I read that the MTX TB is 49 mm but choked down to 46.5 mm just in front of the plate. Is this true? if so can you "un choke" it

 

I've never measured it, but you could bore it out.

 

how do you bore it out

 

You probably need a machins hop to do it and you will need a bigger butterfly plate also.

 

so a 55mm TB issnt worht the extra money....your better off getting a ATX TB?

 

A mtx throttle body can be bored out to 55 mm for about $75.00 shiped from ebay,and an atx tb will cost you about the same from a wrecker, and give you 52 mm. What I did was bought an auto tb, put it on my car and shiped off my stock one to be bored . When I got it back I sold the auto tb to someone who needed it. Each step was an inprovement. (quote]ORIGINAL: neon15

so a 55mm TB issnt worht the extra money....your better off getting a ATX TB?
[/quote]

 

They are like $35 from the junkyard!

 

i would never pay $75 for a TB that is only 3mm bigger...

id rather just save up and get the 55mm

 

Did I mention I re-sold the tb for what I paid for it.So I had an improvement with the auto tb,shiped off my stock one.got it back, put on the 55mm tb for an even better responce.I then sold the auto tb to a friend..I also ported and polished my alluminium intake By the way that is Canadian $$ So in the end I got 6mm improvement in air flow for $68.00 US.and some elbow grease.My guess is about $10 per hp.I think thats a great deal!!!