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- #651
Phil1320
20+ Year Contributor
- 2,256
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- Dec 9, 2002
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Rocky Hill,
Connecticut
I did something interesting last night....I ran 3 passes on normal 93 pump gas then drained the tank and put in 5 gallons of E85 for a somewhat back to back test. I was exhausted from working 2nd shift all week and just didn't have the energy to swap on the hoosiers or do any of the weight loss stuff (seats out, exhaust off). I knew the 60' times were going to be horrendous with these bald 215/45/17 decade old kumho H rated tires. Even if I bogged off the line, they would break loose as boost came up in first gear.
I had literally swapped the DSMlink chip in this afternoon and got it working about 4:30pm, so I basically went to the track with a completely untuned car and just winged it. I worked on the VE map 3 times on the way over to the track and got the A/F dialed in and smoothed out the timing curve. So tonight was an experimental night to learn the DSMlink software and screw around with an alcohol fuel for the first time.
Here's the runs:
13.351 @ 104.91 1.812 ~19psi boost.
13.178 @ 104.74 1.853
13.076 @ 105.09 1.814 Last pass on 93 gas
13.009 @ 106.95 1.812 First pass on E85.
12.882 @ 108.49 1.863
12.841 @ 109.06 1.910 (bogged launch)
12.792 @ 108.98 1.771 (spun in first a bit)
No video or pics. I'll post some screen shots and datalogs for anyone intersted in them. I want to see about overlaying the calculated HP/TQ graphs and map sensor between the 93 and E85 runs.
I changed the global fuel adjustment in DSMlink by changing the stoicheometric value of the fuel from 14.7 to 9.8. That took my global adjustment from like -42% to -13% I think and that made up the majority of the difference in energy content between gasoline and ethanol. After that I kept trimming away at the VE map to lean it out more after each run. (trying to aim for about 11.0 A/F on the gasoline scale wideband) BUT I wasn't running pure E85...there was some residual 93 pumpgas that you can't drain out of the tank as well as what was in both long lines, rail, injectors, filter, and pump. I might have been running something like E70? I think you need to fill the tank a couple times with E85 before it becomes absolutely pure. on gasoline I saw a maximum injector duty cycle of 62%, on E85 I was running about 80%. Same 40psi fuel pressure and similar high 10's A/F ratios. Running an intank walbro 255 and FIC 750cc injectors.
Remember, a little 14b that makes a whopping 32lb/min of airflow and barely can keep above 20psi. I might be able to max out these 750's on E85 with a 16g?
Then I drive the GVR4 over to the shop this morning to meet someone for parts and unload the tool box, gas cans, and track stuff, it wasn't making much boost and felt sluggish. On the way home, I got on it on one straight road...it made 20psi for about a second than a "snap" sound and then no boost. Just smoke. I got it home, pulled the intake, and the comp wheel/shaft is flopping around like the bearing is totally wasted.
Hindsight 20/20 note: I'v been running the AEM boost controller on the A setting at 65% duty cycle for my pumpgas everyday setting and using the B setting for racetrack. It used to be about 20-21psi on the A...but I was only seeing 19-18psi on my first 3 runs. Then when I put the E85 on, I switched over to the B setting of 73% which hasn't been touched or used since the 12.0 @ 113 night when it was making 26psi falling to about 22. Last night that barely made 21psi at all. I turned it up to 85% over those 4 runs which only got me 24psi falling to 20. Guess it just didn't right the bell that I was running more boost controller duty cycle than last time and seeing less boost. Bet the turbo was eating itself last night at the track.
And wouldn't you know it...I sold the last 14b I had this morning. Now the 14b I was planning to move onto the yellow DSM is blown. sux!So while I was thinking last night at home that I had at least got a decent base tune to start the talon project on E85, it seems I made one step forward and then one step back by blowing up the turbo.
Interesting stuff with the E85. Bummer about the turbo
You are welcome, anytime! Gotcha. Using street tires I would run tire pressure at 20 or so in my FWD Laser's in front, in the rear I'd pump them up to 40. 225/50/16 on one car and I had the huge sidewall 15's on my second Laser which were optimal for street tire drag launches, unfortunately I only made 2-3 passes with that car at the '04 shooutout and ran best of 14.5@95 because I had too little fuel in the tank it was hesitating in 3rd gear
. With my first Laser I ran as low as 18 psi in the front...don't think I ever went better than 2.2 60's times though.....maybe one 2.19 or so. I hear you on not wanting to pull to much weight out. If you can do a tranny at the same time that would be great. My A/F's are not relative unless you're running race gas but they are right about 12.2:1. The O2 dump really works great with small turbos. It's almost like increasing the size of your exhaust in a way....by venting the wastegate exhaust gases at the O2, the turbine wheel gets to use the exhaust all to it's own which lets the turbo spool quicker and lets more escape at wide open throttle which gets you some more power, at least this is my understanding......put it this way, when I took off my ported O2 and replaced it with the ported O2 dump, my best run went from [email protected] right down to [email protected] at the same boost level. That simple. I don't know about any 14b cars in Canada, just carfanatic's killer 16g powered car......sorry I can't help you there......how bout it should be you! Go for it !
These are some nice runs....shows you're learning and experimenting which in my experience is necessary with the FWD's for sure. 2.3 60' is definitely a good street tire 60' for the FWD's in my opinion. If you were bogging---you don't wan't to drop tire pressure.....leave it there and raise your launch rpm, or raise the pressure.......
My first Laser had a K&N, modded aircan, hollow cat, 18psi, that's it for mods, blowing through stock muffler and all---with a 2.37 60' went [email protected]. This car had 170,000 original miles, with back seats and spare/tools removed. My key to running that ET was to NEVER go full throttle in first or second gear. I probably went 50% in 1st gear and maybe 75% in second then hammer down in 3rd gear. The turbo still spools very quickly at part throttle and wheel spin was controllable. I was launching around 2500 rpm only. This car had no suspension modification at all and was at stock ride height.......if I ever ran a drag radial and could muster even a 2.1 60' time....it's a 13 second car, maybe as quick as 13.6. But, I never ran after the 14.0 as the Laser was just the fill-in car when I was working on the talon.
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. My car does that every time, street or track.
