[PERFORMANCE] Something interesting that I noticed..
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
[PERFORMANCE] Something interesting that I noticed..
I record the weather conditions whenever I race.
I noticed the following..
My car runs faster in hot temperatures with low humidity than in cooler temperatures with high humidity..
At night, the temps always go down and the humidity goes up quite a bit.. Even though the DA is lower at night, my car runs faster with lower humidity even with very hot temps...
Looking at the actual heat index or DA, theoretically the car should be faster with a lower DA..
For example: I ran 11.14 in a DA of 2700 and later that evening I ran a 11.21 with a DA of 2300...
I wonder if this is normal and others are experiencing the same phenomena?
I noticed the following..
My car runs faster in hot temperatures with low humidity than in cooler temperatures with high humidity..
At night, the temps always go down and the humidity goes up quite a bit.. Even though the DA is lower at night, my car runs faster with lower humidity even with very hot temps...
Looking at the actual heat index or DA, theoretically the car should be faster with a lower DA..
For example: I ran 11.14 in a DA of 2700 and later that evening I ran a 11.21 with a DA of 2300...
I wonder if this is normal and others are experiencing the same phenomena?
Last edited by GrandSportC3; Oct 15, 2005 at 06:14 PM.
Thread Starter
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by big_G
I bet the track temp. is the key...look at your 60 ft. times v. track temp.
Racer
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From: Little Italy MI
Good to hear ur nearing that 10 mark. Olivier sometime ago u stated a
1000 hp TH350 was available to you from somewhere. Is this still
true or did I misread a post? I'm considering one ... Was it CPT?
1000 hp TH350 was available to you from somewhere. Is this still
true or did I misread a post? I'm considering one ... Was it CPT?
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From: State of Confusion
Originally Posted by GrandSportC3
I ran 11.14 in a DA of 2700 and later that evening I ran a 11.21 with a DA of 2300...
My 60' times actually were slightly slower at night....but I thought that this has something to do with the fact that most of the VHT is gone by then...
My 60' times actually were slightly slower at night....but I thought that this has something to do with the fact that most of the VHT is gone by then...
Thread Starter
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by Glensgages
What were your respective MPH-figures for each run, and how-much slower was the short-time on the 11.21 ET-run?
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by 77TSi-meez
Good to hear ur nearing that 10 mark. Olivier sometime ago u stated a
1000 hp TH350 was available to you from somewhere. Is this still
true or did I misread a post? I'm considering one ... Was it CPT?
1000 hp TH350 was available to you from somewhere. Is this still
true or did I misread a post? I'm considering one ... Was it CPT?
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Thread Starter
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by Aflac
that seems odd.. you would think that cooler denser air would make for better times...
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From: Smalltownville Michigan
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St. Jude Donor '09
are you breaking traction at all????everything i have been taught and read says that the moister and cooler the air is, the better the car runs...my thinking is that the engine may be overpowering the car in cooler wet air...
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by Aflac
are you breaking traction at all????everything i have been taught and read says that the moister and cooler the air is, the better the car runs...my thinking is that the engine may be overpowering the car in cooler wet air...
Generally, my daytime passes were usually always faster than my nighttime passes...
Last edited by GrandSportC3; Oct 16, 2005 at 07:12 PM.
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From: Smalltownville Michigan
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St. Jude Donor '09
did you compare to anyone else that was running at the same time? if they did the same thing, that would tell me that the track changed.
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From: Little Italy MI
Originally Posted by Aflac
are you breaking traction at all????everything i have been taught and read says that the moister and cooler the air is, the better the car runs...my thinking is that the engine may be overpowering the car in cooler wet air...
Racer
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From: Little Italy MI
Originally Posted by GrandSportC3
My 200R4 is from CPT but the 1200 HP TH350 is available from a local builder... He want's about $1200 - $1500 for a 1200 HP rated TH350.. A high stall converter for the same power rating is additional $800 or so.. (the guy builds the trannys but not the converters)
Thanks for any info that you may have its much appreciated.
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From: Smalltownville Michigan
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St. Jude Donor '09
Originally Posted by 77TSi-meez
He's saying that the car likes the lower humidity. R u saying the opposite now I'm confused.
that is my line of thought. normally, engines like cooler denser air. However, some of the fastest times in the NHRA are ran at Heartland Park Topeka in the heat of the day in the summer. It's hot and swampy muggy...
