Most efficient way to calm down a chassis

[Elkyman1]

Steve, Shelton and others are all welcome on this, and it is not to find a way to adjust something, but the most effecient and economical way to calm down a wild chassis such as mine with a medium power level added.

Ok, so all you chassis guys and racer's that know how, why, and what to do about these chassis deals when it get's wild, which is the best route to go in say,(my case) and remember, I have a long wheelbase of 116" and 3525lbs. to deal with, and a high I/C and the I/C is just in front om my C/G. I also run a big tire vs say a 31, or 31 x 10.5W tire and weight I could loose with going to a smaller tire.

Now, I set this chassis up this way and it wasn't until I put a 250, then changed to a 200 shot in my tuneup to get this massive wheelie machine to be born, so after calming down my tire psi, and lowering to a 200 hp level tune, I am able to get a little better control of my chassis and how it launches now(and what a relief!!! my oil pan and headers can't take another hit like before)

So, with all that being said, and you guys with more seat and chassis tuneup time vs me, what are your thoughts about changing up things, would you readjust the chassis setup to calm down the front end lifting point, or, (in my case again) keep the tuneup the same, adjust the tire pressure again, and adjust the shocks and front springs as I have changed my front spring/shock package to double adj. and another 50lb. rated spring)? Add some tire pressure and keep a little more wheel speed to slip the tires a bit and cut down on the bite, yet still get good weight transfer? OR, as mentioned, change the lifting point in the chassis?

I would hate to change things now in the chassis since it is working very good, but just needs to be massaged a bit to better perfection to be more consistant. My thought is to just keep some wheel speed up a bit more, and play with the tire pressure again as before that did calm down my wheelie machine.

I have no room for wheelie bars, but, maybe I can make a single wheelie bar work somehow, but time will tell on that area, I could add some weight to the front also, but that would be defeating the purpose I think since my chassis is so heavy now!!! I could see adding weight to a tube chassis car, but I need to be on a diet with this pig for sure, but adding weight is not out of the picture if needed.

So, would you guys change the chassis setup or play with tire psi and shock/spring package?

Thanks for any reply.

John

[kstone3122]

how much front end travel do you have? try reducing your front end travel,and/or tighten up your front shocks. i have 3 inches of travel, and some stocker single adjustable shocks on my luv truck. you ll have to play with that and adjust for different track conditions and weather .

[Dan Neumann Race Cars]

Without going on a hunt to see if you mention these items I'm going to ask... What gear ratio do you run? What ignition box? Do you have front end Limiters? What rear spring rate? What size holes does your 4-link use and what is the hole spacing center?

These are just a few things coming to mind that I'd like to know about your combo before making any suggestions.

Thanks,
Dan Neumann

[Elkyman1]

First off.

Kstone, I had changed my front end travel to 3" (BIG MISTAKE WITH A 250 SHOT LOADED)!!!!, So, I went back to the 2" Travel and it did MUCH better.
I had too soft of front springs too but now I have a higher rate on the fronts, and double adj. from single adj. shocks so now it is unproven and will need some testing the first of next year when I go out for the first time. I set up the 200 shot level and it launched much better but there is defenitely a key factor on my car, and that I learned at Indy for the NMCA Finals. Thanks for your reply.

Dan,
Boy, you ask a lot of questions!!!!!lol no biggie, and here is some info.

First off, I have really long 4 link bars, and I don't know why my chassis guy made them this long, but, they seem to work, and work very well at current time. They are in the 26-27" length with the rod ends in them center to center or there abouts...

The gear ratio WAS, a 4.88 with N/A power crossing at 8000 rpm's, NOW, I have a 4.33 gear and it could probably use even a 4.10 or even a 3.90? ratio for more mph, but the 4.33 seems to keep the rpm's at a nice 71-7200 at the stripe, I launch a 5000 and shift at 7200 and I like that very much instead of twisting this thing so high, just tuff on valve springs don't you know!!!

Ign. is a MSD 7AL3 and it all seems to be working very well also, yes, I could lower the launch rpm, but the conv. is setup for Nitrous and IT is working very well also.

As mentioned above, YES, I have limiters and have them back at 2" of travel at the wheels and it is working well also once I changed it back from a 3" travel.

The spring rate WAS 400lbs. but now I have all new QA1 450lb. springs on there coilover conversion kit with double adj. shocks now, so no more single adj. shocks for me at this level. Some day I may upgrade to Afco up front, but a budget keeps me where I am at now.

The holes in the 4 link brackets are 1/2" dia. and I am not too sure on your next question (hole spacing center) do you mean how far apart are the holes from each other? if so, I can go take a measurement on that and get back to you.

Dan, I learned sooooooo much about my Elky at Indy in 3 days then I have learned in the last 2 year's about nitrous itself! The most important thing I learned while using nitrous for this year was, since I now know what kind of power it takes to lift a 1700+lb. front end up and move a 3525lb chassis with a 1.80 first gear, a 4.33 gearset ratio on a 14 x 32 stiff sidewall tire with a converter worked by Lenny at UCC launching at 5000 rpm's and shifting at 7200 and crossing at 7200 accross the finish was, ready for this??? air pressure in the rear tires!!!! plain and simple, THAT made the whole big picture come clear as crystal for me with the setup I ended up with after the first wheelstand. I de-tuned the nitrous a bit, and changed the tire psi which in turn changed the wheelspeed on the launch and that right there was worth a million dollars worth of time and money spent. That is all I can say on that note.

Now, with the new front springs and shocks, I just have to redial in my front end vs. the rear end suspension and off I go again and I will set it on kill and start kickin some butt again. So, in essence, I have just gave myself the answer to my own question, but I wanted to see what other racers have done in there setup, so I can learn a bit more and keep that info in my notes for future use if needed.

I watched my video in slow motion and I have a fair amount of seperation at the rear but not too much, and it seems to be working very good too, but I can play with that also once I get the front end sorted out, then the balancing act starts all over again!!!

So Dan, what are your thoughts? keep it about the same? your turn.

John