Show us your 60-125mph or 100-200kph times!
#21
I have very similar results at the drag strip. Calculator shows I can go through the traps at a lower rpm than what I am actually getting. I suspect there are several factors causing this. A slight slipping of the clutch, tires, and perhaps some tire distortion? Don’t know for sure, but it’s definitely a thing.
#22
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All I really have to go on is gearing calculator. The speedo in my car is not at all accurate and I wouldn't trust it anyway if it was. I do know that the gear calculator is pretty accurate (at least at normal driving speeds). I do not think my tires are standing up at 120mph. Maybe big balloon drag tires, but not R1Rs.
I ran another test but started in 3rd which was stupid because I was half way through the power band at 60mph with my little turbo. This run I started at about 50mph so I had a rolling start through 60. I lost a ton of time with a 1.0s and 1.2s (3-4 and 4-5) shifts. 14.5 seconds 60-125. So it does validate my first time I got, or at least, the time I got from X speed to X speed. Since I don't have anything better to datalog with, this is about the best I can do.
I ran another test but started in 3rd which was stupid because I was half way through the power band at 60mph with my little turbo. This run I started at about 50mph so I had a rolling start through 60. I lost a ton of time with a 1.0s and 1.2s (3-4 and 4-5) shifts. 14.5 seconds 60-125. So it does validate my first time I got, or at least, the time I got from X speed to X speed. Since I don't have anything better to datalog with, this is about the best I can do.
#23
All I really have to go on is gearing calculator. The speedo in my car is not at all accurate and I wouldn't trust it anyway if it was. I do know that the gear calculator is pretty accurate (at least at normal driving speeds). I do not think my tires are standing up at 120mph. Maybe big balloon drag tires, but not R1Rs.
I ran another test but started in 3rd which was stupid because I was half way through the power band at 60mph with my little turbo. This run I started at about 50mph so I had a rolling start through 60. I lost a ton of time with a 1.0s and 1.2s (3-4 and 4-5) shifts. 14.5 seconds 60-125. So it does validate my first time I got, or at least, the time I got from X speed to X speed. Since I don't have anything better to datalog with, this is about the best I can do.
I ran another test but started in 3rd which was stupid because I was half way through the power band at 60mph with my little turbo. This run I started at about 50mph so I had a rolling start through 60. I lost a ton of time with a 1.0s and 1.2s (3-4 and 4-5) shifts. 14.5 seconds 60-125. So it does validate my first time I got, or at least, the time I got from X speed to X speed. Since I don't have anything better to datalog with, this is about the best I can do.
The shifts kill the time, just roll out in 5th long pull. Trust me bro
#26
Start in 5th like I said way before 60. Then when you roll through it you're already in boost. I'm not sure if this list is supposed to be hit the gas at 60 and count from that point, I would lose time waiting on spool. I do a lot of tuning on my car with 5th gear pulls because it gives you really good data, so I literally have like 20 logs to pick from. 7 seconds seems crazy fast but my car isn't slow either. I like this more people need to hop in this
#32
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Somehow what I wrote got deleted. Anyway.
Rolling through 3500rpm(60mph) to 7000rpm(125mph). Not sure how much more i'm going to get out of a 2560 at 12psi. I could add boost, but I blow out spark in the higher RPM with the stock coils. And my duty cycle gets spicy with more boost. E85 life. It seems to be at full steam around 3500rpm in 5th.
What do we think? Add more timing? It's at like 15* now. Maybe 17* at this lower boost. This engine is kind of high compression, I don't want to push it.
Rolling through 3500rpm(60mph) to 7000rpm(125mph). Not sure how much more i'm going to get out of a 2560 at 12psi. I could add boost, but I blow out spark in the higher RPM with the stock coils. And my duty cycle gets spicy with more boost. E85 life. It seems to be at full steam around 3500rpm in 5th.
What do we think? Add more timing? It's at like 15* now. Maybe 17* at this lower boost. This engine is kind of high compression, I don't want to push it.
#33
Somehow what I wrote got deleted. Anyway.
Rolling through 3500rpm(60mph) to 7000rpm(125mph). Not sure how much more i'm going to get out of a 2560 at 12psi. I could add boost, but I blow out spark in the higher RPM with the stock coils. And my duty cycle gets spicy with more boost. E85 life. It seems to be at full steam around 3500rpm in 5th.
What do we think? Add more timing? It's at like 15* now. Maybe 17* at this lower boost. This engine is kind of high compression, I don't want to push it.
