Horsepower and 1/4 mile Experts Please Comment

[Speedfreak]

I agree with what you said. Because of varying conditions as you mentioned the dyno is the only way to prove the horsepower loss theory. The dyno in this case will eliminate all other factors. Wind,tire spin,track prep,driver,etc. If the lights truly are causing a power loss it will show up. The load on the alternator is either present or is a non-factor.

As far as runflats go the warmer the better. And the new tires on the 08 have hooked up better than any stock tire to date.

I don't think it is as cut an dried as this. If I simply put the car on the dyno with a full battery charge and just turn the headlights on and run the pull the alternator may not even engage in the dyno run because the current draw hasn't gone on long enough for the alternator to engage. What may be happening at the track is I am sitting idling for a period of minutes. This is likely not charging the battery enough (most cars do NOT charge at idle speeds). Then when I finally stage, etc. and launch, the rpm in the engine is finally high enough long enough for the alternator to engage agressively. THEN it shows up. To duplicate the same on the dyno I think I would need to let the engine idle a similarly long period then run the pull, but even then it would be the equivalent of going through just one gear, not four and for a much shorter period.

I am hoping to make it back to the track this wednesday and see if I can gather any more data. A dyno run is in my future too but not this week.

 

[Ray W]

If I go this week I will look for you. I would like to take my s/c 2004. After one pass they kick me out. So it's not much fun.

 

[Speedfreak]

If I go this week I will look for you. I would like to take my s/c 2004. After one pass they kick me out. So it's not much fun.

Ray, just realized you were a neighbor!! Hadn't looked at your signature line. If you can go this week, let me know. Would be glad to hook up with you. Would be great to have someone else there to see if this headlight issue comes out the same. Why do they kick you out? Trap speed to high, or e.t. below 11.5.

 

[Ray W]

Too quick for a convertible. I'll pm my number. Call me Wed. and I will let you know if I can meet you this week.