I have the tpi airbox on my mp112 LS1 is there anything that can be done to get them to flow better? Is the restriction in the snorkel, bottom or both?

http://www.hawksthirdgenparts.com/pr...y%2C-Used.html

This is the type of airbox I'm referring to.

http://www.hawksthirdgenparts.com/pr...Air-Boxes.html

Do these help?

 

Yup gut the bottoms out and make a ram air box to the grille area to force air in. Also check out bad91z's (i think) modded air boxes he sells

 

So the restriction is the bottom half of the set up?

 

Well depends what you are trying to feed. Airbox is only 3" where the maf sensor used to go and that may be too small for some motors. But the place it flattens out for hood to close over is also small and maybe less area than the maf part. Filter bottoms have water prevention pieces in there and they restrict flow, so most cut the bottoms out.
Mp112 ls1 i am not sure how much of a restriction the tpi airbox would be. Biggest you can fit on the intake side is always good to eliminate restrictions. The blower is trying to suck thru a small cross section and the only way to overcome small cross sections is to bump velocity up thru there. That will increase the flow and ram air box mod does help that. Properly sealed the air at higher speeds would build a pressure at the filter side and help "ram" air thru the opening. Its been documented on ls1 4th gens.


How big is the throttle body? I would try to match that size atleast. But my 400whp n/a sbc ran thru stock tpi air box but with a homemade ram air duct and filter bottoms cut out. I then went to a custom 3.5" tube intake and filter in cold air spot and gained little to nothing. Track times didnt seem to change.

 

"Ram air" takes MPH to be effective. "Cool air" is effective at the hit.

Are you married to the TPI concept? If not, you should know that this is good for 11.95 @ 114 MPH with an all-factory internals LS1 and "normal" hot rod bolt-ons:

 

thanks

 

Have you had it on the dyno?

My inclination is you are leaving HP on the table through that TPI box. It's impossible to over feed a PD blower. They love huge openings and no flow restrictions. I'm using 4" pipe on mine with a 92MM TB...I want to go up to a 102MM TB cause I know it will pick up. FYI...going from a 78MM TB to a 92MM TB will yield 20-30HP at the rear wheel on a MP112 LS1

 

no haven't had it on the dyno, Yes I totally agree.

 

As five7 mentioned a ram air type tpi box works with speed. On a static accel test like the dyno the air will not be moving fast even with a fan so the hp gains wont show up and may even be less than a larger tube cai. I do agree larger is better with the blower if you can do it.

 

i tried this on my ls3 set-up and while it helped some at speed i was still way starved for air... also it makes a restriction in front of the radiator so i was losing cooling performance... going to the bigger K&N type cone filter allowed me to get the cool air i needed and have great water and now intercooler performance with a very open front end