Welcome to the discussion.Don't worry about your inexperience.The main thing to get down correctly is your start.I would practise that without the GT2 timer and develop the best method(very little wheel spin but full throttle asap).You must disable the DTC & ESP or the computer will take over and greatly increase your times.I torque up the engine against the brake(1200 rpm max),release brake and slowly go to full throttle.If I mash the throttle I get instant wheelspin.Once you have got the start down the rest is easy.I start in M1 and let the trans shift automaticaly.It will shift at redline even if you don't shift it manually.

I believe Znod doesn't torque brake but I really don't know if it matters.As you can see in the thread our times are extremely close.There is diff in the roads and weather conditions which could easily make up for the small differences in our times.

Looking forward to review your results.

 

Great, we want to see your results and to interest others. You should be able to get some very good times will practice all things considered. With your wider tires, you may be able to escape the wheel spin that messes up so many of our runs--especially mine. On my car, wheel spin causes two type so losses: (1) the obvious one and (2) one that I don't think affects grogan. When I get too much wheel spin, some sort of nanny steps in and fouls up the first to second shift--makes it shif prematurely and hesitantly. I'd like to know how to turn that sucker off. And, you will have no luck with either nanny on--way too much HP is syphoned off. And, of course, we'll help however we can. Mainly it is deal with traction, put the pedal down, and let the car do its thing.
[/quote]

I have experienced this problem in premature and soft shift.In my case it is definitley wheelspin that causes the problem.I usually abort the run when this occurs.

Well Znod I see we are making progress with other 545 owners.For awhile I thought you and I were the only participants in this thread.I know there is a 0-60 time of under 5secs out there,who will be the first to achieve this goal?

 

I got my GT2 today but not sure when I can start using it. Suppose to rain all weekend here in the Bay Area. Wonder how much hydroplanning can affect timing...

 

I assume your kidding.There is no way to get any sort of time on a wet road.It probably is a good idea to experiment with the GT2 just to familiarize yourself with how it works.

We are anxiously waiting for some results from you to see if your times are similar.Don't get discouraged if your first few tries are not good.It will take some practise.

 

I assume your kidding.There is no way to get any sort of time on a wet road.It probably is a good idea to experiment with the GT2 just to familiarize yourself with how it works.

We are anxiously waiting for some results from you to see if your times are similar.Don't get discouraged if your first few tries are not good.It will take some practise.
[/quote]Hi grogan and Eurocarfan:

I agree with everything grogan said. And, be sure and check out our GT2 settings above on this thread--using a 12" roll out in this context. I assume grogan is still changing to 12 inches. If not you could follow me using 12 inches or him using 10 inches. I don't think the difference would be significant--anything but barely measureable at most.

 

Hi grogan and Eurocarfan:

I agree with everything grogan said. And, be sure and check out our GT2 settings above on this thread--using a 12" roll out in this context. I assume grogan is still changing to 12 inches. If not you could follow me using 12 inches or him using 10 inches. I don't think the difference would be significant--anything but barely measureable at most.
[/quote]

Yes I am going to a 12" rollout.I haven't done it yet the weather has been terrible.cold & raining.As soon as the temp gets above 55 and the roads dry out I will try a couple of runs and post the times with the 12" rollout.

 

Hi grogan and Eurocarfan:

I agree with everything grogan said. And, be sure and check out our GT2 settings above on this thread--using a 12" roll out in this context. I assume grogan is still changing to 12 inches. If not you could follow me using 12 inches or him using 10 inches. I don't think the difference would be significant--anything but barely measureable at most.
[/quote]
Yes I am going to a 12" rollout.I haven't done it yet the weather has been terrible.cold & raining.As soon as the temp gets above 55 and the roads dry out I will try a couple of runs and post the times with the 12" rollout.
[/quote]I have a new one for you. I have been getting some wierd inconsistent results (only) lately. It is making it hard to know what is going on. For example, this morning I had a typical time to 80--about 8.65, but, impossibly, my 1/8th was 8.83 at 79.5. Obviously one can't get to 80 before 79.5. Any thoughts. Inverted results like this on have occurred four times recently, but never before.

 

Hi grogan and Eurocarfan:

I agree with everything grogan said. And, be sure and check out our GT2 settings above on this thread--using a 12" roll out in this context. I assume grogan is still changing to 12 inches. If not you could follow me using 12 inches or him using 10 inches. I don't think the difference would be significant--anything but barely measureable at most.
[/quote]
Yes I am going to a 12" rollout.I haven't done it yet the weather has been terrible.cold & raining.As soon as the temp gets above 55 and the roads dry out I will try a couple of runs and post the times with the 12" rollout.
[/quote]I have a new one for you. I have been getting some wierd inconsistent results (only) lately. It is making it hard to know what is going on. For example, this morning I had a typical time to 80--about 8.65, but, impossibly, my 1/8th was 8.83 at 79.5. Obviously one can't get to 80 before 79.5. Any thoughts. Inverted results like this on have occurred four times recently, but never before.
[/quote]

Sounds a little wierd but I do have a possible explanation.Is it possible you let off the accelerator a little before the 1/8 mile mark?This device measures your speed at exactley the 1/8 mile mark,it does not measure the highest speed achieved during a run.If you let off a little early(50' or so)you would have slowed slightly from 80mph and therefore have a slightly lower speed at the 1/8 mark.

