pneumo
20+ Year Contributor
- 3,763
- 61
- Oct 19, 2002
-
Bay Area,
California
Hi all! It's me again, the guy who went 11.98 @114.9 on a 14b with stock sidemount IC, stock injectors, and stock IC pipes. Now I have some real mods on the car and I'm shooting for a ten second timeslip, most likely deep tens.
Normally I wouldn't be so bold and make predictions like this except that something GOOD happened just the other day and I wanted to pass it along to see if it holds water.
First a little background: I had a total of 2 runs this season on the new setup, not much driving time under my belt. Here's the vid of the second, successful run. 11.3 @ 130 mph http://video.google.com/videoplay?docid=3123757668280571397 If you listen to the sound of my motor you can hear me back off the throttle in the middle of first gear. I did this to make sure the tires were hooked up. It's a good thing I did since the logger showed rpm drop back down at that point, indicating the wheels were spinning. It also took too long to get through first gear. The second thing you can hear is how slow I was shifting, the revs spike up at each shift. Obviously I wasn't pushing for my best time. Everything came to a halt at the end of the return lane when the tech inspector kicked me off the track for not having the proper safety gear. I didn't get a chance to really flog the car yet.
A few days ago I took the opporitunity to do a few baseline dyno pulls at the local and growing AWD dyno shop at Full Function Technology ( www.FFtec.com )
This was a VERY good thing!
The first pull was with the same tune I used to run 11.3@130, which netted 439Whp on a Mustang dyno. See first pic below. I read the log and poked the SAFC a few times between runs. The second pull netted 435Whp, but with a broader, flatter powerband.
I was very pleased with the power gains at 6k and 8500rpms. I didn't mind seeing a few peak HP dissapear since the dyno room was getting hotter with my car idling in it. I didn't make any adjustments at 7k rpm, so I figure the slight loss was due to the heat. It was soo nice to see an immediate difference from slight changes in the tune. I'm definately going back again for more dyno pulls, and next time I'm bringing my laptop and Ostrich!
The other reason I'm really excited about this is because my datalogs show I was shifting around 7800rpm during the 11.3 run! My car is holding near peak power all the way up to 8500! Holycrapolie I had no idea my mods were flowing so good.
So where should I shift?
A quick trip to www.f-body.org/gears/ allowed me to see how low the rpms fall at each shift. Here's a quick copy-paste of a speed-in-gear chart for a 1G AWD. For the gear ratios and final drive ratios of other model DSM's, goto www.VFAQ.com/mods/Trannies.html
rpm 1st 2nd 3rd 4th
4500 22 40 61 81
4600 22 41 62 83
4700 23 42 63 85
4800 23 43 65 87
4900 24 44 66 88
5000 24 45 67 90
5100 25 46 69 92
5200 25 46 70 94
5300 26 47 71 96
5400 26 48 73 97
5500 27 49 74 99
5600 27 50 75 101
5700 28 51 77 103
5800 28 52 78 105
5900 29 53 80 106
6000 29 54 81 108
6100 30 54 82 110
6200 30 55 84 112
6300 31 56 85 114
6400 31 57 86 115
6500 32 58 88 117
6600 32 59 89 119
6700 33 60 90 121
6800 33 61 92 123
6900 34 62 93 124
7000 34 62 94 126
7100 35 63 96 128
7200 35 64 97 130
7300 36 65 98 132
7400 36 66 100 134
7500 37 67 101 135
7600 37 68 102 137
7700 38 69 104 139
7800 38 70 105 141
7900 39 71 106 143
8000 39 71 108 144
8100 39 72 109 146
8200 40 73 111 148
8300 40 74 112 150
8400 41 75 113 152
8500 41 76 115 153
To figure it out just look at how fast the car is going in first gear at 8k rpm (39mph) then look at the same mph in the second gear column. answer- 4500rpm. I shifted from 2nd to 3rd at 7800rpm and the rpms droped to 5200. Looking at the dyno chart at 5200rpm the turbo is just barely spooled up! I was loosing power, speed, and time by shifting so early. Next time out I'm going to shift much higher.
Here's where I could use some input. Based on my dyno charts, where should I shift? I plan to try shifting 1>2 at 9k (rpms drop to 5200), 2>3 at 8700 (rpm drops to 5800), and 3>4 at 8k (rpm drop to 6k). The reason I'm asking is because the speed-in-gear chart doesn't take into account the torque multiplication of different gear ratios, so the power getting to the ground will decrease with higher gears. Anyone know how to factor that in?
