Went to the track with new mods…went slower?

lightning25

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So I went to the track Friday night to test my new mods and see just how much difference the 6lb lower, ported blower, SCT2600, heat exchanger, M/T ET streets and a tune from JJ would make.

Well….i went slower!!!
I don’t understand it.

I don’t have my dyno graphs scanned on the computer, but I will try to get them if needed. I am making 40 more hp and 35 more ft-lbs of torque at about the same rpm.

Here are my slip #’s

Last year’s best: this year’s best:

60’ 2.033 2.209
330 5.639 5.883
1/8 8.610 8.863
mph 82.79 84.05
990 11.174 11.476
1/4 13.26 13.68
mph 102.97 99.83


I lowered the air pressure in the tires to 16psi as well, and the track was prepped. I can work on my launches, I just don’t get how I am going slower with more power.

Anyone have any ideas to this huge dilemma ????

Thanks,

Sean
 

ecoastkid

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what was the difference in the weather?

also, every tenth off your 60 ft is about 2 teths off the big end. That would have mad you run an equal time.

I'll bet it was a combo of the two above
 

lightning25

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i have JLP traction bars

temp was about 20 degrees warmer from friday to last year but 3 weeks ago i ran 1 tenth slower than friday night and the temp was only 60.
 

Tazman1

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Seems to me, that you need to practice on the launch of your new found power?

I had the same problem as you since last year. Now I have to buy some better drag radials of some ET streets.
 

lightning25

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no aftermarket stall....i held at about 1400 on the stock stall.

can it be just the launch thats killing me?? what about the extra power and the slower trap speeds?
 

Ct.TOPGUN

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The trap speeds should be higher. Make sure the intercooler pump is operating. Also, the stock converter can be going out based on the MPH. Your 60' times need work to see good results.
Jim
 

02SILVERBULLET

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The trap speeds should be higher. Make sure the intercooler pump is operating. Also, the stock converter can be going out based on the MPH. Your 60' times need work to see good results.
Jim


+1 your 60' was worse and thats a big part, you should be able to gety low 1.8 60's with stock stall, traction bars and et streets, but your 8th mph went up it shows your making more power, but the falling off at the end tells me your ic pump might not be working.
 

Lord Tauk

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Data logging helps debugging issues that may not be driver related.

Like everyone else says, the 2.2 60 foot isn't helping.
 

lightning25

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i/c pump works.
charge temps with my gords ford heat exchanger and new coolant were only 20-25 degrees higher than intake air temps (after my run). and i was using the i/c pump and the fans for my heat exchanger to cool the truck while i was sitting in the pits after each run - i always check to make sure they are both running.

how could i test to see if my converter is going, and what would cause it to go after only 65,000 km's (40,000 miles)? the truck isn't abused and wasn't by the previous owner.
 

Ct.TOPGUN

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It's called heat...

Heat is certainly a part of the answer, but the dropoff in MPH is more significant than the 20* would cause.

Am I correct in my assumption that the truck was previously running stock boost and tune? Now adding 6# lower, blower port, and tuning? A call to JJ seems in order.
Jim
 

lightning25

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Like said above your 60' needs to improve. Try a little more air 18-20psi you might be surprised by the results.
What was the DA? that has a lot to due with performance on a force fed motor. http://wahiduddin.net/calc/calc_da.htm
Your MPH looks low for your mods. How rich is the tune and how much timing?

i'll try more air next time, i should have done it on friday, but i was told that 16psi should be good for those tires.
i don't know all the info for the DA, but it was 85 degrees out, and altitude is 640ft above sea level.
the truck at WOT runs about 11.6a/f and 14 degrees of timing.

Heat is certainly a part of the answer, but the dropoff in MPH is more significant than the 20* would cause.

Am I correct in my assumption that the truck was previously running stock boost and tune? Now adding 6# lower, blower port, and tuning? A call to JJ seems in order.
Jim


not it wasnt stock before the current configuration. it was running with a 4lb pulley, ftvb, jlp intake, traction bars, sct chip and a tune.
i spoke to JJ, he is telling me i need to get my 60ft times down in order for him to see what else is going on.
i have datalogged from a previous run i made this year, in which i ran shitty times as well (different track). the temp was about 60 degrees and i ran a 13.75. i can upload the graphs from those runs on here if you guys want but i don't have them on the computer im on right now.
 

Ct.TOPGUN

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If you just went from a 4#er to a 6#er I believe the performance difference is just weather related.I would not expect much if any MPH increase, but I would expect a better 60' time. Practice your launch techniques and be ready for better weather.:thumbsup:
Jim
 

PhLoBuS

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could be the heat, also make sure you have the newest parameters set on your sct. you have an SCT2600? or do you mean sct2400 or 2800? I was having problems with my 2400 because SCT had the wrong parameters set and it was really limiting my fuel at WOT.
 

lightning25

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could be the heat, also make sure you have the newest parameters set on your sct. you have an SCT2600? or do you mean sct2400 or 2800? I was having problems with my 2400 because SCT had the wrong parameters set and it was really limiting my fuel at WOT.

i have a 2600 MAF

wouldn't a fuel issue be shown in the a/f ratio? if you weren't getting enough wouldn't you start to lean out?

as for adding a 6lb'er, from what i've seen on this site there should be more than just a mile or 2 increase in my 1/4 mile times
 

Lightning_Bolt

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going from 4lb to 6lb = about 2 tenths. Weather = 1 tenth for every 10*. so 20 degree hotter = 2ths slower. every 1 tenth differance on 60ft makes about 2ths at 1/4 mile. so 2 ths slower 60ft is 4ths slower 1/4 mile. :??:
So it seems your times are about right considering the above.
 

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