Scavenger spikes - Dyno numbers?

You should really only buy quality headers and they will more than likely have them. Quality headers will make more hp and torque, but there's more factors involved. I've never seen a back to back test off adding spikes alone. I'm sure they help. You can call a header company and ask them.

I know they will tell you, but people tend to tell you whatever you want to hear to push their product...so, that's why I'd rather have 3rd party test results rather than just believe what something someone says. I'm an engineer some I'm a numbers guy by default.

The high end header companies will do whatever to make more power than the competition, hours in R+D. So they'd only use them if they help. I don't even think they sell scavenger spikes separately. I mean they're proven to make power so why bother with doing so much work to take them out only to see they make less power without them.

You can buy cheap headers, find spikes somewhere, cut the header apart, weld in the spikes. Just to see the difference seems like a PITA.

I don't know what else to tell you.