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vetteguy22

510 subframe/chassis upgrades

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There's been all kinds of debate regarding the strength of the 510's chassis. When you consider the distance of the lower cross member to the firewall, and the heavy gauge steel used on the strut towers/inner fender wells, I seriously doubt there is anything gained by using a brace with pivoting connecting points at the top of the tower. That provide zero torsional rigidity. On the front suspension nearly all of the lateral cornering stress is exerted very low on the front cross member. I would suggest welding the seams and strategically placed truss bracing would be enough to carry the VG33ER. Using a flat box subframe running front to back will not provide as much torsional strengthening of the body as a simple two point roll bar right behind the front seats. Bonding it to the floor and A pillars with a knee high horizontal bar and a diagonal brace would lock the body's torsional rigidity down. 

 

The rear suspension handles more torsional stress than the front. The stock fuel tank sits between the shock towers, but many track cars have a welded box metal cross brace with triangular trusses over the top. 

 

Only picy I could find of mine but you can see the bottom of it 

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Thank you for your response. I like the idea of the rear shock tower brace.

Im sure I will try to incorporate that into my build.

Rob

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if you run the flat tubeing front to rear and tie the two ends of the chassis together it has to help 

i agree a role cage of some type would do more 

contrary to some beliefs strut bars front and rear do help stiffen up the car 

steering box brace and idler arm brace are also great upgrades 

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Thanks Ranman,

i will be using strut bars front and rear. It certainly can’t hurt. 

Also I am going with rack and pinion so won’t need to do bracing for steering box or idler.

Rob

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Rack and pinion will be a nice upgrade. Will it be front or rear steer? What's the application?

 

This is how race engineer Kent Stacy described strut tower braces to me once: they allow the suspension to do the work instead of the chassis. They help eliminate body flex as a part of the suspension.

 

On the rear of a 510, the shock towers aren't as much of a problem as the spring buckets, since that is where the load is transferred. Again, having a roll cage that ties into the rear spring buckets will help a lot to stiffen the rear end of the car. Now if you're going to use a coilover in the rear, then a shock tower brace (in the rear) is a good idea.

 

 

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I’m going rear steer rack and pinion. I replaced the rear sump pan with a front sump to stay rear steer. I picked up a nice MR 2 rack pretty cheap.

mostly went rack and pinion to get the steering box out of the way. It should be a nice improvement though.

Rob

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Roll bars... You're more likely to be killed from your head hitting the very thing that's there to protect you. Only thing worse is not being killed and you have to be forever spoon fed. Ever notice that real race car drivers wear a helmet? Pad  them with foam? Would you hit your head into it at 30 without a helmet? The illusion of safety using strictly racing equipment by novices on the street.

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Good reason to have a bolt-in cage.

Put it in on race day, and take it back out for street use.

 

Cusco - Safety-21 sales pitch:

 

Edited by G-Duax

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Anyone driving on the street with a roll cage should also have real race seats and USE a 5 point harness. Cage or no cage, if safety is of any concern, you shouldn't be driving a 510 in the first place. It's outweighed by everything else on the road by 1500lbs. because it has no modern safety equipment whatsoever. You assume some risk driving a classic Japanese import car vs a modern car, but not driving a Datsun is a life not worth living. 

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4 hours ago, paradime said:

Anyone driving on the street with a roll cage should also have real race seats and USE a 5 point harness. Cage or no cage, if safety is of any concern, you shouldn't be driving a 510 in the first place. It's outweighed by everything else on the road by 1500lbs. because it has no modern safety equipment whatsoever. You assume some risk driving a classic Japanese import car vs a modern car, but not driving a Datsun is a life not worth living. 

 

6 hours ago, G-Duax said:

Good reason to have a bolt-in cage.

Put it in on race day, and take it back out for street use.

 

Cusco - Safety-21 sales pitch:

 

 

I think proof the Subaru helped save the life of the roll bar. Newer cars have much more built in protection than 40 years ago.

