DSE Suspension Testing

[Steve1968LS2]

Originally Posted by Mean 69

I bet they used a 480 slalom, I think that is the larger size that is frequently used? If so, ask Carl C how fast he did the cones several years ago in his leaf sprung car on a 480 slalom.

In everyone's defense on this though, my guess is that there is a whole lot left in DSE's test mule, it just needs sorting. I bet if you optimized the car overall for one performance benefit, it could do really well. Still, there doesn't appear to be "magic" in the setup even though the drama of comparitive numbers in the magazine would suggest it. Unless you know what other cars are capable of, it is hard to draw an absolute conclusion. Which, of course, is typical in competition for all of this stuff.

Mark

I don't think so.. most everyone uses the 420/70 deal except Motor Trend and such who uses 600 foot I think.. then again they are always testing modern cars.

The SC story even said it was 420 foot with 70 foot seperation.

[Steve1968LS2]

Ok.. I had a nice long talk with Kyle at DSE.. here is the jist of it..

DSE did test through a 420 foot set of cones and they were 70 ft apart (like us out west). I sounds like they tried to replicate conditions as closely as possible, even going through the expense of getting new tires for the second test so the comparo would be fair (had new tires in the first test).

The only realy difference is in how we both optain our data. DSE used a VBOX data logging system that employs GPS and lateral accelerometers to determine speed. This is the same sort of system used by companies like GM and I think maybe even Motor Trend. They used the EXACT same spot to test with the cones in the exact same spots.

We use a set of timing lights. A car trips the first light going in and the second set going out. the distance between the lights is 420 feet and there are cones 70 ft apart. This system is widely used in racing and in events like autocross. We test in the exact same spot and we have spray painted marks so the cones and lights are in the exact same spot.

So what does this mean? Hell if I know, but I do belive that DSE was honest in reporting what they came up with and Kyle was very adamant that he stands by his number and would run the car again for any doubters. I've know DSE longer than I've worked here and have zero reason to doubt thier integrity.

Even if there was some flaw with thier equipment the testing would still be consistant and show an almost 3mph gain in the cones. That is a huge gain for such a short distance. When we tested the air ride stuff we got a .4 mph gain and we were happy. A 3mph gain is huge.

I think we just have to chalk up the differences to how the data was obtained (scientific methodology)..

Their skidpad numbers seem dead on given the tires they were running and I confirmed that a 125ft skidpad is quite possible although they most likely could have done bigger with a larger radius. They ran 125 ft since that's all the room they had a Maxton (it's a converted airport)

So, no drama.. just a difference in testing methods. I was very satisfied with Kyles explanation and I know that if he wasn't 2400 miles away he would be happy to run his car through our testing equipment and that shows a LOT.

[sinned]

I still have a HUGE problem believing that simply swapping rear suspension systems netted a .9 gain in the 1/4 mile, that is a massive gain.

[Van B]

Originally Posted by Steve1968LS2

Sure.. you could have a 900ft skidpad if you want. Just plug into the formula. But I have never seen or heard of someone doing a 125 ft one.. heck, the 200ft one us and others use is pretty darn tight. At some point it just becomes a donut.. lol

That doesn't change the fact that the numbers through the cones is all wacked..

The skidpad results seem on track with a car running those types of tires, I had just never heard of a 125ft skidpad.. anyways, that's not really the point of contention.

Sorry Steve, the a**hole in me took over when I read that you said there is NO such thing...

I bought the Super Chevy issue because of the article and was reminded of why I never really liked that mag much. Just doesn't turn my crank for some reason.

[Steve1968LS2]

Originally Posted by dennis68

I still have a HUGE problem believing that simply swapping rear suspension systems netted a .9 gain in the 1/4 mile, that is a massive gain.

I have a hard time believing that Paris Hilton is considered a celebrity, but that doesn't make it any less true.. lol

You would have to know how bad the stock leaf deal was doing. It could have been wrapping up terrible..

[Steve1968LS2]

Originally Posted by Van B

Sorry Steve, the a**hole in me took over when I read that you said there is NO such thing...

I bought the Super Chevy issue because of the article and was reminded of why I never really liked that mag much. Just doesn't turn my crank for some reason.

That's ok.. not my magazine.. lol

Nobody really does less than 200ft though.. it's really just making the testing harder on yourself. But, it that's all the room you have...

[sinned]

I don't know, lots of guys running in the 10.5 class are deep into the 9's with leaf springs and it takes about 60HP to gain a second in the 1/4. I'd have to actually see the before and after tests to believe that, its not one of those "difficult to believe" situations, its just not conceivable unless there was something very wrong with the original springs (which kind of goes back to our last discussion about making sure we are testing "good" OE parts instead of broken worn out parts to make the after results look better).

[Payton King]

The trap speed should be the same for both tests as that is dependent on HP, What was the trap?

[Mkelcy]

Originally Posted by Payton King

The trap speed should be the same for both tests as that is dependent on HP, What was the trap?

From Pro-Touring board:

The quarter mile stuff is hard to peg as well. Too many variables. No such thing as a 383 in 68. But the Leaf Spring to Quadra-Link data is apples to apples:

All other things equal:
Leaf Springs: 15.16 @ 98.62 mph
Quadra-Link: 14.28 @ 101.22 mph

Lemme see.......That's damn near a second with no engine changes.
__________________
Steve Chryssos

[Steve1968LS2]

Originally Posted by Payton King

The trap speed should be the same for both tests as that is dependent on HP, What was the trap?

Well it should be within a few miles (2-4), especially since it was on different days. My 2000 SS ran anywhere from 102 to 107 depending..