My coilover conversion work great!

[SRD art]

Hey Folks-

A lot of you know that my car was used to R&D a new Coilover shock conversion for the front of G bodies. I just wanted to let you all know that the suspension works great and the kit is now available to the public. There are a lot of advantages to switching to a coilover for street, drag, and pro touring cars, and through my research no one had a true conversion kit till now. I hope the hard work that went into my car helps some of you get yours dialed in too. For more info here's a link to the kit ... http://www.speedtechperformance.com/index.cfm?ptype=product&product_id=407&category_id=96&mode=prod

Bangshift.com snapped a few pics of my car on the autocross, you can see my suspension keeps the tires planted and body roll isn't excessive. Overall the car handled great, and I feel very strongly that my NT555 tires were my limiting factor to better track times. Next on the list is some sticky Falken RT615s. Click here and about halfway down in the gallery is my wagon. http://bangshift.com/gallery/hotchkis-autocross-action-at-nmca-west-fontana/

Here's pics of my suspension-

 

[awdblazer]

what is that piece that goes from your outter tie rods to your lower balljoint?
thanks

 

[SRD art]

They're called spindle savers. It's a circle track thing, I guess they get bumped around enough that these simple brackets help keep the steering arm from getting bent. You can get the from Speedway Motors for the "metric" (G body) chassis for about $15. Not sure if I need them or not, but I beat the car pretty hard at the track and at that cost it's cheap extra insurance.

 

[pontiacgp]

you don't need spindle savers for hard driving. They are helpful when your rubbing another car or the wall. What was the difference on you lap times with the coil overs vs the conventional set up

 

[SRD art]

Yeah, the spindle savers may be a bit of overkill but again for the price why not, right? I bet if this guy had spindle savers his car would've been just fine, lol! [youtube]https://www.youtube.com/watch?v=BB-KBaevPqM[/youtube]

That's a tough question to answer because the tracks have changed since running each suspension. What I can say is that the car sticks better now. A big part of that is I went to a larger sway bar, from 600 to 700 lb front springs and now have 200 lb springs out back. Something to consider is that a 600 lb traditional spring and a 600 lb coilover spring are still both 600 lb springs and if shock valving were the same technically the car should drive the same with either set up and you may not see an increase in track times.

From a different perspective, I can say the car is better now because of the benefits of a coilover conversion-

-Since I installed them I've already swapped out front springs. With a coilover the springs are a little more precise in what rate you get, there's more length and rate options available and it's cheaper and incredibly easier to swap springs out. I had 3 different coil springs up front before, and I still wasn't happy with rate and ride height. What a pain to change them out and that was a big factor for changing over to coilovers.

-I had single adjustable Varishocks on the car before. They worked well, but for me I really want to get the best out of my car. With the double adjustable Vikings I am able to really fine tune things, even changing settings for different tracks/ driving situations. With the double adjustables I can change both compression and rebound which both can have their own unique effect on handling. If I want to go drag racing a week after autocrossing I can dial in compression and rebound accordingly to get the weight transfer/ traction whereas Single adjustables are either tight or loose. My boss has a 69 Camaro drag car that's now dipped into the 8 second range in the 1/4. He said he can control the launch, either hard and low or put on a show and pull 3 foot wheelies simply by changing the settings on his front shocks. In my case I can control under and over steer with simple dial adjustments.

-The dials are exposed and aren't hidden inside a coil spring like the traditiaonal set upp, so literally I can adjust all 4 shocks now in probably about 15-20 seconds without having to be a contortionist and squeeze fingers between coils.

-Ride height can affect handling. Getting things low gets your center of gravity down, but super low isn't necessarily the best for steering geometry. With the coilovers if I feel the need I can change ride height in a couple minutes and can do it in a track parking lot. Now I don't have to worry anymore about buying springs, spending the time and effort to change them out and just hoping it puts the car where I want it. Been there done that. I can actually change alignment settings for better track times by changing ride height, making it easier to drive the car to the track and not having to worry about extra wear on the tires.

-On the rear, the Speedtech coilover conversion brackets have 3 positions for the lower control arm mounts, allowing you to change instant center and antisquat. I noticed in photos that where I first installed them the car would squat out back when I accelerated. Doing so would change the front geometry and transfer weight to the rear wheels and off the front. That can really make things "fun" when accelerating out of high speed corners. I've since moved the arms to another position and the car pushes forward rather than squatting when I lay into it, just what I needed. If I want to go drag racing, I can easily raise the car up a little and adjust the shocks for better weight transfer and then adjust the control arm position accordingly.

-Before my rear coil springs would fall out of place if the car was raised high enough. Going to the tire shop for service or ever working on the car off the ground meant having to crawl under it to guide the springs back in place as it was lowered back to the ground. I don't miss that at all.

So in a nut shell, the coilovers make things a lot more convenient for someone who is serious about handling at the road course / autocross or setting the car up for great traction at the strip.



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[pontiacgp]

With the work you did to get the coil overs installed did you ever consider changing the location of the bracket for the uppers so you could use equal length upper control arms. There are more arms to choose from with equal length arms and you can find them with with screw in ball joints so you can play with the length of the stud. I've welded in Howe inserts for the lower control arms so I use the low friction screw in ball joints, I plan to do something with the upper this winter so I can use screw in ball joints on top as well. I agree with you about it being a pain the change the convention springs up front. I have 185 lbs springs in the back and to cure the problem of the spring falling out I use the AK Bilstein series short shock. I noticed the top of your steering shaft knuckle which looks like Sweet or Flaming River, what steering box are your using. I've got a Delphi 600 to put in my GP this winter

 

[SRD art]

Pretty much my goal with the car is to use all off the shelf suspension parts. I know of another G body owner that changed his mount location. I can't help but think that folks that go that far are chasing milliseconds. He competes regularly so I can understand that but since I compete only for fun it isn't important to go that far. What did you mean equal arms, equal to what?

The SPC arms I took off my car had Howe screw in ball joints. I still have the Howe tall ball joints in my Speedtech lower arms. When I swapped on the Speedtech upper arms I bought Proforged tall upper ball joints. I read the Howes are low friction because they have looser tolerances and I also read that some top racers run Proforged without problems. Not sure on the Howe rumor, but the Proforged ones were less expensive and my car is a daily driver so I went with them this time. With the way it is I had about 1 deg of negative camber without any shims. That's about perfect for me so the nitty gritty of playing with ball joint length is probably not necessary.

It's a flaming river knuckle, and an AGR 12.7:1 box. In hindsight I would've bought the Jeep GC box but I didn;t know about it at the time. I wouldn;t be surprised if AGR simply does a quick rebuild on a Jeep box and sells them for twice as much?

Got a build thread for the GP? I'd like to check it out.

 

[pontiacgp]

I didn't make a build thread cause I don't really have an agenda and I'm not one for taking pictures.It's basically a circle track car that just need a little more negative camber and a set of Hoosiers. I get asked quite a few times in the race seasons if they can try it on the track cause I don't have to play by the rules so my car should be quicker than the super stocks they run. I do my upgrades on as little money I can and most of the parts come from the race shop so whatever is available I'll incorporate it into the GP. That Delphii 600 box goes for around $700 up here and since they didn't need it on the chassis that they bought I got my GP. With the equal length arms uppers the ones used on a G body are 1.25 offset so one arm is longer then the other. A good thing about the stock positioning on the uppers it has a lot of anti dive in it.