Coil Car hops

goforit14 · 5/12/14, 9:34 AM

I run lighting sprint. Switched from 4 bar to coil fronts this year. First race the car was hopping alot in the turns. I tied down rear shocks and that help some but still does it when going over bumps. I have 185# coils on both the front and 800 RR bar and 850 lr bar. Any thoughts?

TQ29m · 5/12/14, 11:04 AM

Well, the big problem is you've changed the spring base, by going to a coil front end, you have effectively changed the difference between the "springs", so it's start all over time, I'd give Advance Suspensions in Indy a call, but look for all 4 shocks, bars and springs. It always amazes me, the car probably handled pretty well before, being a 4 bar they usually do, but then someone comes along and changes them to a front coil, and can't understand why it "bounces", beats me, gotta be like the other guy, personally, I see no need for coil overs, except on a pavement car, then they set up pretty easy, but on dirt, not happening, just my opinion, but I wouldn't have changed it, it was built for a 4 bar car, it's not in it's nature to change it, it isn't happy, and it will tell you so till you spend enough to make it somewhat happy again! Bob

goforit14 · 5/12/14, 12:24 PM

Well thanks for your response, I think. My shocks are the CSI adjustables that coil cars run, so don't think I have shock issue. I know lot of opinions on coils vs bars with good points on both sides. Lots of midget guys and some lightening sprints run coils, so I thought I would see if it would improve the car, but did not convert just to be like another guy. If you don't try something new, no improvements can be expected. Thanks...

DAD · 5/12/14, 2:22 PM

Go

Sometimes change for the sake of change is not a good idea. In your case when you get things sorted out the coil over should be an advantage for you. You will have to do some development work to get it right, called learning curve, some people take a little longer than others to get their arms around things. I am one of those people.

What kinda of chassis are you racing?

Coil over springs in the front is a new ball game. They do a real good job of transferring weight and speeding up the reaction time which can be good or bad. We have used Advanced Racing Shocks for years. They invented custom shocks and all the other guys just kinda of followed them. I know they can get you spot on. The other guys should be able to also.

Sounds like your spring rate is off. Your shock people should be able to help out there also. When we have a problem we just call Chet or Cory up at Advanced and (Problem Cured).

Honest Dad himself

MC@Performance Fab · 5/12/14, 2:53 PM

LOL...I"m going to have to agree with the old guy on this one, basically sounds like a lot of spring rate.

goforit14 · 5/12/14, 3:35 PM

Running a Hench chassis. I talked to some other folks, and as light as my car is #930 with me, they think the 185# coils are to stiff. Thanks to Dad for the response. will let all know if lighter coils fix this..

darnall · 5/12/14, 3:59 PM

I ran 180# coils on the front of my stealth midget with a steel block motor.... I have a few friends with coil front lightning sprints and they run 150-160# springs typically... one has gone as light as 135 pound springs...none have ever gone heavier than 160.

DAD · 5/12/14, 4:08 PM

Quote:

Originally Posted by MC@Performance Fab

LOL...I"m going to have to agree with the old guy on this one, basically sounds like a lot of spring rate.

Mac

Do them sand rails bounce a lot too when the spring rate is too high??

Some of that bouncing might also be spring time track conditions that we experience in the east. Given arm length and chassis and axle pick up points and bar diameter it isn't too hard to compute spring rate. Heck I bet Hench could come up with some workable numbers also.

See we can agree to agree ever so often. But that ain't much fun.

Honest Dad himself

TQ29m · 5/12/14, 4:46 PM

DAD, I think of all the TQ chassis I built, with coils, we were usually in the 125# range, and them old Honda's on your nose is heavy, course when I went to this ?600R, it lost a lot of weight, but with the bars, they didn't know any difference, just leveled em out, and went racin, but I still prefer bars over coils, just a lot cheaper, and the way I run mine, it transfers OK, and I don't get any complaints from drivers about how it handles, so it must not be a big deal. Car now weighs about 675#, maybe a bit more, we don't have a problem making the 800# car and driver law! Bob

MC@Performance Fab · 5/12/14, 5:17 PM

Dad I heard things got rained out last weekend, so tell me how did your car do the previous week?

5/12/14, 2:22 PM	#4 Re: Coil Car hops
DAD Senior Member Join Date: Aug 2009 Posts: 5,957	Go Sometimes change for the sake of change is not a good idea. In your case when you get things sorted out the coil over should be an advantage for you. You will have to do some development work to get it right, called learning curve, some people take a little longer than others to get their arms around things. I am one of those people. What kinda of chassis are you racing? Coil over springs in the front is a new ball game. They do a real good job of transferring weight and speeding up the reaction time which can be good or bad. We have used Advanced Racing Shocks for years. They invented custom shocks and all the other guys just kinda of followed them. I know they can get you spot on. The other guys should be able to also. Sounds like your spring rate is off. Your shock people should be able to help out there also. When we have a problem we just call Chet or Cory up at Advanced and (Problem Cured). Honest Dad himself _________________________________________________ Last edited by DAD; 5/12/14 at 2:23 PM.

5/12/14, 4:46 PM	#9 Re: Coil Car hops
TQ29m Senior Member Join Date: Aug 2008 Posts: 6,572	DAD, I think of all the TQ chassis I built, with coils, we were usually in the 125# range, and them old Honda's on your nose is heavy, course when I went to this ?600R, it lost a lot of weight, but with the bars, they didn't know any difference, just leveled em out, and went racin, but I still prefer bars over coils, just a lot cheaper, and the way I run mine, it transfers OK, and I don't get any complaints from drivers about how it handles, so it must not be a big deal. Car now weighs about 675#, maybe a bit more, we don't have a problem making the 800# car and driver law! Bob __________________ "Being old, isn't half as much fun, as getting there"! Ole Robert I!

5/12/14, 9:34 AM	#1 Coil Car hops
goforit14 Member Join Date: Jan 2013 Posts: 96	I run lighting sprint. Switched from 4 bar to coil fronts this year. First race the car was hopping alot in the turns. I tied down rear shocks and that help some but still does it when going over bumps. I have 185# coils on both the front and 800 RR bar and 850 lr bar. Any thoughts?

5/12/14, 3:59 PM	#7 Re: Coil Car hops
darnall Senior Member Join Date: Aug 2009 Posts: 773	I ran 180# coils on the front of my stealth midget with a steel block motor.... I have a few friends with coil front lightning sprints and they run 150-160# springs typically... one has gone as light as 135 pound springs...none have ever gone heavier than 160.