Engineer/math minds HELP!!

[Alky V6]

Maybe using the g-force at each datapoint is the way to do it in this case.....

It might be more accurate.....just didn't know how accurate that g-number is.... I would expect the distance traveled to drop using the g-force to calculate it....

Give me the g-force number at each of the time stamps you had in the last data you gave me....

I was thinking the same thing. The sim will only give a smooth average for tire slip over the timespan of the run. It won't account for erratic tire slip.

 

[Alky V6]

I'm getting 154' at the 1.7 sec mark, but that's with a fair amount of tire slip at the hit (22%), tapering down to 8% by just before the 1 sec mark and 4% tire slip by the 1.6 sec mark.
Is there an accurate way to find out how much tire slip you're getting at the launch? I can't imagine how. I've been able to match your launch rpm and 8040 rpm by the 1.7 sec mark. That should be a pretty fair way of judging tire slip.

And G-force.

edit: Correction to your tire slip numbers. 18, 6, and 3. I also increased the torque multiplier for the TC by .05. That got me right on a 3.4 G at the hit. 156' at the 1.688 sec mark, with the 1.8 gear. 204' at the 2.016 sec mark and 8040 rpm with the 1.69 gear.

 

[BlownV6]

Ok here ya go again!!

.000-0
.050-.71
.100-1.85
.150-2.58
.200-2.95
.250-2.97
.300-2.94
.350-2.81
.400-2.92
.450-3.19
.500-3.40
.550-3.36
.600-3.21
.650-3.06
.700-2.94
.750-2.91
.800-2.91
.850-2.88
.900-2.81
.950-2.69
1.00-2.61
1.05-2.56
1.10-2.54
1.15-2.50
1.20-2.44
1.25-2.34
1.30-2.25
1.35-2.19
1.40-2.11
1.45-2.09
1.50-2.04
1.55-1.94
1.60-1.78
1.65-1.72
1.70-1.78

Ok my single typing finger needs a rest now!!! Mike

 

[Blazer406]

Ok here ya go again!!

.000-0
.050-.71
.100-1.85
.150-2.58
.200-2.95
.250-2.97
.300-2.94
.350-2.81
.400-2.92
.450-3.19
.500-3.40
.550-3.36
.600-3.21
.650-3.06
.700-2.94
.750-2.91
.800-2.91
.850-2.88
.900-2.81
.950-2.69
1.00-2.61
1.05-2.56
1.10-2.54
1.15-2.50
1.20-2.44
1.25-2.34
1.30-2.25
1.35-2.19
1.40-2.11
1.45-2.09
1.50-2.04
1.55-1.94
1.60-1.78
1.65-1.72
1.70-1.78

Ok my single typing finger needs a rest now!!! Mike

scratch that for a min..... I did it wrong....

 

[Alky V6]

And G-force.

edit: Correction to your tire slip numbers. 18, 6, and 3. I also increased the torque multiplier for the TC by .05. That got me right on a 3.4 G at the hit. 156' at the 1.688 sec mark, with the 1.8 gear. 204' at the 2.016 sec mark and 8040 rpm with the 1.69 gear.

Trying to match that G-force curve put a monkey wrench in things. Hold on. Tire slip may not be as bad as I thought.

 

[Blazer406]

Trying to match that G-force curve put a monkey wrench in things. Hold on. Tire slip may not be as bad as I thought.

I zigged when I should have zagged.... still trying to figure out how to get a distance based on the average g-force during the first 1.7 sec....

When you don't use this stuff everyday... it gets rusty....... I'm just trying to find the WD-40 so I can get some of this stuff freed up......

 

[Alky V6]

I'm starting to think that 3.4 G is a spike value that wouldn't really come into play if the tire slip was more smooth throughout the launch.
It appears you had a fair amount of tire slip and momentum in the tires built up just before the tires grabbed to give you that 3.4 G value. Am I off on my thinking?
I'm having to put in a lot of HP into the sim to start to even get close to that 3.4 G number and it's throwing all the other numbers way off. I'm going to start backing out the hp to get my other matches back, and I'll have to settle for a more average G number.

