If I wanted I could stick on the Deka 60lb I had on originally. THats way to much injector for this combo tho and the reason why I went with the 41lb.

 

Shouldn't matter tho. The Terminator will only inject what's needed. I run a 210# injector on my car and I'll never need all that

 

But it does matter, and depending on the combo it can just sit there and ride the minimum pulse width at idle and light part throttle cruise areas. Then you can run into injector timing problems with larger injectors if it's not done properly as well. Now whether the average person tuning their car will even realize these things is a whole different matter but I would say that most wouldn't even realize it because "it works". I tell people general rule of thumb is to target around 80% duty cycle for your combo/injector size to eliminate some of these possibilities.

 

That was my thought or what I've always known/read. You loose the low end tuning with a massively oversized injector. Sure a 210lb/hr on a 5.3 will idle but does it have the same drivability as a properly sized injector. Same thing with a tune which has low res you looking alot of tunability when your jumping 20 KPA between cells when 5kpa gives you much better resolution but makes the table bigger. I'm sure it would work but you would be losing some of that light/part throttle tuning. A 400hp on gas at 80% duty is 28lb, so I'm still way oversized as the 41lb/hr at 80% is enough for 600hp NA.

 

That VE table is......well needs to be fixed.

 

Thanks tips. That's probably the most ridiculous thing you could say. Did you have anything to add or just it needs fixed??

 

He's been posting odd crap in some other threads too. I suspect a bot or troll here

 

Yea most likely. His post count is 10

 

Finally had a chance to look at this as well, looking at the last zip file that was posted...

- Upgrade your software, it's V1 which was released in 2019 I think and currently it's V3.
- That timing table is very generic and has way too much timing in the low RPM at high load and not enough timing at low/mid/high RPM at low load.

What you described here, "My issue is at light throttle The engine revs/accelerates just fine through the RPM 3k+ through all gears (700r4). But when I give it more throttle say half or heavier after like 2000-2500rpms it like hesitates and breaks up basically falling on its face till I let out or get above that 3000-3500rpms. I also floored it when this happened and the car felt like it had no power but the car feels faster sometimes depending on when I stab the throttle and depending on the gear I'm in. I did a datalog of one of the runs and Its very weird... looks like its dropping out of closed loop and going to open loop? Then when I come off the throttle the closed loop comes back on."

Do you have an instance of this in your last zip file log? Give a time stamp of where if you do. What you are describing is more than likely acceleration enrichment or MAP/TPS rate of change disabling closed loop.

 

Sorry, I was working on the car and making some changes. Just started driving it again and got a new log and new tune changes. I'm still rocking V1 sorry, I'm not ready to update and start over just yet.

General breakdown of car:

1978 c3 corvette
Stock 2.70 rear gear
255/60r15 copper mastercraft tires (27" tall)
built 700r4 550hp, 12" 2000 stall stock style converter
Unknown year/mileage 5.3 (pre 04 as it has gen 1 rods)
Stock bottom end, HV melling pump
Stock 799 castech heads (no leaks/cracks) Stock MLS style 5.3 head gaskets
Stock rockers, PAC 1218s, 5/16" moly pushrods and Morel 5315 lifters
Summit OG 8719 stage 1 high lift cam. 209 int./217 exh..550/.550 112 lobe
Dorman LS6 intake
Stock 78mm cable TB
42lb LS3 corvette injectors
1 7/8 Long tubes, 3" dual exhaust with Xpipe full length

So I was able to fix what I think was loading up and the car now pulls pretty good through 5500 in gear 1 and 2. 3rd gear is when load is the highest and I'm not sure its tune related and maybe just mechanical load. I was at a light and when WOT (see log attached) tires did not spin but got a smidge of chirp (my 87 firebird with a 5.3 would light up drag radials before boost and that has a 218/228 cam) so I think its gearing and tire. Pulls good up to 5500, shift manually to 2nd got a chirp and kept accelerating. I pulled to 5k (my stock tach is progressively off so I thought I pulled to 5500-6K) and manually shifted to 3rd, car accelerates but not nearly as fast as gear 1 and two. Stock tach starts floating around 100-110 and I let out which was apparently only 4265rpms in the log. The car feels softer in 3rd does that make sense like the tall tire and really tall gear is bogging the motor down causing me to stick around in the 3-4k range where obviously power isn't very high on a mild cam 5.3?

My thoughts are the car has more mechanical leverage with the 1st and 2nd gear rations which allows more leverage to overcome the gears and tire and spin up, then 2nd kicks in which still has more leverage from the trans plus the 3400ish start, then 3rd kills all my leverage and I have the same 3200ish shift return.

• First: 3.059:1
• Second: 1.625:1
• Third: 1.00:1

I pulled alot of timing out of the spark map in the loaded areas and leaned it out as it felt like it was loading up. The car responded better and that dead spot kinda feels like its gone now. Not sure on the HP of this combo but I would suspect 40hp over stock which would put me in the 320-350hp range depending on motor health and maybe thats just what this feels like? I personally think its the gears that are holding me back but gear swaps in these cars (especially the 80-82 aluminum rear) are almost non existent. You can see in the log graph how 3rd gear looks so much longer and drawn out as thats basically how it feels while driving the car. Maybe my expectations where too high for the car with this HP and gearing. Car drives great on the street as I can mostly never need to go into 4th unless I want to on the highway for fuel economy. I still have the cars 383 which I'm going to build up alittle and maybe that would offer enough tq to keep it moving pretty good with the gearing in this thing. Thinking it will be about 380-400hp 5500k peak with a tiny comp cam 218/224 and ported vortec heads but should make 450lbs all day.

I guess any insight would help at this point. The tune and log are attached.

 

Tune - wouldn't let me attach before.

 

You can update firmware without having to start over. Just be sure to save your tune somewhere then update and when you open it again it'll be saved for the updated firmware

 

Might do that over the winter then.

 

So I decided to just dive in head first. I don't think the tune is perfect but I believe its safe to say if I can rev out in 1st and 2nd that its likely gearing. I pulled the rear out of the car, which looks stamped 2.87 but I counted 2.72 but could have been 2.87. Either way its out and I'm getting 3.73s. When I was pulling the rear I found a few things (of course). The rear feels good (not alot of play and spins smooth) I have the 1350 joints and 3" half shafts. I found that a few had seals broken on the half shaft joints and some broken off and missing which was slinging grease in the plastic end covers and leaking out around the joints. I also found that the batwing brackets were like only 50% welded in on each side. I had to pull the driveshaft and the rear tranny cover so I can swap speedo gears for the 3.73s. Last night I flux welded the batwing brackets as best I could (not alot of room) but they feel much better than before.

• new rebuilt 3.73 rear coming
• New solid Spicer 1350 u joints
• new caps and bolts ( 4 stripped getting them out)
• 15/42 speedo gears
• gona also get a new tach board as I tested the speedo and its off 250 at 1.5k, 400 at 3k and 600-700 at 6k (reads high).

The only thing I haven't touched on this car now is the rear trailing arms and the front hubs/ball joints but I believe they were rebuilt and not factory original. I think the new gearing will really wake this car up and if it does I'll likely leave the motor alone and just iron out the tune. I have to pull the front cover for a leak so I was thinking of stepping up to a stage 2 cam like a 218/228 style.