Bowmans Mod Shop

**WxChaser** · 08-13-2003, 01:36 PM

Thanks Pedro...briefly read the instructions when I checked the display once it shipped to me but didn't see that bit.

**bowman1964** · 08-13-2003, 05:35 PM

ok i took some pics of the prometia's in a friendly battle.and the mach II to the right is only differant by there is no display and the panel is clear to see the lcd.

first was a friendly crank up both and as i load one the other gets to run no load.so in this pic the new prommie is running at a no load of -44c not bad.(this prometia was checked at the dealer and was told it was one of the best he had seen as far as coldest come into the states)
but my fluke dont lie like a softwear based LCD display does.as so many of the people have been buying these mach II's and just because it reads -60c on the display think it is doing that but not....

any ways while this prometia is running no load at -44c and with a ambient room temp of 28.8c which is rather hot(and yes prommies make you room warm,anyone who actually thinks the heat isnt going back into the room is just not thinking)
the modded prometia mach I is running loaded at a nice -41c.

**bowman1964** · 08-13-2003, 05:52 PM

ok now that was friendly enough but lets swap the load and see how the mach II likes a little heat

as you can see the heat load i use stopped the mach II alittle short.
it didnt like my heat....and the modded prommie only goes down to -44c no load and the mach II is -29c loaded

**Fushyuguru** · 08-13-2003, 06:52 PM

Definitely a good example of why no load temps dont mean too much except look impressive.

Excellent prommie mod by the way. Shows the mach II's price for what it is, inflated, like its display temps

**Hobocrow** · 08-13-2003, 08:19 PM

Originally posted by Fushyuguru
Definitely a good example of why no load temps dont mean too much except look impressive.

Excellent prommie mod by the way. Shows the mach II's price for what it is, inflated, like its display temps

I don't see the mach II as over priced...altho expensive, where you going to buy an alternative phase change system?

What the Mach II needs, actually what Chip-con needs is....Bowman....problem solved!

**bowman1964** · 08-13-2003, 08:26 PM

well you guys do get a great display and windows interface more flexable hose(less prone to break).it does have some nice features.
it is just ,what do you want to buy and how much can you spend?

if you want just cooling no extra's get a mach I.

want the whole pie get a mach II

or build your own

**Hobocrow** · 08-13-2003, 08:50 PM

I couldn't agree with you more....What the o/c phase change enthusiast really need is the simple "kit".... then we can build it our self and be damm proud of it!

**WxChaser** · 08-13-2003, 08:56 PM

Remember though...you're comparing a highly modified Mach I running R404a to the stock Mach II running R134a...with stock cap tube length. No special evaporator block or extra cap tube length has been done by bowman on the Mach II yet.

I think the Mach II will perform quite well after gas conversion, and special tune up techniques performed by bowman. More will follow, I'm sure. I'm pretty happy with his preliminary results thus far actually...and his great feedback via the forums, phone, etc also.

Edit - all the reviews I read pre purchase were saying not much improvement at all in temps, but more flexibile hose, better software to interface with windows, and upgradeable firmware also. Not quite sure why there is such a price premium for the II over the I but I bought it for the long run anyway.

**Pimpsho** · 08-14-2003, 08:23 PM

wow i just went throught this whole thread...man where have i been? u have done seen like 5prommis in this whole thread lol i am in awww gj man!!!

**Quickmcj** · 08-15-2003, 05:58 PM

Bowman>

1. Will a better condenser be of great impotance when filling r404a in the Mach I, or is the standart condenser really enough(with extra air flow)?

2. How big will the difference be in performance between an Mach I filled with R404a and no capillary length change compared with a Mach I were the length is changed? Both systems have been given the optimum mass of refrigerant and is therefore not holding the same amount.

Thanks for answering.

**bowman1964** · 08-15-2003, 11:19 PM

Originally posted by Quickmcj
Bowman>

1. Will a better condenser be of great impotance when filling r404a in the Mach I, or is the standart condenser really enough(with extra air flow)?

2. How big will the difference be in performance between an Mach I filled with R404a and no capillary length change compared with a Mach I were the length is changed? Both systems have been given the optimum mass of refrigerant and is therefore not holding the same amount.

Thanks for answering.

