StarquestRescue Posted September 15, 2015 Report Share Posted September 15, 2015 The wallbro pumps are internally regulated at about 80 psi. So that limits your base pressure to the low 50's Are you running table switching? Link to comment Share on other sites More sharing options...
polarisman14 Posted September 15, 2015 Report Share Posted September 15, 2015 (edited) OK. So I guess the first change I have to make is the base fuel pressure. What would you suggest? 50? I won't be running more than 25psi of boost and my turbo runs out of steam a little under 500 crank hp so more than 400-425whp isn't even an option. And I don't know if I am running switched tables or not--can you let me know where to look to find that out? Edited September 15, 2015 by polarisman14 Link to comment Share on other sites More sharing options...
StarquestRescue Posted September 15, 2015 Report Share Posted September 15, 2015 (edited) I would say 50-52 psi base. In ms1 under fuel settings --fuel table selection--switch ve table 1 for ve table 3 when. Would be similar under spark. Edit. Probably some thing similar under ?? If table 3 is not grayed out I would say table switching is on. Edited September 15, 2015 by StarquestRescue Link to comment Share on other sites More sharing options...
polarisman14 Posted September 15, 2015 Report Share Posted September 15, 2015 (edited) Mine's MS2 v3.57 and I am running Tuner Studio (not MegaTune). If I am dropping from 60 to 50psi base fuel pressure, what part(s) of what map(s) will I have to adjust in order to compensate? Phil, do you think 50psi is enough to hit my goal? (Impossible to know for sure but I'd just like a couple opinions before I change stuff around). On TS I found under "Extended" a dialogue box called table switching and this shows fuel and ignition table switching on, greater than 100kpa. What does that mean for me? I assume that means at 100kpa it switches from VE table 1 or ignition table 1 to table 3 which is what has all the in-boost VE values, right? Edited September 15, 2015 by polarisman14 Link to comment Share on other sites More sharing options...
StarquestRescue Posted September 16, 2015 Report Share Posted September 16, 2015 (edited) Ok, you are good on the table switching. Step one, save tune as Old tune. Step two verified that you do in fact have said old tune saved. After you drop the pressure, increase required fuel till it starts and idles decently at the afr it did before. proceed cautiously from there. The ve is probably rich up top since you were likely compensating for dropping fuel pressure with a higher ve #. Modest boost could be way off. Learn how use auto tune on your logs. Smooth out the weird stuff auto tune leaves in the ve. Fine tune manually. Bear in mind i only know enough to be dangerous. Edited September 16, 2015 by StarquestRescue Link to comment Share on other sites More sharing options...
polarisman14 Posted September 16, 2015 Report Share Posted September 16, 2015 (edited) Yeah most people do, that's why we pay the professionals to tune most of the time lol...I have played with the VE analyze live that TS has integrated and will probably utilize the WUE live software as well. The car starts and runs well right now but I know I'll have to mess with it once I change the fuel pressure. It makes sense to me that you'd have to up required fuel if you drop fuel pressure to get the same flow rate through the injectors. I'm hoping with less fuel pressure it will give me better tuning resolution as each change in VE makes a smaller change in fuel injection (in my head). I just didn't know if there was a rule of thumb for VE like every psi of fuel pressure dropped requires adding 2 to each VE table cell (or something like that). I save my tune every time with "save tune as" so I have one for every date...Probably 50 of them in my folder so I am good there. I'm gonna try to get back to my buddy's house Sunday to dial in the fueling at a lower fuel pressure rate. Anyone else agree that 50psi is a good starting point for 400whp on the 75# injectors and walbro 255 pump? Phil, I had decided to leave the base pressure at 60psi initially based on using a HP calculator...So you're saying I can get by with as little as 3 bar for fuel pressure for my power goals? Lower base pressure is better in my mind, longer pump life etc... I can see the VE values being off a bit because of the fueling--My issue now is knowing the difference in old spool vs new spool and compensating for that as the new compression ratio being a full point higher should hit full boost/spool up quicker than old CR, meaning fueling and ignition tables would have to be modified in that range. Let me know if my thinking is way off on this. Edited September 16, 2015 by polarisman14 Link to comment Share on other sites More sharing options...
polarisman14 Posted September 17, 2015 Report Share Posted September 17, 2015 (edited) Bump, anyone have any more input on this? Trying to get my questions answered by Sunday so I can pick up where I left off with tuning. My buddy wants my car out of his garage lol. EDIT: I'll be driving the car back home Saturday morning. If anyone viewing this has any suggestions on how to make the existing tune safer that'll be fine. Obviously I know, no boost, no higher rpms, minimize load as much as possible etc, make sure the car is fully warmed up before I leave, etc but if there are any simple changes I can make that'd be much appreciated. I will leave the fuel pressure as is until I get the car home as the tune is functional right now. Edited September 17, 2015 by polarisman14 Link to comment Share on other sites More sharing options...
CaliConquestAlex Posted October 30, 2015 Report Share Posted October 30, 2015 http://www.filedropper.com/2015-10-08200020 http://www.filedropper.com/2015-10-08194653 Tune file and datalog posted. Link to comment Share on other sites More sharing options...
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