Losing power in high rpms
05-28-2009, 12:58 AM
#1
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Losing power in high rpms
So i went to the track today with some really dissapointing results and my last race has led me to believe that this truck is really losing power in the higher rpms.
My last race i came off the line well, shifted to 2nd with little wheelspin and hit 3rd with no problems. The friend i raced has a 535i from the 80s thats been having engine trouble. I killed him off the line and all the way until 3rd. While i had it pinned in 3rd, i saw that my friend who was formerly 1-2 car lengths back was walking right by me. At this point driver error comes right out of the equation. I am ahead of him, he's driving a car that might make (140whp at this point) and it walked by me.
Any ideas? A friend of mine is thinking that it might be my shitty autolite iridiums. According to him iridiums are suppose to be pre-gapped, but these werent.
My last race i came off the line well, shifted to 2nd with little wheelspin and hit 3rd with no problems. The friend i raced has a 535i from the 80s thats been having engine trouble. I killed him off the line and all the way until 3rd. While i had it pinned in 3rd, i saw that my friend who was formerly 1-2 car lengths back was walking right by me. At this point driver error comes right out of the equation. I am ahead of him, he's driving a car that might make (140whp at this point) and it walked by me.
Any ideas? A friend of mine is thinking that it might be my shitty autolite iridiums. According to him iridiums are suppose to be pre-gapped, but these werent.
05-28-2009, 08:43 PM
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first thing that came to mind is fueling, it sounds as though your not getting the fuel need'ed. What are the specs on the ride? What injector's are in there?
05-28-2009, 08:54 PM
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I can try to log an actual pass next wednesday.(not sure how sac raceway will like me driving with a laptop in the pass seat though?)
On the colorado forum i'm at, i was basically told it was my gears. That they were too high for drag racing. However, coloradoss(on here) has them with his automatic truck and NorcalSS(i think he's on here) had a friend with a stick and 4.10s. Both of which were pulling 14s instead of my crap times.
I did these two logs this morning, but the same person who told me my 4.10s were an issue also told me that they were useless. What should i be recording on a log? I don't use my hptuners all that often.
Viciouskid- the rpms climb like usual, but it just feels like the power drops off a cliff.
the 1st little log was the exact tune from last night.
the 2nd is when i went completely back to oem settings, but removed the tq management. I'm not sure it made much of a diff.
Average time without 4.10s:
RT: .196
I1(60): 2.457
I2: 6.923
I3: 10.496
I3 MPH: 69.118
I4: 13.581
ET: 16.193
MPH: 87.145
Best time of the night w/ 4.10s
r/t: .082
I1: 2.467
I2 .000
I3 10.757
I3 mph: 67.2
I4: 13.9
ET 16.513
MPH: 88.913
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05-28-2009, 09:00 PM
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someone with more tuning expierence then me could provide more information, but whats your airflow/fueling table's, and timing tables look like? maybe the tune is out of whack since the 4.10's...
05-28-2009, 09:37 PM
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I'd hope someone with more experience could chime in too. I never touched them, my "tune" was really basic. I picked it up back when this was the only option to remove the speed limiter and TQ management. I've been a bit gun-shy to mess with anything else.
