VTT inlet self re-tune

I've been screwing around with my tune sense I got and installed some new VTT inlets.

Basically I took SPXX's E60 map and modified it for 100% E85 and also have my own tuned PID values in place (with re-scaled I axis's etc) and turned down the boost limit multiplier to 2.6 originally, but I decided that with the new inlets I should play around with that. Note that I'm in denver, so higher altitude. Also note I'm a manual XI.

Mods are: VRSF down pipes, Fuel It! inline 255, VTT inlets, VRSF stepped 5" FMIC, VRSF charge pipe (both charge pipe and inlets are heat wrapped), BMS DCI, running MHD flasher for the tunes, SPEC stage 3+ with steel SMFW.

Anyways, originally I just upped the boost limit multiplier to 2.8 but then I noticed it was requesting 16.6 PSI above 6000 RPM which I wasnt so comfortable with. So my question is, what is a decent requested PSI to taper to going to redline?

Currently, at this altitude I can hold 13 PSI, which is pretty awesome. I suspect that at sea level I could hold 2.5 or so PSI more than that (14.7 -> 12.2 ambient pressure here). So I re-scaled and modified the boost limit multiplier table because it only went up to a little over 300 g/s MAF, and I'm pulling something like 500 g/s, then modified the last cell to reduce requested boost at higher RPM. Now it requests 15.5 or so at redline.

Anyways, here is the data zap of it: http://datazap.me/u/shushikiary/de78-boost-limit-multiplier-re-axised-and-adjusted?log=0&data=3-6-25-29

My question is, should I reduce the taper even further, or do you think that's ok (especially for when I drive to sea level).

Not to derail, but why is your boost so low? I'm in Foco and am hitting almost 20psi (stock dps, stock inlets), on a E50 tune and the car runs great.

I could up the boost limit mulitplier to 2.9 like SPXX has in the original tune and hit 20PSI in the mid range. I'm not super comfortable running 20 psi because I suspect that at lower altitude the requested boost will then go above 21, and I'm not willing to risk that unless I know that wont be the case (I'm not willing to exceed the TMAP, because I like safety).

Mid range pressure is easy, high PSI at redline is where we'll struggle with our little turbo's, they just cant flow enough air to maintain pressure.

Quote:

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Originally Posted by shushikiary

I've been screwing around with my tune sense I got and installed some new VTT inlets.

Basically I took SPXX's E60 map and modified it for 100% E85 and also have my own tuned PID values in place (with re-scaled I axis's etc) and turned down the boost limit multiplier to 2.6 originally, but I decided that with the new inlets I should play around with that. Note that I'm in denver, so higher altitude. Also note I'm a manual XI.

Mods are: VRSF dshuliipes, Fuel It! inline 255, VTT inlets, VRSF stepped 5" FMIC, VRSF charge pipe (both charge pipe and inlets are heat wrapped), BMS DCI, running MHD flasher for the tunes, SPEC stage 3+ with steel SMFW.

Anyways, originally I just upped the boost limit multiplier to 2.8 but then I noticed it was requesting 16.6 PSI above 6000 RPM which I wasnt so comfortable with. So my question is, what is a decent requested PSI to taper to going to redline?

Currently, at this altitude I can hold 13 PSI, which is pretty awesome. I suspect that at sea level I could hold 2.5 or so PSI more than that (14.7 -> 12.2 ambient pressure here). So I re-scaled and modified the boost limit multiplier table because it only went up to a little over 300 g/s MAF, and I'm pulling something like 500 g/s, then modified the last cell to reduce requested boost at higher RPM. Now it requests 15.5 or so at redline.

Anyways, here is the data zap of it: http://datazap.me/u/shushikiary/de78-boost-limit-multiplier-re-axised-and-adjusted?log=0&data=3-6-25-29

My question is, should I reduce the taper even further, or do you think that's ok (especially for when I drive to sea level).

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@shushikiary I'm trying to rescale the pid tables in my spxx beta pump map without much success. Would you be willing to post those tables or share your current map? Thanks.

I'm happy to share the bin, but I dont have a drop box or anything setup to do so, if you like I can email it to you.

In the mean time here are the PID tables: Attachment 45899

16psi is nothing... I'm tapering from about 24psi to 20psi

Quote:

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Originally Posted by shushikiary

I'm happy to share the bin, but I dont have a drop box or anything setup to do so, if you like I can email it to you.

In the mean time here are the PID tables: Attachment 45899

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Thanks for sharing. Much appreciated. I would be curious to try those, especially p factor. I'll pm you with my email. Would be much easier to copy and paste.

One thing you should keep on mine, these cars base things off target load more than boost. If you are reaching your target load at 20 psi 5000 feet, and it only takes 17 psi at 0 feet, you will just get throttle closure and wgdc changes while still reach only target load.

I think people get to hung up on boost levels and not everything else that makes us want to run the boost levels.

If I'm wrong someone please correct me. But the logic behind our DME is to be able to run the same at any elevation and condition.

Quote:

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Originally Posted by Mrpikolo

One thing you should keep on mine, these cars base things off target load more than boost. If you are reaching your target load at 20 psi 5000 feet, and it only takes 17 psi at 0 feet, you will just get throttle closure and wgdc changes while still reach only target load.

I think people get to hung up on boost levels and not everything else that makes us want to run the boost levels.

If I'm wrong someone please correct me. But the logic behind our DME is to be able to run the same at any elevation and condition.

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Correct, that is the point of load based tuning.

From what I've been able to gather, when I changed the target load it didnt adjust the boost or the timing at all, because I was so far under in actual load. The load requested seems to be more of a load limit, where if you exceed the load requested it will intervene but if you're not it wont.

So from that, even at 19 psi midrange, I'm far enough under target load it doesnt intervene at all. What does adjust the requested boost though is the boost limit multiplier.

Anyways that's all to the side, my real worry is what boost I should be targeting at redline. I dont want my shaft speeds to be silly high, and to get 13 PSI at this altitude I'm already running 75-85% WGDC, so my thinking was for that same WGDC at sea level I should be able to hit 15 or so PSI, so I was thinking I want my boost requested to be at that PSI there so I dont just push the turbo's to their limits at sea level as well, though I guess that would be no different than now at this altitude.

I should also note that when I changed the boost limit multiplier it changed my load requested. Normally I only request in the 190's or even 180's even though my load request table says 210 for most of the cells. However, when I changed the boost limit multiplier to 2.8 from 2.6 my requested load is now regularly in the low 200's. I find that interesting. Further, when I tried to lower boost requested at high RPM I tried lowering the load request table at high MAF g/s and it did nothing, I even reduced it down to 175, and yes my load requested then finally dropped, but my requested boost and timing didnt change at all (pretty sure its because my load actual was still below that). However, when I changed the boost limit multiplier the requested boost then went down, even though the requested load stayed the same.

I know for sure that right now at 13 PSI (about the max I can put out) it only puts out about 140-150 actual load which is no wear near the 193 or so requested. I suspect at sea level it wont exceed the 193 either.