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Problem with FAST LSX rt intake

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Old 02-27-2011, 12:20 PM
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Also, on cabe driven setups, it is very important to mechanically introduce the additional airflow needed at idle for cam/head setups etc.. Using base airflow tables to obtain a stable idle will cause funky surges when driving. The IAC can only do so much. I like to leave the base airflow close to stock, add to the startup airflow tables and crack the blade open to obtain my target IAC count at idle. Once thats done and startup and P/N idling is good, then i'll work on drivability with the follower and cracker tables since they are only affecting airflow mostly when the vehicle is moving or when there is a rapid change in TPS. Alot of times, the cracker table can be reduced because you have manually increased airflow at closed throttle via the blade adjustment. Also have to make sure fuel and spark are optimum before airflow tuning.
Old 02-27-2011, 09:46 PM
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No surging here,very solid!!
Old 02-27-2011, 09:53 PM
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Originally Posted by Rhino79
I have found they are more difficult to tune, but most of the time its because people try to keep adding air to the cracker and follower tables. A lot of times, the surging is from a condition where there is TOO much airflow. When the PCM or ECM has a target idle speed to hit and the airflow commanded is too high, it has to resort to pulling timing to try to curb the overspeed condition and it can cause a buck-nasty surging effect that usually goes away upon coming to a full stop (at the same time the throttle cracker airflow is disabled). Yes they can be more involved to tune, but a good tuner can tame it for sure.
so guess you agree its a tuning issue lol

Originally Posted by Wheatley
No surging here,very solid!!

i heard you had a badass tuner lol!!!
Old 02-28-2011, 12:08 AM
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Originally Posted by skeet
so guess you agree its a tuning issue lol
Yessir!
Old 02-28-2011, 12:31 AM
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It idle pretty good for a while then it starts speeding up slowly and slowing down, and it does that a few times and then it stalls, like it's searching.

I've got an idle clip but I don't know how to upload it.

I'm reading up on how to set up hp tuners to check IAC, LTIT & STIT. Never really tuned for idle before.

I also have a problem with my temp gauge not working.

Also i don't know how much difference it would make but the converter and transmission aren't in the truck yet.
Old 02-28-2011, 12:47 AM
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I read that IAC count should be 40-60 counts for a cammed engine compared to 60-80 for a stock is this right? The cam I had before was 226/226 .585/.585 112LSA, the new one is 226/230 .598/.600 113+2 LSA.

Do I check the TPS volts with a test meter or is there a way to check that with HP Tuners?
Old 02-28-2011, 08:48 AM
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Check the iac counts in your scan tool, open the tps a little at a time with the engine warmed up untilthey settle into the correct range. I would also think the trans would need to be installed to get the idle air accurate.
Old 09-23-2011, 12:01 PM
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I got Geoff Skinner @ Engine Power Systems in Baton Rouge to tune it and Dyno it. It made 338 RWHP and 290 ft lbs of tourque the torque curve is wide and flat, when I get home in a couple of weeks i'll try to post it up.
Old 09-25-2011, 09:10 AM
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Originally Posted by Wheatley
No surging here,very solid!!
I bet you not using the FAST 102 throttle body, Geoff Skinner said there is a design flaw, in it and has talked to the engineers at FAST. They weren't even aware of the airflow problem in the idle part, because they aren't tuners.
Old 09-25-2011, 11:15 PM
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Originally Posted by ByuTrukr
I got Geoff Skinner @ Engine Power Systems in Baton Rouge to tune it and Dyno it. It made 338 RWHP and 290 ft lbs of tourque the torque curve is wide and flat, when I get home in a couple of weeks i'll try to post it up.
Not to shabby Geoffs dyno isnt so forgiving!
My old setup only put down 301 there
Post up your graph!


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