yank ss4000 and slower times?
Originally Posted by JNorris
If the DA was about the same and your setup is the same except for the converter swap then you have to point a finger at the converter. However from your first post it looks like you also put in a new transmission.
I would make a few more passes and see if your times get better.
Going from a 2800 stall to a 4000 stall should keep you in the engine power band much longer. You should go at least .2 quicker in the ¼.
Are you sure about the DA numbers? I know my car will be ~.35 slower in the 1/4 with a DA of 1800 vs a DA of -200 and it will not 60 as well either.
John
I would make a few more passes and see if your times get better.
Going from a 2800 stall to a 4000 stall should keep you in the engine power band much longer. You should go at least .2 quicker in the ¼.
Are you sure about the DA numbers? I know my car will be ~.35 slower in the 1/4 with a DA of 1800 vs a DA of -200 and it will not 60 as well either.
John
By the way John, thanks for yoru response to my post about my new converter making my 2-3 shifts hit the limiter!
Bill
I have run into something strange with my ss4000 to from all stock to cam only to head cam 90-90 setup my convertor would 60 the same from 1.58 to 1.65s around that its weird to me because if ya got 100 more hp form a SI car and 60 the same thats strange to me and never figured it out!my convetor would never lock on the dyno either!The overall time got alot better si with convertor it ran 7.7 to 7.8 1/8 cam only it ran7.39-7.5 and H/C 90/90 its avg was 6.98-7.2 but the 60 nver really changed!Now why would that be? HA!Tuned with tq management deleted too!I wonder if its just all the convertor has got even when I lighten the car some it was the same its very consistant with the 60ft I bet If I had 600 hp that convertor would still 60 the same ha! 
Originally Posted by Bill'sWS6
Always trying to learn something new...... Can you please tell me what DA is?
By the way John, thanks for yoru response to my post about my new converter making my 2-3 shifts hit the limiter!
Bill
By the way John, thanks for yoru response to my post about my new converter making my 2-3 shifts hit the limiter!
Bill
Simply explained DA or density altitude is a measure (in feet) of air pressure based on your track elevation, temperature, barometric pressure, and dew point or humidity. It is also part of an ET/MPH correction factor.
The lower the DA is the more horsepower your engine will make and the faster you will go because there is more oxygen in a given amount of air.
As and example:
Spring/Fall racing conditions
Track elevation = 185ft
Temperature (F) = 50
Altimeter Setting raw with no correction (barometer) = 30.25
Dew point (F) = 35
The DA would be –657ft, which is great air. With this DA my car will run 6.96 – 7.02 in the 1/8.
Summer racing conditions:
Track elevation = 185ft
Temperature (F) = 85
Altimeter Setting raw with no correction (barometer) = 30.10
Dew point (F) = 65
The DA would be 1953ft, which is poor air. With this DA my car would run around 7.3x in the 1/8.
See link below for a DA calculator:
http://wahiduddin.net/calc/calc_da.htm
There is also a good article in the June Car Craft magazine, which does a good job of explaining density altitude.
John
Last edited by JNorris; Apr 17, 2006 at 09:35 AM.
