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One of our members just asked me a question by PM that I felt warranted a posting that others could see. It concerned traction control. The 6-speed SSRs do not have traction control.

The reason is that the much stronger rear axle used on the 6speed, an Eaton axle, lacks a sensor needed for traction control. Gm apparently used this axle regardless of that deficiency, as they knew they needed a stronger rear axle because of the SSR's WEIGHT.

You see, the loads transmitted to a rear axle are NOT solely dependent upon power applied, but also are greatly affected by vehicle weight, as:

1. The extra weight generates a much higher AVERAGE driving load (force required to accelerate an object is proportional to its mass, so do the math . . . ). This is why commerical trucks have such HUGE rear axle assembleis even though the horsepower is often lower than on an SSR.

and

2. The extra weight enables a much higher shock load to be transmitted before the rear tires break loose and dissipate that shock load. This is because available friction is proportional to a combination of vehicle weight, tire footprint, and stickiness of the rubber used, and the vehicle weight is the factor with the most impact in the formula.

So, GM NEEDED the stronger axle, but probably did not agree to omit traction control without a great deal of soul searching, as the traction control WOULD have provided two very tangible benefits:

1. The start of tire splippage would have triggered a rapid reduction in power applied, as a computer can react and "lift off the gas pedal" much faster than any human can, and would thus have lowered the duration of shock loads on that axle AND on the entire driveline,

and

2. The computer could "lift off the throttle" (and retard spark at the same time) much faster than any human and thus MIGHT prevent a small loss of traction from turning into a major loss of control or accident.

So, GM had both mechanical durability and safety reasons for wanting traction control, but simpky couldn't get it with that axle without paying for a retooling that the SSR's volume cannot justify.

We'd like to think that especially in this price range of vehicle, we can have everything, but in practice sometimes we cannot.

I look at my own situation with my 04 automatic SSR that now has a Z06 cam, dual exhaust, and supercharging, and thus exceeds the power output of a stock 05 / 06 SSR by a considerable margin. I wonder how durable that 8.6 axle will be with this new power. But, I also know that traction control has been an appreciated control saver more than once under wet road conditions. I for one value the safety higher.

To put this in stark perspective, one of our site regulars was killed a few weeks ago in a traction related accident. I'm pretty sure he was driving a 6 speed SSR, and thus had no traction control to react faster than he could when he encountered black ice.

Also, read my postings under my "supercharger marathon" thread. Traction is THE issue.

Jim G
 

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Jim, unless road conditions warrant, I turn off my traction control when driving around town. Here is the reason. Twice when I braked a little hard and started around a corner I lost power and almost didn't clear the intersection in time, because of the traction control. Is this normal??
 

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woohoo said:
Jim, unless road conditions warrant, I turn off my traction control when driving around town. Here is the reason. Twice when I braked a little hard and started around a corner I lost power and almost didn't clear the intersection in time, because of the traction control. Is this normal??

I've had this happen also, I have tried to pull away at an intersection and the tires spun on gravel, and it dang near got me hit. I turn it off just about every time I'm in the truck:eek
 

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Glad to know I'm not the only one this has happened to. My husband blames it on my lead foot, but I know better.
 

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I have this problem with my Avalanche also. Traction control is a great idea, just not all the time:banghead
 

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I never have a problem with traction in my SSR even with the added power, 6 speed and no traction control. I think the biggest difference between the automatic and 6 speed is that I control when I am going to downshift and feel I have more control in my SSR then any automatic I have driven to include a few race only cars I have owned. I can control traction by feeling the weight transfer and side load on the rear axle. I am not saying that I can't fry the tires off the rims or chirp the tires at 60 mph but I prefer the added control. The down side to a 6 speed is the constant shifting (I love it), and the more inconsistent times at the strip due to having to shift.
 

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I have an '06 6-speed. I don't miss traction control and would probably disable it if I had it.

However, I am not a typical driver, having learned to drive on a combination of Farm Combine, 26' non-articulated truck, ?? foot articulated grain truck, welded frame dune-buggy, and various muscle cars. I learned WAY early how to drift a corner with throttle... perhaps becoming a lost art. I also don't worry about Deborah as she is a championship caliber autocross (SCCA Solo II) driver... So we've got it covered.


I understand GM and today's market and why they added it... in fact, I thought it nice that it could be disabled. Of course, the 6-speed avoids the whole issue.
 

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FriscoTX_SSR said:
I have an '06 6-speed. I don't miss traction control and would probably disable it if I had it.

However, I am not a typical driver, having learned to drive on a combination of Farm Combine, 26' non-articulated truck, ?? foot articulated grain truck, welded frame dune-buggy, and various muscle cars. I learned WAY early how to drift a corner with throttle... perhaps becoming a lost art. I also don't worry about Deborah as she is a championship caliber autocross (SCCA Solo II) driver... So we've got it covered.