I have another vehicle(grand cherokee with hemi) that I experienced this condition.It is slower than my 545 so I am able to go a full 1/4 on my test road(if I am brave enough).On a couple of runs I was't brave enough and let off early.I had results that made no sense,14.52 sec @ 86mph.When I don't let off early the results are 14.47 @94+ mph.

If you know you are not letting off early this can not be the problem.Then I would suspect a malfunction in your GT2(I hope not)

 

Hi grogan and Eurocarfan:

I agree with everything grogan said. And, be sure and check out our GT2 settings above on this thread--using a 12" roll out in this context. I assume grogan is still changing to 12 inches. If not you could follow me using 12 inches or him using 10 inches. I don't think the difference would be significant--anything but barely measureable at most.
[/quote]
Yes I am going to a 12" rollout.I haven't done it yet the weather has been terrible.cold & raining.As soon as the temp gets above 55 and the roads dry out I will try a couple of runs and post the times with the 12" rollout.
[/quote]I have a new one for you. I have been getting some wierd inconsistent results (only) lately. It is making it hard to know what is going on. For example, this morning I had a typical time to 80--about 8.65, but, impossibly, my 1/8th was 8.83 at 79.5. Obviously one can't get to 80 before 79.5. Any thoughts. Inverted results like this on have occurred four times recently, but never before.
[/quote]

Sounds a little wierd but I do have a possible explanation.Is it possible you let off the accelerator a little before the 1/8 mile mark?This device measures your speed at exactley the 1/8 mile mark,it does not measure the highest speed achieved during a run.If you let off a little early(50' or so)you would have slowed slightly from 80mph and therefore have a slightly lower speed at the 1/8 mark.

I have another vehicle(grand cherokee with hemi) that I experienced this condition.It is slower than my 545 so I am able to go a full 1/4 on my test road(if I am brave enough).On a couple of runs I was't brave enough and let off early.I had results that made no sense,14.52 sec @ 86mph.When I don't let off early the results are 14.47 @94+ mph.

I am not with you totally mon. The above let-off time/speeds make sense to me--slower/faster time and speed given let off/no let off. My tests are showing quicker to 80 than 79.5.

But, you helped me think more clearly about the issue. Note that I did not let off; I went all the way past 90 to over 93 (i.e., the meter does show the max speed achieved, but not the related time). But, an implicit let off may be possible.

What if my car is shifting shortly after 80 mph, but right before the 1/8 is done. Could my car have slowed slightly during the shift. If so, this phenomenon could explain my seemingly slightly low 1/8 speeds. I will do some calculations and see if my car may be shifting to, I guess, 3rd (or would it be 4th) at around 80 mph.

It would be great if we could reconcile all. I know you--you'll calculate too. And, you might get it done before me since we now are off to run Sat. morn. errands. Thanks for thinking with me. And, please let me know what speeds you think your car is shfting at; you mentioned some of this before, but I can't recall.

If you know you are not letting off early this can not be the problem.Then I would suspect a malfunction in your GT2(I hope not)
[/quote]

 

Sounds a little wierd but I do have a possible explanation.Is it possible you let off the accelerator a little before the 1/8 mile mark?This device measures your speed at exactley the 1/8 mile mark,it does not measure the highest speed achieved during a run.If you let off a little early(50' or so)you would have slowed slightly from 80mph and therefore have a slightly lower speed at the 1/8 mark.

I have another vehicle(grand cherokee with hemi) that I experienced this condition.It is slower than my 545 so I am able to go a full 1/4 on my test road(if I am brave enough).On a couple of runs I was't brave enough and let off early.I had results that made no sense,14.52 sec @ 86mph.When I don't let off early the results are 14.47 @94+ mph.

I am not with you totally mon. The above let-off time/speeds make sense to me--slower/faster time and speed given let off/no let off. My tests are showing quicker to 80 than 79.5.

But, you helped me think more clearly about the issue. Note that I did not let off; I went all the way past 90 to over 93 (i.e., the meter does show the max speed achieved, but not the related time). But, an implicit let off may be possible.

What if my car is shifting shortly after 80 mph, but right before the 1/8 is done. Could my car have slowed slightly during the shift. If so, this phenomenon could explain my seemingly slightly low 1/8 speeds. I will do some calculations and see if my car may be shifting to, I guess, 3rd (or would it be 4th) at around 80 mph.

It would be great if we could reconcile all. I know you--you'll calculate too. And, you might get it done before me since we now are off to run Sat. morn. errands. Thanks for thinking with me. And, please let me know what speeds you think your car is shfting at; you mentioned some of this before, but I can't recall. You'll have to allow, of course, for the difference in our tire diameters if you choose to calculate. See you later.

[/quote]I have thought about the issue, and am at a loss. My car could not be shifting into 3rd at more than about 62 or 63 mph assuming (1) that R&T's speed per gear values are based on (1) a 275 / 35-18 tire size (as is implied) and (2) that R&T's 6.5k rpm max speeds in 2nd/3rd of 62 and 95 are correct--given this tire size.

And, I completely missed what you said above: "You are right about the diff in ratio due to tire size.The standard goodyear RSA 225/50 are 25.9" dia. Guessing you have PS2 that are 245's(19")dia. is 26.7." But, no, my tires are 275 X 30-19 and, thus, have a diameter of about 25.7" diameter. Thus, I acutally have a very small effective rear-end factor better than yours rather than what we have been saying.