Q45 TB Question

[gomer23]

First off how to you guys with this throttle body do your intercooler piping? My outlet on my intercooler is 2.5 and the opening on the trottle body is 3.5. Would I have to get a reducer for the intercooler from 2.5 to 3" then run 3" piping to the throttle body then get another reducer to go from 3" to 3.5" or is that a bad idea?

Second question is the pigtail for the TPS plugged into my RB25 harness but the plug from the RB harness that would go into the TPS doesnt fit so do the wires just match up or how should I get that plugged in? Thanks.

[ItzGenX]

If you throttle body did not come with a pig tail with plug, i'd see if the stock rb25 tps would switch over. If it fits, no wiring required.. As for the coupler piping issue, the best method would be get an intercooler with the same size outlet or closest, more are 3in in and 3in out. If you want to use the existing intercooler you stated, you would want to 'even' out the pipe sizing at least a foot before it gets to the throttle body to prevent WOT turbulence at the throttle body. If there is turbulence right at the throttle body, you'd ruin the whole point of going with a bigger throttle body (air whirlpools and flows backwards at the outer edges). For this primary reason, the pipe section that goes into the throttle body should be of the same size. If I was with your setup and wanted to retain your setup, I would use a 2.5-3in reducer, then when it gets into the engine bay (about halfway in the pipe or sooner at the intercooler 2.5-3.5 if you want) use a 3-3.5in reducer. Then use a 3.5 in pipe the rest of the way to the throttle body.

[s13point5]

if you have a S1 RB25 then you can just swap your RB tps onto the q45 throttle body. if its S2 then it requires wiring.

[gomer23]

I forgot to mention it is a S1, so I will just do that then.

For cleanliness reasons would it be a better idea to go a different route with the Throttle body then? Isn't there a adapter to make the stock TB work now? If doing this 2.5" to 3.5".

[BoostFab]

First off how to you guys with this throttle body do your intercooler piping? My outlet on my intercooler is 2.5 and the opening on the trottle body is 3.5. Would I have to get a reducer for the intercooler from 2.5 to 3" then run 3" piping to the throttle body then get another reducer to go from 3" to 3.5" or is that a bad idea?

just run a 2.5" -> 3" reducer at right of the intercooler, and utilize 3" intercooler piping to the throttle body, and use a 3" - > 3.5" reducer at the throttle body. what's the point running a large throttle body and a straw to push air through it ?

if you must run 2.5"; get one of these 2.5"->3.5" : http://www.siliconeintakes.com...7fbd0