any guess or opinion would be great

[poprocks440]

i went to the track yesterday after 2 years off of racing but still kept up on the car because its my weekend cruiser. 2 years ago i tried NOS. didnt work due to a clogged screen. so while at the track when i ran out of NOS i removed the bottle and cleared the line. i had colder plugs. timing from 38 to 32 and a mix of 110 and 93 octane and an inch and a half taller slick and ran a best of 11.86 with a 509 purple shaft. that was all 2 years ago. in these 2 years i removed 509 and put in the .564 hydraulic from comp cams w new lifters timing chain pushrods stock stamped rocker arms. had stamped on it 2 years ago also. this was degreed and all done right. car runs awesome. so i put the street plugs back in it ngk 7 heat range. no race gas. timing back to 38. and my 28x9 slicks. inch and a half lower than 2 years ago for better gear.my best run was a 12.09 and lost some 60 foot. so i went back to 32 timing and ran a 12.59. how did i run a 11.86 with no nos and 32 back then? :eusa_think:

 

[Hemi Rebel]

Changing the cam is going to completely change the characteristics of the engine. Its all about airflow. Basically the engine is an air pump. Air in the intake and out the exhaust. Everything needs to work together. Just changing one thing may not necessarily give you the results you want. That goes for the whole drivetrain. Rearend gear, tire size and stall speed of converter need to be taken into account as well. Did you change anything with the heads? Are the valve springs right for the cam? Do the coils bind with the extra lift? Do you have a high enough stall speed? That will hurt your 60 foot times bad

 

[bigmanjbmopar]

With the hydro cam and lifter set up you should have taken the heads off and had some work done to them triple springs etc ported bigger valves maybe, those hydro cams especially comps love big flow heads

Plus what HR said ;)

 

[poprocks440]

i didnt do anything to the heads. and the springs are good up to .600 lift. no valve floating. i talked with my friend who was there and he thinks that we did turn the timing back to 38 when i made that 11.86 pass. im going to test n tune here in two weeks. the same day i lost my 3 tenths my buddy lost a half second b/c of the air qualitly. he had to lean out with the jets just to pick that half back up. and he didnt touch his car. im not going to freak out just yet. lol