Re: my current project

by bracketchev1221 Thu Oct 30, 2014 8:38 pm

The other part of the puzzle is front end looseness. The back end can't do anything on its own if the front is too stiff and can't move to put the load on the rear.

by dynchel Thu Oct 30, 2014 8:47 pm

Front end is rebuild stock with a one inch sway bar. Springs are big block springs with one coil cut Monroe sensatrac shocks. I have done some lightening. The front bumper is gutted, no a/c or heater, no brake booster, washer bottle, and charcoal canister M.I.A. aluminum intake, aluminum wheels, battery in the trunk (RR).

by dynchel Thu Oct 30, 2014 11:01 pm

http://www.chevytalk.org/fusionbb/showtopic.php?tid/313218/
This was one go round of asking.

http://www.chevytalk.org/fusionbb/showtopic.php?tid/315013/
This was another.
I'm really not sure what I am doing wrong. The ride height is a little high (needs to be for exhaust & tire clearance) standard coils did not fix the problem, neither did the station wagon springs. I ran old sensatrac shocks, tried cheap oil shocks, finally h/d replacements (gas). The lower arms are PMT fabrication aftermarkets with poly bushings. The upper arms are adjustable spohn arms with pivot joints in the front. (The rearend has a poly bushing) I have relocation brackets welded to the rear end housing, but they didn't seem to help. Finally I have a 9C1 sway bar and global west frame supports. The rear is the original with a powertrax locker and Richmond 373 gears. The tires a brand new mastercraft avengers size 295/50/15 on 15X8.5 wheels. I run the air pressure at 32 psi. If I do a burn out you can see the marks go from dark to light because of the hop. I don't race it, but I do like to show off by lighting 'em up once in a while. If anyone sees any glaring problems that I am missing please let me know.
Thanks, John

by bracketchev1221 Thu Oct 30, 2014 11:20 pm

Look here, it looks like lowering and softer springs is a common answer.

http://www.chevelles.com/forums/showthread.php?t=577585&highlight=wheelhop

by bigredlaguna Fri Oct 31, 2014 12:42 am

This article is an easy read and may help you figure out the traction issues.

http://www.superchevy.com/how-to/148-0309-chevrolet-chevelle-rear-suspension-tips-parts/

by jerry46765 Fri Oct 31, 2014 1:16 am

John -

Are the adjustable upper control arms close to stock length? If not, try to get them there.

How much rake is in the car (rear higher than front)? Any rake is too much, get the car close to level.

The reason I ask if hop is less at the dragstrip then on the street, the dragstrip has tons of grip, and if you had less hop at the track than you could focus on traction, as in tires. If not, no big deal, more to next item.

Rather than change a number of things, do a test. Go run the car at a common spot that is easily accessible so you can repeat tests without much hassle. Do a run, or a couple runs as you are driving it now, make sure tire pressures a 32psi in all four tires. Note wheel hop is in all gears or only 1-2 gears but stops at 4000rpm in 2nd as an example.

Then remove 15psi from the rear tires. Tires are also a spring. Repeat the test, and note if there is a difference.

If hop is the same, then focus moves from rear spring rate, and you try something else.

You are trying to solve a problem.
It's a step by step process.

Thanks -

Jerry

by jerry46765 Fri Oct 31, 2014 1:33 am

One more thing, I have a 2005 Gibbs Silverado with a magnacharger on it and depending how I launch it, it will shake the fillings out of your teeth. Revving up to stall, holding the brake and then launching will hop till you lift. But, flashing the converter results in really good leave.

Maybe also try different approaches to leaving fast; idle and then stab it, hold brake rev it up, and/or something else as to not induce wheel hop.

