Recommended Boost settings
93PearlVR-4
04-12-2004, 10:37 AM
I'm going to be adding 13G's, LS6+MAFT, and a Greddy Profec B Spec 2 this weekend. I'd like to know what I can run with a stock fuel system. Everything else is currently stock on the car. I have a boost gauge and an A/F gauge and i'll also be datalogging. Also how much difference will i be feeling in how the car pulls after I install these mods. Thanks in advance.
Igovert500
04-12-2004, 01:20 PM
Um, not sure about the boost settings, you will have to monitor knock, fuel cut, and IDC of you fuel injectors. Chances are you will get fuel cut if you don't upgrade to larger (440cc/550cc) fuel injectors and upgrade your fuel pump. All in all though, good mods.
93PearlVR-4
04-12-2004, 09:20 PM
what injectors and fuel pump would be recommended? I don't plan on doing many other performance mods except maybe a downpipe. Would 450's be enough or should I go with 550's? What fuel pump would be recommended? How much would my fuel economy suffer from the injectors and fuel pump because this is my daily driver?
Sorry about so many questions but I'm just trying to find some stuff out so I can do everything the right way.
Sorry about so many questions but I'm just trying to find some stuff out so I can do everything the right way.
Igovert500
04-12-2004, 09:50 PM
Your fuel economy will suffer a bit, but you can keep it good if you aren't racing around all the time. Plus with the MAFT you can lean out your longer drives to get better mileage. I've heard of guys running one step away from knock and getting 40+mpg highway.
Denso fuel pump is a good one (used in supras i believe), sold on http://www.3sxperformance.com/fuel.asp for $240
the other option is a walbro which is like $150 at gtpro.com I have heard the denso is a slightly safer setup, and i don't really remember why, but either could be (and are quite commonly) used.
As far as injectors, with the 13Gs I would think 450s would be ok as long as you didn't turn the boost up too much, but 550s would probably be the better choice. Plus with the MAFT you can tune for your specific injectors, so to be on the safe side I'd go with the 550s. You can always lean it out/tune for daily driving and then REALLY tune for raceday.
Also, I would highly recommend a downpipe, with those mods switching to a downpipe will give you really good gains. You'll definantly notice the difference. Good luck - Geoff
Denso fuel pump is a good one (used in supras i believe), sold on http://www.3sxperformance.com/fuel.asp for $240
the other option is a walbro which is like $150 at gtpro.com I have heard the denso is a slightly safer setup, and i don't really remember why, but either could be (and are quite commonly) used.
As far as injectors, with the 13Gs I would think 450s would be ok as long as you didn't turn the boost up too much, but 550s would probably be the better choice. Plus with the MAFT you can tune for your specific injectors, so to be on the safe side I'd go with the 550s. You can always lean it out/tune for daily driving and then REALLY tune for raceday.
Also, I would highly recommend a downpipe, with those mods switching to a downpipe will give you really good gains. You'll definantly notice the difference. Good luck - Geoff
93PearlVR-4
04-13-2004, 08:10 PM
Everything I keep hearing and reading says that 550's are bad with the LS6/MAFT combo. Is this true? Would I be better staying with 450's?
Igovert500
04-14-2004, 02:24 PM
Where did you hear/read that?
I have every intention of running the 550s, 15gs, and ls6 MAFT. I have never heard of anyone saying that this is a bad combo. Obviously it can be hard to tune, but that is true of any setup with the MAFT. Can you post some links to where you heard this?
I have every intention of running the 550s, 15gs, and ls6 MAFT. I have never heard of anyone saying that this is a bad combo. Obviously it can be hard to tune, but that is true of any setup with the MAFT. Can you post some links to where you heard this?
93PearlVR-4
04-14-2004, 04:54 PM
Most of the things I've seen about them not working are on 3si. Not sure if it matters but they are mostly with people running some type of other fuel controller like a SAFC. Here are some of the links: http://www.3si.org/forum/showthread.php?t=205846 http://www.3si.org/forum/showthread.php?t=208059
Igovert500
04-14-2004, 07:44 PM
Ok, I read most of the 2 threads, and I think the problem is the lack of knowledge of tuning rather then the injectors. It can be pretty difficult, especially without the correct datalogging equipment. Essentially, most of them have MAFT, airfuel controller, larger turbos and larger injectors. With these, you have to tune for your injectors with the MAFT, and then fine tune with the SAFC or other AFC because it doesn't have wide enough range for large corrections. For every person on there that has a problem, there are tons who don't. When you start tuning, you really need to datalog/read the info your car is giving back to you. Many don't know how to correctly fine tune theirs, so they post asking for help. The ones that have it working don't have a reason to post, so it seems as if there are nothing but problems. I wouldn't let this discourage you from modding. I would almost guarentee you will have the same problems with any sized injectors. Grungaholicvr4 (sorry if I spelled that wrong) was having problems tuning his MAFT with the stock 360s.
Just my .02
Just my .02
Automotive Network, Inc., Copyright ©2025