salem

Didn't someone already post the link to the other thread proving that the 70mm is a minimal increase over stock (~2whp) and they had dyno runs to prove that, while the 75mm depending on the brand added anywhere between 7.5-10.5 whp over stock?

So In this case bigger is better !! and dont even mention BBK they dont count with their stupid 78mm all in one piece crap. i was a BBK customer and fan for the longest as a teenager, and that was only because most people had their stuff on their cars in the street racing scene (affordability). Correct me if i am wrong, but didnt BBK start making the 78mm after they made the seperate throttle body (70 and 75)mm . they waited until all the competition's tb's went into production, and then came out with the 78mm combo.

As i said earlier precision-wise accufab probably does the best job, but the 200$ markup for their product for an additional 1.5-2 whp is so not worth it, because if someone is really that **** about this, the rational thing to do would be starting off with a faster application (car) in the first place.

cliffyk

It may well be that someone posted that, however if defies Accufab's flow numbers.

Also if they simply slapped a 70mm TB on the stock upper plenum I would expect no improvement as the stock plenum is the weak link (again, look at Accufabs flow numbers)...

salem

thanks for the last post with the link. is that your webpage? props

cliffyk

Yup...

Did you see this page? It's an analysis of various sized TB's, with the working area of the TBs WOT openings presented.

You'll see that the OEM 65mm TB has a WOT working area of 2668mm², and that a 70mm TB has a 3148mm² area. This is a 20% increase in flow area at WOT. The stock TB is a bit undersized for the engine's needs, however I assure you Ford did not make it THAT much (20%) undersized.

Returning to the Accufab data you can see that the stock TB, on any after market plenum (except the C&L which didn't do well with the stock TB), actually outflows a 75mm TB on the stock plenum.

Also evident is that a 70mm TB, on any after market plenum, is capable of flowing more air than the engine could possibly need at 1.8inHg--as low a manifold vacuum as you'd want to see without getting into charge velocity issues.

Again, when running n/a you want the intake air to be flowing freely, but you also want it flowing fast...

salem

Youre absolutely right, that made me think if the same guy who posted that on his webpage has a way of measuring the amount of CFM needed for sucking in air at 8 pounds of boost (just an example)

dwtjr3

i got the stack racing 70mm and plenum at the same time and i put them on about 2 weeks ago, i love it i notice a pretty big difference in acceleration esspecially after i adjusted my tune

Soldier GT

Update guys.. Found a used accufab T/B and Plenum (75MM) setup for 220 bucks, shipped. Thanks Kerns!!

salem

I called professional products and asked one of the guys there about the engineering involved and made him aware about that spreadsheet of accufab that was linked to this thread. The same guy told me that PP is Ford's stock throttle manufacturer . He also mentioned that some of accufab's employees go on forums (like this one), without telling who they work for, start threads that lead to the conclusion that they are supposedly number 1 for tb's. That's some Sneaky Marketing Techniques for ya (if he's telling the truth). Finally, he admitted not knowing exactly about CFM numbers (didn't think it's that big of a deal).

04BlueGT

Funny how this thread twisted to address PP quality and ignored his question about the Stack Racing piece.

Just for kicks, I bought the Stack Racing plenuma and the Edelbrock 70mm TB for my GT. Took all of 20 minutes to install and get rolling. The SR plenum looks almost identical to the Accufab at half the cost. Granted, I've seen nothing in the way of empirical data comparing it to anything else, but my air flow has improved - bitch whistles, especially at shutdown.