Author Topic: 51mm Throttle Body  (Read 4723 times)

Offline Jezza-7

  • Members
  • *****
  • Posts: 3832
51mm Throttle Body
« on: November 28, 2011, 06:43:53 pm »
Would like to do a little write up on the 51mm throttle body, that many of you know, that Justin is making on the forum.

I got one of justin quite a while back now when he first did them so i have had a good few months of experience with it. Justin is a good friend of mine and have been in touch with him from the start of my G40 days. Many many months ago Justin said to me that he was designing a 51mm tb and showed me his work and i was really impressed. He said that he was going to make a few of them and see how they got on. Justin has been running his tb for a lot longer than myself so hopefully he can give a little more detail on how much difference it made (motorway driving etc) as i didn't really do much motorway driving with it on. 

When i received it i compared the difference between my de-wedged tb and the new 51mm tb. In comparison there is a lot of difference and you can really see the difference in restriction between the two. I thought, this should help the airflow a lot, and after putting it on you could feel a difference between the two. Its a shame i didnt have a complete standard one to compare them to really. Boost pressure had decreased by approx 1-2 psi so you could see straight away that the restriction was removed to help the air flow.

The porting and polishing was really good which i believe is vital when carrying out work like this to the throttle body. Even the inlet t-piece for the body was ported to help that airflow be a little smoother.

When it was first put on the revs were a little high to start with but sometimes the throttle plate inside can get a little sticky which is what i thought my problem was. After removing it a couldnt really see any problems with it so i just stuck it back on and after some adjusting on the throttle cable stop it was better. After a few more miles it had bedded itself in and has been perfect since then.

All in all a very good throttle body and anyone looking for that extra bit of power must have one of these. 

Cheers Justin for your hard work and effort buddy!