Angrey
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Thought I'd share some real world results that I've been steadily updating/modifying as I go with my car on a 60-130 pursuit of lower times.
First is the car on OE suspension setup and "street" or track focused tires. This is a Fourth Gear (1:1) rip all in the same gear. As you can see, the total torque output in the low rpm and speed area isn't enough to overwhelm traction but once it gets enough engine torque, the car maintains a fairly constant acceleration at the limits of what it can do with the tires spinning. This was me punching it in 4th, feeling/hearing the car labor and then feathering the throttle to keep it from totally running off, all in 4th gear. d torque output management or traction controls. This was prior to the MoTec and any sophisticated torque output or traction management. The dyno results at the time were around 1100 and 870, but we dialed back the timing 4 degrees so it was probably around 1000 rwhp and somewhere around 800 rwtq
This is the same day/conditions, but trying to start in 3rd, and shift to 4th. Keep in mind, the shift had to be gentle because the torque was just too much and would spin on the downshift with anything other than a granny shift. As you can see, it improves the low end, but adds the delay of the ginger shift, so a marginal loss of time between the two tradeoffs. Also, the run above and this run immediately below this, I tried to run around 22 psi and the tires spun on the rim and threw off the balance (evident on the drive home). These are 18" wheels and street tires.
This next run is after the MoTec. The Dyno output with the MoTec was 1125 and 750 rwtq. The tuner figured we were getting significantly less torque because they weren't ass aggressive with the lower timing and cam values, but created a nice table top 750 across nearly the entire rpm range. This is also with Nitto 555R2's at about 25 psi (as low as I could go without spinning the tire on the wheel and losing balance).
As you can see, I made an error in my calculations. I had setup the driveline so that I could do a full 60-130 rip in 3rd gear, with my RPM limit at 8500. However, I did not take into account the wheel spin that even the MoTec allows (an extra 3.5 mph on setting 1) so it was right at the top of the run that I would have to do a 4th gear shift and lose momentum.
As you can see, the 555 R2 did help the traction and forward grip, but because of the tire height and combination with the trans/diff, I couldn't make it without a shift. So on to the next phase which was 18" bead locks and MT SS.
The DA and weather were good, but as you can see we're still beyond what traction can actually use and put down. The car spins the entire run and the rear actually got a little out of shape during the run (something that surprised me that I hadn't experienced with the MoTec thus far). This is on 23 psi on the MT's. I'm told that if I lower the pressure to around 17 or 18, it will help significantly so that's the plan for my trip out. This is also on 800 ft-lb drag rate springs. The car with the MT's and the springs feels VERY floaty and soft like a water bed. Not sure how you drag focused guys drive around this way all the time. It feels like I'm trying to play basketball in a pair of crocs.
As you can see, the 4.82 run is again, spinning the entire way, it's at the absolute limit of what the car can physically accelerate forward before the traction breaks and spins. The MT SS (at 23 psi) helped marginally, but the real change between the 5.08 run and this was simply the removal of the shift at the end. With some crude calculations, it's pretty much what the 5.08 run on the 555 R2's would have been without the extra shift delay. The MT's are 29" tall so there's a slight loss of multiplied torque (which doesn't matter at this point because we're beyond traction anyway) but it allows me to do a rip all in 3rd gear from 60-130.
Interestingly, below is the 50-150 (which has the shift into 4th) and you can see from the 140-150 split, it's still making steam and did that section in 1.03 seconds. It's still eating at nearly half a G of acceleration at 140 mph.
Couple of final takeaways. I plan to lower the pressure and maybe try to add some heat to the MTSS's on the next outing to see if that helps, maybe get into the low 4's. Also I find it curious that these are such flat, constant acceleration. While it's unique, I'm wondering if I should "stab" the throttle just before the 60 mph mark instead of rolling through it. Maybe that will get the car to squat and help the low end acceleration for a bit. I'm not getting any additional weight transfer on the hit. I'm happy the car rips and honestly, the car is a bit scary for me at this point (even with the MoTec) because it just eats and eats and eats and continues to climbing like a madman.
It's obvious but worth pointing out that the same output on different wheel/tire/spring configurations has such an impact on how quick the car can accelerate. It's unlikely that even with all the torque and power available that I'm seeing the full output until very high triple digit speeds. Most of the motor's ability is wasted or choked to keep from spinning too badly at lower speeds. It's like driving around with a fire hose but only shooting a water gun because the traction just can't handle the full sauce.
