Went to the Strip. Trap Speed dropped

[SCalla1384]

Hey guys, so I went up to the strip with Nitto NT555R's. Only got in 3 runs. Had a terrible night, very very dissapointed. Had the Nittos at 27psi, launched at 2,500rpm and kind of feathered it.

Best 60 foot 2.42 I think I feathered the clutch way to long. So obviously need to improve on that. Not really worried to much about that.

Also, back in April when I had my Magnaflow with BBK o/r X I was trapping at high 103 low 104, last night was pretty cool out about 60 degrees and with the o/r Prochamber and SLP c/b my trap speed was only 101.8

Is it because the car needs a dyno tune? Did the BBK o/r X make that much of a differance over a Mac o/r Prochamber? MAF possibly dirty? Maybe a leak on the Intake side? Maybe just cooler air? But 2-3mph worth? Anyhelp is very appriciated, I was really dissapointed on my times, my best run was a 14.2 @ 101.83 with a 2.42 60foot Thanks for any help guys - Shaun

 

[sneaky98gt]

What were your 60s when you were trapping higher?

-Will

 

[Stan Weiss]

You ran 13.69 with the 104.29 with 2.26 60'. Maybe where did .5 (1/2) second of et go might be a better question.

 

[BlownStangGT]

First off, if you were running your nitto drag radials at 28, that was WAY to high. They would be down to 20psi or lower! Nitto's also need a good long burnout! Your trap speed might have went down because you were messing around at the start to much. Sometimes when you think you are feathering it off the line you are actullay coming out of the hole way to slow! Just go to the track and mess around. 3 passes will not give you enough experience. You need to learn to launch on those drag radials!

 

[peepeeskillz]

First off, if you were running your nitto drag radials at 28, that was WAY to high. They would be down to 20psi or lower! Nitto's also need a good long burnout! Your trap speed might have went down because you were messing around at the start to much. Sometimes when you think you are feathering it off the line you are actullay coming out of the hole way to slow! Just go to the track and mess around. 3 passes will not give you enough experience. You need to learn to launch on those drag radials!

i think the nitto 555r is the regular tire and not the drag radial, i may be wrong

 

[Mike97gt]

Hey guys, so I went up to the strip with Nitto NT555R's. Only got in 3 runs. Had a terrible night, very very dissapointed. Had the Nittos at 27psi, launched at 2,500rpm and kind of feathered it.

Best 60 foot 2.42 I think I feathered the clutch way to long. So obviously need to improve on that. Not really worried to much about that.

Also, back in April when I had my Magnaflow with BBK o/r X I was trapping at high 103 low 104, last night was pretty cool out about 60 degrees and with the o/r Prochamber and SLP c/b my trap speed was only 101.8

Is it because the car needs a dyno tune? Did the BBK o/r X make that much of a difference over a Mac o/r Prochamber? MAF possibly dirty? Maybe a leak on the Intake side? Maybe just cooler air? But 2-3mph worth? Anyhelp is very appriciated, I was really dissapointed on my times, my best run was a 14.2 @ 101.83 with a 2.42 60foot Thanks for any help guys - Shaun

For future runs remember to log all weather data so you can accurately tell what is going on..

without knowing the temp,baro and humidty for either the 104 run or the 101 run it's impossible to know what is going on..

Even if temps are the same if you had really high baro pressure the night you ran 104 and low baro when you ran 101 that is some of the difference right there..


If you still have the dates and times from those runs you can go to Welcome to Weather Underground : Weather Underground and find the closest weather station to the track and look under the history for that day and they have a breakdown of the entire day... Most weather stations update every 15 minutes or so and all of this is logged on the site.


Other than that your 60's are terrible ( no offense).. I suggest getting a g-tech meter and finding a nice flat spot to practice launching on and then go back to the track when you can get 2.0-2.1

 

[Winters98GT]

i think the nitto 555r is the regular tire and not the drag radial, i may be wrong

no, those are drag radials.

You should be seeing 1.8's with the nittos. I would run them at around 16-18psi. I've run them as low as 12psi before. They need to be fried in order to perform properly. A good healthy 10 second burnout.

Don't get too caught up in the MPH. Your run is too inconsistent to really be comparing anything, and temp is just one factor. DA is what you need to look at, but not before you get that 60 foot down.

 

[SCalla1384]

For future runs remember to log all weather data so you can accurately tell what is going on..

without knowing the temp,baro and humidty for either the 104 run or the 101 run it's impossible to know what is going on..

Even if temps are the same if you had really high baro pressure the night you ran 104 and low baro when you ran 101 that is some of the difference right there..


If you still have the dates and times from those runs you can go to Welcome to Weather Underground : Weather Underground and find the closest weather station to the track and look under the history for that day and they have a breakdown of the entire day... Most weather stations update every 15 minutes or so and all of this is logged on the site.


Other than that your 60's are terrible ( no offense).. I suggest getting a g-tech meter and finding a nice flat spot to practice launching on and then go back to the track when you can get 2.0-2.1

Thanks for that info on the WeatherUnderground. I checked, on 4/29/09 when I ran a 13.69 @ 104.26 it was like an average of 47*F. And the Baro pressure was a lot higher.

And lol I know my 60 foot times are awful. Ive ran 2.1's and 2.2's I just had a crappy night on Friday. I do have a GTech meter so Ill have to go practice thanks for the advice man.

You ran 13.69 with the 104.29 with 2.26 60'. Maybe where did .5 (1/2) second of et go might be a better question.

Im not to worried about that yet. I know thats from my horrible launches. Ill get that back down.

Im going to get a dyno tune this weekend. So Ill have numbers on Saturday Thanks for the help guys

 

[saxmanJJ]

I have the same tires and usually run them between 14 and 16PSI at the strip.

They need to get very, very hot to work well as the other person said.

Try launching around 3000 to 3500 rpms too and see how that goes (I launch around 3500 rpms with a 5-speed and 373's).

Good luck, you'll get it down after some experimentation.

 

[saxmanJJ]

Oh, and if you are trapping 104 with those mods you have a strong running motor! (I'm guessing you don't have the cams and long tubes yet).

 

[SCalla1384]

Oh, and if you are trapping 104 with those mods you have a strong running motor! (I'm guessing you don't have the cams and long tubes yet).

Lol thanks man. Yea that trap speed is good for a low 13second run or even high 12 second. But that was back in April with the Temperature nice and cool and the baro pressure higher and obviously less humidity. Ill be doing some HiTech stage 2s probally by November or December.

So anyways, theres no way my trap speed would have dropped from 103 to 102 from going to an o/r BBK X pipe to a o/r Prochamber right? I thought 2Vs see the most HP gain from Prochambers than any other mid pipe?

 

[Stan Weiss]

You do understand what effect weather has on the HP output of an engine?
BP = 29.92 Temp = 47 Humidity = 5% DA = -775
BP = 29.42 Temp = 69 Humidity = 85% DA = 1500
That is a difference of 2275 feet DA or about 6.5-7% less HP