Intro and Update: Slugmobile and Mean Mini! (long read, but worth it)

[wheming]

MeanMini:
Went to Freaky Friday night racing at Fayetteville Motorsports Park 4-8-2016. Left later than i wanted so i felt rushed and behind. But the racing still hadn't started until after i arrived.
My goals were to try and match some boost levels of previous runs last year and do some comparisons.
First run was crappy. Didn't get a good burnout, and spun badly on launch. Should have quick lifted and got back on, but i just wasn't thinking as it was my first race since last year.
More details and the timeslip are here http://www.turbo-mopar.com/forums/sh....php?p=1105255
The second run took forever in the staging lanes, and by then i decided i just wasn't having fun. Lots of bikes there, and way too many idiots. I thought the pits were a secondary dragstrip with the burnouts and bikes flying up and down. So i decided it was going to be my last run after the Pontiac G8 in front of me oiled down the track. I did get my second run in after the clean up. And with the help of a bit better burnout, and the fresh spray on the track Mini hooked a bit better. 2nd slip is in that linked thread. You can see in the video i shifted to 3rd a bit early, and before the shift light even lit. I probably missed out on a 12.9x because of that.

I was doing some comparisions and i figured i would look at average boost level through the run. Last year i dealt with some significant boost creep. Now, the boost is in check thanks to TU's super 38mm internal wastegate puck. Brian did a great job getting it modified to work (you need to rework the arm where the puck attaches) and it is doing a good job of maintaining the boost.
So run 1 the average boost was 15psi. (I calculated from the time the staging limiter was released, i think. When the turboflag bitcount was 200).
Run 2 the average boost was 15.7psi. And the run was very near identical to a previous run on 7-17-2015.

Interestingly however, the average boost calculated on the 7-17-2015 run was 17.1psi.

Also i found something and changed it Friday morning before racing. It always bothered me why the boost seemed to drop off after shifting.. i got to looking at it and found when going through the gvalve, the wastegate can wasn't getting bled off properly when lifting, or when the boost dropped. So in last years logs, you can see the boost drop after the shift and it stayed low until the turbo started creeping again.

I posted the logs of the racing on Friday 4-8-2016 in the other thread, but for convenience here they are again.

[wheming]

MeanMini:
Spent some time today working on the A/C. It hasn't been right since reinstalling and converting over to the 93 style R134a compressor, expansion valve, and an aftermarket universal parallel flow condenser. I had previously wired in the high pressure switch, and charge the system to a guestimate, due to the smaller condenser.
It work work, but not well, and the compressor would never cycle off.
The 1993 style R134a expansion valve has a temperature cycling switch that is basically in the same circuit as the high & low pressure switches. It does get another wire the white wire (18 WT) from the natural colored 8 way behind the battery.
I recently got the connector i needed to wire in the 93 temperature cycling switch.
I did boost the charge a bit, but it may still be low. I'm not having much luck getting the compressor to cycle off.
But, the system is cooling a bit better. It may still need a bit more charge, but i will try giving it a test drive tomorrow and see how it does.

I'm thinking i will need some decent functioning a/c for the trip to Memphis.

[Vigo]

Are you actually using gauges? What is your low side pressure? The compressor will never cycle if the low side pressure never drops, such as if you are OVER charged.....

[wheming]

Are you actually using gauges? What is your low side pressure? The compressor will never cycle if the low side pressure never drops, such as if you are OVER charged.....

I was, believe it or not!
Although i'm not sure exactly where the factory had the pressures.

I could see the expansion valve cycling, and the suction pressure was reading about 33 then would drop to about 27 or so as the expansion valve cycled. This was checking things with the a/c on MAX, but the fan on low. I was trying to see the compressor cycle.
I looked at it today and i ordered a new temperature cycling switch. When i turned on a/c it did not come on, and jumping the switch starts thse compressor.

I think the temperature switch should cycle the clutch when the evaporator temp gets around freezing, which is right around where i was with the suction pressure.
I'm figuring the temperature switch cycles the clutch off when the evaporator (cabin temp) is low enough that the coil is mostly flooded and getting some liquid to hit the probe (cycling the clutch off before liquid gets back to the compressor).

Here's the other thing you'll hate. I forgot to weigh my can before adding! I suspect i put in about 3 ounces though. But that won't mean anything since you don't know how much was already in.

I ordered a new cycling switch which i will have tomorrow.

[Vigo]

The reason i asked is because you can more or less fill the system based on low side pressures instead of going off of weight once the weight specs are rendered wrong by modifying something.

If the low side pressures never got low, the evaporator was not freezing. The low side relies on the heat it's absorbing through the evaporator core to keep low side pressure as 'high' as it should be. If the evaporator freezes externally, the refrigerant doesn't soak up any heat and boil off internally, and low pressures get very low. If it's not doing that, the evaporator isn't freezing. I would go by low side pressures first and foremost and treat compressor cycling at idle as an anecdotal clue at best.

