I finished swapping over to an HSR and was curious on what size intake to run, 3.5 or 4. I will be using siliconeintakes.com to build it. HP level is around 480-500 flywheel. I did a search but could not find a lot of info.

 

On my motor I ran a 3.5" setup vs stock TPI camaro intake but with gutted filter bottoms + ram air ducting to get a ram air effect at speed.
Track results appeared to be same exact times...no real gain in power either way. This was with a 3.5" maf too so the entire system was 3.5" vs the TPI camaro stuff.

I'd just build a 3.5" since it should be abit cheaper and have plenty of air flow to support 500hp.

 

I thought the tpi intake was more restrictive than that. I have one laying around somewhere complete, maybe I will do that. Otherwise, the 3.5 was more likely the way I would go.

 

People claim it is a restriction, but on my 11.4's motor, it didnt make any difference.

 

That good to know, I may just go that route instead. Thanks Orr

 

Were you also using the stock lid with probable kn filters?

 

Yeah it was stock lid, stock MAF but with screens removed (left the fins), and K&N filters with the bottoms of the lower box cut out with cheap dryer ducting run from bottom of boxes to fog lights.

crude/cheap but effective enough







green is where I cut. See theres the factory scoop plastic behind the fog lights that I wrapped the ducting around to help force air to flow upwards to filter boxes