mods

Friday, April 3, 1998. Temperature: 65°F.
Modifications:	Basically stock Z28 with 305 TPI, apart from the following: Accel distributor cap & rotor TPIS spark plug wires TPIS air filters Valvoline 10W-30 synthetic oil
Best Run on the Day:	15.90 @ 86 MPH
Willie's Comments. This car is completely stock, except for the modifications listed above. I believe that without these mods, the car would be about 0.1 to 0.2 seconds slower. My reaction times stink, but never having raced in recent history, I learned a lot. I launched at 1,100 rpm. Very slight wheelspin. The tires were almost new Goodyear Eagle GS-C's. The transmission shifts at 5,400 rpm (1-2) and 5,200 rpm (2-3). This is way to high for a stock 305 with the "peanut" cam. The transmission should shift at 4,500 rpm for maximum results. I've discovered that over 4,500 rpm's, the engine revs, but does not pull.
Friday, April 24, 1998. Temperature: 75°F.
Modifications	3.42 ratio ring & pinion GM dual catalytic converters Custom 3" cat-back exhaust TPIS airfoil and M.A.F. screens removed Manual fan switches
Best Run on the Day	15.74 @ 88 MPH
Willie's comments: I expected about a 0.2 second increase with these mods. My comments: The results were in-line with Willie's expectations, with a 0.16 improvement in 1/4 mile ET. The 60' and 330' times were virtually unchanged, which shows that the major improvements from these mods were achieved in top end HP.
Friday, June 19, 1998. Temperature: 97°F.
Modifications	Final phase of mods before the Paxton supercharger is fitted. Crane Gold 1.6 roller rockers Jacobs Omni-Magnum ignition Changed to Valvoline 20W-50 Synthetic Manual fan switches
Best Run on the Day	15.56 @ 88 MPH
Willie's comments: Nil. My comments: Good results here, with a further 0.18 reduction in ET. This is especially true considering the high ambient temp of 97°F on the day. Definite improvement in 60' and 330' times too. I believe that the 1.6 rockers have allowed the engine too breathe a little more, the stock cam is very restrictive in these cars. (They don't call the '87 cam a peanut for nothing!)
Friday, July 10, 1998. Temperature: 95°F
Modifications	Paxton Supercharger (7 psi boost). Removed Paxton exhaust recirc system & replaced with K&N breathers. Removed Paxton's air filter and replaced with K&N filter. TPIS 52mm Throttle Body. TPIS Large Tube Runners. TPIS Manifold Base. TPIS Level IV PROM.
Best Run on the Day	14.47 @ 96 MPH
Willie's comments: My plan was to install the TB, runners, base and prom only, but I got impatient and installed the Paxton. According to TPIS, their Level IV prom along with TB, runners and base should net an improvement of 0.4 seconds. Whatever improvement above and beyond that should be attributed to the supercharger. I gained 1.1 seconds. A one-tenth second improvement is approximately equal to 10 horsepower, so I gained around 110 horsepower with these modifications. The car definitely pulled harder, but still is lacking power over 4,500 RPM. Future modifications include a cam and headers.
Friday, October 16, 1998. Temperature: 80°F
Modifications	Bosch Fuel Pump. Replaced Jacobs Omni-Magnum ign with Jacobs Pro-Street ign system. AutoMeter Vacuum/Boost & Electric Fuel Pressure gauges. Raised fuel pressure to 53 psig (vacuum line disconnected). Paxton dipstick oil cooler. Alston sub-frame connectors. Front sway bar removed (at the drag strip only)
Best Run on the Day	14.34 @ 96 MPH
Willie's comments: Not many mods since last time, but one important one. I discovered that with the stock fuel pump, my fuel pressure was dropping from 48 psig (with vacuum line disconnected) to 41 psig. TPIS told me that maximum acceptable drop-off at WOT should be no more than 2 psig. Well, what a surprise!! I'm dropping 7 psig -- not good at all. This means my engine is leaning out on the upper end, causing a loss of power and potential of blowing her up!! With the new Bosch fuel pump, my pressure not only holds at 53 psig, but rises under boost to 60 psig (7 psi boost). Removing the front sway bar allows more weight transfer at launch to the rear. The front end definitely lifts much more without the sway bar. I like it. Gained 0.14 seconds. Obviously, fuel pressure was a problem. Now, I'm getting enough fuel, but the car still does not have any upper end guts. I've got to replace Mr. Peanut. This cam was meant to be installed in my grandmother's car, not mine.
