Very little MPH gain with 100# valve springs

[DougsfastZ]

So the times you see in the sig were with the stock valve springs, but last week, with new 100#'s from John's performance, I only ran 13.17 @ 101. Kept the same boost, the weather was a little better, and I change my plug gap from .030 to .035

I can feel a difference on the street, but thought I would pick up more MPH. I'm running at 17 lbs.

Does this sound right? Anything else I could do to pick up more MPH?

Thanks,

Doug D

 

[XLR8]

How much mph did you pick up from the 1/8th to the 1/4 before and waht did you pick up after the valve spring change?

 

[NEARING]

Originally posted by DougsfastZ
So the times you see in the sig were with the stock valve springs, but last week, with new 100#'s from John's performance, I only ran 13.17 @ 101. Kept the same boost, the weather was a little better, and I change my plug gap from .030 to .035

I can feel a difference on the street, but thought I would pick up more MPH. I'm running at 17 lbs.

Does this sound right? Anything else I could do to pick up more MPH?

Thanks,

Doug D

What the outdoor temp&humidity the same for both runs?