Seam welding the chassis?

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wantsum?
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Seam welding the chassis?

Post by wantsum? »

I just wanted some input from the far more experienced builders here. My 1970 1600 is getting a complete nut / bolt restomod. Powering it will be a SR20DET with a stock SR Trans and a Ford lsd 8.8 rear end. Now the power goals are 300whp low boost and pushing 400whp race trim. This car will be DRIVEN. Track days to canyon carving. I'm planning coast to coast trip for this car.

My current question is seam welding. With the power goals is it required? Over kill? Will it remove to much chassis flex and lead to cracking?

The frame it's self is in pretty nice shape. I'm preparing to media blast and put it in epoxy until all of my mounts and brackets are complete.

Input fellas?

Thanks
Nathan
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spriso
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Re: Seam welding the chassis?

Post by spriso »

We normally just inspect the spot welds and replace any corroded areas. We will fully weld out the areas that we modify for the SR20DET swap, but other than that, I find that the frames are quite stout and have handled the SR power just fine.

Let us know if we can help with conversion parts!

Michael
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wantsum?
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Re: Seam welding the chassis?

Post by wantsum? »

spriso wrote:
Let us know if we can help with conversion parts!

Michael
I actually have all the parts you provide! Just waiting on a engine jig to be available so I can weld the mounts in!

Nathan
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RCMike
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Re: Seam welding the chassis?

Post by RCMike »

I would be highly surprised if you needed to seam weld the chassis. On the other side, you are discussing turning it up to 400whp for racing. Are you planning to drag race it? I would suggest that 400 is WAY too much for road racing of any type, without a complete redo of the chassis. Driving a roadster in the mid 300s, it was scratching for traction in a straight line when you really let the turbo spool.. It's very drivable, but...

I think about 250-275 would be the ultimate sweet spot for power on a reasonable sized circuit.. Mine accelerates reasonably hard into the 130s. And I only have 200whp.
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Re: Seam welding the chassis?

Post by Alvin »

My 2 cents:
Sounds like fun!!!
Like Michael mentioned, the frame is stiff. Seam welding does wonders for unibodies, but the roadster is literally built like a truck.
With your power goals, I would focus on getting alot more rubber to the ground and making suspension modifications. 400whp through 205-width tires is fun, but not what I'd call safe in the canyons or satisfying on the track :)

This is my friend's Datsun 510 with an old-school S13 SR20DET. It makes 413whp on high boost. Low boost is 300-something. It hazes tires in 2nd and 3rd on low-boost:




Get at least a 245-width tire, update the suspension and brakes, and enjoy!
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Re: Seam welding the chassis?

Post by spyder »

Overkill is the sure cure of paranoia! :shock: :wink: :shock:
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Re: Seam welding the chassis?

Post by Jdflyer »

Alvin wrote:This is my friend's Datsun 510 with an old-school S13 SR20DET. It makes 413whp on high boost. Low boost is 300-something. It hazes tires in 2nd and 3rd on low-boost:

And we now have my new goal 8)
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Re: Seam welding the chassis?

Post by redroadster »

Have you tried a test weld on the frame ?
certainly looks rusty , I have welded things I thought would weld okay only to find it burnt up /melted easily = a lot of the frame strength is gone
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Re: Seam welding the chassis?

Post by wantsum? »

The rust is all surface stuff. It's getting all media blasted before anything is done. I believe I'm just going to add some welds to the engine side and some where the real axle ties in. The rest I'll leave alone. Thanks all!
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Re: Seam welding the chassis?

Post by Vinnyz »

How is this project going so far??
73' Datsun 240-Z turbo
70' Datsun SRL-311-1374-SR20det 6 speed
69' Datsun SRL-311-12334-Solex 44 w/B cam
07' BMW Z4 coupe-Daily
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datsun1500
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Re: Seam welding the chassis?

Post by datsun1500 »

Vinnyz wrote: Tue Dec 13, 2016 11:30 pm How is this project going so far??
It’s up for sale as an unfinished project. Shame.
I remember when no one wanted the 1500s......
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Down under 311
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Re: Seam welding the chassis?

Post by Down under 311 »

Most of the spot welds are dubious at best put a screwdriver in there and see if they lift - mine one in every three held - rather than seam weld would suggest stitch weld the edges
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