[JustinKA2012]

Ok, so I found a totaled X and the guy told me $250 and I could pull whatever I want..... Sooo.....I went for the trans, entire 4x4 system, cluster, console, wheels/tires (because mine is 2wd and I'd like to attempt the swap while I have an extra car). Anyways, I also took the upper and lower intake manifolds. So, I have a Q45 throttle body in my garage that I've never been able to use, but it looks like with a little fab work that I could make it fit (I have a friend that works at a pretty reputable machine shop that made me a custom plenum, smoothed the runners and welded it all together for my '00 SI last year). Here's where I foresee failure: TPS sensor, I have no idea if they're compatable. Anyone ever attempted it? I see that people do it frequently with the ZX's, actually found a write up of a VG30 with dual custom plenums and dual Q45 throttle bodies that gave me the idea. Will I run into issues because 90mm is TOO big? I've searched everywhere for a modified VG33 manifold with a Q45 TB but I haven't found so much as someone asking the question. I'm about to have to replace the knock sensor in the next few weeks so I'll be messing around with the lower manifold off anyway, to me that is justification to have it bored/polished and do the upper modifications and throttle body if I can get some advice on the TPS.

 

[Ggeiss]

If you have a multi-meter you could measure the resistance of the two sensors over their full range. Some TPS sensors are as simple as a potentiometer. If they match each other, find the pin out and go from there.

If they don't match each other, you could find a way to modify the original sensor to mount to the new throttle body.

I don't think that having a larger throttle body would cause any ill effects if the rest of the engine is built to breathe easier as well.