First is the car on OE suspension setup and "street" or track focused tires. This is a Fourth Gear (1:1) rip all in the same gear. As you can see, the total torque output in the low rpm and speed area isn't enough to overwhelm traction but once it gets enough engine torque, the car maintains a fairly constant acceleration at the limits of what it can do with the tires spinning. This was me punching it in 4th, feeling/hearing the car labor and then feathering the throttle to keep it from totally running off, all in 4th gear. d torque output management or traction controls. This was prior to the MoTec and any sophisticated torque output or traction management. The dyno results at the time were around 1100 and 870, but we dialed back the timing 4 degrees so it was probably around 1000 rwhp and somewhere around 800 rwtq
This is the same day/conditions, but trying to start in 3rd, and shift to 4th. Keep in mind, the shift had to be gentle because the torque was just too much and would spin on the downshift with anything other than a granny shift. As you can see, it improves the low end, but adds the delay of the ginger shift, so a marginal loss of time between the two tradeoffs. Also, the run above and this run immediately below this, I tried to run around 22 psi and the tires spun on the rim and threw off the balance (evident on the drive home). These are 18" wheels and street tires.
This next run is after the MoTec. The Dyno output with the MoTec was 1125 and 750 rwtq. The tuner figured we were getting significantly less torque because they weren't ass aggressive with the lower timing and cam values, but created a nice table top 750 across nearly the entire rpm range. This is also with Nitto 555R2's at about 25 psi (as low as I could go without spinning the tire on the wheel and losing balance).
As you can see, I made an error in my calculations. I had setup the driveline so that I could do a full 60-130 rip in 3rd gear, with my RPM limit at 8500. However, I did not take into account the wheel spin that even the MoTec allows (an extra 3.5 mph on setting 1) so it was right at the top of the run that I would have to do a 4th gear shift and lose momentum.
As you can see, the 555 R2 did help the traction and forward grip, but because of the tire height and combination with the trans/diff, I couldn't make it without a shift. So on to the next phase which was 18" bead locks and MT SS.
The DA and weather were good, but as you can see we're still beyond what traction can actually use and put down. The car spins the entire run and the rear actually got a little out of shape during the run (something that surprised me that I hadn't experienced with the MoTec thus far). This is on 23 psi on the MT's. I'm told that if I lower the pressure to around 17 or 18, it will help significantly so that's the plan for my trip out. This is also on 800 ft-lb drag rate springs. The car with the MT's and the springs feels VERY floaty and soft like a water bed. Not sure how you drag focused guys drive around this way all the time. It feels like I'm trying to play basketball in a pair of crocs.
As you can see, the 4.82 run is again, spinning the entire way, it's at the absolute limit of what the car can physically accelerate forward before the traction breaks and spins. The MT SS (at 23 psi) helped marginally, but the real change between the 5.08 run and this was simply the removal of the shift at the end. With some crude calculations, it's pretty much what the 5.08 run on the 555 R2's would have been without the extra shift delay. The MT's are 29" tall so there's a slight loss of multiplied torque (which doesn't matter at this point because we're beyond traction anyway) but it allows me to do a rip all in 3rd gear from 60-130.
Interestingly, below is the 50-150 (which has the shift into 4th) and you can see from the 140-150 split, it's still making steam and did that section in 1.03 seconds. It's still eating at nearly half a G of acceleration at 140 mph.
Couple of final takeaways. I plan to lower the pressure and maybe try to add some heat to the MTSS's on the next outing to see if that helps, maybe get into the low 4's. Also I find it curious that these are such flat, constant acceleration. While it's unique, I'm wondering if I should "stab" the throttle just before the 60 mph mark instead of rolling through it. Maybe that will get the car to squat and help the low end acceleration for a bit. I'm not getting any additional weight transfer on the hit. I'm happy the car rips and honestly, the car is a bit scary for me at this point (even with the MoTec) because it just eats and eats and eats and continues to climbing like a madman.
It's obvious but worth pointing out that the same output on different wheel/tire/spring configurations has such an impact on how quick the car can accelerate. It's unlikely that even with all the torque and power available that I'm seeing the full output until very high triple digit speeds. Most of the motor's ability is wasted or choked to keep from spinning too badly at lower speeds. It's like driving around with a fire hose but only shooting a water gun because the traction just can't handle the full sauce.
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