[tmoss]

Originally Posted by Coupe50h

Yea well flow #'s arent everything.
I still think a gt-40 can outperform a tfs street intake, given the right combination, and they both outperform the stocker by far.

That statement can go either way, depending on the application of the combination of parts. The smaller cross section intake will normally produce more air charge velocity.

I did an Explorer intake for a guy who was very happy with the results. His friends all told him he'd make more power with an RPMII intake. This was an 58cc AFR165 head car with an E303 cam. I wish I had the rest of the details in my head but I don't - I'm visiting my youngest daughter in college this weekend or I'd post up the combo and comparison dyno. The dyno is on my website in the Community section in the Photos folder. Long story short, he put an RPMII on the car and lost area under the curve through the mid 5,000 rpm range and then the Explorer hung right with the RPMII through 6,200 rpm. This combo needed the smaller cross section. He put the Explorer back on the car.

So, back to my original recommedation to use the smaller cross section - this car is a street car and I think it will be more driveable in traffic and still make good power. Would it make more with a ported lower? Without a doubt. How much? Can't say because there are lots of tuning and installation/build factors that can affect it. The difference in the example above was 24lb-ft and 8HP peak numbers, but the difference was apparant across a wide rpm range.

If 69 fastback want's to shift the torque/power band to the right on the curve and make some more peak power, then use the TF intake, but it may come at a loss of average torque/power over the rpm band. One way to tell is to do some dyno testing to see. He must make a decision about where to make his power and what kind of driveability he desires.

Edit - got back home and here is the two dyno curves of that combo.........It is fortunate when you can get customer feedback that includes some dyno test results. With that said, keep in mind that dynos and flow benches are tools - the real test for both man and machine comes at the track.