In general, expansion valve 134 systems like to run closer to 40-45 at idle than the 33 you have now. Keep adding!

[wheming]

Thanks for the suggestion.
I figured i would have to charge by suction pressure with changing some things. I was concerned about overcharging, so wanted to add slowly and test other factors in the process.
Different condenser, and longer line going to receiver-dryer. But retained the stock R12 evaporator. I think the 93 van calls for 36oz of R134a. I figure it probably should take less. I think i'm at about 28-30 right now.

I should have time before work tomorrow to try more. But i want to install the new temp switch first. I still have a few ounces left in a can.

Thanks for the help!

Sent from my SAMSUNG-SM-G870A using Tapatalk

[wheming]

... I would go by low side pressures first and foremost and treat compressor cycling at idle as an anecdotal clue at best.

In general, expansion valve 134 systems like to run closer to 40-45 at idle than the 33 you have now. Keep adding!

https://youtu.be/1qTg9ws0lAs

Temperature switch arrived but was open package and appeared used, and not sure if bad, but it didn't cycle the clutch after starting van. Installed an old temp switch and compressor cycled on.
Put in the remainder of the can i had, maybe a couple oz's but you see it is probably still a bit low.

With a/c on MAX and blower fan on high, suction pressure cycling 29-42.

[wheming]

Oops double post

[wheming]

Worked on a/c a bit today. Finally got the new temperature cycling switch and installed.
Weird that once installed a/c clutch only cycles on for about 3 seconds. I have added slowly, and only gas, so hopefully i don't end up overcharging again.
Eventually the a/c was running and cycling on/off the compressor, but i think it may still be low. On the roadtest it appeared to work the a/c well, but the temp outside was cooler than normal. On the way home though after getting fuel, the a/c wasn't working well, and wasn't cycling on as it should.
I'll have to look at it more tomorrow. I did take a short video when it appeared to be working properly.
https://youtu.be/qHBC6Vl7wlk


Sent from my SAMSUNG-SM-G870A using Tapatalk

[wheming]

Looking ahead to see when i can actually get some track testing in with Mini. All this rain pattern plus the cooling system issues have really killed my racing opportunities. So far this year i've been once!
At this rate, it doesn't even look like I'll have many chances before SDAC. I don't know how this same stuff seems to happen year after year!
I do see at least 1 opportunity to race 1/8 mile before SDAC, and hopefully they'll be a test&tune at the 1/4 in Fayetteville on one of my days off. Otherwise i guess the testing will be in Memphis!

[mopar-tech]

Wayne- I was going over some old video tape captures this morning and I found one when Gus was racing Slug up at the Valley.

I'll try and upload it today.

Gary

[wheming]

Wayne- I was going over some old video tape captures this morning and I found one when Gus was racing Slug up at the Valley.

I'll try and upload it today.

Gary

Cool! Thanks Gary. Look forward to it.
I had to take Slug for an inspection recently, and i realized how much i miss driving her. Put less than 300 miles on her over the last year due to the unresolved mystery noise.
Hopefully she'll get some attention over this fall/winter and make her re-debut next year. We can't exactly have Mini be faster than Slug, can we?

[mopar-tech]

Video will be uploaded inside the hour I think, going over tape and doing a Daytona compilation video at the moment.

[mopar-tech]

https://youtu.be/q1EMBW3JExI

[2.216VTurbo]

Nice to have some never seen before 20 year old footage That gold GLH still alive, who's the caretaker of it now?

[Force Fed Mopar]

Video will be uploaded inside the hour I think, going over tape and doing a Daytona compilation video at the moment.

Little off topic, but you wouldn't happen to have any video on Rick Lozier's black nitrous V6 Daytona would you? I own the car now, have always heard 12's out of it but never seen a track slip or video...

[mopar-tech]

Nice to have some never seen before 20 year old footage That gold GLH still alive, who's the caretaker of it now?

Not sure who owns the GLH, I can ask on the NE-SDAC list.

I have more video too of Gus, as far back as 1995 I think.

- - - Updated - - -

Little off topic, but you wouldn't happen to have any video on Rick Lozier's black nitrous V6 Daytona would you? I own the car now, have always heard 12's out of it but never seen a track slip or video...

Where was the car run? I have several hours of SDAC and track video.

[wheming]

Thanks Gary, that's good stuff.
Watching that video is making me think Gus was running lower air pressure than i have.
And some cameo's from ButchN and James Dempsey. I can't remember that gold GLHT though.

[mopar-tech]

Thanks Gary, that's good stuff.
Watching that video is making me think Gus was running lower air pressure than i have.
And some cameo's from ButchN and James Dempsey. I can't remember that gold GLHT though.

Here, have another-

[Victor]

I don't remember the gold GLH either. Nice to see old runs of Gus. I loved those Bogart wheels.