Front end rise

STR001 · 03-08-2015, 10:20 PM

I have a 87 Camaro stocker that I recently finished. I tested it at the track yesterday. When launching the front end will lift the front wheels about 2 foot off the ground. The front end will recoil and then almost fully extend a second time. The frontend will stay raised up during the entire run. It has Lakewood 90/10 front struts. 50/50 rear. Moroso trick springs 220 lb. rate with 1/2 coil cut. Travel is about 4". Is this a strut or spring issue? Or a combination of both? Any help or suggestions greatly appreciated. Jason

tj310 · 03-11-2015, 09:05 AM

I believe I went with the 70/30 Lakewoods and stock springs cut 1/2 coil ,our seems to settle down nicely. ---Trevor

FED 387 · 03-11-2015, 11:56 AM

possibly also look into 4 cylinder Gen III front springs stock length to start with then maybe cut a little off as you experiment to see where you are going, along with adjustable steel limiters in place of the rubber bumpers on the lower control arms--- those 90-10s are not letting the front come back down consequently the high ride height down track---remember shocks do not determine the ride height of the vehicle the SPRINGS do so I would be looking into what ever you can to lower the static ride height to begin with---FED387

Sean Marconette · 03-11-2015, 01:58 PM

How loose is the front end without the springs? If it's binding while extended that could be an issue. Strut adjustment on my car makes a huge difference on how fast the front end comes up and down. How much weight is on the front end makes a difference too. The weight bias and the ability of the strut to control your specific combination may be outside of the non adjustable struts.

What happens if you raise the front end off the ground with a floor jack like its launching and then drop it. Does the strut react quick or does it keep the front end up?

What's the backend of the car doing during a launch? That may be influencing the front end as well.

Sean

KEN BUGAJ · 03-11-2015, 09:11 PM

Check your Private Message

STR001 · 03-11-2015, 10:32 PM

Thanks for the great feedback guys.

FED387- you are exactly right. I don't feel that the 90/10 shocks are letting the front end come back down. As Sean suggested, I jacked the front end up and let it come back down. However, the front end doesn't seem to drop quickly. I have the lower control arms loose so they wouldn't bind up. I do think I probably need to cut another 1/2 coil off the springs to bring the front end down some more. Trevor- I used to run a V6 spring with the 90/10 struts and the front end used to stay raised up during the full run also. Which is the reason that I switched to a trick spring. What do most stock eliminator guys use for struts? Also is tie downs legal in stock eliminator class? Jason

Eman · 03-16-2015, 10:00 AM

Not sure what you mean by recoil. My 90/10's do keep the frt. up, if you let the car down on the lift it takes a while for the frt. to settle. Global West makes bushings that won't bind. I don't have a stocker but I had steel bushings made with grease fittings so the arm just drops freely. It took a few in and outs to cut the Moroso springs down enough to get the reaction I wanted. Those springs can get your heart pumping! Morgan's book is good, but it's not an easy read.

STR001 · 03-17-2015, 11:03 AM

Enman: What I meant by recoil was that on the launch the nose would rise and transfer the weight. Then the nose would come down (recoil) and raise up a second time. Only this time the nose would stay up throughout the entire run. I think I have that issue solved since I have freed up the lower control arm resistance. I did come across some nice heavy duty steel bushings for the lower control arms at www.ubmachine.com They look like good quality stuff. Should have them here in a few weeks. For now I shaved down the polyurathane bushings to free up the lower control arms to see if my theory will work. Plan on testing the car this weekend so i will let you know how it goes. Jason

Eman · 03-19-2015, 08:39 AM

I had a similar problem. The car would launch and the frt. would rise then drop and rise again. A video showed tire spin causing the frt. to drop suddenly. Weight transfer and adjustable rear coilover shocks helped mine.

SSDiv6 · 03-19-2015, 11:34 AM

The use of Polyurethane bushings have been discussed to death on this site.
They are effected by temperature changes and can bind the control arm travel.
When Polyurethane material does not deflect, therefore, it stiffens the travel of the control arm.
Recognizing that everyone wants to save their pennies, for drag racing, you need to use Global West, AFCO or UB Machine control arm bushings. My preference and recommendation is Global West.