I understand GM and today's market and why they added it... in fact, I thought it nice that it could be disabled. Of course, the 6-speed avoids the whole issue.
6 SPEED RULES THE ROAD:agree Having total control with upshifts and downshifts when I feel the need ............... Not the computers NEED!!!!!:smash
 

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I think the bottom line is with the six speed you need to pay attention to what you are doing and drive.
The SSR is actually quite well behaved when pushing the limits. If you need to learn, take it to an autocross event or two or three:)
 

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I'm intrigued by your autocross photo... I've done all of my autocross in vehicles that "feel" much "lower"... And I've certainly had my share of spins. In fact, Deborah holds the area record for "best spin" back when she was learning in a 1997 Del Sol: About 720 or so one way and still had the car "wound up" enough to do a full 180+ the other way, just when she thought she had it out! :eek

So, the reason I'm intrigued is I have a question now that we own this 4700 pound "feels very high" (at least feels high to us, with our years of lowered sports car and even some formula car driving) SSR muscle car beastie:

Will a STOCK (meaning factory tires, not lowered, not stiffer anti-roll, etc - bone stock) SSR spin before it rolls on smooth dry concrete? Another way to ask the same question: Can you put it on the roof with steering inputs?

Obviously, rollover is possible if you hit something, go off an emabankment, etc. This has been (very unfortunately) proven and discussed here. I'm asking for PROOF POSITIVE that a factory SSR is safe to autocross.

??
 

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Well, I do have the Hotchkis sway bars on mine and now the Eiback lowering springs. The photo was only with the bars. I went balls out one run with a friend holding on for dear life in the passenger seat. Was riding the rev limiter in first gears briefly through the slalom then on the binders for some turns. Thought for sure I was going to loop it (spin) got completely off the throttle and let the rear slide. It scrubbed some speed, got back into line (posi is a wonderful thing) and I stomped the throttle. Still can't believe I didn't hit any cones. Did the same thing on the back side of the course. It doesn't handle like my other car which is about 2000 lbs lighter but it does handle very well is well mannered and wants to stay on all four.
 

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I autocross mine all the time and just love it! It stays on all fours just fine. The crowd loves the roar of the 5.3 litre exhaust. Too bad they changed the exhaust note on the later models after 03. Do it man! You will love it.:seeya
 

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The larger rear axle is there for overspeed issues when you accidentally downshift into a too low geat. The rear tires have so much traction, they do not break free when you accidentally do this so a stronger axle was required.
The traction control lis missing because we could not get the supplier to do this work because of the low volume and short leadtime. We have a different ABS unit than the Corvette, so we could not go there. We did not have enought time or money to do a different ABS unit for the SSR. There is significant leadtime to develop the software for ABS/Traction Control units.
 

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JimGnitecki said:
I look at my own situation with my 04 automatic SSR that now has a Z06 cam, dual exhaust, and supercharging, and thus exceeds the power output of a stock 05 / 06 SSR by a considerable margin. I wonder how durable that 8.6 axle will be with this new power. Jim G
I suspect that as long as we have a torque converter in front of it - we will be OK with that axle. Time will tell . . .
Blast
 

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My spelling and grammar left a lot to be desired in my last message, but the info was there. When we were doing manual development, the shock loading was the issue for the transmission as well as the axle. On acceleration, the transmission had to be beefed up and appropriate ratios selected for the gears in order to handle the torque. Until the tires break free, there is more load on the drivetrain in the SSR than in the other high performance vehicles. There is more tractive effort force generated by the SSR tires because of the tire size, the tire compound, and the weight. With an automatic transmission, the shock loading is tempered. We did not have a durability issue during validation. Those of you with more power than the '05 can consider changing to the larger axle if you feel the need or if the first one doesn't survive.
 

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Generation Gap?

I am surprised that dragracing has not been part of this discussion. To accelerate best from a stop, the engine rpm needs to be up a bit and that is hard to get initially with an automatic. A stick can allow the engine to be revved prior to launch and the clutch slipped, maintaining good rpm for acceleration. Traction control would defeat this and dragracing IS the main reason to get a stick!
 

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Discussion Starter #20
freezer: 2005ssr6speed and I have discussed that axle swap (8.6 automaitc axle to Eaton 6-speed axle).

Is it as easy as we think it is?

Do you need to change driveshaft ( THINK we do)?

To prevent the PCM from going crazy, you would simply disable traction control?

Is ABS affected?

We also suspect that the power loss through that big axle is much larger than with the 8.6 axle. Is that the case?

Danko: The purpose of a hi-stall torque converter is to simulate that very same "letting out the clutch at a higher rpm", except that the torque converter is more consistent than a human.:)

In both cases (letting out clutch at higher rpm and using a hi-stall converter) there is a LOT of (destructive) heat generated . . . that's a cost of trying to go FAST!

Jim G
 
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