i have a y7 on a t25 on 5 pound... stock fuel and stock block... when i hit like 6500 RPMs i here a crackin noise from the exhaust or the motor really cant really tell.. wonder what it was

 

i dont have any power lost either

 

Id have to hear it, but if its cracken noise id get off the throttle cause it might be detonating.

 

thats your rods telling you that you'll be seeing them soon...

 

I had that same problem... Mine ended up being my heatsheid... But that doesnt sound like the problem in your case. sorry

 

Ha ha ha.

 

you have no fuel management? ie chipped ecu, fmu, injectors?? All stock??

 

Could be a crack in the manifold. I had this noise on my Xterra. It was a hairline crack right next to the manifold flange. Check it out.

 

I have it on my honda.....i used to have the exact same noise on a toyota and when i looked it was the distributor sitting halfway off.......got a new bolt and it went away...

same noise but the distributor is sitting fine on my honda.

 

crackling as in bb's in a tincan sound = detonation. Do something about your engine managment fast.