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

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

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

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

Re: Front end rise
 

Check your Private Message

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

Re: Front end rise
 

QA1's SA on mine and AFCO DA on the rear. Its not legal to tie down the front in stock.

Sean

Re: Front end rise
 

Don't think your supposed to run tie downs in stock but we put a pair of chains on to limit travel for testing . Didn't matter much ---Trevor

Re: Front end rise
 

Check the control arm bushings too -- make sure you can pivot them without the springs and shocks with about 5 POUNDS resistance-----open em up in the bore so that there is almost no resistance when they pivot--- also cut a minute amount off the snubber on the upper arms too ----if it helps cut a little more off--- keep doing this until you see no more improvement then leave em alone---your problem it seems is after the front end has risen it is not coming back down---- now you will hafta figure why its not coming down something is keeping it up WHAT???-- FED 387

Re: Front end rise
 

Take the shocks loose and look for any change, but I'm betting on some bind elsewhere.

Re: Front end rise
 

Just an update: I took the front moroso springs out of the car today so that I can cut another coil out to get the ride height correct. I noticed that the lower control arm bushings seems to be binding. These are new polyurethane bushings and seem to be thicker than the stock rubber ones. I cut the bushings down some to give some added clearance. It looks like there is no resistance issues that I can tell. So hopefully this help solve the front end rise issue. Thanks for all the help and suggestions. Jason

Re: Front end rise
 

Yes, I used poly on the Mustang as well Jason and had to do some trimming to free it up.

Re: Front end rise
 

Look at using these:
https://www.motorstate.com/site/cata...=66&loadord=71

Re: Front end rise
 

To be polite, guessing is tough and of course a lot of us have no other way to approach fixing a problem. But there's a complete way out. Complete answers to all of your suspension questions can be found in one book. Very easy to understand too. Very easy. You can buy this book on Amazon used approx. $40 usually. Then you'll have everything you'll ever need to know in one book. It's titled "A Chassis Book - DoorSlammers" by Dave Morgan.

Re: Front end rise
 

Had it before there was even an Amazon...still have to put hands on the car. If a book could easily solve all problems then there would be no need for this forum. ;)

http://i434.photobucket.com/albums/q...psfdoiqv4q.jpg

Re: Front end rise
 

An exceptionally thoughtless reply. Good for you. Really trumped gathering a complete education right there.

How about this - With the book, you do not need anyone here.


Jesus.....:-/

Re: Front end rise
 

Really??? You could have well just quoted yourself Bruce...and let's leave Jesus out of it. :rolleyes:

Exceptionally thoughtless reply? You were being condescending suggesting that a book would "completely" negate any need for inquiry or discussion about a specific problem. Books are wonderful things at times, but they do not always provide the wealth of experience from those that have "been there - done that". It is infuriating at times to ask questions and get responses like "hit the search button" or "buy a book". To paraphrase, I believe my reply is "very easy to understand...very easy". Let's just say your reply was poorly crafted and leave it at that. My apologies to Jason for fouling his thread.

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.

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

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.

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.

Re: Front end rise
 

I have always just cut the teeth from the ends of the inner tube in stock replacement bushings. Cheaper, and never bind. Bolts in the uppers long enough to bottom in the upper-inner shaft, then shortened just enough to not bind, should be able to rotate the washers under the bolt heads. My lowers right now have steel self locking nuts so I can adjsut the drag on the control arms. they should just drop from their own weight, not connected to the spindals. Been doing it like this since the Jr Stock days in the mid 1960s. Cheap and never a bind issue.

Re: Front end rise
 

Yep, an old trick that still works; I believe either Moroso or Competition Engineering used to sell bushings that were already modified.

The difference on the OEM version of the control arm bushings is the inner sleeve is bonded to the rubber material. Therefore, it pivots on the steel sleeve and does not rotate on the rubber material.

In Polyurethane bushings, the sleeve, instead of remaining static in the bushing, also tries to turn inside the bushing when pivoting.

Polyurethane does not have the low friction and the load bearing characteristics of Teflon or Nylon thermoplastics, therefore, while pivoting, it will flex under load.

Re: Front end rise
 

Similar to Ed on my stocker:

Used stock rubber bushings on the lower arm assembled with never seeze on the bolt and inside the steel tube for lube that never leaves. Added lock nut tightened until bind the loosened til free. Intall bolts front to back for added safety and peace of mind.

For the strut / shock use the best you can afford. Started with the Koni adjustable strut but when I got the car to leave hard the front end would slam down and upset the rear suspension. Santhuff is well worth the money not only for the full adjustability and good valving but the fact that they stand behind their produtct.

Re: Front end rise
 

I do lube the shafts where the bushings pivot. Guess I left that out. I certainly agree about the Santuffs! I have used about everything else. Had them re-valved, etc. Nothing had the adjustability or control of the Santuff.

Re: Front end rise
 

There are definite differences in polyurethane control arm bushings from brand to brand. Some polyurethane compounds are 'sticky', for lack of a better term. A lube like Permatex Super Lube between the bushing and the sleeve makes a big difference.

Re: Front end rise
 

Polyurethane will also dry out and crack over time. Have a Fox body with adjustable rear control arms with poly bushings. The bushings dried out and cracked into pieces and fell out.