Funny Looking VE Table?

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Funny Looking VE Table?

Postby AWB » Wed Sep 06, 2017 6:59 pm

I'll start with the hardware. 5.3, LS1 cam, China GT45 turbo, decapped stock injectors which flowed 82lb/hr at 58psi, run by a Gold Box with a TinyIOX that is handling the wideband and some extra I/O.

As you can see in the attached MSQ the VE values decrease under boost, this is the opposite of every other forced induction VE table I've seen. I'm not very worried about it, because the truck runs great(it went 98mph in the 1/8th on only 11psi), just trying to learn as much as I can about tuning and EFI.

I will add that the injector size in reqfuel is incorrect, I played with this early on to get the base tune closer and never fixed it. The actual flow of the injectors should be 74lb/hr(base fuel pressure is 50psi). Also, the injector dead time is likely not correct, I played with this some but haven't bothered to get it nailed down. I'm not sure how these could cause the funny VE values though.
Attachments
2017-09-06_21.10.39.msq
(275.38 KiB) Downloaded 19 times
2017-08-25_21.54.49.msl
(1003.29 KiB) Downloaded 13 times
AWB
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Re: Funny Looking VE Table?

Postby turbo conversion » Thu Sep 07, 2017 1:52 pm

You need to get reqfuel and injector time correct before doing anything else.

This will save you a ton of headaches in the long run.

David
1976 Datsun 280Z L28ET Garrett GT35R T3-T04E stage3 50 trim 63 A/R housing custom grind cam 2000-6000 rpm 440cc injectors intercooled 18 lbs. boost
3" exhaust turbo back LC-1 o2 sensor Hallman manual boost controller EDIS 6 ignition batch fire 60mm throttle body 5 spd T5 borg warner 3.54 lsd
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Re: Funny Looking VE Table?

Postby elutionsdesign » Fri Sep 08, 2017 7:12 am

Just means your air flow is dropping, probably the turbine is too small to flow any more.
Graduate of EFI University.

I build, repair, install and tune Megasquirt systems in North Dakota and beyond!
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