 

[BlownV6]

I'm starting to think that 3.4 G is a spike value that wouldn't really come into play if the tire slip was more smooth throughout the launch.
It appears you had a fair amount of tire slip and momentum in the tires built up just before the tires grabbed to give you that 3.4 G value. Am I off on my thinking?
I'm having to put in a lot of HP into the sim to start to even get close to that 3.4 G number and it's throwing all the other numbers way off. I'm going to start backing out the hp to get my other matches back, and I'll have to settle for a more average G number.

Im sure there is some energy that gets transfered from the tire speed(spinning) to when it starts hooking and does defenetly accelerate the car and add to that spike. I have had runs that didnt have as much slip and still had around 3.2gs anyway. Mike

 

[Alky V6]

Im sure there is some energy that gets transfered from the tire speed(spinning) to when it starts hooking and does defenetly accelerate the car and add to that spike. I have had runs that didnt have as much slip and still had around 3.2gs anyway. Mike

There we go! That's what I was going to ask next. A good G number from a more stable launch. I was having a heck of time getting over a 3.2 G number for the .5 sec mark.
When in the timeline are you seeing the 3.2 G?

 

[BlownV6]

I cant really acuratly tell you because I dont have my old logs anymore , but it was in that .5 to .7 zone then starts falling back off. Mike

 

[Alky V6]

What is your time delay to full power and what is a more typical 60' time? Not looking for the best 60'. Just a more typical with a low tire slip (9-10%) launch.

 

[Alky V6]

I'm getting some high bhp here. How much do you figure you're losing to the blower?

 

[Alky V6]

Dusty, what kind of torque multiplication factor do you think we're working with here? Right now I'm using 1.7.

 

[BlownV6]

Dusty, what kind of torque multiplication factor do you think we're working with here? Right now I'm using 1.7.

Typically around .980 60', in real bad conditions it will still go 1.01.
The man that built the blower says it takes 400hp to turn the blower at the rpm &boost that Im at. Mike

 

[Alky V6]

Typically around .980 60', in real bad conditions it will still go 1.01.
The man that built the blower says it takes 400hp to turn the blower at the rpm &boost that Im at. Mike

The .980 will make things easier for me.
So add the 400hp to the bhp I'm getting now. Yikes. I can see why you're bending heads.

 

[Alky V6]

Time delay to full power?

 

[Blazer406]

When I use the 121.322 mph as a v final, I can calculate the average acceleration it takes to get to that speed in 1.7 sec. I get 104.67 ft/sec squared for the average acceleration (in this case.... and equivalent constant acceleration).

Now I use that "a" from above..... I can then calculate a displacement.

In summary, I came up with traveling 151.248' at the 1.7 sec mark.

When I try and use the different "G" values from the datalog..... I only come up with a V final (@ 1.7 sec) of around 91 mph........ which doesn't look correct unless you are slipping the tires probably 25% or so..... which doesn't seem reasonable to me.

Below is a screenshot of the calcs.

 

[Alky V6]

Wow, that's interesting. The current numbers I'm playing with are giving me 151' @ 8040 rpm. I'm having trouble extending it out to the 1.7 sec mark, though. 1.678 is about as close as I can get it, without more info. I wonder if the 1.7 sec mark is reasonable considering the time lost to extra tire slippage. I'm working with more avg factors here.

 

[Blazer406]

The more I look at it.... the more slip I think you have...... I'm wondering if a taller tire with more contact patch would help? Say.... a 36" tire?

If you are hitting high gear in 150' ...... you still got 1170' to go.... all in high gear!

 

[Alky V6]

The more I look at it.... the more slip I think you have...... I'm wondering if a taller tire with more contact patch would help? Say.... a 36" tire?

If you are hitting high gear in 150' ...... you still got 1170' to go.... all in high gear!

With the TC coupling the way it is to give him only 13% slippage by the top end, that is helping him out A LOT. It's like having a variable rearend gear ratio change through the top end.
With the current numbers I'm playing with, and figuring a .988 60' and 3.1 G launch, I'm seeing a max tire slip at the launch of 7%.