As the title suggests, I would like some input from any of you who have monitored your boost and vacuum reading at various stages of the motor's activity.

Specifically:

1-maximum boost (please include pulley %) with rpm,
2-maximum coast down vacuum on level ground from highway speed (60-80mph),
3-and finally, idle vacuum.

Important caveat, please do not use analogue gauge readings as they are prone to parallax and are just generally not very accurate. If you have collected these data with some type of high resolution digital boost/vacuum gauge or reading converted from OBD2 readers, they would be greatly appreciated!

 

(edit) oops, didn't read your no analog statement...

 

I just deleted a whole bunch of just driving around data runs, so I'll have to go from memory. I could have better numbers tomorrow. I think the DashDyno reads in PSI positive and negative.

Max boost about 16.5 psi at 7500 with 17% pulley
Idle is about -6.5 to -8psi
Coast down, never looked that close, but I remember around -11psi

Again, this is foggy memory, I can get more tomorrow unless you really want it tonight, then I could go for a quick drive.

 

Phoenix, AZ ~1100 feet above sea level
15% pulley, Alta V1 TMIC, 7000 RPM
Max Boost = 14.3 psi
Max coast = -11.7
Idle = -6 ac on and -7.7 ac off
These are off the top of my beer coated memory from a Scanguage II using an Xguage to calculate boost instead of MAP.

 

1. 15.6 psi >7,000 rpm (16%+2%)
2. anywhere from -7 to -10 ish
3. -8 ish

Scanguage II

 

Wow...we're kinda all over the map a bit...I suspect that I have either/both boost/vacuum leak somewhere because of my numbers...

1-14.5psi (low) @7000rpm, 15+2%, DFIC (cause slight pressure drop?)
2-coast down neg 11.5-neg 12.3
3-idle neg 5.5-neg 6.2

 

My gauge is analog so I can't play

 

you might also want to consider what modifications have been done, such as cam, big valve cylinder head, catless exhaust when trying to compare readings from one car to another.

 

I'm happy just to get the few feedbacks that I can get...considering all the "mad modders" out there, I figured I'd get more samples from Minis with the right instrumentation...

 

Unfortunately I didn't have a digital boost input till right before I added the Turbo, so most of my logs wouldn't be helpful. I do know that on dyno runs I used to get 17psi max with a 15%+2% combo.

I came across this test run (below) which I think is when the car was in an "intermediate" stage (i.e. no Turbo, 0% pulley + 2% Crank, modified internals). Yellow is boost, Purple is GPS-measured speed, Red is RPMs.


I can keep digging around if you think it would be useful...

 

Well I tried and proceeded to screw up the Auterra Dyno-Scan install and have lost the key. Spend the better part of the afternoon looking for the CC receipt to request a new key. And the G2X...arghhh lets not go there. Still working with them to get it right. You'd think after a year they would stop repairing the unit and send me a new one.

 

Why did you go and screw it up? Nothing better to do?

 

LOL...I knew you had to have been busy somewhere in the background...

 

I am putting in my DFIC 2 on the weekend so I will let you know if there is a noticable drop in any of the readings

 

Your help is always appreciated...

 

Edited my first post.

 

 

I edited post #4. My memory was a little askew and after driving around today, I got some accurate readings...

 

Needed memory space on the phone so uninstalled a bunch of stuff I never use. Figured I'd do a clean Dyno_Scan install too since I had all the files for like every Marque. Not to often I need to read a Kia codes. Auterra already sent me a new key...quick turnaround. I'm impressed.

 

I'm just giving you a hard time. It's like your sig. The best of intentions and then it goes downhill quick.

 

works4me, the label on your graph for the boost/vac is in psi. Is the vacuum in psi or in Hg? I'm leaning towards in Hg because you're seeing over 20 psi of vacuum. That is equal to 40 in Hg and a perfect vacuum is only around 30 in Hg. Also, almost 20 psi with only a 2% crank pulley

For the rest of you, are you giving vacuum readings in in Hg or psi? I'm guessing psi since you are all in the 10-12 range for deceleration. I can't play in this thread either because I only have an analog gauge but I get comparable readings at idle and max boost but I don't get quite as much vacuum as you guys on deceleration.

 

Anyone else using the Auterra Dyno-Scan for Palm....I have some questions but we should move that elsewhere.

 

psi

 

Your question may be Palm specific, if not I have the Dashdyno and Dyno-scan for the laptop.

 

I'm assuming my gauge stays in one scale all the time...so it's psi...