smaller pulley how can I calculate to confirm the actual boost I'm making along with the boost I will make if I got a 3.1 or 2.9 pulley at high altitude?

I had a 2.8 pulley but was told I was putting out 15psi which was unsafe at my current compression ratio.Help me out here

 

[ezdaar]

Bud, you need a boost and wideband.
Don't guess with your build.


Check performancetrucks.net forced induction section for better answers.

 

[JennaBear]

15psi at 5000' is about the equivalent of 9psi at sea level, not unsafe.

 

[Price32]

@JennaBear...quit playing games with my heart LOL! seriously? how did you get that calculation? did you take into consideration my mods and compression ratio?

 

[JennaBear]

Really simple actually....

2.3L blower
3L of engine displacement per revolution

7.25" pulley / 2.8" blower pulley = 2.6 blower revolutions per engine revolution

2.6rev x 2.3L blower = 5.98L of air
5.98L of air pushed into 3L of engine = 1.99 pressure ratio
1.99p/r x 12.23lb/in^2 air density @ 5000' = 24.34psi standardized
24.34 / 14.7lb/in^2 at sea level = 1.65 pressure ratio
14.7 x 0.65 = 9.6psi of boost at sea level

All that matters in the end is how many oxygen molecules are crammed in the cylinder, not the absolute pressure seen. 15psi at 5000' has the equivalent O2 molecule count to 9.6psi at sea level.

---------- Post added at 02:27 PM ---------- Previous post was at 02:21 PM ----------

Happy to further explain with a full breakdown of an Oxygen molecule, by diving into the molar mass

 

[Price32]

Okay that is pretty simple...I also just found out that youre also a molecular scientist and border line rocket scientist...I also think my brain just did a manual reset after reading that equation and I now have t relearn everything That I once knew..LOL!

 

[JennaBear]

I am actually a scientist , just help out BBP where I can

 

[Price32]

Thank you @JennaBear I really appreciate you giving me some good guidance on this one. Time to pulley back down..OH YEAH!

 

[JennaBear]

I also recommend getting rid of your throttle body spacer....

 

[Price32]

I already did, I just need to update the sig....Anybody wanna buy a throttle body spacer? asking price is $1,000,000 dollars...my loss is your gain LOL!

 

[ezdaar]

Hope your going to do more than just toss a pulley on it.

 

[Price32]

What else would I need to do? I'm open to suggestions @ezdaar

 

[JennaBear]

Monitor your system accordingly (ie. gauges, wideband).

 

[Price32]

Yeah, I started looking into gauges once it was brought up by ezdaar. I'm looking at the LM-2 digital controller...any suggestions on a good one?

 

[JennaBear]

LM is a good one. I am running a PLX DM100 and an Aeroforce Interceptor. AEM Uegos are good too.

 

[Price32]

Thats awesome, I'm gonna do some digging into those now. Does BBP sale any?

 

[JennaBear]

We do.

 

[Price32]

I'll buy them from you then. Your top recommendation on what I will need please...

---------- Post added at 02:06 PM ---------- Previous post was at 02:04 PM ----------

When are you guys coming to colorado to tune some cars at high altitude?

---------- Post added at 02:14 PM ---------- Previous post was at 02:06 PM ----------

Nevermind just checked the calendar October 22nd an 23rd.

 

[ezdaar]

Best of the best would be duel Aeroforce interceptors.
Next,
A dedicated boost gauge and a Aeroforce.


I always prefer a Dedicated Boost gauge, but that's also coming from a "turbo" setup, not a Blower setup.

 

[JennaBear]

I like both the PLX and the AEM. Justin ran the LM series and had no issues with them. Really go with what looks best, but you want a boost and wideband gauge.

Yes, Justin will be tuning in Denver in OCT.

---------- Post added at 04:24 PM ---------- Previous post was at 04:24 PM ----------

Best of the best would be duel Aeroforce interceptors.
Next,
A dedicated boost gauge and a Aeroforce.


I always prefer a Dedicated Boost gauge, but that's also coming from a "turbo" setup, not a Blower setup.

I agree, this is my setup, best of both worlds.