Saturday, January 2, 1999. Temperature: 70°F
Modifications	High boost impeller fitted to supercharger. Supercharger boost now 9.5psi, up from 7psi. SLP 1-3/4" ceramic coated stainless headers. Strip exhaust system: 2-1/2" duals with racing glass packs, exits in front of rear tires. Click here for a picture of the strip exhaust system.
Best Run on the Day	13.89 @ 101 MPH
Willie's comments: Not only did I break 14 seconds, but I reached 100 mph!!!!! I'm excited. That's an improvement of 0.44 seconds from my previous best of 14.33. Not bad for "peanut"!! Now, to replace Mr. Peanut with my Crane cam...... Footnote: All of Willie's ET's since the 52mm TB was installed were run at less than full throttle! Willie's friend Tim Burgess suggested to Willie that he should physically check to see if the throttle blades are opening completely at WOT. In Willie's own words..... " So I did and what a surprise. Not only are they not completely open, but far from it. I'd guess the throttle blades are 15 degrees from horizontal. I installed this 52mm TB back in October I believe when I installed the large tube runners, TPIS base and supercharger. And now I find out I haven't been at WOT since then!!!!"
Saturday, June 2, 1999. Temperature: 70°F
Modifications	NOTE: Willie raced his Camaro WITHOUT the supercharger installed. Original 305 engine rebuilt. Balanced & blueprinted block assembly. TRW forged pistons. Corvette L98 aluminum heads. 1.94" / 1.60" valves, 58cc chambers. Crane 2032 hydraulic roller Compucam. 214/220 duration @ .050, .482/.496 lift (1.6 rockers), 112 LSA. Gear drive for cam. TPIS Level IV PROM upgraded to a custom Level V PROM. Art Carr 2,000 rpm hi-stall torque converter. Synthetic shockproof gear lubricant and limited slip additive. Urethane motor mounts. Stewart high flow water pump
Best Run on the Day	14.23 @ 99 MPH
Willie's comments: This is a tough one, because of several changes, both negative and positive. Let's start with the negative. No supercharger -- lost about 1 second (100 hp). I dropped my compression with the rebuild (used 0.051 thick head gaskets). It's probably around 9.0:1. This should work well with the supercharger, but in normally aspirated mode, I lose power. Let's say 0.2 seconds. Negative: 1.2 second loss. Positive. I lost 80 pounds -- 50 pounds for aluminum heads and 30 pounds for the supercharger. Worth 0.08 seconds. Cam and heads -- let's back calculate to get this number. So I lost a total of 1.12 seconds (112 hp). My time of 14.23 is slower than my previous best of 13.89 or a difference of 0.34 seconds. This infers a loss of 34 horses. Based on the fact that the supercharger is worth approximately 100 hp, the difference is 68 horses (100 - 34). Therefore, the cam and heads are worth around 70 horses. If this logic works, then I should gain about 1 second after installing the supercharger, which should put me in the high 12's. But the major concern now is traction. I lost 0.2 seconds without the supercharger. With the supercharger, my problem will be compounded.
Saturday June 12, 1999.
Modifications:	Paxton supercharger refitted to engine.
Best Run on the Day:	13.14 @ 108 MPH
Willie's Comments: This ET was with street tires and not taking advantage of my 2,000 rpm stall converter. I had to launch from an idle because of severe traction problems. My 60 foot time was 2.10. And in the upper rpm range, the engine just didn't seem to pull as usual, especially in third gear. On my fourth pass, it literally crapped out and set a Code 43, electronic spark timing. Inspection of the video of that run shows I was blowing black smoke out the exhaust pipes as soon as I hit second gear. My previous best (with the supercharger installed) was 13.89, a difference of 0.75 seconds. I used the same tires and launched off the line from an idle. This technique is the same I used to use. My 60-foot times were a tad slower (e.g. 0.05 seconds), which means I lost some power on the low end (expected). The general rule of thumb I always use is 0.1 seconds = 10 horsepower. So a gain of 0.75 seconds infers a gain of 75 hp. I calculated 70 to 80 so I think I was right on!! I won't be racing again until the end of July. By that time, I'll have a line lock installed and this time I'll be borrowing Tim's tires (drag radials). Tim told me his tires are only good if you heat them up a lot. With the line lock, I'll be able to do burnouts like Tim. I plan on launching at 1,500 rpm and if the engine bogs, I'll pull the converter and send it back to Art Carr for them to raise the stall speed. I get one free adjustment.
Friday September 17, 1999.
Modifications:	3.73 ratio ring and pinion. Timing set @ 38 degrees total. Fuel pressure reduced from 52psi to 50psi. Water injection disabled. Underdrive pulley on supercharger to allow the engine to rev to 6,000 rpm without exceeding S/C redline. Drag radial tyres. Street exhaust system & a full tank of petrol!!
