UKZR1
08-16-2009, 07:47 AM
Thought this would be interesting -
For the first time ever I did some drag racing this year -
I've not been happy with my car all year. I've been disappointed with the drag times and particularly the terminal speeds from the start at Shakey (12.7 116Mph) right through to the Mopars at the pod (13.03 109mph) Its not just been on the strip either, I had noticed a distinct lack of pull in 4th from 6500 upwards and then there has been its thirst this year. Its always been thirsty but that's down to the mods and my heavy right foot but this year has been a joke. This was highlighted on the recent trip to Holland when I travelled with other Vettes I was filling a full tank when others didn't even need fuel!!
Having never dragged the car before I had no benchmark to compare it to. It hit home that something was a miss at the Mopars when I watched a couple of Vipers run. Only last September I drag raced some Vipers down a German runway whilst on a Viper trip. I won each race by quite a margin. Unfortunately there was no electronic timing gear so again I still had no bench mark. I did have video of the runs and my Shakey runs. I compared the time spent in 2nd and 3rd gear on the runs on the video - over a second more in third every time.
The only thing I had done over the winter was changed out the injectors (Accels) (4 leaking stock injectors). I had tried to connect my scanner after Shakey but couldn't get the vehicle to respond. I persevered last week and got it working. Whilst the left bank was running great you could see the ECM was significantly reducing fuel to the right bank. I suspected a problem with the new injectors. I pulled the plenum Friday night with a view to fitting the stock ones to see what that would change. As soon as I pulled the plenum the problem was obvious.
Each of the butterfly's on the Right bank were very slightly open and the ports on the plenum side of the valves coked up. On inspection I found the arm that operates the valves had come off. So whilst the left bank was running full power the right had 8 extra injectors trying to dump fuel with nowhere to go and no extra air. The ECM handled this amazingly well. I removed all 8 plugs and all were exactly the same colour - the right colour. The car was also MOT'd in this state and the emissions were spot on.
I pulled the battery to reset the fuel tables and by the time I got on the M1 it was clear the car was running smoother. The mpg was better and still improving. My best run of the day was 12.38 @ 118mph with a very strong headwind. Previously I couldnt get out the 13's at this slightly up hill track.Im running very tired Goodyear F1's btw
Its a shame it took me so long to sort it out and also a shame the car wasn't running strong in the other rounds. However if I didn't take part in the previous rounds the extent of the problem may never have been highlighted. I now have a benchmark of how the car should run. Interestingly I finally dug out the Gtech Pro Nutz got me a couple of years back. The cars been weighed previously so I had a pretty accurate weight entered in. I only actually remembered to stage it the once yesterday and it got my ET within 1/100 of a second and over read my terminal speed by less than 1/2mph. very impressed.
After the last 2 visits to the Pod I had had enough with this drag racing lark. Felt like you just spent the day pushing your car about for hours queuing but yesterday was fantastic, no real queues all day. A dam shame about the wind though. All I need to do now is work out how I did a 1.9 sec 60' at Shakey and replicate that every run instead of the near 2,1/2 secs I usually do. That should see me into the 11's.
My best run of the whole series must be the run with C5Blow yesterday. Time wise it wasn't the best for either of us but we were side by side the whole way up the strip. Both are loud cars it must have been good to watch. I'm hoping Kerensa has it on video. Just to show how side by side we were here are my times
60' 2.3645
330 5.7249
1/8 8.4551 @ 91.79
1000' 10.7308
1/4 12.7375 @ 116.56
..and Daves
60' 2.3632
330 5.7927
1/8 8.5431 @ 90.52
1000' 10.7757
1/4 12.7820 @ 116.70
For the first time ever I did some drag racing this year -
I've not been happy with my car all year. I've been disappointed with the drag times and particularly the terminal speeds from the start at Shakey (12.7 116Mph) right through to the Mopars at the pod (13.03 109mph) Its not just been on the strip either, I had noticed a distinct lack of pull in 4th from 6500 upwards and then there has been its thirst this year. Its always been thirsty but that's down to the mods and my heavy right foot but this year has been a joke. This was highlighted on the recent trip to Holland when I travelled with other Vettes I was filling a full tank when others didn't even need fuel!!
Having never dragged the car before I had no benchmark to compare it to. It hit home that something was a miss at the Mopars when I watched a couple of Vipers run. Only last September I drag raced some Vipers down a German runway whilst on a Viper trip. I won each race by quite a margin. Unfortunately there was no electronic timing gear so again I still had no bench mark. I did have video of the runs and my Shakey runs. I compared the time spent in 2nd and 3rd gear on the runs on the video - over a second more in third every time.
The only thing I had done over the winter was changed out the injectors (Accels) (4 leaking stock injectors). I had tried to connect my scanner after Shakey but couldn't get the vehicle to respond. I persevered last week and got it working. Whilst the left bank was running great you could see the ECM was significantly reducing fuel to the right bank. I suspected a problem with the new injectors. I pulled the plenum Friday night with a view to fitting the stock ones to see what that would change. As soon as I pulled the plenum the problem was obvious.
Each of the butterfly's on the Right bank were very slightly open and the ports on the plenum side of the valves coked up. On inspection I found the arm that operates the valves had come off. So whilst the left bank was running full power the right had 8 extra injectors trying to dump fuel with nowhere to go and no extra air. The ECM handled this amazingly well. I removed all 8 plugs and all were exactly the same colour - the right colour. The car was also MOT'd in this state and the emissions were spot on.
I pulled the battery to reset the fuel tables and by the time I got on the M1 it was clear the car was running smoother. The mpg was better and still improving. My best run of the day was 12.38 @ 118mph with a very strong headwind. Previously I couldnt get out the 13's at this slightly up hill track.Im running very tired Goodyear F1's btw
Its a shame it took me so long to sort it out and also a shame the car wasn't running strong in the other rounds. However if I didn't take part in the previous rounds the extent of the problem may never have been highlighted. I now have a benchmark of how the car should run. Interestingly I finally dug out the Gtech Pro Nutz got me a couple of years back. The cars been weighed previously so I had a pretty accurate weight entered in. I only actually remembered to stage it the once yesterday and it got my ET within 1/100 of a second and over read my terminal speed by less than 1/2mph. very impressed.
After the last 2 visits to the Pod I had had enough with this drag racing lark. Felt like you just spent the day pushing your car about for hours queuing but yesterday was fantastic, no real queues all day. A dam shame about the wind though. All I need to do now is work out how I did a 1.9 sec 60' at Shakey and replicate that every run instead of the near 2,1/2 secs I usually do. That should see me into the 11's.
My best run of the whole series must be the run with C5Blow yesterday. Time wise it wasn't the best for either of us but we were side by side the whole way up the strip. Both are loud cars it must have been good to watch. I'm hoping Kerensa has it on video. Just to show how side by side we were here are my times
60' 2.3645
330 5.7249
1/8 8.4551 @ 91.79
1000' 10.7308
1/4 12.7375 @ 116.56
..and Daves
60' 2.3632
330 5.7927
1/8 8.5431 @ 90.52
1000' 10.7757
1/4 12.7820 @ 116.70