If you can, Please post back here how the oil pressure tables i provided work.Originally Posted by AvilaLSX
They currently only have a few people using them other than myself and may still have a couple kinks or clarifications to add
Good bad or ugly,
I dont have any secret information so everything i have found thus far is from digging and sifting and some educated guessing
Ok so I got to spend some time testing out changes to these tables while I tuned the car. This is a dry sump lt1 corvette gs. It has TSP el c7 cam and BTR trinity intake and more. 12.5:1 compression. This is the second one I?ve seen that sat in the 40-50psi range at higher rpm. Did it stock before mods and after.
When I look at the high and base pressure tables, it seems it is what GM is commanding. I believe the high and low desired tables are models GM engineers set up for the ECU to know what to expect from this pump at different RPM & oil temp.
On the base/High tables I changed the rpm axis to extend up to 7500 rpm and commended the high side to get into the 70 psi range. It is not able to match what I am commanding. The oil pressure fluctuates worse as it tries to. It will hold the 45psi steady. Gets as high as 55 and fluctuates to 50-55.
What did work well was using the torque enable/disable settings. I can see an immediate spike to the high side at my requested torque.
The minimum table is set to like 2psi. I bumped it to 10 but I have not done enough testing to know how this table applies. If it is just a minimum to trigger an oil light? Idk.
I sent the tune with the oil pressure base/high tables back to stock values, but torque set to enable high pressure in the 4500/5500 rpm cells.
Thank you for the detailed feedback here.
I appreciate the feedback that the oil pressure torque control tables work as expected, it was a long shot in the source to link them to engine torque.
I agree with you on the base and high desired tables, They appear just to give the ECM an idea of where the oil pressure should be.
The minimum table I have recently been calling the threshold table. In my experiments if you set the values in the table high (600kpa) ish, you should see the oil pressure switch to high mode in the cels you choose.
I have had multiple customers very happy with just this table before i identified the other ones.
Interesting...I had my LT1 rebuilt, DOD/VVT delete, but left the OEM stock oil pump. It is variable and it runs low pressure during lower RPMS. They go as low as 10-15 PSI during low RPMs.
Wondering if this could be tuned so it doesn't run so low pressure? Is that possible or am i mistaken about this post?
Thanks,
Pjs
For a long time now I have wanted access to oil pump tables to see GMs strategy. Thank you for making that possible. It seems like they are all reluctant to go to the high side IMO. I should?ve asked about the minimum table ahead of time to try that before sending the car. I did see your explanation in earlier posts but I didn?t make sense of it myself at that time.
Look forward to testing more on future cars with all the extra tables you have to offer.
Maybe the motor was setup loose on clearances. Aluminum blocks tend to ?open up? more as they get warmed up. That is why the big split in these modern 0w40/5w50 oils (my opinion). Hopefully it shoots up with RPM. Maybe try a thicker oil. Maybe your builder already recommended something. 5w50 mobil1 supercar might be worth a shot.
He did recommend thicker oil. I've been running 15w-50 ever since. Pressure does go up with RPMs, typically steady around 40 PSI. I'm just nervous about it being so low at idle and low RPMS, e.g. what if I decide to floor it, will pressure come up quick enough one day....
Pjs
I just rebuilt a l83 with ls7 lifters and it seems to have some lifter noise when it’s in I would assume the low pressure table when I unplug the solenoid motor runs quite as a mouse. Where do i go to get access to those tables?
Recently HPT added oil pressure control tables to VCM editor.
They got the Engine Torque Enable and disable correct
[ECM] 28332 and [ECM] 28333
However, their implementation of the High,Low tables is incorrect.
[ECM] 26410
[ECM] 26411
It is offset by half a row.
Screenshot 2025-04-30 102900.png
HPT does not yet have the Minimum oil pressure Threshold table defined
They have enough for you to confidently use trq based controls to switch the oil pump into high mode.
However, until they add the table, they do not have the table to switch the oil pump into high mode based on engine rpm and temperature.
