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Motor and Drivetrain / Pressure vs Coolant Boiling Points
« Last post by fabr on Yesterday at 07:03:36 PM »
There is a direct correlation to coolant or water boiling point based on how much pressure it is under. Whenever the subject of boiling over or "overheating "comes up it usually concerns peoples concern that 210 /220/230 or even more is overheating.Most people believe that due to distilled water boiling at 212* at sea level that it is bad to run their engines at 210. That is not the case. Here are a couple charts that show that with a coolant system capable of holding pressure and a cap of high enough PSI water/coolant boils at much higher temps and therefore should remove concerns of an engine running at 210 or even more without harm or consern of boil over. Some race teams even pre-pressurize their cooling systems so they can run their engines at temps nearing 250* . They have their reasons.

 There are literally hundreds of charts to be found verifying this relationship between pressure and boiling point. On the other side of the coin,vacumn lowers the boiling point dramatically. Ever seen water boil at room temperature?
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"AP" General Discusion / Re: car derived sxs
« Last post by Baloo on July 19, 2018, 12:25:43 PM »
speed range, well probably not that fast  I was never a racing driver I think about what could go wrong to much lol
don't think I will be the high side of 60 very often at all,  the only place I have to ride is my track which is tight and twisty  so was aiming for a short wheelbase to make it turn quick and be nimble,  will be registered for road use as well so  that's when it will see the higher speeds I guess

i see this as a prototype and making a revised version staright after this, a second golf has found its way to me via ebay already
just couldent say no to a VR6 4wd version for $300, looking to evealuate the first one which is an 1800cc turbo  the audi 20v engine against the second one which is 2.8 normaly asperated ( for the moment )  should be an intereesting comparison  and of course it will be 4wd


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"AP" General Discusion / Re: car derived sxs
« Last post by fabr on July 19, 2018, 09:28:42 AM »
onto the work bench and I can see where the suspension tops need to be
just need to copy over the engine mounting position in the same way  and I can get rid of the old body shell I keep tripping over


Back to your topic,baloo,it looks like you have a good game plan . I'm really interested in the results. I had envisioned a slightly longer wheel base for high speed stability. That brings up the question of what is your anticipated speed range for this project.
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"AP" General Discusion / Re: car derived sxs
« Last post by fabr on July 19, 2018, 09:24:19 AM »
I just asked re: Chassis.  Hope they respond.

And they did.  Not a lot of detail, but some insight. 

Quote
Good Morning Jeffrey,

We use bronze welding because it has very slight flex in it as you say.I have brazed a lot of things in my fabbing life and I would only use brazing on sheetmetal ,never in a structural application . Yes,I an agree that it allows a very small amount of flex but it is that flex that will allow the bronze or brass filler to fail much sooner than a weld. It also induces less localised heat in the tubes, increasing strength. Reading between the lines of that they are saying that less skilled welders are needed to assembly the frame. They are using thin wall tubing that can ,with a lesser skilled laborer,induce way too much heat into the weld creating a much larger HAZ(heat affected zone) that is not a good thing.

Regards
 
Henry
 
Henry Siebert-Saunders
There is a reason the suspension is tigged. Plain and simple it is because it is the much stronger joining practice. Lots of new cars are using sil bronze brazing on sheetmetal bodies/built up structures as is used in unibodies and it is a better method than welding or spot welding of thin sheetmetal for that application. 
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"AP" General Discusion / Re: car derived sxs
« Last post by Baloo on July 19, 2018, 07:03:55 AM »
onto the work bench and I can see where the suspension tops need to be
just need to copy over the engine mounting position in the same way  and I can get rid of the old body shell I keep tripping over

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"AP" General Discusion / Re: car derived sxs
« Last post by Baloo on July 19, 2018, 06:57:35 AM »
that gives me the position for the wishbone pick up points but not the strut tops
so

weld a couple of discs in the suspension tops to give me a 12mm hole like thus



and use these to capture the position for the strut top



wheelbase is set at 2100mm which is the shortest I could fit into with legs out straight



base layer will have to be 2" box section for now but I am treating this as a prototype and will make another after ironing out all my mistakes lol

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"AP" General Discusion / Re: car derived sxs
« Last post by Baloo on July 19, 2018, 06:52:08 AM »
so I finished stripping the golf down as far as I could, decided for the time being I would use the golf front subframe in the back and another up front


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"AP" General Discusion / Re: car derived sxs
« Last post by Yummi on July 19, 2018, 06:09:19 AM »
I just asked re: Chassis.  Hope they respond.

And they did.  Not a lot of detail, but some insight. 

Quote
Good Morning Jeffrey,

We use bronze welding because it has very slight flex in it as you say. It also induces less localised heat in the tubes, increasing strength.

Regards
 
Henry
 
Henry Siebert-Saunders
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"AP" General Discusion / Re: car derived sxs
« Last post by Yummi on July 18, 2018, 01:53:22 PM »
I suppose you did see the suspension arms are tigged?

I just asked re: Chassis.  Hope they respond.
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"AP" General Discusion / Re: car derived sxs
« Last post by dsrace on July 18, 2018, 01:46:20 PM »
motor sure cleaned up nice.

fabr i don't know why they would braze any structural tube member together. must be missing something or there's a mixture in that rod ????
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