Caltrac adjustments

Suspension Tuning, Troubleshooting, Design and Discussion

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JohnDougherty
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#16 Post by JohnDougherty » Sun May 14, 2006 2:23 am

I finally gave up on my lakewood slapper bars on my 71 Nova and installed a set of Caltracs.
I used the bottom hole with 1/16" gap. I kept my 5 mutli leaf springs. The shocks are Comps set at 90/10 front and 60/40 rear. Stock Nova front coil springs and factory snubbers on the front A-arms, no limiters. Hoosier QTP tires @ 16 psi.
Best pass tonite was a 12.32 @ 109 with a 1.670 60 foot time. 1/8 mile time was 7.81 @ 87 mph.
The car leaves hard and goes straight. Very little body seperation on the rear, but the front end comes up quick and settles back down fine.
I'm very happy now. Before (with the lakewoods) I would get a 1.69 60 ft one pass and a 1.77 the next.

Something has me puzzled, I launched the car by stalling it to 2000 and flashing to 3800 and ran the 1.67 60 ft time. If I stall the convertor up to 3000, the engine had a slight bog right after I let go of the brake pedal. It feels like an accelerator pump issue, but im not sure. Almost like it hooked harder and bogged the engine down.

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Craig W.
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#17 Post by Craig W. » Sun May 14, 2006 3:50 pm

If you aren't pulling the tires off the ground yet, you need all the travel you can get at this point. When you start having trouble keeping the front end down, then you'll want to limit the travel.
Craig Watson
2QuickNovas Racing
5.23@131

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sverbus
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#18 Post by sverbus » Mon May 15, 2006 9:19 am

Cool thanks Craig
'70 Nova
434 small block
Best so far of 10.51 @ 131mph with a best so far 60' /1.46

Ron69SS
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#19 Post by Ron69SS » Tue May 16, 2006 1:36 am

sixpackmotorsports wrote:
also we found out that the front spring mounts in ovas are different than camaros, the camaro mounts make the car sit lower but provide a not so good postion for instant cernter, by making nova monts fit we were able to get the instant center where we wanted it. we used astro van fiberglass mono leafs in the rear, we had to machine our own front eye mounts to bolt to the spring, but they were so stiff and the price was unbeatable. i lost all my pics of the setup when my computer crashed, but next race i see the guy we sold the susp[ension too i'll snap some pics and post em.
Hey guys,
Thought I'd chime in here. Newbie....first post.
I have a 69 Nova. When I built the car, I changed the front spring mounts to Camaro mounts to get the car a bit lower. This also moves the IC up.
The difference between the Camaro parts and the Nova parts is about 1 inch. Someone asked this. The Nova mounts being lower.
I never really thought about the difference this would make in the launch, so good point. And thanks for bringing it up. Of course going to the Nova mount in my car will raise the rear a tad. So this will be a tuning aid, and an easy swap.
I just recently went back to CalTracs (from a much different setup) with mixed results. I had but one good 60ft....the rest were out the window. But my slicks were totally used up.
So since then, I've added Moroso trick front springs, split mono rear springs, moved the CalTracs to the upper hole, and I have a new pair of Hoosier C07 radial slicks to put on the car. Hope to get out this weekend. BTW....the front spring mount now has me intrigued.....
The car is street driven, not trailered. Best thus far has been a 10.20, on the motor, @ near 133. 60ft on that pass was a poor 1.51. The car has gone 1.44......and I believe it should go 1.3's.
So I'm all ears to the CalTrac tuning stuff.
I have a good coach. The goal is to treat the car like an A/SA car.....but I have more power......well more than most A/SA cars.

Ron
69 Nova, 498", 9.91 @ 133.63 with 4.10's
10.0's with the 3.73's, sometimes.
9.41 @ 143 with a 150 shot
Pump gas, NA, Driven to and from the strip

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John_Heard
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#20 Post by John_Heard » Tue May 16, 2006 9:18 am

Hi Ron & Welcome to the site.

Just a side note for everyone on those split Mono's, when they are shipped from Calvert they have some stickers with part numbers on them, both on the front and rear of the spring. It would be a good idea to write those down somewhere as the printing won't hold up to solvents, etc. Calvert will want those numbers if you call up and want to change spring rates/heights.

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jones_performance
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#21 Post by jones_performance » Thu May 18, 2006 6:46 pm

Beyond wrote: Sixpack - how much height difference is there between the Nova and Camaro spring mounts?
its not much, its been so long since we did it i cant remember exactly.
Kevin

JohnDougherty
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#22 Post by JohnDougherty » Thu May 18, 2006 11:31 pm

My 67 Camaro front mounts are about 3/4" lower than my 71 Novas mount.

