Changing to coil overs on the front of 71 Nova

[bert]

Hi everone, I'm changing out the stock A arms upper and lower to Global West TLC tube A arms. I'm going with a coil over double adjustable shock from QA1. I want to use a coil over so I can access the adjustment knobs easily (I know that Afco makes an killer double adjustable front with adjustments at the top and bottom # 3870 BNC but I was told that it will not work with the Global West TLC A arms). My question is I have Morroso front coil springs on the car now with the stock A arms that have a 213 spring rate, The springs that are being recomended with the coil over set up are 350 spring rate. The car weighs about 3270 with driver now and should weigh about ten pounds less ( off the front ) with the new set up. Should there be that much of a differece in spring rate from a standard coil spring to a coil over spring?

[a1elec]

i cant help you on spring rate but a tip on the global west a arms. if you decide later to switch to a front steer rack the global arms will not clear the rack. i found out the hard way. had to switch to trz arms john

[Craig W.]

If you jack the up the front end so that tires are off the ground, you should be able to reach through the spring to adjust your shocks. I can on mine.

[BillyShope]

The spring rate difference might be due to a difference in linkage ratio between the two designs. It's the wheel rate that is significant and, with different linkage ratios, the two spring rates might provide the same wheel rate.

The linkage ratio is the horizontal distance from the inner lower arm pivot point to the center of the tire patch divided by the length of a line from that same pivot point which intersects perpendicularly the centerline of the spring. The wheel rate is the spring rate divided by the square of the linkage ratio.
http://www.racetec.cc/shope

[John_Heard]

Most people that have switched over to the QA1 coil over setup haven't liked them due to lack of available spring rates and overall travel. You might do a lot more research on those before buying them. They may be a big problem if your car needs plenty of travel to work. Typically the regular coil spring setup is better for travel, and has far more options for spring rates.

Regular coil overs are nice for adjustability, but they too can restrict your travel. How fast is the car and what are the goals for it?

[ytnova]

Contact mike or todd at trz motorsports. They have lower control arms made for use with a coil over setup. They also make a new upper pocket and mount, requires some welding, but very slick. Ditto on the qa1 thing also. I used trz's regular lower arms which have a 1" deeper pocket and was able to use a stock length spring, no cutting, to acheive my desired ride height. I also used a shock from a 70 camaro which was 1" longer than the stock nova one.

[supernova]

i cant help you on spring rate but a tip on the global west a arms. if you decide later to switch to a front steer rack the global arms will not clear the rack. i found out the hard way. had to switch to trz arms john

John is right, Global West will not allow a front mounted rack.
I did lots of research before buying any front end components. I also used TRZ. Dave Lemmonds has some nice stuff also. I put a front mounted rack in at the same time to save time in having to do it later. I have a bbc but used sbc Moroso trick springs. I did my whole front end set up for about $1600.00.

[David Lemmond]

From my experience, if you use a coil over with a 12" spring, you will need a 425 lb spring.

[bert]

Most people that have switched over to the QA1 coil over setup haven't liked them due to lack of available spring rates and overall travel. You might do a lot more research on those before buying them. They may be a big problem if your car needs plenty of travel to work. Typically the regular coil spring setup is better for travel, and has far more options for spring rates.

Regular coil overs are nice for adjustability, but they too can restrict your travel. How fast is the car and what are the goals for it?

I scaled the car and it weighs 3215 with driver, 1650 up front, Qa1 spring split is at 1700 to go with 250 or the 350 spring rate. I went with the 250. The car has a best of 10.03 @ 136.8mph. My 60 foot times are not so great and vary between 1.39 and 1.44 so I'm trying to get the front suspention to work and improve the 60s. This is a Caltrac car and pulls the wheels very little I think due to a stuck front end suspention, I'm not wanting to do big wheel stands I just want a more consistant launch. Thank you for the replys and I'm open to coments and sugestions.

[John_Heard]

So you've already got the QA1 setup with the 250lb springs correct?

What kind of travel do you have with the setup measured at rest and at full extension (tire comes off ground)?

[bert]

So you've already got the QA1 setup with the 250lb springs correct?

What kind of travel do you have with the setup measured at rest and at full extension (tire comes off ground)?

Yes I allready have that setup. Where I would like to set the ride height I will have about 3 1/2 inches of travel before the tires are off the ground.

[John_Heard]

That's not enough for how fast the car is now (in my opinion), but plenty for when it gets into about the low 9's or so. Does that make sense? You're probably getting close to that transition stage where you would need to start limiting travel and or slowing the shocks down to control wheelstands.

It's going to be far more sensitive to shock settings than it would be with more travel. For instance if it runs out too early it can upset the car. Have you ran it with the new setup in it yet?

[bert]

I have not ran the new set up yet, weather permiting I'll test it on saturday.

[John_Heard]

Try and get some good video of the car launching, it will help a lot in your setup to understand what it is doing.

If you haven't ever shot a car before, or the person that will be doing it for you hasn't done it, read this; http://www.dragstuff.com/techarticles/v ... nsion.html

Hopefully that article will come in handy.

[chpcamaro]

i must say getting the right springs for my car on my qa1's was a job and pricy lesson but they do work great now that i got them setup with the right springs also make sure you get the R's for dragracing. like john said do lots of reading and i hope you get lucky the first time with the springs you try. oh if you need springs i have a few brand new sets i'll sell cheap sense i will never need them now lol that i found the ones i needed
rob