Thanks -

by dynchel Fri Oct 31, 2014 3:27 am

Thanks guys, that gives me some new things to try that i hadn't thought of. John.

by bracketchev1221 Fri Oct 31, 2014 5:02 am

Let me clarify one point that I keep making. When I refer to the ANGLE of the bottom bar, to be parallel or flat, it is in reference to the frame rail. Not to the ground. All of the measurements in the suspension are to be taken with the frame sitting parallel to the ground and then the rear at ride height. This is easier on jack stands because it eliminates the issue of different size tires or lowering springs in the front. For example, my ladder bars actually have a downward angle from back to front. I believe they are 3-5 degrees down in front.

my current project - Page 3 7479-1970-Chevrolet-Chevelle

my current project - Page 3 7479-1970-Chevrolet-Chevelle

by dynchel Fri Oct 31, 2014 6:46 am

The one thing I am getting from what everyone is saying is that my car is raked (higher in the rear)...its not. The car is level. By the way ray that's a sweet '70 you got there. jocolor

by dynchel Fri Oct 31, 2014 6:57 am

my current project - Page 3 IMG_20140929_083323496_zps8rkempsf

this was taken about a month ago, the day before the new tires wen on. Point being its not "jacked up"
my current project - Page 3 Chevellerear_zps78xmdkbq

my current project - Page 3 Chevellerear_zps78xmdkbq

This would be my ultimate stance, I LOVE the way this sits. Unfortunately, I'd have to lose the side pipes as they bottom out over speed bumps now.

by Joe73 Fri Oct 31, 2014 8:06 am

Any idea what size those rear tires and rims are? Offset? Is the rearwheel well lip rolled?

by dynchel Fri Oct 31, 2014 8:10 am

No, but we can ask him Very Happy

. I will read through his build thread before asking though.

by dynchel Fri Oct 31, 2014 1:06 pm

my current project - Page 3 IMG_20141031_125752546_zpsokacbzwx

Here they are. All powder coated with stainless turn buckels. Even if they don't work (I really hope they do) they will look nice for a total of about $75.00.

by thatfnthing Fri Oct 31, 2014 3:24 pm

Good luck!

by dynchel Fri Oct 31, 2014 3:27 pm

thatfnthing wrote:Good luck!

Thanks, at least I always liked the way they look.

by 77mali Fri Oct 31, 2014 5:46 pm

Those are nice. Hope they work out.

by dynchel Mon Nov 03, 2014 5:23 pm

my current project - Page 3 IMG_20141103_161441238_zpszs6e1th7

Well they work!!! No more wheel hop. They work a bit to well though as the car won't spin the tires on a dead punch anymore...I kinda liked that. Oh well I accomplished what I was after, no wheel hop with the 9C1 sway bar intact.

by driveit Mon Nov 03, 2014 5:26 pm

Awesome. Take a vid sometime and post it up. I would love to see it in action!

by thatfnthing Mon Nov 03, 2014 5:27 pm

Way cool! Sounds like you now have a marketable product, also.

As for the burnouts, you'll just have to amp up the power. Smile

by Wallyuph Mon Nov 03, 2014 5:39 pm

Put a line lock in and you should be able to do the burnouts

by bracketchev1221 Mon Nov 03, 2014 5:39 pm

Glad it worked out for you. So when is it going to the track?

by dynchel Mon Nov 03, 2014 5:41 pm

thatfnthing wrote:Way cool! Sounds like you now have a marketable product, also.

As for the burnouts, you'll just have to amp up the power.

I know, my 300 h/p (maybe) motor seemed faster when it had no traction. If only I didn't have mortgage, daycare, & a wife I'd have the fastest G3 around NE Ohio. As for marketability, I could tell anyone that wanted to know what I did to copy it. Hell I just saved a pic of a Lakewood bar and copied it (adapting as necessary to work with what I have). I used the (already installed) relocation brackets as a starting point and went from there.

by dynchel Mon Nov 03, 2014 5:44 pm

Wallyuph wrote:Put a line lock in and you should be able to do the burnouts

I've had a line lock wired (but not plumbed) for several years. I replace brake lines pretty regularly at my job, but never got the ambition to open up a functioning system to plumb it. Call me lazy.

by dynchel Mon Nov 03, 2014 5:49 pm

bracketchev1221 wrote:Glad it worked out for you. So when is it going to the track?

I'd love to. The nearest track (Thompson raceway park) is a hour into the country from me. I rarely drive that car more than a few miles from home...especially to drive a hour (with 373 gears) to beat on it. If I was to break something it would be a while till I could put it back together. (I have some bogus expenses currently, ie 3 trees that need removed & rear patio doors removed and filled to fix flooding problems)

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