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Anyone use Holley HP EFI on an LS1?

Not being a smartass but one of your problems is mailing off computer to get tuned no one can program a computer that's gonna be perfect for every motor take it to a tuner/dyno and get it done right where they can see what it's doing to make proper adjustments or have lebron bring it to flatnasty with him. I have a guy down here that's very good with tuning and trouble shooting these motors
 
NTIDWELL said:
Not being a smartass but one of your problems is mailing off computer to get tuned no one can program a computer that's gonna be perfect for every motor take it to a tuner/dyno and get it done right where they can see what it's doing to make proper adjustments or have lebron bring it to flatnasty with him. I have a guy down here that's very good with tuning and trouble shooting these motors
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Certainly not being a smartness either. I appreciate any input anyone has, but if you've read what I've posted:
Jim's performance did the tune. So mailing it off doesn't work. I agree. Kind of kills his business model though.
I have an appointment Monday with a tuner to make another attempt to tune.
I'm in northeast PA. Nowhere near Labronn. So if this guy can't get it I'll change fuel injection systems, sell what I've got and tune it myself.
 
yankster said:
Certainly not being a smartness either. I appreciate any input anyone has, but if you've read what I've posted:
Jim's performance did the tune. So mailing it off doesn't work. I agree. Kind of kills his business model though.
I have an appointment Monday with a tuner to make another attempt to tune.
I'm in northeast PA. Nowhere near Labronn. So if this guy can't get it I'll change fuel injection systems, sell what I've got and tune it myself.
Click to expand...
:dblthumb: I'm sure your tuner will get it worked out and I'm really sure you'll be happy with the Holley system Good luck hope it all works out for you
 
Have you adjusted your air fin on intake it might not be far enuf open making it higher rpms at idle
 
There is an Allen screw on side of throttle body that will allow you to adjust plate to open up faster we had to open it up on my 02 lq4 do to increased fuel at idle make sure when you open throttle wide open plate is opening all the way up a lot of info on ls1 tech talking about this. (We had to have my old one set where it wasn't shut all the way ) it basically a manual override for iac
 
I have been on the phone twice today with Holley about the HP. On hold first time 46 min., second time almost 30 min. Good thing I am at work ;D. The plug and play unit for the LS is Pt # 550-602 on their web site it is out of stock. Tech told me backordered units will ship next week. He said they couldn't keep EFI stuff on the shelf. I asked how long of a wait if I ordered today, he couldn't tell me.
 
Seems like I saw a picture of Bombshell somewhere with what looked like the MSD Atomic rails on there. Did this help? How do you like it?
 
1TONTJ said:
Seems like I saw a picture of Bombshell somewhere with what looked like the MSD Atomic rails on there. Did this help? How do you like it?
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When I first installed it and got it into learning mode it acted the same as before. I had to modify the exhaust because the header was so short it was sucking back fresh air and confusing the O2 sensors. I ended up drilling the throttle body hole out as well (5/32"). I had the idle screw opened so far that I couldn't get it to idle correctly, even with the TPS sensor mounting holes slotted and rotated back. I also added an Advanced Adapters VSS input to the computer which keeps the idle up when it sees a speed. After that it was completely tunable. I raised the idle to 800 rpms and played with timing and fuel mixture while she was driving to get it as close as I could. It still stalls occasionally if you go from heavy throttle to heavy brakes but I can live with that. May happen two or three time in a day of wheeling. I'm sure that the Jim's setup would have been fine with a decent dyno tune but I gave up on that due to my location.
If anyone needs a Jim's computer and harness for a LS1....

Heres a before and after of the exhaust. I cut the tips off the mufflers and welded on v-band clamps. I bought some stainless 2.5" 90* elbows and I coped and welded them together leaving the center open like an x-pipe. This added 24" of exhaust length to each bank but only sticking out 2" farther than before the mod. Before this the O2 sensor would jump from 11:1 all the way to 16:1 with no consistency. Now it's set at 13.8:1 and never gets out of the 13s.
 

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I've had more bad tunes from Jim's performance than good ones.

sounds like you swapped it out though? If not, I'm in north NJ and have a good dyno tuner here if you need it.
 
You could also manually tune the fuel table around idle and run whatever exhaust you want.
 
yankster said:
I ended up drilling the throttle body hole out as well (5/32"). I had the idle screw opened so far that I couldn't get it to idle correctly, even with the TPS sensor mounting holes slotted and rotated back. I also added an Advanced Adapters VSS input to the computer which keeps the idle up when it sees a speed. After that it was completely tunable. I raised the idle to 800 rpms and played with timing and fuel mixture while she was driving to get it as close as I could. It still stalls occasionally if you go from heavy throttle to heavy brakes but I can live with that. May happen two or three time in a day of wheeling. I'm sure that the Jim's setup would have been fine with a decent dyno tune but I gave up on that due to my location.
If anyone needs a Jim's computer and harness for a LS1....
Click to expand...
I have a problem with mine dying as well. I brought it to a tuner an hour away and he leaned it out a lot and got it running much better, but when I got home it died while unloading it. I guess it needs to be warmed up a little? I'll have to take it wheeling to see if it still dies after heavy throttle to brakes.

I may try drilling out the throttle blade trick too. Did you use the AA VSS sensor that mounts onto the Atlas tail housing? I don't have the VSS hole in mine.
 

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