Best run stock was 13.31@106mph with a 2.2 60 ft back in late March. Then I got the vararam on the car and ran on April 15th and went 13.05@107.65. Both of those nights had good air in negative DA I believe. Tonight I went out with full exhaust and a tune from HPTuners and I only went 13.26@107.20mph with a 2.1 60ft. What gives? I'm sure the air had a bit to do with it, but so much as for me to run terrible times. Here is how the weather was tonight.

Temperature: 76
Humidity: 80%
Pressure: 30.02 in.
Dew Point: 62°F



April 15th Tonights slip
60' 2.071 [] 2.153
330 5.636 [] 5.782
1/8 8.529 [] 8.709
MPH 84.78 [] 82.99
1000 10.980 [] 11.182
1/4 13.055 [] 13.362
MPH 107.65 [] 107.20

Why would my times and mph be so slow? Anyone have any ideas? Also, what would the DA have been tonight with

 

What RPM are you shifting at? That could be making a bit of a difference as your trap speed could be a tiny bit higher.I shift my 2000 FRC as the needle hits 6k (so it is executed before I hit the rev limiter)I have a bunch of 13.teens 108-109 with a best of 13.08/110.23.This is with a blackwing stock H pipe and corsa touring.G Y run flats coming out of the hole at about 2k with 2.1-2.2 60 ft .

 

Did you log any of your runs? Need to see how the fueling is when you enter WOT/PE or possiblr Knock retard. If trims are positive, PCM will add that amount of fuel, as well as the PE commanded AFR fuel requirementsw and car may be a bit rich. Also, look to see what is happening with the TPS. Make sure it is not being closed for any reasons like wheel spin. DId you turn off traction control?

If you can, post a copy of your tune or e-mail. I will take a look. Some times a second pair of eyes helps.

Ed

 

Dave,
Just go out another night before you get too worked up over the numbers. Just answer this simple question, does the car feel stronger?

I've been to Atco and run 12.89 with just a vararam. My buddies GTO was running 13.5 that day. Went on another night, with no changes to the car and best I could manage was 13.1, and my friend couldn't even make it into the 13's, pulling low 14's all night.

Air, track prep, and even a bit of luck all add up in your favor sometimes, against you at other times. Now, if you go another time and your getting consistant sucky results, than start to look at your tune.

Just let me know when your going down again and if it's after my break-in I'll try and meet ya.


Ed,
Very gracious for you to look at his tune, but Dave had a local tuner do the updates and would have to get the file from him.
I'm still thinking about buying a copy of HPTuners for my own use.

 

I'm gonna see if my tuner can take a look at the car tomorrow and we can do some street tuning to check things out. I wasn't able to log any runs last night because he had to go to a wedding. If things don't work out I guess I will take it to ECS or Cartek and see what they have to say. The car doesn't feel any stronger than when I had the headers on with a bad o2 sensor, and overall it feels just a tiny bit stronger. I think something is up....

 

Oh yeah, and I did have the exhaust leak fixed so there shouldn't be any issues there.

 

there's the problem. To get in the 12's... you almost have to get into the 1.9x range for the 60'.

I was able to do that with my 2002 A4... and got a 12.9x run on factory tires & the factory converter..

 

But even with full exhaust, vararam, and tune even a 2.2 should put me into a high 12 I would think. I thought if I cut a 1.9 60ft then I would go mid 12's with these mods I have. I had to move the front o2 sensors back about 12", but it hasn't set any codes. Think that may be a factor?

 

The air definitely slowed you down some. Just let us know when you go next time and maybe some of us will join you and shoot you tips or watch your runs.

 

no. During WOT - the C5's PCM ignores o2 sensor data.

 

Ok well I talked to my tuner and he said we will take the car to the track and data log the runs and make some changes. I might let him make a pass in my car to see what it is fully capable of.

 

MPH (trap speed) is the indicator of power....not ET.

In worse air (alot worse if you were negative D/A previously) you went almost the same MPH as your previous best. That means you are in fact making more power. As others have stated, ET improvements are mainly found in the bottom of the run (launch technique, available traction and track prep, and a little good (or bad) fortune).

What I find interesting is the fact you where down close to 2 MPH in your eighth mile times but made up most of that in the last half of the run. While the only way to know is to have logged the run, I think the warmer weather may have caused some slight knock events and the computer was pulling timing out the first half of the run slowly feeding it back in (thats what it does) during your trip down the back half of the run (hence the trap speed being almost the same). That could be from a tune that was maximized in cooler conditions when this type of thing wasn't a factor. It just might take a little less sensitivity in the knock sensors. All of this is purely hypothetical on my part but the bottom line is the more tools you have at your disposal (as you get more serious about this hobby), such as a scanning tool to data log the run....a wideband O2 sensor installed, etc. etc., its a lot easier to diagnose what may have happened.

Also, get a cheap weather station....they fit in your pocket and work great. No more guessing how good or how bad the air is on any given track outting. Once you get one you will feel naked at the track without it. They are only a couple of hundred dollars....makes a nice birthday gift or something from the wife....LOL
Kestral is the company that manufactures them....use Google search for more info....you can buy them on this country's favorite auction site as well.

Good luck with the car....a year from now and $5000 dollars later your next post will read "just missed getting into the elevens"

It never ends....may as well accept it and start buying the supporting "tools" you need to make your life easier now!

Cheers,
Tony

 

that's always good idea.

But I don't know how to put this any nicer... but your launches are just plain crappy. Your trap MPH says you are putting out -at least- factory HP... and with factory HP you can cut 1.9x to 2.0 60' times on factory tires.
A good "rule of thumb" is that for every tenth you shave off in the 60'... you'll likely get one-and-a-half times off at the end of the 1/4.

take your 13.31 with 2.2 60'...

if you lower your 60' by two tenths... that would equate to 3 tenths total off the 1/4... and would put you at 13.01 ET

Lower your 60' by 3 tenths and you'll then be in the 12.9x.

2.0 60' can be reached by any stock C5 on factory tires.

"Tunes" are always good But IMO your problem is elsewhere (in the launch).

 

I am fully aware of C5's being able to reach 2.0 60fts because I have done them. My best so far is 2.05 which is decent but not great. And I understand it will go faster with a better launch, just wanted it to go a little faster regardless of 60 ft.

 

I have seen a lot of success in the 1/4 if you can pull off a good start. My A4 was pulling 12's all day long with just exhaust and Callaway Honker. When I put on headers and Gears with a high stall convertor my time went back up because I couldn't start worth a damn (street tires). Bottom line, launch a bit harder if your car can handle it...otherwise get some drag radials.

 

i ran a 12.9 with a stock 2000 m6 on a nice day with normal tires.

ran a 12.5 with headers,xpipe, intake and tune.

ran a 12.2 with above mods and 4:10 gears.

car has potential with a drag radial burnout and great launch for high 11's.


the c5 is an amazing car

seat time and improved launches and shifts will aid you in what you are looking for too.


~ nick

 

Tony, thanks for the input. I will talk to my tuner and see what he says about the possibility of that being the problem. It would somewhat make sense considering the closeness of the 60ft times between the runs.