Tuesday, July 21, 2009

Fuel Strategy, Strata & Pb

This year I have been trying to make a bit more HP without spending too much $$. One thing I tried was some different race fuel. I did a little research about E85 and thought that would be cool. Too bad it's not available around here, at all. I even got in touch with the local Rockett brand dealer about their new E85 race gas. He's not carrying it, no demand. Then I heard about some super new VP stuff called Q16. Apparently it's a little tough to tune. We (Adam Fuhs) and I eventually settled on C16.

I get the tank nice and low in the evo and add a 5 gallon drum of the C16. Did some driving to mix the fuel.

First set of logs results in very similar AFR's to pump gas. Second set of logs is a bit richer and the car stinks a bit more. By the 3rd logging session this car reeks. To the point I'm almost dizzy. The AFR's are also very rich. Pretty sure we're into the C16 now.

At this point we're a little confused. A little searching shows the specific gravity of gasoline is slightly higher than the C16. As it turns out the gasoline and C16 stratify. They form layers and don't create a homogeneous mixture. Gasoline on the bottom and C16 on top. Hence the leaner AFR's shifting to super rich AFR's. Called up VP and they confirmed the theory. Unleaded and leaded gas don't really "mix".

Off I go to drain the evo's tank so I can move onto something else. What am I using the leftover for??

I hate to say it but the lawn didn't get cut any faster.

One thing I finally learned was how much fuel my car has when it hits the "E" light. Without the luxury of a tow vehicle and trailer I bring race gas with me and mix with the leftover in the tank. This means I calculate how much fuel I need to get to the event site and make sure I'm at "E" or below. Thing is I never knew how much gas was actually in the tank. I estimated about 3 gallons. So I drained the tank fully. Then slowly refilled with pump until the light turned off. 2.3 gallons. At the 1/4 tank mark the evo has 4 gallons left. Sweet, now the octane numbers for the mixed gas will be more accurate.

Now you might wonder how to figure out what your octane is once you mix the gas. It's pretty simple as the octane is based on proportion of one fuel to the other.

Your variables:
A = Pump Gas Octane
B = Volume of Pump Gas (gallons)
C = Race Fuel Octane
D = Volume of Race Fuel (gallons)

The math:
(A x B + C x D)/(B + D) = New Octane of Mix

A = 93 Octane
B = 2 gallons
C = 104 Octane
D = 5 gallons

(93 x 2 + 104 x 5)/(2 + 5) = 101 Octane

So that was my fuel saga. I'm back to regular old 104 unleaded. Oh well.


Saturday, July 18, 2009

7-11-09 NNJR SCCA (or the benchmark version 2)

Photo: Courtesy of Steve Wasp

So I was excited to run this event. Not only was there no pressure but it was held on the old NNJR lot. This is the place where it really all started for Kevin, Dan and I in the Civics. Can't forget Ed Morfe in his A4. We would battle constantly. There was no consistency. One guy would win one week and get crushed the next. That was probably 6 or 7 years ago at this point.

Well after I get through tech Mr. Uber Car Whore (PA :P) asks me if I want a co-drive. Typically I say no. This time it was Pat Salerno. That's a tough one to turn down.

Anyone who read my DOTM on the Autox4u site may remember that he and Junior are 2 drivers I looked up to (and still do). Pat has also been one of my raw/PAX benchmarks at National events for several years now. He's in a very fast, well setup car and has been for a while. That's the best kind of benchmark.

So we proceed to swap runs and just have a good time. We both noted the lack of grip. The lot was very dirty in spots and the car is way too stiff for that site. Pat never did get down to my time, but was very close. Did I mention I don't think there was a clean run in this car all day? It was very cool watching Pat drive. He's alot like Corey R., but more aggressive and amped up. I could tell he was a LFB guy the moment he started driving. Very precise and controlled. A bit of contrast to my style of tossing the car.

Here's our fast videos from morning runs and a couple side view shots of my afternoon runs. Also corded the front tires in the afternoon. 34 runs sucks. Thankfully I've got another set coming from Hoosier and some input to help them last longer. I <3>