Doc's NOS System on his Slant-6 powered 68 Barracuda

Bob Stepp wants to point-out that the "mule" engine we used to "shake-out" this new Fogger II nitrous system is a well worn factory built 225 short block with a mild cam, (dual pattern "Dutra Special" grind) a well ported big valve head, Dutra repop Hyper-Pak intake and "Dual Dutra Duals" cast iron exhaust manifolds. The car weighs 2840 with DD in it. (ready to race)

Most of the NOS parts were picked-up used as part of a Power shot plate system. ($250.00 Included an empty tank) Another $300 had to be spent on 6 Fogger II nozzles, tubing, fittings, fuel regulator etc. Good thing the "drag car" already has a good fuel system in it or another electric pump and other "plumbing parts" would have also been needed. Even so, a new 3/8 fuel line was run from the rear electric fuel tank pumps (dual electric fuel pumps) up the driver's side of the car. This new fuel line is dedicated to the NOS system.

A lot of the hard lines and fittings in this system are "hardware store" items. The four, 3-way distribution blocks were "custom made" by drilling - tapping and screwing-on a third flare fitting "leg". To prevent any chance of leaks, this joint was screwed together clean and soldered shut for insurance. The best selection and prices on brass fittings were found through McMaster-Carr. (They have a good web site)

You need to check closely for leaks. I had a leak on the fuel side and a least 4 on the NOS side of the System.
Checking for high pressure leaks on the Nitrous side of the system is a two person job and needs to be done with a full bottle. I had leak-checked the system once with a "low" bottle and found a couple of leaks, which I quickly fixed with additional fitting tightening. The bottle was refilled and once at the track we tested the new system again. The first "hit" at full pressure popped one of the small nozzle feed hard lines right out of the compression sleeve and bin nut! We also found 2 more small leaks we did not see during the first check. Lucky we did this second check prior to making a pass and that we had extra hands (and eyes) around to help. ( slantsix.org webmaster Chuck Rivers had come-out to watch us race as well as having Bob Stepp and my son Allen along as "crew")
The bad news is that this final check and repair work was done "track-side", between rounds, with limited tools, in the dark and dirt. Basically the old at the rack track "thrashing" that nobody likes to do. (and every racer seems to end-up doing!)

Bottom-line Results: Baseline pass, (no NOS) 14.63 @ 91.8 mph
First NOS pass, 13.21 @ 101.4 mph. The car picked-up 1.4 seconds and 10 mph with an 80 HP shot!(#18 NOS #20 fuel jets)
Baseline pass was driver only, second NOS pass was driver & co-driver (Chuck came along for the ride, add 170 lbs)
I hit the button about 1/3 the way through 1st gear and held it on the whole pass. The engine pulled hard and did not miss a beat. The car picked-up so much that we ran out of gear at about 1200 feet (4.56 rear-end ratio) so we watched a lot of glowing shift light as we kept the hammer down and screamed through the traps off the power. (about 5800 RPM) Pulled out the sparks plugs and all of them looked fine.
Houston - We Have Spray! - DD