precision H versus S inlet

[DGC]

Are there reasons to go with the smaller (S) inlet versus the larger(H) one?
Most of the blogs recommend S but is there a danger of mating a 4 inch
cold air to the 3 inch turbo? I already have a 4 inch and was planning on the
H cover, but maybe bigger is not better?
Thanks,
DGC

 

[TurboBob]

H is 4" in , 3" out Its BIG and makes sense for front-mount intercoolers only.

S is 4" in, 2.5" out and fits with big-neck stockers, and the stock location PTE intercooler.

E is 3" in, and 2" out which matches the stock in and out sizes.


Bob

(I run the S)

 

[RUQWKNF]

The only major benefit would be if you were running high boost levels, as the H cover would give slightly cooler charge temps vs the S cover. Most Buick owners don't typically reach that boost level or warrant needing the large H cover. (IE: 29psi and faster than 10 flat range) The S cover is plenty for almost all applications. The H cover does have some alignment issues with stock location intercoolers. Also, there is nothing wrong with running a 3" inlet comp cover and 4" cold air system. I did it for years with no downsides. I also did see a difference in spool up characteristics and throttle response for the better.
HTH

Patrick

 

[bison]

The only major benefit would be if you were running high boost levels, as the H cover would give slightly cooler charge temps vs the S cover. Most Buick owners don't typically reach that boost level or warrant needing the large H cover. (IE: 29psi and faster than 10 flat range) The S cover is plenty for almost all applications. The H cover does have some alignment issues with stock location intercoolers. Also, there is nothing wrong with running a 3" inlet comp cover and 4" cold air system. I did it for years with no downsides. I also did see a difference in spool up characteristics and throttle response for the better.
HTH

Patrick

At what point do these housings show a benefit? I have yet to see any difference in charge air temps on any of these when used with a decent intercooler and meth injection at engines from 550hp up to 800hp. All seem to fall right around ambient. Im thinking they would show a greater benefit in an application where the compressor would be at high speeds for extended periods of time. A lot of the diesel engines use this technology but it was never used on passenger cars to my knowledge.