Hammer Down

Is 1706 at 9pm not a good thing?

mthis

its noot good,

same track summer time i ran 12.8 with my car and winter time i ran a 12.4,
the diff was +3500DA to +700DA

MB_Forever

-1706 would be a lot better

Marcus Frost

At -1706 you'd have to push the car down the track because any attempt to launch it would probably put it into a wall.

There is such thing as bad negative DA as well...

-m

hooleyboy

IMO 1700ft is not a bad DA, considering its the summer. My best run to date was at about 1700ft DA and coming along with that was a 1.56 60ft.

There are times in the winter (our race season) and we dont even get that good. Let it be noted that its also depends on the tracks actual elevation too. Speedworld in AZ is like 1300ft above sea level.


For me 1700ft seems do-able.

JAYCL600

not only traction issues in serious neg DA, but aerodynamic drag increases enough to negate the HP increases

Hammer Down

The reason why I ask is that Friday night at Sac it was 1706 @ 9pm. I hope that this Friday is cooler than last Friday.

bassn_07

1700 isn't bad at all but it's also not the best. I'm fairly new to the sport and so far from what I've seen the lower the DA the better. I could almost guarantee that if we get a -1000 DA day here at Sacramento our cars would be fast. We might need to do longer burnouts and stage as fast as possible to keep the tires from cooling but with a little practice and some adjustments we should do well.

Lets just hope for the best and deal with what we get. If we get somewhere in the mid 80's we should be good because days are getting shorter and nights cooling down quicker.

Mikesamg

It's already a lot cooler today then it was yesterday and this whole 100+ weekend. We should be good even when it was 100 two weeks ago it cooled down fast come 9pm. When Alan ran his 11.2 the high for the day was 96 and come 9-10pm it cooled down into the 70s. I'm keeping my fingers crossed for a cooler day.

Marcus Frost

Excellent point... air density is a big part of DA and the lower the DA, the higher the air density... the higher the air density... the more drag, just as you said. There seems to be a perception here that the lower the DA the better, and it's just not the case.

In my experience, somewhere between 500-1000 DA is best for running a good ET and pulling good trap speeds...

-m

Hammer Down

So if we can end up with 500-1000, it should be a pretty good night

bassn_07

I really hope I get a -1000 DA day here so I could come back to this thread and post my times just to give Marcus *****...lol. Last year at Sacramento with just a VR600 and street tires I ran a 11.5 with -500 DA or so, I can't remember the exact number but it was below sea level.

I could be totally wrong on this but I would be willing to bet I will run faster and quicker when the weather cools....no doubt. I'm not talking about below freezing temps but just some good solid low 50's temps.

hooleyboy

I just want one shot at running in neg DA. There are race tracks that get in the neg DA and are slightly down hill. Thats going to give you a nice time for sure. What I would give for that.

Remember this: most tracks dont do any track prep before a race day. Unless there are stupid fast cars that track prep becomes a safety issue.

My rule of thumb is: Your burnout should be long and hot, Get both tires spinning. When you pull to the line your tires should still have some smoke coming from them. You will hookup on a non-prepped track if you do it this way with slicks.