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From: State of Confusion
Originally Posted by Aflac
that is my line of thought. normally, engines like cooler denser air. However, some of the fastest times in the NHRA are ran at Heartland Park Topeka in the heat of the day in the summer. It's hot and swampy muggy...
I don't follow the NHRA circuit like I used to (back-then, Heartland Park Topeka hosted their National event in late-September/early-October, so the air would've been much-better than mid-summer ), but I'm assuming you are talking about low-ET at HPT, which would be a function of traction, clutch, and gearing, and how efficiently the available HP is being used.
Topeka has ALWAYS been one of the best-prepped tracks on the tour, which may explain the low-ETs that we see in bad-air.
The Tony Schumacher-driven, Alan Johnson-tuned U.S. ARMY Top Fueler went 336 +tax at Columbus, and 337 & change at Brainerd, earlier this year, 2 tracks never known for low-ET:
they ran the big-speed due to nearly-optimal atmospheric conditions.
Ollie:
you said earlier that you slowed-up .07-seconds in 1320', slowed-up .02-seconds in 60', and lost 2 MPH when the air got slightly-better.....
#1- I think the fact you LOST 2 MPH in better air says it wasn't making as-much smoke at 2300' DA is it did at 2700' DA.
#2- 'typically', for each .01-second you gain/lose in 60', your 1320' ET is effected approx 1.5-to-2 times as-much, when all other factors (DA' and available HP ) remain the same, and the trap-speed would remain constant.
(i.e.- a 60' that is .02-slower would typically mean the 1320' ET would be .03 or .04-seconds slower, but you slowed-up .07 seconds)
In the evening run, you were slower to 60', but even-SLOWER the further you went, when compared to the earlier 11.14 run.
I've not seen the ET-slips, but I'd 'guesstimate' the 11.21-run, when compared to the 11.14-run, was:
+.02x to 60', which you already stated
+.035 to 330'
+.05x to 660'
+.06x to 990'/1000'
+.07x to 1320'
..... am I even-CLOSE?????
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With all the other variables...like engine, trans and rear temps etc taken care of..
I'm inclined to think of the mixture/timing etc and not making power. If you lose 2 mph, you aren't making as much power.
So my thoughts are that your tune is pretty close in the low humidity/hot weather.
Humidity is moisture and moisture displaces space that could be taken up with oxygen. So even though temps are down, you aren't getting as much oxygen in the cylinders as you might think. So if tune was good in the heat..or even a little fat, when humidity goes up, you may be even more fat.
I know the A/F ratio is a neat tuning tool...but it's just that. it is NOT a final determiner of correct jetting. Only plugs will tell you that on a motor doing what you're doing.
I know you are just starting to play with jetting on it,,,but you need to get a high intensity light and magnifier so you can really see deep into plugs and get someone to spend a little time with you showing you what is what. Reading plugs is as much art as science. Listen to whoever you find that knows there stuff.
What have you noticed on baro pressures?
JIM
I'm inclined to think of the mixture/timing etc and not making power. If you lose 2 mph, you aren't making as much power.
So my thoughts are that your tune is pretty close in the low humidity/hot weather.
Humidity is moisture and moisture displaces space that could be taken up with oxygen. So even though temps are down, you aren't getting as much oxygen in the cylinders as you might think. So if tune was good in the heat..or even a little fat, when humidity goes up, you may be even more fat.
I know the A/F ratio is a neat tuning tool...but it's just that. it is NOT a final determiner of correct jetting. Only plugs will tell you that on a motor doing what you're doing.
I know you are just starting to play with jetting on it,,,but you need to get a high intensity light and magnifier so you can really see deep into plugs and get someone to spend a little time with you showing you what is what. Reading plugs is as much art as science. Listen to whoever you find that knows there stuff.
What have you noticed on baro pressures?
JIM
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From: Lakeland, FL
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St. Jude Donor '03, '06, '17
Originally Posted by 77TSi-meez
Is this local builder someone notable with a website? If not could you share some info on how to contact them. Last..... How good r they?
Thanks for any info that you may have its much appreciated.
Thanks for any info that you may have its much appreciated.