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Discussion Starter #1
Just curious...would stiffer shocks/springs in the rear effect the quarter mile times? I would think the time would improve, since there is less energy being exerted downward on the rear of the car....is that true?
 
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Discussion Starter #2
It's tough to tell, since going stiffer in back can often hurt launch and make the car slower in the 1/4 mile.

It's more of a "how is the car set up" kinda thing.....
 
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Discussion Starter #3
Get some HAL 12-way shocks and you should be alright.
 
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Discussion Starter #4
I contacted HAL after hearing reports that they would puke after just one cold winter, while they did not come out and admit that is a problem they saud they did not recommend them for daily drivers in my climate. WI is colder in winter than PA(trust me I grew up in NW NJ) so judge for yourself and based on your usage of the car wether HALS are right for you. Having them in front can definetely help the launch.
 
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Discussion Starter #5
Stock SS springs, Bilstiens in all four corners, F body sway bar, HA rear bar with BMR adjustable rear control arms. This setup got me to the 4th fastest bolt on car on the ET page.

I don't believe a stiff setup isn't the worst thing at the strip. :D
 
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Discussion Starter #6
Eric : stock springs isn't a very stiff setup ;)

I can just tell you that changing spring rate much at all (even 10-20%) in back had negative effects on straight-line launching. Take that for what it's worth.....

And in front, lets just say my setup (which is, umm, "not soft" :D ) isn't conducive to weight transfer either....
 
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Discussion Starter #7
I got a 1.74 60' time on my only good run (with current mods) with GW front springs, rear Impala springs, Konis at their stiffest settings, HO bar and GW rear control arms. I agree that with a good track preparation and a naturally aspirated 350 there is no need for a lot of suspension work to hook on drag radials.
 
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Discussion Starter #8
I run a stock type setup, and I've had a best sixty of 1.69, so far, and it will go down even further. I've got plenty of motor, too! I run the firmer Bilsteins all around, stock springs, Hotchkis front and rear swaybars, and upper and lower trailing arms.

Good track prep, and Hoosier 15X11.5 QTP's give me consistent low 1.70's, every time out. Suspension work really isn't necessary, with good tires, and a good track, unless you have a monster motor, and a monster shot of juice! HTH
 
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Discussion Starter #9
I think stiffer is better as long as you can maintain traction. (I'm sure the girls would agree
)

I had a real traction problem with my wagon with it's stock springs (this was during stage 1 on my sig) On the street or track it would wheel hop like crazy. Even with the airlift bags aired all the way down. The stock wagons are 225# springs.

This spring I installed stock Civi Caprice springs (140# springs (Impalas are 160#)) that I got free from the board. Put headers, Hot cam, and a 2500 converter in it and went from 15.1's and 90 MPH to 13.7's at 98 MPH and my 60' went from 2.1xx to 1.9xx (This is on the same 275-60 15 Kelly road huggers)

I picked up two tenths in the 60' and traction is still better than with the 225# springs. I now need slicks because I still get a little tire spin off the line and am breaking them loose again going into 2nd gear.
 
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Discussion Starter #10
Originally posted by AutocroSSer:
Eric : stock springs isn't a very stiff setup ;)

What do you mean? They also have 169k on it.
 
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Discussion Starter #11
Mean what I said....the stock springs are relatively soft.

I have played around with stiffer springs in back before like Family Truckster mentioned (both 1A2 wagon springs and some Moogs of similar stiffness). I found the same as he did.....even that "relatively little" jump in spring rate resulted in a car that became VERY tough to get it to hook up on the street. Made for some cool looking stunts (hey, lets look at Ed break the tires BACK LOOSE in a straight line when he floors it at 30 MPH :D ) but didn't help the car go faster......

I'll let you in on a secret to handling from my car (but it also helps the car hook up).....my car is sprung and bar'ed a lot softer in back than you probably think ;) . Stock rear springs, HAL shocks, 30mm rear bar....that's it! I've tried stiffer in back (both bar and springs) and while it is fun, it is NOT faster.
 
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Discussion Starter #12
stock class drag racers with coil spring setups run the softest coil that will hold up the car to a predetermined height.the upper control arms are positioned higher on the third member to acheive the desired pinion angle.the lower control arms are much stronger,all bushings are roller bearings.the rancho adjustable shock is being used alot.sway bar left intact,some use an airbag in the passenger side.
the front control arm bushings are super loose or roller bearings.front end alignment is changed quite a bit.the front shock(both travel and rebound)is important.
controled pitch rotation is what you want.
 
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Discussion Starter #13
Bob : although I have a decent idea/guess anyways, just curious as to what are they going for as far as front end alignment?

My guess : slight toe-out, cambered out slightly at rest (caster doesn't really matter other than being equal since hopefully you aren't turning while going down the dragstrip
). Under power (i.e. picking up the front of the car) this would goto zero toe and zero camber (if adjusting front geometry a bit) and lead to the least possible rolling resistance down the track....

I'll also note as far as MY suspension setup (which is "handling oriented").....if I were setting it for ONLY road course (i.e. higher speed), I'd go stiffer in back on the springs and probably minimize (if not downright eliminate) the rear bar. Would get the desired handling, lose the weight of the rear bar, allow better articulation.......and also launch from a dead stop like absolute crap (i.e. wheelspin.....and lots of it.....even with sticky tires).

However, as is my car is setup for LOW SPEED handling (i.e. autocross and street), I've kept the bar and soft springs.

I'm really surprised more folks around here haven't started playing major chassis games on these cars for drag racing. While the car would lose some (if not all) streetability, I also believe that you could make some nice ET gains for the relatively low cost of suspension mods compared to power mods.
 
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Discussion Starter #14
Hey guys, any suggestions on the proper pinion angle? I've been playing with the angle and for lack of track time I'm stuck in limbo. One change produced a slightly better 60' and a little quicker ET. The next change, another turn down on the pinion caused spin and a -0.1 change in 60' yet the split times were much quicker and the ET was the same as the previous run even with the slower 60'.

I've been using a stiff shock setting in the rear (6/8) with a loose (0) setting up front. I've got IC brackets and the BMR adjustable RCAs.
 
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