Hello,

I am here in San Antonio on vacation and I took my car to the local track tonite. This topic is not about the Evos times, sorry, it is about altitude and gas factor.

I took my 91 stock Honda Civic SI to the track, my best time before was 16.8 in Tucson(3100ft), that was with no spare tire, no floor mats(weight reduction), absolutely no gas, running on 91oct and no cat.

I ran today in San Antonio racetrack. I started running my car with 87oct and 1/4 tank. I already dropped .2sec compared to Tucson on my first couple of runs on 87oct , my car had the cat and no weight reduction. Then later on I added 5 gallons of 93oct to an already exiting 3 gallons of 87.

My car gained an additional 2 mph higher trap average and .3sec quicker.

Would I have taken my car under the same condition like in Tucson(weight reduction, less gas on the tank, no cat) and I would had drop another .2sec and probably another 2MPH.

I know that my history about my Honda civic might sounds irrelevant to some of you, I am not trying to impress no one here, I am just bringing you a different point of view.

Summary:

.5sec faster and 2 mph faster with just altitude and going from 87 to 91oct(3gallons of 87oct+5 gallons of 93oct)

Would have been another .2sec and another 1-2 mph with all 93oct gas, weight reduction and no cat.

16.8@82 in Tucson(SIR) 3100ft optimal conditions
16.3@84 in San Antonio Raceway (600'ft) under adversing conditions

Feel free to comment.

Thanks!!


Carlos

 

Good post, interesting to see the difference.

 

Remember that there is a greater difference on a non-turbocharged car, so the difference on an Evo would be less. Also, Carlos, we'd need to see the full timeslip of each run, because a change in 2mph should only give a .2s increase in ET, so if you improved by .5, that would indicate better driving, which can't be attributed to altitude.

 

My first 4 runs were clons:

a) 2.40 60' 1/8 10.68@65.07 1/4 16.63@82.19
b) 2.42 60' 1/8 10.66@64.85 1/4 16.661@82.24
c) 2.36 60' 1/8 10.72@63.27 1/4 16.78 @81.14
d) 2.40 60' 1/8 10.69@64.39 1/4 16.68@81.92

Then I drove away from the track, added 5 gallons of 93oct (to an existing 3 gallons of 87oct) from an nearby Exxon gas station. Now my 10.5-11 gallon tank was more than half but less than 3/4 full.

5th run) 2.34 60' 10.58@65.01 16.52@82.42
6th run) 2.37 60' 10.44@65.97 16.36@83.86
7th run) 2.42 60' 10.65@64.06 16.63@82.01
8th run) 2.40 60' 10.65@64.99 16.63@83.32

The one thing I must mentioned is that 3 runs were made with the clutch slipping. This is not something new, my clutch was bad already.

Also, like Warrtalon mentioned before the driver factor is something to consider. I have no doubt that the car improved because I only ran a 16.8 once in Tucson(SIR 3100ft).

Warr, I also agree about the N/A cars, they can improve significantly specially on this times frames(16 to 17 sec 1/4 miles) .

I am taking the car back on Friday/Saturday with straight 93oct, no spare tire and low gas.

This is a pic of the car(Honda), everything is stock except a cheap $25 ebay air
filter. It is not the first time I have taken two vehicles to race at the track, run a car a few times and switch... a lot of fun

 

Clayton! Are you in the Springs already? In that case, welcome to the Rockies! How's your car taking the 18% power drop...

Carlos,

I thought that your Si trapped 82.8 mph at SIR Tucson...that would be a .5mph improvement, not 2. Am I right, bro? Anyways, half a sec faster without any mods is outsdanding...

 

Sergio,

I have the inmense luck to see Albert tomorrow, he must be perhaps the most knowleadable 4g63 engine amateur you can encounter in your life. Remember Sergio when we use to live and race in San Antonio 10 years ago with the Eclipses Albert always used to offer us tranny repairs for free, parts install for free, engine tunning and many many other things that this guy showed us about the 4g63. That guy had vision of the future, he was looking for 6 speed custom tranny for his Eclipse back then..


He just sold the Eclipse FWD because he had it for over 10 years and was tired of the same thing. Not bad for a guy that trapped 124mph on a FWD 225/50/16 street tires uhhh?

Remember, when someone hit my Eclipse and Albert fix it on his house with special tools?. I might see some serious numbers on his Mitsubishi Starion "Superturbo" tomorrow night.

 

We just got here tonight, but my Evo doesn't arrive until next week...

 

Welcome!

 

Yeah, Albert is a great guy and very knowledgeable. He sure built a fwd beast capable of low 11's at 124+...I remember when I used to beat him with my 91 Talon with just a MBC, but that was before he got serious with mods.
Funny thing is that none of us had an Eclipse: you and Albert had a fwd Laser and I had the Talon Please tell him I said HI!