CLASS RACER FORUM - suspension and ignition setup need help

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Re: suspension and ignition setup need help

It sounds like you are pretty much maxed out given the restrictions. I agree with Alan about testing the limits of launching be it thru timing events or other means. The testing never ceases for any of us...

Re: suspension and ignition setup need help

Another engine builder, who is a friend of mine, and responsible for some historic performance, told me "it isn't so much that we know what makes the car go fast, it's that we know so much about what doesn't make it go fast, or even makes it go slower". All of that comes from testing, relentless, exhaustive, tedious testing. Unfortunately, there is no known substitute.

Re: suspension and ignition setup need help

Four wheel scales? 50/50 or better? Just some things to think about.

Re: suspension and ignition setup need help

After giving this some thought I maybe would be inclined to look to the other end of the track instead of beating a dead horse....err, tire I mean. :p

Re: suspension and ignition setup need help

Do they check your tires other than size? Some companies sell products to rejuvenate your tires. Think about that and let it "soak" in.

Re: suspension and ignition setup need help

Can you retard the cam any? If so try that and bring the timing in more aggressive. Larger "worked on" intake, delay the secondary slightly on the carb. Also, I would try a 7" rim. By the picture the tire looks like it is starting to run over itself like it is to low on air. But, I know you do that to try and hook. The other way would be to put a 4.30 gear in it and let that hook and then try to be more aggressive with the timing and use more torque through the trans low gear setting. Also, do you have a soft hitting converter? By the way that is FLYING! for anything much less a very stock appearing car. Like everyone said testing, testing, testing. Keep up the good work.

Re: suspension and ignition setup need help

I raced one of these cars about 20+ years ago. It was a 331 small block, TH400 and 5.13 combination.

If you take a side view of your car and draw the imaginary lines through the rear control arms you will find the instant center of the car probably about 6-8 feet in front of you, maybe more. The IC needs to be about where the engine block/trans come together or at worse the front of the engine.

According to the rules, you might be able to do the following. The UMI adjustable upper links really don't do much more than adjust the pinion angle, kind of like the upper link in a ladder bar car. So, if you can find another upper control arm - you only need one, cut it in half, mount the half to the rear and then have your stock arm mounted in front to the frame and bring it down on top of the half. Tack weld it there, do the other side and then pull them out to weld them up. Put these in and you just moved the IC where you need it with "stock" parts. I think you will be very pleased with the 60' after this modification.

Re: suspension and ignition setup need help

We downloaded this MicroSoft Excel file which was a big help in understanding, and getting the rear edge geometry set up in our 81 Malibu. All instructions are in the file. Measure the end point locations of all rear control arms and enter them in the spreadsheet. It will then calculate and graphically depict the Instant Center location and several other critical dimensions. You can then alter the numbers to see what you need to change to arrive at the Instant Center you desire. Good luck.

www.patooyee.com/calculators/4BarLinkV3.0c.xls

Re: suspension and ignition setup need help

Quote:

Originally Posted by marina blue (Post 511378)

I run my 66 chevelle in a club racing event called supercar shootout. Stock tires, stock intake, stock exhaust manifolds. I'm running an msd digital 7 box with a stock eliminator style big block. Best run 11.22 @ 122mph. I know there's more in it and I'm looking for someone with the knowledge and talent to help me. I'm willing to meet at etown atco or cecil county and compensate anyone willing to help me pick the car up.

My combo is a "stock appearing" 360hp automatic with a turbo 400 and 4.56s. The motor made 660 on the engine dyno running through the stock exhaust manifolds, correct oval port heads, and cast iron intake which uses a holley.

G70-14 redline. Best 60 ft 1.74. I'm pulling out 15 degrees of timing for 1.5 seconds leaving off the foot brake. I know the digital 7 is capable of much more than I'm using it for now. I have santhuff springs up front with del alum bushings and single adj. QA1s. In the rear UMI adj. uppers, boxed lowers stock springs and sway bar and double adj QA1s. I'm losing ground to some of the other racers who have figured out how to get high 1.5 to 1.6 60 fts.

No hop bars are allowed. not much else. Trying to leave with full bore timing blows to tire away. Rear shock settings are another area where I know someone with more knowledge could be helpful.

Front springs are Santhuff 250lb. rear springs are stock. Front shocks are QA1 single adj. Rears are QA! double adj. Adjustable upper arms are technically not within the rules but are not enough of an infraction that anyone complains. 6 inch rims are all that's allowed but most racers run 7s. The basic premise of the class is that the cars appear stock to the casual observer. I'm running a turbo 400 with a 2.10 first gear with all light weight internals as well as a 12 bolt with 4.56s with a spool and gun drilled axles.

Bottomline is there is no magic in that MSD box and you've got to launch with full power. key to that is getting the front suspension to work so all the weight is on the back tires and it won't happen with those shocks nor A arms that are stock.

The 2.10 1st gear is hurting not helping and who built the trans?

What exactly is your performance goal?