Re: Stack Injection and Power Loss
Hi, all. Re. Jim C's thought that almost all DFI 8 stack set-ups use TPS, I'm not sure that's accurate. I don't. I run in MAP mode and have no problem with large droplets(?) at idle, with Venom 36# injectors.
Re. air filters vs. stacks, I copied Bill Bayard's set up, and got definite increases in HP, Torque AND area under the curves on the chassis dyno when I switched from 8 K & N 3.5" tall filters to 90mm velocity stacks, specifically, 20 HP and 20 ft. lbs. Most noticeable was the HP, which went from a peak of 350HP at 5900-6000 then falling off, to reaching 370 HP at 5300-5400 RPM and remaining flat at 370 HP all the way up to 6500 RPM where we shut it off. The Torque curves showed a similar improvement, but not as glaring.
Re. the discussion on a separate piece of plexiglass and sealing off the air box, question;
Are'nt we talking two separate things? 1, sealing to keep dirt out of the motor (doesn't have to be perfectly airtight) vs. 2, Airtight to provide an accurate MAF input. Re. 2, If you run the ECU in MAP mode (vs. TPS), don't you get most(?) of the advantages of an actual manifold fuel sensor? Without having to have a perfect measurement of intake air?
I'm running ACCEL's DFI, and since I went to manifold referenced fuel pressure regulators, I have had zero problems. The plugs (after a little individual cyl. tweaking) all look great and matched. The fuel pressure goes as low as 35psi slowing down in gear in idle/over-run, idles about 40 psi, with a nominal 44psi setting at WOT. It pulls cleanly from 1500 RPM in 5th gear.
Attched: what it look's like. I have K&N filters in each body duct a-la Bill Bayard. So far so good.
347"/Accel Gen 7 DFI/TWM