OK
1st the condensor is very well suited.nothing i have trown at them has affected them with lots of air flow.run the fan at full speed and they are fine,if you run them slower the excess heat causes the hi pressure to rise very bad.

second quetion ....well this is what happenns.if you dont change the cap tubing,you get excess refrigerant flowing into the evaperator that cannot boil of fast enough,this causes the pressure to rise, also because the compressor cannot move that amount of gas fast enough to keep it in a 10hg vacuum,so it goes up to 5psi maybe.
now where i add cap tubing to reduce the flow and slow down the refrigerant going to the evap.this keeps excess refrigerant from filling the lines and thus keep the load down on the compressor and less load = more vacuum.more vacuum = colder temps.so the prommie with 2 to 5psi low side is only boiling at-40 to -45c where the prommie running in a vacuum is boiling close to -60c
which would you want?

**Quickmcj** · 08-16-2003, 06:52 AM

Bowman>

Thanks for a fulfilling answer. It is very useful knowledge.

**Gary Lloyd** · 08-16-2003, 07:03 AM

Yep. And if the cap tube goes the other way, being too restrictive, then the high side pressure must be elevated in order to push enough refrigerant through. This raises the temperature of the liquid and the pressure which the compressor must pump against, both of which give you a higher evap temp. Aside from that limit, less restrictive gives you faster pulldown, while more restrictive gives you lower temps. Not restrictive enough or too restrictive, either way you lose. And just right means just right for one specific heat load. Everything is balance and trade-offs.

**Quickmcj** · 08-16-2003, 11:15 AM

A TEV valve would do the job?

**bowman1964** · 08-16-2003, 12:53 PM

Originally posted by Quickmcj
A TEV valve would do the job?

TEV's cannot opperate at that low of a heat load.too bad thou

**Quickmcj** · 08-17-2003, 03:42 AM

Yeah...

I have actually been told the same by a technician at Chip-Con but would not believe him.

But when you says so too

**bowman1964** · 08-17-2003, 03:13 PM

well WxChaser i got yours changed out.and is running.the factory fan isnt running fast enough to keep the head pressure down,so i added one temperary until i wire the factory fan straight to the 12v power source.
but this is a nice one.
unloaded temps are hitting -58c which supprised me a little.this one i added a slightly differant cap tube lenght.and it seams to be working slightly better

**bowman1964** · 08-17-2003, 03:17 PM

ok this is where the boys meet the men

fully loaded and i am again supprised it is running so strong hard to see in the pic but -45c loaded..

**JCviggen** · 08-17-2003, 04:12 PM

looking great!

could you hook the unit up to a USB and see what the evaporator temp is like?? seems to me the sensor on mach II reports 10-15C too low

**WxChaser** · 08-17-2003, 04:54 PM

Bowman you are one awesome dude (I can't wipe the smile off my face at all now).

Will call shortly.

**Hobocrow** · 08-17-2003, 05:26 PM

Originally posted by WxChaser
Bowman you are one awesome dude (I can't wipe the smile off my face at all now).

Will call shortly.

Excellent! I'm really happy for you....I know you can't wait to get that prommie back in you hands.

Bowman did it again!.....

**Pedro Rocha** · 08-17-2003, 05:56 PM

That's great!

Bowman, you should really consider a Europe Tour - all mods you can make here could pay you a very nice vacations

**Pedro Rocha** · 08-17-2003, 06:00 PM

Originally posted by JCviggen
looking great!

could you hook the unit up to a USB and see what the evaporator temp is like?? seems to me the sensor on mach II reports 10-15C too low

Very good idea JC, please do that I also suspect the measure are not to accurate..it is just a matter of connect the the USB to any internal port and install the software, myself or any other MachII user are more than happy to send the SW you if necessary

Here are what I get with a standard (no 404 mod, no extra fans) unit a idlle

**Nico** · 08-18-2003, 01:06 AM

Bowman,

Did you just add some cap tube to WXChaser's unit? If so have you got some pic's of a cap tube join? I would have thought that was a pretty trick feat.

**Tom Holck** · 08-18-2003, 04:54 AM

Originally posted by Quickmcj
Bowman>

Thanks for a fulfilling answer. It is very useful knowledge.

I will ad to Bowman;
A prommy R404a with standard kapillaertube, can't hold mutch, its only a little better than standard Prommy.
But one thing.. it have a VERY fast booting time. The temp drop instantly, so if that is importent, it might be an option. The mod is very chip an not complicated to do.

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