Rolling through 3500rpm(60mph) to 7000rpm(125mph). Not sure how much more i'm going to get out of a 2560 at 12psi. I could add boost, but I blow out spark in the higher RPM with the stock coils. And my duty cycle gets spicy with more boost. E85 life. It seems to be at full steam around 3500rpm in 5th.
What do we think? Add more timing? It's at like 15* now. Maybe 17* at this lower boost. This engine is kind of high compression, I don't want to push it.
#35
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Edit* this car is kind of built just to thrash. Just rip it at every opportunity. I could do endless 60-125 rips until I ran out of gas if I wanted. So it's tuned rather safe. I'd also be far more confident if I had a knock sensor.
Last edited by Erat; 09-06-2020 at 05:47 AM.
#36
Regarding beeng faster with using only fifth gear, just do the math of average HP from 3500 to 7000 vs 5500 to 7000, there's no way your faster with single speed run, even adding 0,25s to a shift.
That last table only shows how diferent 400hp are different in different countrys, i have a 400hp miata faster than a 997TT, 18PSI is faster than a veyron with the "same" 400hp.
#37
I was really looking forward to the discussion we are having here. Good points were made.
If anyone has a dragy or driftbox, please let us know and post your setup.
For the guys, who can only take datalogs (including me), we should make 1:1 gear runs from say 2000rpm to fully spool even the laggiest setups and compare from there.
My run posted above was 50mph all the way to redline at 7300rpm in my 1:1 gear and a 4.1 diff.
Please go on guys, I like where this goes
edit:
We should all buy dragys and keep it at 60-125mph
If anyone has a dragy or driftbox, please let us know and post your setup.
For the guys, who can only take datalogs (including me), we should make 1:1 gear runs from say 2000rpm to fully spool even the laggiest setups and compare from there.
My run posted above was 50mph all the way to redline at 7300rpm in my 1:1 gear and a 4.1 diff.
Please go on guys, I like where this goes
edit:
We should all buy dragys and keep it at 60-125mph
Last edited by der_vierte; 09-07-2020 at 01:15 PM.
#38
I was really looking forward to the discussion we are having here. Good points were made.
If anyone has a dragy or driftbox, please let us know and post your setup.
For the guys, who can only take datalogs (including me), we should make 1:1 gear runs from say 2000rpm to fully spool even the laggiest setups and compare from there.
My run posted above was 50mph all the way to redline at 7300rpm in my 1:1 gear and a 4.1 diff.
Please go on guys, I like where this goes
edit:
We should all buy dragys and keep it at 60-125mph
If anyone has a dragy or driftbox, please let us know and post your setup.
For the guys, who can only take datalogs (including me), we should make 1:1 gear runs from say 2000rpm to fully spool even the laggiest setups and compare from there.
My run posted above was 50mph all the way to redline at 7300rpm in my 1:1 gear and a 4.1 diff.
Please go on guys, I like where this goes
edit:
We should all buy dragys and keep it at 60-125mph
Last edited by Newaza; 09-07-2020 at 03:14 PM.
#39
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Ok, I measured my wheel radius with a yard stick on my crappy uneven garage floor and it is almost 11". That gives roughly 22" diameter, a bit different from the 23.1" on the calculator. If I use a 43 series tire in the calculator I get 21.9. This works much better, nope I can't do 125 in 5th.
#40
Hey Andy I just looked at you head replacement video. On that video you "timed" 60-120 in 5.8 seconds. After watching that I have to agree with kamel6k that you may want to check your logging software speed against a gps. I'm still a firm believer in the dragy data though against most other forms of diy measurements for performance metrics. I've tested the dragy, the g-tech (older version), and the perfexpert app. (its a paid app) while at the track. The dragy was by far consistently the most accurate to timeslips from the track, and yes you would trust the timers at a nhra sanctioned track over other forms of diy timing measurement. Prize money is on the line so it has to be accurate. The dragy is also the only one that I've tested so far that shows road slope. If money is tight The perfexpert app wasn't too terrible. The perfexpert did require a little practice to get the start sensitivity correct for the most accurate results. It also was the least accurate of the three a tried so far. The perfexpert app consistently displayed a higher trap speed by several mph in the 1/8th than track slip. However once you set it up right the 0-60mph measurement was usually within a couple tenths(perfexpert usually displayed 1 to 2 tenths quicker) of the others, so not great but not horrible either considering the price.