went to the drag strip last weekend, not so great

General discussion relating to club happenings and items related to Merkurs in general such as "Merkur sightings". If you just signed on, please feel to start a new thread and introduce yourself here. Posts specifically regarding either the XR4Ti or Scorpio should go in those specific forums. Feel free to make suggestions on improving this forum here as well.
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86XR4Ti_John
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Post by 86XR4Ti_John »

I would put ANY amount of money that the 60' gains would far outweigh the rolling resistance due to sticky rubber.

Any decent car that will be raced will have more than adequate power to overcome a small amout of rolling resistance, but most cars like this will spin too easily in 1st gear making for $#!%^& 60' times.

remember 1/1th in the 60' equals 2/10ths in the 1/4. Eg, a 2.6 second 60' time vs a 2.2 second equals nearly a whole second in the 1.4 mile. Thats HUGE M'kay?
John

86 Xr, lowered, cossie rear sway bar, wheels, intercooled, big vam, PE superchip.
91 Talon TSi, well modified, 5spd all wheel drive, runs 11's.
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EVIL_XR4
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Post by EVIL_XR4 »

I think the rolling resistance thing is something to think about when you've sorted out your combo and you've been running the same ET for a long time and can't better it...then you start looking at dropping weight and little things like lighter rims and tires with less rolling resistance. My best times in my Mustang are with 16's all around with huge tires front and back. I'm sure if i switched to Welds with Mickey Thompson front runner skinnies i'd pick up a little time, but i like to keep my car in "street trim" so i know my car will run the same on the street as it does the track.
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DPDISXR4Ti
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Post by DPDISXR4Ti »

BeefFajitas wrote:Or maybe that's a good test for a frozen caliper.....
Glad someone's thinking here. :thumb
Brad
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86xrmerk
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Post by 86xrmerk »

well see i took my stock xr with a open stock downpipe, and CAI, thatsIT, i broke a 1.9 60 ft on stock phone dials with mismatched tires. and also ran a best of 15.2 at 89 mph, ran that for 4 weeks straight then blew my differential. so something is definately wrong...
B-bye
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whitelx
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Post by whitelx »

last weekend I dynoed the car and I can see where the problem is. t is way too rich through the midrange. Every time I would shift the rpms would drop and it would bog. I did make two changes between the track runs and the dyno, I removed the high flow cat and installed the DG clutch adjuster. It made decent peak power, but my average power is in the toilet because of the rich condition through the midrange. It will pick up a lot once I get that fixed. I have a Moates F3 and Jaybird on the way. :)

Image



I hit the local 1/8th mile track last night. Times did improve. First run was a 9.68 @ 77mph. Next run I tried advancing the cam 3° and it slowed down to a 9.783 @ 70mph. I returned the cam timing back to 0 and made a couple more runs.

My best pass of the night:
R/T ..... 0.802
60'....... 2.310
330 ..... 6.302
1/8 ..... 9.445
MPH .... 79.66

So I dropped 3 tenths and picked up 5mph. The track wasn't prepped all that well tonight and I was getting a little spin off the line and at gear changes. I think the small amount of tire spin between shifts may have helped though as it kept the RPMs up and in the power band.

Once I get the chip I'm going to head back to the dyno for some tuning. I wish I could tune it myself on the street, but my JAW wideband still hasn't made it back to me.
1986 XR4Ti - 294rwhp/315ft-lbs
1992 Mustang 5.0 notch - 434rwhp/445ft-lbs
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hEaT
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Post by hEaT »

Looks a little lean up top too.
Joe
1985 Nimbus Grey XR
2017 Ford Focus RS
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whitelx
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Post by whitelx »

hEaT wrote:Looks a little lean up top too.
12.5:1 is fine.
1986 XR4Ti - 294rwhp/315ft-lbs
1992 Mustang 5.0 notch - 434rwhp/445ft-lbs
http://www.youtube.com/user/whitelx
hEaT
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Post by hEaT »

whitelx wrote:
hEaT wrote:Looks a little lean up top too.
12.5:1 is fine.
Even under boost? I thought you wanted to be a little richer than that.
Joe
1985 Nimbus Grey XR
2017 Ford Focus RS
BeefFajitas
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Post by BeefFajitas »

As long as it's not detonating, it's not a problem.
-Nate
'85 Merk. Back together. Only thing stock is the head and block.
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whitelx
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Post by whitelx »

hEaT wrote:
whitelx wrote:
hEaT wrote:Looks a little lean up top too.
12.5:1 is fine.
Even under boost? I thought you wanted to be a little richer than that.
its on the high end of safe, but it's still safe.
1986 XR4Ti - 294rwhp/315ft-lbs
1992 Mustang 5.0 notch - 434rwhp/445ft-lbs
http://www.youtube.com/user/whitelx
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