i maxed my maf out too on my bpt 20gxtr bb w/ 10cm hotside.. but i tried to buy an aps 65 or 70.. but they dont sell to the US anymore.. im thinkin about the perrin big maf? or the perrin "blow thru boost tube"
You need an IAT sensor with the 4BAR. 300g/s is the old max before the new COBB SD mapping. Even then, the injector scaling and maf scaling can be tweaked some to raise the actual air flow if that is the issue. If you're going to shoot for 25 PSI or higher, get an OMNI 4BAR. Speed density is a cheap swap parts wise, but the tune will take considerably longer, even if your tuner is experienced. Tuning a MAF only deals with a voltage of a sensor and making sure the air flow calculation allows for proper fueling. When you get into speed density, it becomes air flow versus pressure versus rpm, making a 3D table with much more data. Even on 16BIT ECUs, SD is a very viable option, and if you're running open source there is a ROM hack that emulates the group N rom and looks very similar to a standalone ECU. Very nice stuff if you get the bugs worked out. So, no matter what tuning option you are using, Speed Density is well worth the effort. If you only have 750cc injectors, those should actually max out quite easily on a 20G if the AFRs are on the conservative side. Local car I drove while it was tuned maxed the injectors at only 20 psi peak tapering to 19 PSI by redline. If you're really shooting for 24 PSI or so with that 20G, double check your fuel system's ability to meet the demands. It's better to have some headroom. You'll see some people talk about "atomization of the fuel" being an issue with larger injectors. I was able to get 30MPG in my car (self tuned) with ID1000cc injectors on a road trip to florida. Good luck bud.
Or just go speed density. All you need is an IAT sensor after the intercooler and a competent tuner. Most times it's an issue of the injectors being maxed out and an incompetent tuner behind the laptop using the MAF as an excuse when in actuality, the car is out of fuel.
i maxed my maf out too on my bpt 20gxtr bb w/ 10cm hotside.. but i tried to buy an aps 65 or 70.. but they dont sell to the US anymore.. im thinkin about the perrin big maf? or the perrin "blow thru boost tube"
You need an IAT sensor with the 4BAR. 300g/s is the old max before the new COBB SD mapping. Even then, the injector scaling and maf scaling can be tweaked some to raise the actual air flow if that is the issue. If you're going to shoot for 25 PSI or higher, get an OMNI 4BAR. Speed density is a cheap swap parts wise, but the tune will take considerably longer, even if your tuner is experienced. Tuning a MAF only deals with a voltage of a sensor and making sure the air flow calculation allows for proper fueling. When you get into speed density, it becomes air flow versus pressure versus rpm, making a 3D table with much more data. Even on 16BIT ECUs, SD is a very viable option, and if you're running open source there is a ROM hack that emulates the group N rom and looks very similar to a standalone ECU. Very nice stuff if you get the bugs worked out. So, no matter what tuning option you are using, Speed Density is well worth the effort. If you only have 750cc injectors, those should actually max out quite easily on a 20G if the AFRs are on the conservative side. Local car I drove while it was tuned maxed the injectors at only 20 psi peak tapering to 19 PSI by redline. If you're really shooting for 24 PSI or so with that 20G, double check your fuel system's ability to meet the demands. It's better to have some headroom. You'll see some people talk about "atomization of the fuel" being an issue with larger injectors. I was able to get 30MPG in my car (self tuned) with ID1000cc injectors on a road trip to florida. Good luck bud.
Since I derailed this thread, here's a question for the OP:
Were the JDM heads port matched to the larger bore? If not, you have significantly higher compression. Not necessarily a bad thing, but it's something for people to note when it comes to the power made.
sryy to steal ur post/thread build thing... im sorta still new to igotasti,, but ur build is very impressive!! i want to do a full twin scroll set up on my v.7 bugeye when i get done with this hybrid 2.0/2.5 build on my 05'
Blow thru maf is something I recommend against to be honest.
Blow thru maf is something I recommend against to be honest.
You don't need a Maf cover for SD, that's wasting money and reducing functionality of the system. You can run a hybrid mode that switches from MAF to SD. This way you retain lots of resolution in both putting around town and at WOT.
+1... In just about every case. :tup:
+1000.
I'm a big fan of hybrid mode. I have used this strategy with great success. The only thing I found is that moving the temp sensor skews the MAF scaling a bit in one direction but it doesn't really matter much because it seems to be the same amount across the board, so it is a delta error. You just rescale it to the new temp sensor location and be done.