Note to HPT: I am happy to help you help the community by getting these tables defined correctly.
Please feel free to reach out and we can discuss.
Update 6-9-2025: HPT has fixed the High and Low desired pressure tables offset issue, but the Axis are still backwards
Last edited by will_974; 3 Weeks Ago at 07:47 PM.
Hi will_974 ,
In the latest beta, I'm seeing new oil pressure tables (attached). Do these new tables look correct to you? One table I don't see is "Oil Pressure High Desired" (table 50006). It looks like they did shift the values in [ECM] 26410 vs what you posted. My tune downloaded is from a 2019 Corvette Grand Sport with the LT1.
I'm wringing out a new 416 build that's for track days and Time Trial events and I'd like to run it at higher pressure in the upper rpm ranges. Experimenting with oil pressure changes on a race track is not real appealing! lol
Screenshot 2025-06-09 183604.jpg
Last edited by 96GS007; 3 Weeks Ago at 06:51 PM.
They look correct as far as the data in them,
However the axis are still backwards.
the Nominal flow pressures are more for diagnostics as far as i can tell, they do not actually control the Oil pressure.
Where you want to look is under System->Variable Oil Pump
Where you will find the Enable and disable Torque thresholds along with some RPM limits that can help you achieve what you need.
I have not personaly tested HPTs new oil pressure tables in System->oil pump however I trust they did find the correct values.
The oil pressure threshold table that is more nuanced than a strict rpm limit Hp tuners does not have defined yet.
If the tables that HPT has defined in System do not work send me a PM and I will work with you to get the correct tables defined.
Last edited by will_974; 3 Weeks Ago at 07:49 PM.
Thank you! That makes perfect sense. The axis looked backwards to me but I have the scars to prove that what seems logical isn't always the case.
I have an SCCA event this Saturday so I'll have a chance....weather permitting....to test the Torque thresholds. Currently I have the solenoid unplugged and the diagnostics turned off so I have a good baseline for what the high-side oil pressure should look like. I'm quirky I guess in that I like to have as much of the GM diagnostics turned "on" as possible.
I had a chance to do some street driving yesterday and as you state Will, going in under "System" and changing the thresholds keeps the pump running at high pressure.
I lowered the rpm threshold to 500 rpm and set the torque enable / disable thresholds to 101 and 138 respectively.
On my ~25 minute drives, I hit a range of data points just cruising around and going WOT up to ~5800rpm. The oil pressure with the solenoid connected (and using the aforementioned settings) looks just like the oil pressure with the solenoid disconnected (min, max, and averages pressures across the load and rpm spectrum). The DTCs are enabled, no CEL.
Looks like success!
Thanks!
Any harm in running it like that?
For context, mine is a totally built normally aspirated 416. 570 to the wheels
I've read in a few places....so take it for what it's worth....that GM did the variable oil pressure strategy for fuel economy. All ears if someone knows the real reason.
For a street car and/or something with a basically stock engine, I'm not sure I'd bother with changing it.
Mine is bone stock with the afm turned off, but all of the factory parts are still there. I used the same settings you posted, and ran it for about 100 miles, running 65-70 mph at low load with the cruise on it stays about 50 psi, I read in another post somewhere that over in countries without EPA incentives the cruising oil pressure is 45-50 psi. I got basically the same results that you did. But before the oil reaches operating temperature it gets a little over 70 psi under light acceleration. I'm going to leave it a while and see what happens, unless some one has a different opinion.
Mine is bone stock with the afm turned off, but all of the factory parts are still there. I used the same settings you posted, and ran it for about 100 miles, running 65-70 mph at low load with the cruise on it stays about 50 psi, I read in another post somewhere that over in countries without EPA incentives the cruising oil pressure is 45-50 psi. I got basically the same results that you did. But before the oil reaches operating temperature it gets a little over 70 psi under light acceleration. I'm going to leave it a while and see what happens, unless some one has a different opinion.I'm hoping some of the experts chime in...
Last edited by [email protected]; 7 Hours Ago at 08:26 AM.
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