Author Topic: HR bar  (Read 117 times)

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Online Tim Hensley

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HR bar
« on: September 28 2019, 02:42:15 AM »
Also, with cars that have the stock rear HOUSING, the instant center isn't in a good spot. Seems to help to keep airbags in & run them at low pressure & even side to side (with our swaybar). Something like 5psi each side seems to do the trick. The rearend tries to come up into the car, which makes it LOOK like the rear squats & is pushing down on the rearend, but it's actually the other way around. The bags will help keep the weight on the rearend for traction. If over 5psi seems to be needed, I would get our airbag spacers (HR-0350) and try 3psi or 5 psi with those. Get too much air & they work like a basketball & hurt the launch.
Arizona GN109 forged rotating assembly
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Online Tim Hensley

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Re: HR bar
« Reply #1 on: September 28 2019, 03:29:18 AM »
That went badly tried to past and copy a old quote from the  turbobuick.com about the HR bar needing air bag straight from Paul himself from HR. And I have a few questions.
  I have a set I never installed. All it will do at 5 psi is stiffen the spring rate up a little, is that right?
This was written 10 years ago is this what you would do?
I installed new moog stock replacement spring 3 or 4 years ago and a new set of KYBs removing a set of cargo springs and OEM shocks.
The KYB shocks are gas and should add a little spring rate over most drag shocks.
My Hellwig bar sat a little behind center line of the axle and the rods that connect the bar to the frame where at  a bad angle when at the stiffest setting.
Iím not sure the HR bar will help my 60 foot but it field my obsession to spend money needlessly. I also ordered a set of aluminum GN wheels.
Good thing itís shutdown this month I get the privilege of 10 hr days with Saturday and Sunday
Arizona GN109 forged rotating assembly
DLS 210-210
Champion irons
Extreme Auto stage II trans and converter

Offline reality

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Offline reality

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Re: HR bar
« Reply #3 on: September 28 2019, 06:41:51 AM »

Offline Scoobum

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Re: HR bar
« Reply #4 on: September 28 2019, 07:31:25 AM »
No bags when I raced my car. Made my adjustments via the QA1rear single adjustables.
« Last Edit: September 28 2019, 07:51:05 AM by Scoobum »
109 235 Cubic Inch Stock Stroke Balanced Rotating Assembly
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Offline Scoobum

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Re: HR bar
« Reply #5 on: September 28 2019, 09:26:29 AM »

A quote from Chuck Leeper. 'Girls squat, cars don't.'


Your car looked okay on launch...other than it breaking loose. If it was 'tricycling' on launch...then I'd throw an airbag on one side. Otherwise,,,don't bother with bags.
109 235 Cubic Inch Stock Stroke Balanced Rotating Assembly
Stock Crank
TRW .030 Pistons
Stock Rods
Stock Timing Chain/Gears
212/212 Flat Tappet Cam
JB Racing Heads
Stock Rockers
5.7 TT Race Chip
Built 2004R
AC 16930
6262 JB

6.72 at 104.67-25 PSI

I see slow people

Offline Steve Wood

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Re: HR bar
« Reply #6 on: September 28 2019, 10:03:27 AM »
I thought we had discussed instant center in your earlier thread some place, but maybe not.

At any rate, G Bodies are notorious for poor IC location.  I swear that some of them could be jacked enuf to put it behind the car but normally it is at the front of the car or even in front of the car.

It's easy to calculate the location (although it would quicker if someone would invent a self leveling laser that would throw a dot on the floor so you don't have to wait for the plumb bob to stop swinging around)

Turbobuicks tend to launch much better than naturally aspirated cars because they have so much more torque at lower rpms.  I think that is the reason that people keep trying to tell us that 1.7+ is a good short time.  They simply don't understand that Turbo cars are a bit like electric cars when it comes to launching.

In the older days, we saw some Buicks hitting the 1.4's for short time without much technology but a lot of torque and they were all on bias ply slicks as I recall.

I have a set of drops built by Chuck for the lower control arms.  They pulled the IC way back and the car rose up on launch like a '65 Mopar super stocker.  Unfortunately it came back down about 35 mph and blew the tires away.  Slicks might have saved it but I was on drag radials.

Kevin Slaby has some drops for the front of the upper arms which appears to be, geometrically, a better solution as they keep the IC closer to the anti-squat line.  Jason Goodwin was talking was talking about using them on the new car he built and you might PM him and ask his opinion.  They are not new but until we started running into the nines frequently, no one really worried about IC per se.

It has been mentioned frequently, but drag radials and "old fashioned" slicks don't react the same way and faster cars use much different suspensions due to the reaction of the tires.

If your wife is out of sight long enough, you could swap over the coil overs in the rear as that seems to be the latest fad, but, again, I think you have to be making a lot more power before you see the benefits. (you could come over today and help me finish up the new coilover installation on my Miata, if you are bored)

OH, yeah!  You were talking about air bags! LOL  They can definitely help and they were popular in the old days.  They will help with the car's reaction time by directing some of the torque to moving forward rather than lifting the nose of the car.  Again, they probably work better with bias ply slicks than radials.  Jeremy and Dan mentioned the chatter problem and I think that works in favor of slicks-if that becomes a problem.  From a personal standpoint, I would probably rather move the IC back under the car and leave a bit more compliance where the rubber hits the road spot.

In the end, I think a lot of the solutions we are offered work better on naturally aspirated cars due to the way torque is applied to the rear end as opposed to how it comes in on a turbo car.  Our cars often launch really well in comparison.  Jeremy might have some pics of his single wheel Buick launching with 28 psi of pressure in the passenger side air bag!!






Steve Wood

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A lot of broken parts does not make you a racer; it makes you a slow learner.