[原创]在群里问的一个chassis structure问题

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Riikanbkk楼主
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#1 [原创]在群里问的一个chassis structure问题

帖子 Riikanbkk楼主 »

在群里问的一个chassis structure问题

My Celi although it is a yota, but cramped tiny engine bay quite headache for maintenance, a shame to yota's easy servicing fame. Esp. that darn heavy tranny, impossible for one man to handle, can't DIY replace clutch insitu... Always envy of FR cars have open front-end easy engine / tranny service[其实,俄也很少开真FR,俄在这儿说的是纵置桑塔纳passat B.2,小时候帮家长单位折腾过学修车了], so decided made my tubular front-end has its forward-bottom bar a detachable part, then I could one man remove engine assembly fast, without jacking front-end up skyhigh.
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Quite proud of the convenience, but worried about strength integrity. As my understanding, longitudal engine / subframe usually mounted directly to the beams, just a (minor) bracing at forward-bottom position is goodenough. But transverse engine placement, the front engine mount arguably bearing heaviest load, and rests completely on that forward-bottom bar.
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Thus am really worrying whether that detachable piece could hold. Or course would be goodenough for daily running, but as rallye heritage, I do want she can hold while violently jumping / dropping etc. lol. 🤣

Tubulars are 1-3/4" 0.10" thick 4130 quite strong, but small flange( cut from 4mm plates bought at watsadu... ) and total 10 * M8 stainless bolts... seems flimsy 😥 I did lil male / female mating for flanges, but structure just seems too weak.

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Thoughts:
method1, weld flanges shut. But later servicing etc. would be mega headache.

method2, weld additional tubular bracing. Not only quite some work, but hardly any space left available...

Or if it could hold with lil more reinforcements? method3, all high strength 12.9 bolts with high torque.

Of course best would be method4: DIY machining some solid proper QD tubular connector and weld on. But time is luxury maybe for later.
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Didn't found 12.9 flange nuts nearby shops, so just generic bolts / nuts and DIY made some 3mm thick 304 washer. Lol since they're 12.9 had no distress torqueing em down to 37Nm.
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👆 Above these're my conscious flow. What're your thoughts, could this might be hold steady for like, rallye jumps etc.? ( suppose my welding sound. Some ugly argon issue happened, but grind rewelded and double pass )
Anyway, easy removal / reinstall engine assembly like a FR, is agreeable no doubt😁 esp. Celica structure are lil more optimized for whole assembly teardown replacing, that rallye heritage lol

好亲友回复我的:
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For comparison, a lot of 90's Honda's have a similar design, but there are only three engine mounts: rear of the engine that bolts to the front subframe, transmission to chassis, cambelt side to chassis. There are also torque mounts left and right at the front, but they are not load baring. Often people fit traction bars, which are not really needed, I normally remove the bars, but retain the sturdy cross-bar, to help with rigidity, see the next picture.
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我的回复
--------Wow million thanks! First time learning this quirky Honda style👍, now having a clearer picture front chassis loading, slight more confident to my situation
Riikanbkk楼主
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#2 Re: [原创]在群里问的一个chassis structure问题

帖子 Riikanbkk楼主 »

不折腾diy的不一定能理解俄说的,再补充一下。

先发DIY同好亲友的beemer,纵置/其中很多是FR 就是折腾engine 可以车头大开门,非常容易下手羡慕啊
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这个对于折腾tranny是超级利好。因为tranny只是mount on beams,轻轻一松开mount & axle就可以有空间操作clutch 或者轻松整个取下。不像横置/多数FF车tranny & engine 下面是large subframe pita
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横置transverse engine placement,有多种多样运行和生产好处,但是subframe 变成了很复杂的最重要结构件。比如换个clutch,如果tranny比较小、也有帮手帮着用力定位,可以把tranny 往一边推开,勉勉强强挤出空隙操作维护;但是大部分车机舱根本不够空间掰不开,而且如果是自己单独DIY不好稳住tranny 不方便,基本上还是建议,先想办法把发动机稳好,然后拆掉整个subframe,然后一边稳好engine 一边拆掉tranny。。。折腾完后,再原样全装回去。。。

图是俄常规性操作
dismount subframe...
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flywheel & clutch...
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普通买菜车FF总之虽然麻烦还是能自己单人DIY的,一夜夜班足够;但是如果变速箱比较重,比如Celi的E154f tranny + AWD transfer,重量赶得上一台1.3发动机,空间狭小,AWD transfer 螺丝很多需要精准,仅仅是换个flywheel clutch小操作,即使是专业dealer也要一班人折腾两三天。。。

Garage / shop 人多,一群大汉协力合力操作,也勉强能不拆subframe,仅仅左右分开换离合片;但是单人DIY的话,yota AWD tranny 太死重了,难点在于装回去时即使用吊机吊着,一个人的力气也根本没办法推着死重tranny 精确回到所有安装螺丝位,所以一个人DIY:除非你超级有时间(一月起),否则mission impossible。

这就是custom tubular frontend 的好处所在。和纵置车一样可以前车头大开门,只要断开电路/液路/转向(很快,熟练了一个人半天),就可以轻轻松松把车头机械全部作为一个总成下下来。Lol. 总成摆在院子里,想怎么拆怎么拆,对AWD tranny 也可以像对 engine 一样随心所欲修改了(做梦哪天俄要能买得起狗牙哈哈)
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纵置倒不是FR的专利,FF车(以前)一样有很多是纵置的,俄小时接触的最早的桑塔纳(passat B.2)就是纵置前驱,tranny to final drive 90°转向,对称伸出FF axle。 而且VW后来名气很大的syncro,quattro,group B体裁上也基本是对称纵置、后面加上prop shaft。Lol对称AWD至少外观上比主流的养眼多了,主流的纵置transfer偏置额外伸出一根轴、前面diff一般也偏置和sump犬牙交错、虽然工作很好但体裁外观容易引发OCD

桑塔纳32b
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group B quattro
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