Any other input is welcome!
Normally I wouldn't be so bold and make predictions like this except that something GOOD happened just the other day and I wanted to pass it along to see if it holds water.
First a little background: I had a total of 2 runs this season on the new setup, not much driving time under my belt. Here's the vid of the second, successful run. 11.3 @ 130 mph http://video.google.com/videoplay?docid=3123757668280571397 If you listen to the sound of my motor you can hear me back off the throttle in the middle of first gear. I did this to make sure the tires were hooked up. It's a good thing I did since the logger showed rpm drop back down at that point, indicating the wheels were spinning. It also took too long to get through first gear. The second thing you can hear is how slow I was shifting, the revs spike up at each shift. Obviously I wasn't pushing for my best time. Everything came to a halt at the end of the return lane when the tech inspector kicked me off the track for not having the proper safety gear. I didn't get a chance to really flog the car yet.
A few days ago I took the opporitunity to do a few baseline dyno pulls at the local and growing AWD dyno shop at Full Function Technology ( www.FFtec.com )
This was a VERY good thing!
The first pull was with the same tune I used to run 11.3@130, which netted 439Whp on a Mustang dyno. See first pic below. I read the log and poked the SAFC a few times between runs. The second pull netted 435Whp, but with a broader, flatter powerband.
I was very pleased with the power gains at 6k and 8500rpms. I didn't mind seeing a few peak HP dissapear since the dyno room was getting hotter with my car idling in it. I didn't make any adjustments at 7k rpm, so I figure the slight loss was due to the heat. It was soo nice to see an immediate difference from slight changes in the tune. I'm definately going back again for more dyno pulls, and next time I'm bringing my laptop and Ostrich! The other reason I'm really excited about this is because my datalogs show I was shifting around 7800rpm during the 11.3 run! My car is holding near peak power all the way up to 8500! Holycrapolie I had no idea my mods were flowing so good.
So where should I shift?
A quick trip to www.f-body.org/gears/ allowed me to see how low the rpms fall at each shift. Here's a quick copy-paste of a speed-in-gear chart for a 1G AWD. For the gear ratios and final drive ratios of other model DSM's, goto www.VFAQ.com/mods/Trannies.html
rpm 1st 2nd 3rd 4th
4500 22 40 61 81
4600 22 41 62 83
4700 23 42 63 85
4800 23 43 65 87
4900 24 44 66 88
5000 24 45 67 90
5100 25 46 69 92
5200 25 46 70 94
5300 26 47 71 96
5400 26 48 73 97
5500 27 49 74 99
5600 27 50 75 101
5700 28 51 77 103
5800 28 52 78 105
5900 29 53 80 106
6000 29 54 81 108
6100 30 54 82 110
6200 30 55 84 112
6300 31 56 85 114
6400 31 57 86 115
6500 32 58 88 117
6600 32 59 89 119
6700 33 60 90 121
6800 33 61 92 123
6900 34 62 93 124
7000 34 62 94 126
7100 35 63 96 128
7200 35 64 97 130
7300 36 65 98 132
7400 36 66 100 134
7500 37 67 101 135
7600 37 68 102 137
7700 38 69 104 139
7800 38 70 105 141
7900 39 71 106 143
8000 39 71 108 144
8100 39 72 109 146
8200 40 73 111 148
8300 40 74 112 150
8400 41 75 113 152
8500 41 76 115 153
To figure it out just look at how fast the car is going in first gear at 8k rpm (39mph) then look at the same mph in the second gear column. answer- 4500rpm. I shifted from 2nd to 3rd at 7800rpm and the rpms droped to 5200. Looking at the dyno chart at 5200rpm the turbo is just barely spooled up! I was loosing power, speed, and time by shifting so early. Next time out I'm going to shift much higher.
Here's where I could use some input. Based on my dyno charts, where should I shift? I plan to try shifting 1>2 at 9k (rpms drop to 5200), 2>3 at 8700 (rpm drops to 5800), and 3>4 at 8k (rpm drop to 6k). The reason I'm asking is because the speed-in-gear chart doesn't take into account the torque multiplication of different gear ratios, so the power getting to the ground will decrease with higher gears. Anyone know how to factor that in?
Any other input is welcome!
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30. I was worried that I still wouldn't have enough power to get into the tens. Going from 11.3 to 10.9 is a big jump! Could raised shiftpoints alone get the job done?
BTW I'm car #64, right lane. I wonder what mph it could've hit if the clutch held all the way through 4th? Stay tuned!