Enthalpy, exactly, absolute pressure is only 1 part of the entire equation why FI cars do NOT get the SAE #s at sea level.. FI cars DO get faster going to sea level, but not like what NA cars do, which often times is the full correction factor..

 

Enthalpy,

the 24.8 is the absolute pressure when the dyno run was executed..

Also, the weather data you were looking at is for the 1st of August, not the 31st when the dyno run was executed.

I calculated out the density, etc., for the data @ 2:15pm that day:

Density altitude was 8018 (assuming 5000ft elevation where he is)
Absolute pressure 25.111
Relative density is 78.56%, or 21.44% correction for sea level.

Since his correction factor was 24%, then where the dyno was specifically was hotter (98deg vs 93 according to weather.com), etc.

 

http://www.ambientweather.com/sebaprco.html - weather stations correct their barometer readings as well

And, just to let you know... the red graph, at 13psi was the pressure my gauge was reading. The absolute pressure (which is what a map sensor reads: Manifold Absolute Pressure) was significantly less. I'll post a datalog of the run tonight if anyone's interested.

 

Ya, the MAP sensor should read around 3 psi or so less at that altitude, which always freaks people out when they see the two different readings on the standalone and boost gauge.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by servion &raquo;</TD></TR><TR><TD CLASS="quote">And, just to let you know... the red graph, at 13psi was the pressure my gauge was reading. The absolute pressure (which is what a map sensor reads: Manifold Absolute Pressure) was significantly less. I'll post a datalog of the run tonight if anyone's interested.</TD></TR></TABLE>

So you mean to tell me that you have a self zeroing gauge that automaticly calibrates 0 to whatever the ambient pressure is every time you turn it on?

look the MAP sensor reads absolue pressure. it is calibrated of an absolute vacuum. so is your boost gauge. they shouldnt have a different reading. if they do one of them is faulty.

 

Enthalpy, what he said is correct. I've seen 3bar and 2bar map sensors and they all read lower than what the actual pressure is in your intake mani.

 

off topic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itr206 &raquo;</TD></TR><TR><TD CLASS="quote">your tq is better then mine too, but mine doesnt drop off. </TD></TR></TABLE>

what can be done in the tune to prevent torque from dropping off at high rpms? more/less fuel or timing?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1.8T_EG &raquo;</TD></TR><TR><TD CLASS="quote">off topic

what can be done in the tune to prevent torque from dropping off at high rpms? more/less fuel or timing?
</TD></TR></TABLE>

I think the ITR cams combined with the much better breathing JG/Edelbrock VictorX intake that ITR206 is running caused the torque to plateau and stay higher.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by devoid &raquo;</TD></TR><TR><TD CLASS="quote">Enthalpy, what he said is correct. I've seen 3bar and 2bar map sensors and they all read lower than what the actual pressure is in your intake mani.</TD></TR></TABLE>

HAHAHA

really? thats funny i have a .7 bar spring in my tial 40mm WG. with the boost controller disconnected the datalogs from my haltech show that the GM 3 bar MAP sensor reading between .68 and .72 bar.

if you guys are getting differnt readings between the boost gauge and the MAP sensor then one is wrong. guaranteed.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Enthalpy &raquo;</TD></TR><TR><TD CLASS="quote">

HAHAHA

really? thats funny i have a .7 bar spring in my tial 40mm WG. with the boost controller disconnected the datalogs from my haltech show that the GM 3 bar MAP sensor reading between .68 and .72 bar.

if you guys are getting differnt readings between the boost gauge and the MAP sensor then one is wrong. guaranteed.</TD></TR></TABLE>


actually 3/4th of the 3 bars i see are off. they usually read 2-3 psi different from most boost gauges. however, the new aem firmware has updated this and apparently there are three different gm 3 bar's because they have a calibration table for each one. but via hondata's software, they are usually off quite a bit. so you dont really know if its the boost gauge or 3 bar, i usually split the difference.


as far as the other post about altitudes and dynojet software not correcting it. you're probably right there. but most dynos, especially up north and out west, ive found that they use their own portable weather stations that correct this factor due to altitude....but honestly, i havent given much thought, too busy, but great point scott. but i still dont think the 24% factor is out of the question. even if you say, hey, he really is boosting 2.5 psi more, so what, thats 15.5 psi, and still good numbers. every car is different, boost pressure doesnt really mean **** when you compare 20 million different turbos and different engine components

 

Mase you need come back to the West coast and tune my **** again!

 

go up a mile high and try it, afterall, we ARE talking about mile high altitude..

i've seen this personally on haltechs and aems.. using vdo AND greddy boost gauges.. i'd rather not mention crapometer..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by servion &raquo;</TD></TR><TR><TD CLASS="quote">PFI is located in Fort Collins, CO. I'm using the AEM EMS v1.11

These are some pics from last season, but you get the idea


</TD></TR></TABLE>

man that is so sleeper its crazy!!!

you've just got to take it out and race SOME crazy **** on the street
(yeah its illedgal as **** but **** it).
go find a carrera or an m3, thaaat would be funny,
especially the m3.

 

Hell yeah man, I street this thing all the time. The only difference visually between now and the pics is that I'm rollin' on stock HX wheels

I don't streetrace though (don't have the ***** since an unfortunate incident a couple years back)

I just need to tint the windows to hide the rollbar

 

Awsome!

I can't wait to finish my setup...

 

What elevation are you at?

That is the nature of high altitude boosting. Any high altitude standalone user will be able to confirm this. Gauge pressure and aboslute pressure are 2 different things (Ben teaches about this at EFI101)

 

obviously where there's never a worry for low vaccuum, having to figure out absolute pressure #s with a calculator (instead of your head) so you can correctly map out a compressor map, etc..
"enthalpy@tamparacing.com"

 

Great numbers

 

I don't understand the T3/67's unless your looking for some SERIOUS times. A smaller turbo'd guy would smoke it. by the time the smaller t3/t4 hit full boost the t3/67 would just be starting boost

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by quik sol &raquo;</TD></TR><TR><TD CLASS="quote">I don't understand the T3/67's unless your looking for some SERIOUS times. A smaller turbo'd guy would smoke it. by the time the smaller t3/t4 hit full boost the t3/67 would just be starting boost</TD></TR></TABLE>

Go drive a T67 then say that. ITR206 says his T3/T67 is no laggier than his T3/TO4E 60 trim. I am seeing 15 pounds of boost by about 5000, 5500 RPM's. A T3/TO4E 57 trim might have a 1000 RPM advantage over me, but after first gear it doesn't matter one bit. My car holds full boost basically through every shift. I have a buddy with a disco potato on his 84.5MM ITR in an EK coupe, he told me how badly he's gonna own me off the line with all his torque, but even driving on rubber-band 17" street radials I can stay even with him through first and by third i'm putting bus lengths on his car. It's a great turbo, don't underestimate it just because it looks too laggy.

 

IF they are making the same amount of HP, the one that spools quicker and is able to hold that power is gonna win. So he does have a point. if the guy with the t3/t4 spools 1000 rpm quicker, makes the same HP and it doesnt fall off then he WILL win, its not really a discussion at all.

 

well obviously these guys who buy the t3/t67's arent looking to make around 300whp, most want 450whp+ like me

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flip1199 &raquo;</TD></TR><TR><TD CLASS="quote">well obviously these guys who buy the t3/t67's arent looking to make around 300whp, most want 450whp+ like me
</TD></TR></TABLE>

Or are dyno queens

 

that's an amazing machine...

 

Nice numbers