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But a roll cage doesn't need to be solely for protection. The reason it was brought up here was for chassis stiffening. If you want a supremely built chassis, you will need a roll cage or at least a simple roll bar. The added protection from the roll structure is a bonus...when looking at it from the point of view we're discussing.

 

Saying that you don't need a roll cage is true, but within the context of this argument, a roll cage does, in fact, help with chassis performance.

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17 hours ago, datzenmike said:

 

 

I think proof the Subaru helped save the life of the roll bar. Newer cars have much more built in protection than 40 years ago.

 

Okay now, lets not spin off into hyperbole. Sure a Cusco roll cage is not the same as a professionally built diagonally reinforced 6 point cage, but come on. Very few modern cars are designed to truly withstand a high speed rollover. Why do you think roll cages are standard safety equipment required on nearly all manufacturer race cars? Put it this way, for a car to receive a Good (witch is the highest) rollover rating it must withstand a strength ratio of 4X the weight of the car or above. Sounds impressive but a 30 miles per hour collision exerts nearly 30 g’s of force. Granted that energy is rapidly absorbed by collapsing metal, but there is only a few inches of space between the roof and your head. Will a cusco roll cage pass a safety inspection for SCCA sanctioned GT racing? No, but I'd rather have it there on a track day at Buttonwood. 

 

One thing for sure, the chassis on modern cars are far more rigid than a 4 door 510's. 🤔 My advice for vetteguy, build yourself a track car with the 510 and get your wife and grandkids a Subaru wagon with a Cusco roll cage. 😆

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From what I've heard is that they will pass, because they are FIA approved....

 

23 hours ago, datzenmike said:

I think proof the Subaru helped save the life of the roll bar.

Aw, come on Mike....

You have become a cult follower of Subies 'Feel the Love' bull shit commercials...

Seen another commercial the other night, kind of like the 'save the old holocaust survivor in Russia, and save a pet by joining the aspca.

They are selling 'miracle water' in what to looks to be a 4 oz. bag.

Even had people claiming their lives had been turned around by drinking the 'miracle water'.

All of them rank right up there with the 'feel the love' crap, and chevy truck commercials.

Edited by G-Duax
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Subie commercials? Stopped watching TV about 6 years ago, I mean when would I have time? 😄. Last I remember was Zoom Zoom. No, wait.... If commercials are that bad it's because the viewers are stupid enough to watch them. What I mean is, you have to be half stupid to pay to watch TV in the first place. Sooner or later you move on and what's left are the the condensed great cud chewing unwashed masses. At least you see some of it. Sooner or later you'll quit watching 'TV' like I did.

 

 

 

510s are stiffer than everyone gives them credit for. Added bracing is fine but most wouldn't know the difference with or without it. Roll bars ruin the looks and utility of the 510, or any car. Form follows function. If it's form over function you want, just get a front and rear spoiler and some flairs.

 

 

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My brother & sister-in-law had a Subaru Forester.  Rolled it on the freeway after being hit from the back/side, sister-in-law 8 months pregnant with their two other kids in the car.  Everybody came out uninjured.  No roll bar :P  (orange stuff in the cabin was a smoothie or something...can't remember for sure)

 

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I must agree that we are straying form my original post. A roll bar or cage would definitely be the most advantageous way to strengthen the car but for my application, it’s not practice. I appreciate all the input you guys have given and will incorporate some of that into my build.

like I had originally said, I’m new to Datsun so was looking for the input form others who have been doing it and have much more experience in this field than I do.

thank you,

Rob

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As with any question asked on Ratsun, once it's been answered within a reasonable point of finality it devolves into arguments on the periphery. There's nothing of substance left to add, so here we are.

 

BTW Matt, glad your family was OK, but if your brother's Subi had a roll cage, the shoothy wouldn't have spilled. :op

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited by paradime
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