03-08-2015, 10:20 PM	#1
STR001 Junior Member Join Date: Jan 2012 Location: Claxton, Georgia Posts: 55 Likes: 0 Liked 0 Times in 0 Posts	Front end rise I have a 87 Camaro stocker that I recently finished. I tested it at the track yesterday. When launching the front end will lift the front wheels about 2 foot off the ground. The front end will recoil and then almost fully extend a second time. The frontend will stay raised up during the entire run. It has Lakewood 90/10 front struts. 50/50 rear. Moroso trick springs 220 lb. rate with 1/2 coil cut. Travel is about 4". Is this a strut or spring issue? Or a combination of both? Any help or suggestions greatly appreciated. Jason

03-11-2015, 09:05 AM	#2
tj310 Member Join Date: Sep 2009 Location: Dresden On. Canada Posts: 460 Likes: 0 Liked 0 Times in 0 Posts	Re: Front end rise I believe I went with the 70/30 Lakewoods and stock springs cut 1/2 coil ,our seems to settle down nicely. ---Trevor

03-11-2015, 11:56 AM	#3
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,416 Likes: 522 Liked 330 Times in 178 Posts	Re: Front end rise possibly also look into 4 cylinder Gen III front springs stock length to start with then maybe cut a little off as you experiment to see where you are going, along with adjustable steel limiters in place of the rubber bumpers on the lower control arms--- those 90-10s are not letting the front come back down consequently the high ride height down track---remember shocks do not determine the ride height of the vehicle the SPRINGS do so I would be looking into what ever you can to lower the static ride height to begin with---FED387 Last edited by FED 387; 03-11-2015 at 11:59 AM. Reason: addl info

03-11-2015, 01:58 PM	#4
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 792 Liked 275 Times in 76 Posts	Re: Front end rise How loose is the front end without the springs? If it's binding while extended that could be an issue. Strut adjustment on my car makes a huge difference on how fast the front end comes up and down. How much weight is on the front end makes a difference too. The weight bias and the ability of the strut to control your specific combination may be outside of the non adjustable struts. What happens if you raise the front end off the ground with a floor jack like its launching and then drop it. Does the strut react quick or does it keep the front end up? What's the backend of the car doing during a launch? That may be influencing the front end as well. Sean __________________ Sean Marconette 84 Mustang 5060 SS/N

03-11-2015, 09:11 PM	#5
KEN BUGAJ Member Join Date: Nov 2001 Location: LEXINGTON NC. Posts: 389 Likes: 43 Liked 18 Times in 7 Posts	Re: Front end rise Check your Private Message

03-11-2015, 10:32 PM	#6
STR001 Junior Member Join Date: Jan 2012 Location: Claxton, Georgia Posts: 55 Likes: 0 Liked 0 Times in 0 Posts	Re: Front end rise Thanks for the great feedback guys. FED387- you are exactly right. I don't feel that the 90/10 shocks are letting the front end come back down. As Sean suggested, I jacked the front end up and let it come back down. However, the front end doesn't seem to drop quickly. I have the lower control arms loose so they wouldn't bind up. I do think I probably need to cut another 1/2 coil off the springs to bring the front end down some more. Trevor- I used to run a V6 spring with the 90/10 struts and the front end used to stay raised up during the full run also. Which is the reason that I switched to a trick spring. What do most stock eliminator guys use for struts? Also is tie downs legal in stock eliminator class? Jason

03-16-2015, 10:00 AM	#7
Eman Member Join Date: May 2014 Location: E TN Posts: 473 Likes: 16 Liked 133 Times in 76 Posts	Re: Front end rise Not sure what you mean by recoil. My 90/10's do keep the frt. up, if you let the car down on the lift it takes a while for the frt. to settle. Global West makes bushings that won't bind. I don't have a stocker but I had steel bushings made with grease fittings so the arm just drops freely. It took a few in and outs to cut the Moroso springs down enough to get the reaction I wanted. Those springs can get your heart pumping! Morgan's book is good, but it's not an easy read.

03-17-2015, 11:03 AM	#8
STR001 Junior Member Join Date: Jan 2012 Location: Claxton, Georgia Posts: 55 Likes: 0 Liked 0 Times in 0 Posts	Re: Front end rise Enman: What I meant by recoil was that on the launch the nose would rise and transfer the weight. Then the nose would come down (recoil) and raise up a second time. Only this time the nose would stay up throughout the entire run. I think I have that issue solved since I have freed up the lower control arm resistance. I did come across some nice heavy duty steel bushings for the lower control arms at www.ubmachine.com They look like good quality stuff. Should have them here in a few weeks. For now I shaved down the polyurathane bushings to free up the lower control arms to see if my theory will work. Plan on testing the car this weekend so i will let you know how it goes. Jason

03-19-2015, 08:39 AM	#9
Eman Member Join Date: May 2014 Location: E TN Posts: 473 Likes: 16 Liked 133 Times in 76 Posts	Re: Front end rise I had a similar problem. The car would launch and the frt. would rise then drop and rise again. A video showed tire spin causing the frt. to drop suddenly. Weight transfer and adjustable rear coilover shocks helped mine.

03-19-2015, 11:34 AM	#10
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 3,043 Likes: 712 Liked 1,577 Times in 581 Posts	Re: Front end rise The use of Polyurethane bushings have been discussed to death on this site. They are effected by temperature changes and can bind the control arm travel. When Polyurethane material does not deflect, therefore, it stiffens the travel of the control arm. Recognizing that everyone wants to save their pennies, for drag racing, you need to use Global West, AFCO or UB Machine control arm bushings. My preference and recommendation is Global West.