Ok well I fix the coolant leak and installed my accufab intake plenum and 75mm tb but now for some reason the car seems laggy up top. I still have the stock intake on there but did take the resonator box off. The cold air should be here in the next day or two. I checked all their lines twice and I did everything perfect no kinks and everything is back where it goes. I adjust that lil spring that connects the tb to something else and that seems to help a lil but still feel like the car want to give more but is being held back by something.. U think that its possible that 75mm is to big for an na wit almost no mods……………

 

It could be a 75mm is for a heavily modified car. If you open your exhaust you will gain the power back plus some more

 

Check and make sure the throttle return spring isn't reaching the end of it's extension before the throttle reaches 100% open. This was happening to me for the first 3 weeks I had the blower on the car and once I fixed it, I thought I found another 40 horses.

 

I would check that. I had a 75mm TB and plenum on my car when i had my 4.6, also h pipe, catback, saleen pulleys and it felt good. but all cars are different, yours could be leaning out on top making it feel lagging.