High performance handling for Astro/Safari vans

[Loopie]

Hi...Mike is it?...Derek here, but even my closest friends call me Loopie.
I've been reading a bit here and I gotta say...I'm a huge fan of your ability to get the info across in such an easy to understand manor. GREAT job and I'll be steering as many people as I can your way Mike. Outstanding job. :beer:

So how about this.....I need a MUCH higher rate coil spring for the front of the 2wd Chevy Astro/GMC Safari. How high? Think of a sports car owner that drives his car on the street but will compromise comfort to have that spring deliver on track day.
I want to be in that range with the van But the van will weigh about 5400lbs total.

I suppose the real question at this time is...is a custom coil along those lines do-able within the stock van suspension design?
Secondly..if it would need to stay stock height, no problem. The right spring rate is of primary concern...but a 1" - 1.5"max drop would be nice. Do-able?

(I'm sure you would need some detailed info to spec out the spring exactly...but this is a project that'll span the next 12mths or so and I need the final corner weights before we can get into those details(like the v8 swap and whether I go iron or aluminum heads)...assuming the spring is do-able

Thanks for your time! Cheers :beer:

[Spring Guru]

Loopie,
Thanks for the kind words. I make an effort to boil down my explainations to the most easiest to understand terms. I call it my "Modified KISS Method" - "Keep It Simple because I am Stupid"

I hate it when I ask for an answer to something that I do not understand and the bozo to whom I am speaking to goes out of his way to make sure thta I know that he knows more about the subject than I ever will. I refuse to be that way.

Now moving on. The spring you need would be a custom made set. We would need to know all the final specs before we went forward with them. Pricing depends on the final design. So when you get 'em all figured out, let me know. - Mike

PS Keep passing the word about us.

[Loopie]

Could you give me the upper price range of what this pair of springs might cost?
I see you've given a few quotes in the forum here for a pair of coils at just under $200. I'm definitely ok with $2-300 for this project. Much more than that and I'd have to think twice....I'm just curious now if you think I might be requesting what turns out to be some magical $600 pair of springs....LOL

Thx Mike.

Loopie

[Spring Guru]

OK Loopie, if nothing falls in place, tooling, wire diameter, winding program, setting sun, rising moon, etc. the top end could be a lot of money.

Seriously,until we have all the details of what is needed we can not provide a quote. However, if the springs could be a stock item that is used for another application and if so you are looking at 189.95 for the pair. But if they are not and have to be custom wound the price goes up from there. And what the price could be depends on the design of the nneded spring. - Mike

[ratrace2]

Originally Posted by Loopie

Hi...Mike is it?...Derek here, but even my closest friends call me Loopie.
I've been reading a bit here and I gotta say...I'm a huge fan of your ability to get the info across in such an easy to understand manor. GREAT job and I'll be steering as many people as I can your way Mike. Outstanding job. :beer:

So how about this.....I need a MUCH higher rate coil spring for the front of the 2wd Chevy Astro/GMC Safari. How high? Think of a sports car owner that drives his car on the street but will compromise comfort to have that spring deliver on track day.
I want to be in that range with the van But the van will weigh about 5400lbs total.

I suppose the real question at this time is...is a custom coil along those lines do-able within the stock van suspension design?
Secondly..if it would need to stay stock height, no problem. The right spring rate is of primary concern...but a 1" - 1.5"max drop would be nice. Do-able?

(I'm sure you would need some detailed info to spec out the spring exactly...but this is a project that'll span the next 12mths or so and I need the final corner weights before we can get into those details(like the v8 swap and whether I go iron or aluminum heads)...assuming the spring is do-able

Thanks for your time! Cheers :beer:

Hey Loop,


So, you want'a drop a 350 cui in that big dog and make it run like a dragster?

Start with cheap first.

Front End:

New front springs, find the stock spring rate and go up 100 lbs.
OR, just cut a coil out of your stock springs and the rate will go
through the roof.. . .and lower it a bit...watch your camber.

New Polyurethane, or Brass busings(Eaton), that should tighten it up.
New Front sway bar 1" or bigger if you can find it.
New Front Gas shocks, that should add about 75 lbs of spring rate.

Back End:

New Afco spring slider (summit racing)
New Ladder bars (Spohn.net).
New springs, Stock +1.
New Polyurethane busings (Eaton).
New Sway bar......1" or bigger....I bet Eaton could bend on for ya!!!


Try the cheap stuff first.
But next time find the "curb weight" of the truck not the GVW.
Aluminum heads, or Iron Heads. . .not a big'e for a good design.
Year, make, Model, purpose of modifications. . .BIG'E........
TRACK, DRAG, Pro/street. . . .etc. . . . .


Best of luck, RR2

[Loopie]

Thx for the interest in my project RR2

*Warning...half a book comin' at ya...but hopefully an easy read...

Oh yea Baby...She's gonna run. If all goes as planned, I'm duplicating bolt for bolt this SB400 build Chevrolet 406 Big Block - Chevy High Performance

It's still a free-for-all in most of Canada, so carbed is ok.

"525 lb-ft of peak torque at 3,500 and 428 peak horsepower at 5,000 rpm"

"At 2,300 rpm, the engine was already making 471 lb-ft of torque. Can you say burnout? We also tried several tricks including more timing, changing carburetors, and adding a 1-inch spacer, but none of the changes improved upon the initial numbers. The Coast High Performance 406ci put up its best power numbers running 91-octane, 35 degrees of total timing, 15/8-inch headers, and a 750-cfm HP Holley carburetor."

As for handling...I'm looking for cornering and fish tailing control...not dragstrip. I need this van to stay flat.

I have zero issues with cutting springs and as I understand it, the coil in this application is the kind that can be cut. I'm just concerned that the stocker with a coil out of it won't be as stiff as I might like. I'm sure this is where Mike will come in down the road and hopefully recommend an in-stock coil he has or perhaps he'll be able to recommend a coil that'll work if cut down.
Wheel alignment for sure after any ride height adjustment. I actually like just a tad more negative camber, even on a daily driver.

These vans use a front sub-frame. I'm going to buy a complete donor. Pull the sub-frame out and go thru the front suspension 110%. Put the v8 on it and when it's all ready...it's a one day swap to get it under the van
I think there are 3 different stabilizer bars for these vans, all over an inch in dia...I'll certainly acquire the thickest one (1 1/4") if the donor doesn't have it. I'm thinking to convert the end links to the "bearing" style or maybe even fab up some spherical links.

I'll also start with the thickest stock rear stabilizer bar available and go from there. Axle wrap has to be addressed, I know that much...but I haven't actually read up yet on getting deeper into a road handling rear leaf setup. It's on the list.

Shocks...the best I can afford for this given application. Shocks are so much more important than most give them credit for. They have a very demanding job to do.

She's a heavy beast I'm afraid RR2. Just after I bought the van, the local landfill installed brand new scales...1/3 tank of fuel, one bench seat out of it(about 100-120lbs) but two 80lb passengers and myself(200)...5190lbs as I recall. It's a '97 GMC Safari AWD with the very heavy leather seats. I won't know final weight until the 2wd swap and v8 swap are done. I generally only have the one bench in it tho...that helps. I'll also run the bench over the rear end once the v8 is in to help with weight distribution a bit more.