Wow, I was not aware that you had a Fastman TB too Fabian. Thank you so much for conducting a unbiased, no-nonsense (albeit not exactly scientific) review of both TBs. While this isn't being done in a ISO 9001 certified lab, it doesn't get any better than this, folks!
A few statements, clarifications, and notes:
Naturally because I port stock castings (just like Dan Arcand bores stock castings too), my TBs and his are often compared. Frankly for me, such a comparison is flattering.
Dan does FANTASTIC work, and he's a real nice guy to boot. I've never bought anything off of him myself but I've sent other people his way for TBs and I've shot questions off of him a time or two.
There is a place for both TBs, the way I see it.
If you are looking for a show-quality piece, buy the Fastman. Or better yet, spend the 375 (or more) on the F&B/MHP/MM/Arrington throttle bodies, as those are well ahead of anything you can do to a stock casting.
If you are looking for a cheaper alternative that is not quite show-quality, but works more than well enough for most...you may want to consider talking to me.
Rob is correct in that I have no means, at this time anyways, of verifying the size of a TB inlet from one to another. I can verify the backside
, thanks to templates that I have made. I am purchasing a tool that will allow me to make crude inlet measurements at least, to back up what I sense by touch and by sight. Because of the way I port the TBs (the 4.7 and 3.7's in particular), it's not as simple as just measuring the diameter, as it tapers to the blade size.
As far for the remarks that Fabian and some others have made about the finish, the more TBs I do, the more pieces I purchase to use at my disposal to decrease turnaround time, enhance the overall quality and finish, and to turn out a better product. I have some more equipment coming in this week. It should also be noted that I can do a finer (e.g. mirror) polish, but Irf either did not opt for it or we did not discuss it. Fabian and I discussed it and we concluded that he would try it basically as-is. 06Grand4.7 has a mirror-polished FRP TB and he is happy with it. I have offered (prior to this review being made) to mirror polish Fabian's 3.7 FRP TB for a minimal fee, should he decide he wants something more.
I'd be more than happy to submit a TB for an independent flow bench test. that would really be the most accurate way of determining where these ported/bored stock casting TBs stand. The results would be fascinating to say the least!
Thanks again Fabian...it would appear that the reviews continue to speak for themselves.