4" Intake Questions

[KazeSupra]

I did a quick search and couldn't really find too many answers. I wanted to know what all of the people running bigger turbos use for a air flow converter (MAP, MAS, MAF, etc.). I'm thinking about getting a Holset HX35/40 hybrid turbo with a 4" inlet. I wanted to run 4" piping, but I'm not sure what to use for an air flow converter. I know you can get a GM MAS, but it's 3" (I think), and I don't want to restrict my incoming supply of air. I wanted it to be a relatively easy solution. Can someone help me out? Any information on this would be great. Thanks.

Chris.

 

[SethA]

Can't you just run a 3" GM MAS in a blow through setup? You could have a full 4" intake up to the turbo then.

Seth

 

[99gst_racer]

Yeah, what he said. ^^^^

 

[KazeSupra]

Great info guys, thanks. Did a quick search and found some more information, but not clear enough for me, so I have a couple of more questions.

On the blowthrough setup, where can I locate it? Can I do it after all of the intercooler piping, just before the throttlebody? I did another search and found that some people can drive with intercooler piping blown off. Is that how they do it?

Secondly, my turbo outlet is going to be 2.5", so I'm going to have 2.5" piping all the way through the system. would it be best to get a 2.5" MAS, or get a 3" mas and have it taper off somewhere...my goal is to be matched up as evenly as possible. I'm portmatching everything, as well as running the proper sized piping for every part of the application. I'm looking for 500whp on my setup. Let me know what you guys thing. Thanks again.

Chris.

 

[99gst_racer]

For a blow-thru set-up, mount the 3" GM sensor 4-6" from the throttle body elbow's bend. You cannot drive with your IC piping blown off. To mount the 3" sensor with your set-up, you will need to find silicon couplers that reduce 3" to 2.25". You will need a total of two couplers. There is no such thing as a 2.5" MAS. Only 3" and 3.5". The 3" is recommended for most set-ups. Click Here to learn more about the MAFT translator and blow through set-up.