Best Run on the Day:	12.998 @ 109.28 MPH
I recorded Xray info and discovered I was running way to rich. Actually, the fuel pressure was set for the track exhaust. This "rich" run confirmed that I do need to bump up the pressure with the track exhaust -- yep, it really does flow better allowing more fuel to be used. I reduced the pressure to 50 psig (down from 52 or 53 psig --didn't have my TPIS gauge, only the in-dash gauge). On the second run, I also bumped up the total timing to 36 degrees (up 4 from the first run). No other changes other than fuel pressure. Phil (driving Willie's car) ran a 13.21 @ 105.25. Frankly, I was VERY surprised. That's only 0.07 seconds away from my best. I think this tells me that advancing the timing really did make a difference. I was tempted to not change anything for the third run, but decided to give it 38 degrees total. For the third run, I really didn't know what to expect. This is the first time I've seen my car from the stands and it was actually quite exciting. She really moves!! I was blown away when Phil tripped the clock at 12.998. I just couldn't believe it!! He beat my previous best by 0.15 seconds. So now the next time we race, I suppose I won't have any excuses.
Saturday January 15, 2000.
Modifications:	Replaced Art Carr torque converter with a LevelTen 2,000 RPM high stall torque converter.
Best ET on the Day:	12.57 seconds
Best MPH on the Day:	110.80 MPH
On my first run, I recorded a 12.96 @ 110.80 mph. This barely beat my (Phil's) previous best of 12.99 @ 109 mph. I did not take advantage of the torque converter on this run, as witnessed by my 1.97 second 60-foot time. This is only marginally better than my previous all-time best of 2.05. I saw the tach hit 6,000 rpm as I crossed the finish line. If I were not running the SC, this is optimal, but since the SC redlines at 5,400 engine rpm, I knew I was over-revving. I was very uncomfortable knowing what I was doing. On my second and last run, I brake stalled to 1800 rpm and let fly. I have never felt a launch as hard as this one was. I could feel the rear of the car "squat" and I shot out of there like a rocket!! I really felt sorry for the guy in the '99 4.6L Mustang GT in the next lane. He never had a chance. As soon as I launched, it was no contest. (Willie's 60' ET on this run was 1.835 seconds, awesome! - Jim) The over-revving problem occurred on this run at the tail end. I decided to leave the transmission in OD. Well, I found out that at WOT, my transmission will not shift into OD. I'm not sure if this is normal. When the transmission was not shifting into OD, I had to let off the gas pedal so it would shift. So, I was not accelerating for the last two seconds of this run. My time was 12.57 (0.39 seconds faster), but only at 106.72 mph, 4 mph slower than my first run. (The slower MPH is due to the fact that Willie let off the throttle before the end of the run, to prevent over-revving the SC. - Jim) I have another SC pulley being fabricated that will give me an additional 400 engine rpm. This should definitely help out my problem. My two runs today were with my full street exhaust system.
Saturday July 15, 2000.
Modifications:	50 HP nitrous oxide shot. No water injection. Timing retarded by 3 degrees (35 degrees total timing).
Best run on the Day:	12.04 seconds @ 112.86 MPH
I had a premonition before racing last night. I felt I was going to break something. It came true. I lost Drive & Overdrive and the torque converter will not lock up, even manually in second. Last night's first run was the first time I tried my manual torque converter lockup switch. I engaged it at 5,300 rpm's in Drive. I was amazed at how much reduction in engine rpm's I saw. I'm guessing, but it was at least 1,000 rpm. On my second and last run (this was previously decided), the TC did not lock up when I threw the switch. Curious, but I didn't think much of it. Maybe I turned on the wrong switch? It's possible because my line lock switch is adjacent to the TC switch. On my way home, I got a little squirrelly. At WOT, it would not shift into Drive, the engine just revved. I'm surprised my stock transmission has lasted this long. I might use this "opportunity" to upgrade, shall we say?? So in a way, this bad news can be construed as good news, although I might be out a pretty penny.

ORIGINAL SPECIFICATIONS	305 ci (5.0 litre) Tuned Port Injection V8. 190HP @ 4,000 rpm, 290ft/lb @ 2,800 rpm 700R4 automatic Originally bright blue metallic, presently white. Purchased Feb 28, 1998 with 99,000 miles.
ORIGINAL OPTIONS	IROC-Z Preferred Equipment Group 3 Custom gray cloth seats Performance axle ratio (3.23) 4 wheel disc brakes 245/50VR16 Goodyear "Gatorbacks".