Originally posted by azgn
track times would be nice from all this "high boost" activity on pump gas (and I would exclude the pump gas + alcohol folks...that ain't pump gas)
anybody? (please include car weight....)
I've posted my recipe and results before - I'm sure a search will turn them up. Stock longblock (untouched heads with stock valvesprings, stock cam, stock intake, balanced with main studs and 95,000 miles on it now), CAS V2 frontmount, 72 injectors, fuel pump, atr headers (probably still slowing me down due to poorer spoolup), THDP, ATR dual 2.5" system with UltraFlows (I've never run uncapped), and until last month a modifed stock D5 2800 stall converter. I run Exxon 93 Maryland (spit, ptui, it's as bad as CA's rfgII) pump gas with no injection of anything else, and run 20 deg of timing at wot in all gears at lv8's > 225, verified with a timing light. Most of the tuning that someone asked about IS done by making your own chips.
I started with a stock big neck intercooler, TE34 turbo (a tick smaller than a TA49), and ATR 2.5" mandrel bent downpipe. I could run 16-17 psi boost in 3rd gear and with street tires about 13.2 at 102 mph on a 65 deg evening at Englishtown. Changed to the V2 and could run 18.5-19 psi in 3rd gear and got down to 12.57 at 107.5 on a 60 deg evening at Cecil Co. I had to keep the O2's at 800 mV in 3rd gear; leaner meant less boost and netted less power. At this point I was way past out of injectors with redstripes - I was running a base fuel pressure of "only" 62 psi because any more didn't raise the wot o2's any more. Yes, I know one guy who went 10.80's on redstripes but on pump gas you need more fuel. Stepped all the way to 72's because I wanted to prove to myself that I could make them driveable on the street, and because I never wanted to buy any more injectors
. Got to maybe 108 mph with more tuning to go and then I switched to a PTE54 turbo and THDP. My 60's were bad, about 2.0, but after some serious tuning I was running 12.30's at 109-110 mph at Capitol and a few 110.2-110.4 mph passes at Cecil Co, both on mid-60 deg evenings (that's typical here between 8 and 10 pm in the summer). I added a RJC power plate but honestly saw no difference - I had tuned for 3 deg of knock retard with O2's about 790 mV and both stayed the same after I added the plate. Before and after runs were within 2 hours of each other but no timeslips. The PTE54 allowed me to lean the O2's down to 775-780 mV or so without slowing down, and I run 24-25 psi in first and second and 22-23 psi in third. On one pass where I must have hit someone else's VHT and my Nittos hooked I got a 12.18 at 110.48 at Capitol with a 1.85 60'. Last month I installed a Yank converter, about 3200 rpm stall (2900 at zero boost), and now I can fry the Nittos immediately if I launch with more than 4 psi and no matter how soft I launch I break them loose when the boost tops 20 psi (even from a dead idle, just flooring it). A friend loaned me his QuickTimePros and while I spin those too for 5-10 feet on a 4-5 psi launch I get 60's of 1.80, and at the NE Regional Meet on Oct 10 I got my best et on one pass, 12.15, and my best mph, 111.00, on another pass, on a cloudy 60-65 deg day at Cecil Co. On the 12.15 pass there was more knock than I usually get, up to 3 deg on the 2-3 shift that was back to zero in a second. On the 111.00 pass there was no kr anywhere.
I've weighed my car once at Englishtown (4040 lbs) and once at Cecil Co (4014 lbs), with a full and 1/2 tank of gas, respectively, and my tools and other junk that I always have in the trunk and back seat, the trailer hitch
-)) and me. I did take the toolbox out for the NE Meet, which shocked my friends and probably helped maybe .02 sec.
Is that enough detail for you guys? The secrets are a turbo bigger than most people recommend for "only 12.0's", for the extra efficiency, a good frontmount, and careful fueling.