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John_Heard
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#23 Post by John_Heard » Fri May 19, 2006 7:42 am

I'm surprised there is that much difference. When you say they are 3/4" lower, you mean the Camaro spring bolt hole is 3/4" further from the body than the Nova right?

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#24 Post by JohnDougherty » Fri May 19, 2006 9:44 am

Actually the Camaro perch puts the car lower. The hole is closer to the body.
I will take a closer look and see if I can measure it with some calipers.

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#25 Post by JohnDougherty » Fri May 19, 2006 12:20 pm

As close as I can measure, its almost 1 inch lower on my Camaro than on my Nova.
Next question is, do I want the Nova mounts or the Camaro mounts for my Camaro?

Ron69SS
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#26 Post by Ron69SS » Sat May 20, 2006 1:41 am

JohnDougherty wrote:As close as I can measure, its almost 1 inch lower on my Camaro than on my Nova.
Next question is, do I want the Nova mounts or the Camaro mounts for my Camaro?
I figured 1" difference as well.
So maybe the question for me is, do I want Nova or Camaro mounts for my Nova?
I'm being an ass............

Anyway, I think it's a tuning thing. You should try both and see what the car likes.
Of course the Nova mounts will raise the car a bit. Also moves the IC lower....which might mean the CalTracs will like a different setting and preload.
Raising the rear of the car changes the CG as well.

I'll be out tomorrow night with all my new stuff.......and I'll post the results. I haven't messed with the front spring mounts though.

Ron
69 Nova, 498", 9.91 @ 133.63 with 4.10's
10.0's with the 3.73's, sometimes.
9.41 @ 143 with a 150 shot
Pump gas, NA, Driven to and from the strip

Ron69SS
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Joined: Wed May 03, 2006 1:30 pm
Location: Portland, OR

#27 Post by Ron69SS » Mon May 22, 2006 2:28 pm

BTW....the results were good!
69 Nova, 498", 9.91 @ 133.63 with 4.10's
10.0's with the 3.73's, sometimes.
9.41 @ 143 with a 150 shot
Pump gas, NA, Driven to and from the strip

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Mike Peters
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#28 Post by Mike Peters » Tue May 23, 2006 11:37 am

sverbus wrote:So how many truth or value do you guys put into a set of front end travel limiters? Right now I have none on my nova and when it launchs, it doesnt pull the tires quite yet, but I'm lookin at the sky for good portion of the run...

advice/ideas??

Scott
No limiters for your deal yet. You need the suspension travel for pitch rotation. Nose up attitude comes with the territory when running something like 90/10 shocks. However, you could look for a stiffer setting in the shocks to see if that would bring the front end down or a really big Top Fuel wing mounted on the hood :lol: . Adjust the shock's rebound tighter if you can and see if you can still hook. If you still can't stand to have the front end up, put limiters on it and throw a 100# bag of sand (figuratively speaking) in the back.

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sverbus
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#29 Post by sverbus » Wed May 24, 2006 9:47 am

Mike...yeah I don't mind the front end up, but sometimes, and only sometimes it will blow the tires off affter about 30feet or so. Not always, so I was thinking that the front end going up so far was hitting the rubber mounts and bouncing back a bit causing the weight to change on the tires enough that they come loose.

If I come to far up on the converter it destroys the tires regardless of setup, but that's driver error. If i launch the car around 1800 or so, (it's got a Coan 9.5" 4200) it launches nice and solid.

Solid enough that I'm starting to worry about my rearend.

later fellas,

Scott
'70 Nova
434 small block
Best so far of 10.51 @ 131mph with a best so far 60' /1.46

BBNova
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#30 Post by BBNova » Tue May 30, 2006 6:20 pm

Lot of good info being thrown back and forth here. I have been trying to decide if to install Cal Tracs. I am running the ole' slapper bars with multileaf springs setup. It has seemed to do well so far, but I am under the impression that 60ft. times will drop some and become more consisitent with Cal Tracs. The car varies from a low 1.6 to a high 1.5 in the 60 ft range and will run high 7.20's to low 7.30's in the 8th. There are still a few motor issues to work out to gain consistancy, but I want to make sure the suspension is acting as it should.
Is an upgrade to Cal Tracs a wise choice? The motor makes about 510 horse running through a T350 with a Hughes 10'' 4500 stall and a 9in. rear. Sometimes I think the 60ft's should be a little lower.
There is a decent amount of body travel up front, but the front tires don't come up and it hooks as good as I can tell. The tires have broke loose a few times, but I chalked it up to inadequate burnouts on my part.
Also, the shocks up front are Lakewood 90/10's with stock replacement springs and out back are stock replacement shocks that have been in place for about 10 years. I know they need to be replaced, I just don't know what works best.
Does the shock requirement change from slapper bars to Cal tracs? I am new to suspension tuning, so any advice would be appreciated.

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