4.8 with a 70mm turbo cutting out at 5200 rpm

[gowin2fast]

Here are my specs

1970 chevelle

running speed density open loop
4.8 from a 2002 silverado
ls6 cam and valvesprings from a 2002 corvette
edelbrock pro flo intake
ls9 injectors
92mm fast throttle body
70mm master power turbo wastegate set for 6 psi
31x4x12 intercooler
turbo 350 transmission with a 3500 stall
Tr6 plugs

This is the first vehicle I have ever tried to tune. I wanted to learn how to use hp tuners and since this motor was only $250 i figured why not learn on this. I have read many stickies on here and ls1 tech and have learned quit a bit. For some reason, my car has started cutting out around 5200 rpm and I can not figure out why. I am not sure if it is tune related or what. Any help would be appreciated. thanks for any help in advance!

ls9 final2 with ls9 spark table and fuel tables2 w intercooler.hptdrive to shop.hplstomp from shop.hplstomp to the shop 2.hpl

[gowin2fast]

I forgot to mention. I have an aeromotive boost reference fpr that sees manifold vaccum

[mecanicman]

How fast you going, what gear you in when this happens? Are you coming up against speed limiter? What are plugs gapped too? Config could use some work, where is commanded afr high res?

[gowin2fast]

I would say 35-40 mph in first gear. I have 3.08 rear gears. My plugs are gapped to .025.

[mecanicman]

Do you have a speed sensor tied into the computer?

[gowin2fast]

I do not

[mecanicman]

I suspect you dont have enough timing. But your not scanning enough to see. I suggest getting rid of map sae and injector flow rate. You have 2 unsupported parameters I cant see, between 2bar and cylinder airmass, and under injector duty cycle. What are they? Add commanded afr high res and a/f error. Run your current file and make sure your afr is inline. I have made some modification to your file, have look. I dont recommend trying it until you have confirmed afr.

[gowin2fast]

Thanks a lot! I will make the changes and see how it goes tomorrow. I appreciate the help!

[gowin2fast]

i figured out the problem! One of the plug wires was not on the coil all the way. I took it to the race track and it went 12.3 at 112. In my log, the chart and the table have two different reading for map?? Any idea why this is? thanks in advance. Also for some reason it kept pulling timing???? I can not figure out why it is doing this?


ls9 final2 with ls9 spark table and fuel tables2 w intercooler.hpt
12.36 at 112 timing still messed up.hpl

[Cyrperformance]

Hopefully someone will chime in on the timing issue, it didn't show any KR in the log, but you will want to add bigger injectors, you were 80+ a few times.

[gowin2fast]

Yeah, the ls9 injectors are not going to cut it lol. Any idea why the chart and the table are showing two different map readings?

[Cyrperformance]

Delete the Map SAE in the left column of the table. That may be causing the slight difference. I only see about .1 to .5 variance not really sure unless the SAE is throwing it off.

[gowin2fast]

ok I will do that. I saw on one table the 2 bar map was reading up to 190kpa but the charts and the histograms read under 150

[Cyrperformance]

yeah it looks like it is cutting the difference between the 2 readings in the table and plotting that into the chart, also what is the unsupported parameter under the map 2 bar? if your not using that PID then delete it, also delete the injector lb per hr PID and the last line that list unsupported parameter if your not using it.

[gowin2fast]

Ok, I deleted all of the unsupported parameters and all of the other stuff I didn't need in my table. So, I was thinking the car was only making 7psi of boost.....was it really making 13???

[Cyrperformance]

Do you have a boost gauge in the vehicle? Should be run off the manifold as to show accurate amount actually entering into the engine. Not sure but does look like it in the table.

[gowin2fast]

I do have a boost gauge, but I did not watch it during the run. I deleted a lot of stuff on my configuration but I need rear end gears before I can drive it again. Lol

[Cyrperformance]

I found that using a GoPro like camera to record the gauges works really well. I found an SJ4000 (looks just like a GoPro) for $80 and $20 for 2 extra batteries and 110 charger, on Amazon that works really good. I use it for when me and the family go riding and after the first couple times of use I ended up getting three more to put on the kids bikes. Then watched Sloopy Mechanics Fairmont videos and thought, good idea. It just came in super handy as I am having issues with my WB going out at certain points.