| Author | Message | ||
     Ohsoslow |
i now know what a huge impact it can have on times and trap speed. made it back out to the strip again last night with some friends, no matter how hard i tried i couldnt get back into the 10's, my best run is 10.77 @129, last night best i could hit was a 11.09 @124. my 60ft's were much better last night mid 1.7's up to low 1.8s compared to high 1.9's the first time out. still had a great time, my buddy with a nitrous kawasaki concours (40 shot) fried his clutches after the 6th pass of the night. | ||
| Williep13 |
Air quality plays a huge factor in your ET seems to be especially sensitive with fuel injected bikes. If your your running the same set up you were running last year and you took a tenth off your 60' that should pick up your ET by at least 2-3 tenths so the air must have been real bad. To compensate for bad air I will gear lower to get better 60' ft because it's not going to be pulling on the top end any how so its a waste of gear to leave any out there for it. Just my two cents. | ||
| J2blue |
I can vouch for that. After running 4 nights at our local drags(as a newbie) I noticed without fail my best times came at the end of the night when the air temp was 20 degrees cooler than when the first run began. Humidity usually goes up during that same time, though. One night I experienced the drop in atmospheric pressure a distant storm created and was amazed at how quickly everyone's times were affected. | ||
| Ohsoslow |
yup! i was disappointed with my E.T.'s and trap speeds so i went home and pulled out my old slips and realized that my 60ft times were much better and could only think one thing, that the air was poor on this day. williep, my bike (1125cr) is stock except for an exhaust and E B r ECM, running the same exact setup as i was last time. | ||
| Hybridmomentspass |
Yes, air makes a huge difference. There are certain tracks where I usually can run a good number, and some tracks where I am always off Willie - Thats a good idea, never thought of that, I only have one rear sprocket now, maybe I should look into one or two more to keep with me | ||
| Williep13 |
The altitude and atmospheric pressure is what has the effect. Humidity can effect the performance of the bike but the atmospheric pressure is what will cause your bike to slow down or speed up a couple tenths within a couple hours. Atmospheric pressure in it's simplest form is essentially the weight of the air. The heavier the air the harder it is to cut through it slowing you down. At higher elevation's the air is thicker creating more atmospheric pressure (Garrett- This is why Bristol is 2-3 tenths slower). J2blue- That is typical to have your best times at the end of the night when temps are down and the air starts getting still. That's why people love evening and night qualifying. Ohsoslow- I wouldn't be disappointed drag racing is all in the 60 ft' everything after that is just a bonus. It's hard to get extremely fast times in the summer unless your just there on one of those good days. Garret- I have a whole range of gears. I am pretty sure your running a 19/51 most the AHDRA guys are in the index classes it is a good idea to have more than a couple gears. I run a 20/50 usually unless the track is crap I will run a 19 to help my 60 ft. I have 49-53 and then 19-21. | ||
| Hybridmomentspass |
You nailed it, 19/51. I want to get a tooth each way on the rear sprocket. And then build a lift where I can keep my bars on, while pulling the rear wheel. Gears are just so expensive though, like 50-60 bucks each, two more gears is 120 bucks. But no, that is part of the plan, to play with gearing more. Plus with this motor build it will change things up a little (diff cams), putting power at different spot. Yeah, Bristol is such a nice track, I love going to race there, but Im always 2 tenths off there no matter what. Sucks. | ||
| Williep13 |
The front sprockets are cheaper and its like going about 3 1/2 on the back which is a good jump but you could try a 20 you might like it. I was running a 50 on the back last weekend at Atco and went to a 51 and droppped my ET by a tenth. Because of track conditions I could have probably went to a 52 and and got more out of it. With your new motor you may want to play around with gears more to see where your getting the best of it at the top end or on your 60'. My gears should work if you want to try them at Bristol to get idea of what you want before you buy them. | ||
| Hybridmomentspass |
what are you doing now about stabilizing the bike to swap gears etc? | ||
| Williep13 |
I normally take my lift to the track but if I don't have it I just use a scissor jack. |
