Please watch and diagnose

New motor in ladder bar, strut front. Watch this and slow it down and help me get this car right.

Thanks

https://youtu.be/th-Cc7i1q5Q

While the video was shot at a really good angle (showing a perfect mix of both the dr. side & back of the car), it really needed to be shot a lot closer to the car to get a better idea of what might be going on. You didn't mention what issues have you concerned, but a few possible things I noticed from the video........

It's too far away to tell for sure but it kinda looks like it launched to the left a little. If it did launch left, and if the new engine is making more power/torque than before, it's possible an increase in power could make a ladder bar car start to launch to the left. If this is the case, and if the rear housing is sitting straight/square in relation to the car's nose-to-tail centerline, it might just need a small amount of preload adjusted out of the passenger side ladder bar.

It also looks like it has a small amount of launch body-roll. But there is no way to tell for sure from this video if it's caused by the car wadding up/compressing one sidewall more than the other. Or if it's from ladder bar flex, housing flex, or chassis flex.

And it also looks like the front suspension is kinda stiff. It didn't seem to drop hardly any when the front tires were in the air (does it have travel limiters adjusted real short, or strut valving adjusted real tight?). And when the front tires came back down it didn't seem to compress much (does it have real stiff springs, or is it riding on the strut bump stops?).

Got any good pics of how the struts & ladder bars are setup while sitting at ride height?

Thanks for taking the time to analyze it.

Yes, it does go a little left at launch. Making about 200hp more. No issues before. I'm in the process of measuring and analyzing myself. I did check the heim joints and they are good to go.

Really want to get a handle on the body roll.

I'll make some minor changes and get more video this weekend.

what rear shocks?

Rear shocks are Strange SA with 150lb springs. Front is Strange struts.

I have replaced the heim joints and bolts on front of ladder bars, they were a little sloppy. I'm going to adjust the preload and get some video this weekend.

PanaVet wrote:Rear shocks are Strange SA with 150lb springs. Front is Strange struts.

Are the front struts Strange tube chassis style struts or Fox Body struts (full chassis or backhalf car?) ?

My car looked like that in the front end. Was just too stiff. When I loosed the front struts the nose came up more, transfers weight better ad drives like a different car. Fronts up about 8-10" and it carries them out a ways.

If it is the full on on Strange tube chassis Ultra Struts the adjustment is OPPOSITE of what you might think. IE, on a rear shock you turn the adjuster clockwise to tighten them. For Strange Ultra struts you turn them clockwise to loosen them up. Backwards from a rear shock. I tired turning them CC thinking it should get looser, but it didn't. Finally to to Strange and they told the deal. They are set just about in the middle of the adjustment range now.

It's Strange tube chassis....thanks for that tip!!!

PanaVet wrote:Rear shocks are Strange SA with 150lb springs.........

A 150lb rear spring might be too stiff for a full tube chassis door car depending on how much the car weighs & it's front/rear weight bias. What length Strange S/A rear shock & length rear spring are you using, (a 5205 or 5206 with a 12" spring, or a 5207 with a 14" spring)? And what is the shock's current bolt center to bolt center installed height while the car is sitting at ride height.

If the car has the "correct" (or in the ball park) rear spring rate for it's total weight/rear weight bias the shock's C/C ride height measurement will be around......

5205 = around the 12-5/8" to 13-1/4" range.  
5206 = around the 13-7/8 to 14-1/2" range.
5207 = around the 15-1/4" to 16" range.


Body-roll happening from the car wadding up/compressing one sidewall more than the other (and not because of ladder bar/housing/chassis flex) can be caused by a few different things. Running the slick air pressure too low is one possible cause. Dead hooking a car with the side-to-side preload a little off is another (especially with air pressure too low). And using a super steep ladder bar angle can sometimes be another possible cause.

I got her sorted out...changed the heim joints and adjusted preload. Working good now. Thanks for the help.

PanaVet wrote:I got her sorted out...changed the heim joints and adjusted preload. Working good now. Thanks for the help.

That's good.
Were the rod-ends in bad shape, or just replaced as a caution/maintenance thing?

The heim joint bolt was worn on passenger side. They looked to be the original items when Don Hardy built the car in early 90's.

BTW I had 125lb springs...I misspoke when I said they were 150lb. I put some new SA Strange shocks/springs and new tires on her after I fixed the suspension issues. The fronts are old non-adjustable strange struts.

Got consistent 1.26 - 1.27 60' now. Leaves straight now.

PanaVet wrote:.............They looked to be the original items when Don Hardy built the car in early 90's.

.

Wow a genuine Don Hardy car, that sounds like a cool piece of history right there.  

DILLIGASDAVE wrote:While the video was shot at a really good angle (showing a perfect mix of both the dr. side & back of the car), it really needed to be shot a lot closer to the car to get a better idea of what might be going on. You didn't mention what issues have you concerned, but a few possible things I noticed from the video........

It's too far away to tell for sure but it kinda looks like it launched to the left a little. If it did launch left, and if the new engine is making more power/torque than before, it's possible an increase in power could make a ladder bar car start to launch to the left. If this is the case, and if the rear housing is sitting straight/square in relation to the car's nose-to-tail centerline, it might just need a small amount of preload adjusted out of the passenger side ladder bar.

It also looks like it has a small amount of launch body-roll. But there is no way to tell for sure from this video if it's caused by the car wadding up/compressing one sidewall more than the other. Or if it's from ladder bar flex, housing flex, or chassis flex.

And it also looks like the front suspension is kinda stiff. It didn't seem to drop hardly any when the front tires were in the air (does it have travel limiters adjusted real short, or strut valving adjusted real tight?). And when the front tires came back down it didn't seem to compress much (does it have real stiff springs, or is it riding on the strut bump stops?).

Got any good pics of how the struts & ladder bars are setup while sitting at ride height?

more power with no other changes will do oppositeof what you said, it will drive right.
thats what that car is doing , drifting right

Uhh, not on a ladderbar car it wont.

DanH wrote:more power with no other changes will do oppositeof what you said, it will drive right.
thats what that car is doing , drifting right

richter69 wrote:Uhh, not on a ladderbar car it wont.

Dan, are you talking about the launch it's self (initial hit), or after the launch (recovery period)?

If you're talking about the initial hit/launch, with no suspension changes and adding more power a ladder bar car's (& 4-link car w/anti-roll) current side-to-side preload settings usually launches the car to the left at the initial hit. That's because of the increased rotational engine torque load being applied to the right slick. It's true that combining this situation with a bunch of wheelie bar height stagger could make the launch go right, but I don't see any wheelie bars in the video.

If you're talking about the recovery period after the initial hit/launch (where it went back to the right after the left launch), he never said if the car it's self drifted/drove back to the right on it's own, or if he corrected it back to the right after the left launch.

yes , the R/R sprung will act likea hard tail till the spring is over comed. The more power added, way less time