Page 2 of 2

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 10 Jan 2019 11:49
by Danthewire
We built a racecar back in the day (See Butters 68 page57 featured project) that had a tube frame inside the front frame rails, through the center of the car connecting to the rear subframe. Then a rear tube frame off that to the rear bumper. With a roll cage tying it all together.That car was super quick, and responded VERY well to weight jacking and small chassis adjustments (very sensitive).
The motor was probably around 125-130 hp.
It was a huge amount of work.

For what you are doing I wouldn't bother with it, just make sure the car is solid (fix the rust) do the sheet metal braces as described by others and do the doubler plate that Keith did on the rear control arms.

I built a 81 Malibu stock car a few years later with a full cage etc we hung a weight off a 10 foot piece of tubing to see how much it flexed.....
That was a full framed car it was an eye opener how bad it was. Had to do a complete re-design...
The little 510 uni body was a far far superior platform.
Hope that helps.

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 10 Jan 2019 12:54
by vetteguy22
Great input. Thanks guys.
Rob

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 10 Jan 2019 13:17
by bertvorgon
Funny, I was looking at some pictures today, and these popped up. One of the best mods I did for steering/frame flex was to REALLY triangulate the steering box brace, not just some little plate to the body, with a small back up pieces.

With real race tires we did a test and watched the frame really start to twist at the box mounting area, so Andy and I came up with this setup.

As a heads up, the brace to the drivers toe board must accommodate the tallest tire you might run in terms of full steering lock. I have lost just a hair of left turn capability as when we did this, 23" tall tires x 15" were not the norm. No biggy in 99% of turning situations.

Bottom line it made a seat of the pants feel difference.

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 10 Jan 2019 17:46
by icehouse
bertvorgon wrote:
10 Jan 2019 13:17
Funny, I was looking at some pictures today, and these popped up. One of the best mods I did for steering/frame flex was to REALLY triangulate the steering box brace, not just some little plate to the body, with a small back up pieces.

With real race tires we did a test and watched the frame really start to twist at the box mounting area, so Andy and I came up with this setup.

As a heads up, the brace to the drivers toe board must accommodate the tallest tire you might run in terms of full steering lock. I have lost just a hair of left turn capability as when we did this, 23" tall tires x 15" were not the norm. No biggy in 99% of turning situations.

Bottom line it made a seat of the pants feel difference.
Why didn't you guys just put a rack in it? I can see why the average dude doesn't, but you two! Cake!

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 10 Jan 2019 19:10
by bertvorgon
Called clearance!

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 11 Jan 2019 08:51
by icehouse
clearance around your already built exhaust?

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 11 Jan 2019 16:16
by bertvorgon
Where would I put the rack.....

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 11 Jan 2019 16:26
by icehouse
bertvorgon wrote:
11 Jan 2019 16:16
Where would I put the rack.....

Just convert the motor to front sump. That's what we did on our L series racecar.

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 11 Jan 2019 17:28
by bertvorgon
There is no way in hell I would do that now....plus, is not the anti-roll bar in the way?

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 11 Jan 2019 17:52
by icehouse
bertvorgon wrote:
11 Jan 2019 17:28
There is no way in hell I would do that now....plus, is not the anti-roll bar in the way?
Yeah I thought we were talking about back when your bad ass racecar? yeah wouldn't be any point now. You'd have to redo to many things.

Re: 510 chassis/subframe upgrades to compensate for added hp

Posted: 11 Jan 2019 21:41
by bertvorgon
When you look back at the time period when I built the car, 1978, our steering boxes were in excellent shape, and, there was not the selection of racks out there that you can choose from now. Most everything was still steering boxes.

It was not till we all started running the bigger and stickier slicks that that we all at almost the same time, had the dreaded steering wheel shake, which we determined was the worn worm and sector gear.

We all upgraded to the HL510 box, put BRAND NEW worm and sectors in and on we we went. Mine is still there today but I must admit, at 27 years since we did that, it is getting that "on center" wear issue, still passable, but thankfully I'm not using full on race tires.