Fuel Cut Defence
- Thread starter NewGen
- Start date
crisp said:
Crisp,
If you have a brand new pump, you should be fine considering HKS tuned w/ it. If you do decide you want more power/larger injectors I'd suggest a walbro. Also, one thing to remember.. when you install the walbro it's a good idea to drill out the J-tube on the block for the fuel pressure regulator return. It has a restriction in it designed to give the fuel rail enough pressure to limp home in case of a FPR failure.. but if ran with a walbro you may have problems controlling fuel pressure at idle..
hottscennessey said:
Ahhhh... I have seen the comments about this "J-tube" often... but your explanation is the most clear so far.
Yes, I do believe sticking with the HKS theme over the years has helped me keep my car running well. (Except for the "short" that had me "down" for over five years!) I will continue to follow the advice from HKS on most matters of "system balance" on my car.
Thank you for your input.
-crisp
is there any advantage to running 550s with the walbro fuel pump and tuned with an safc2 rather than using the lex afm?
i've been in talks with one of the local shops and this is the route they are recommending.
they said i wouldn't need the lex afm or the afpr?
anyone running this set-up
i've been in talks with one of the local shops and this is the route they are recommending.
they said i wouldn't need the lex afm or the afpr?
anyone running this set-up
obviously, u lose a certain amount of adjustibility with running the stock afm. think about it, add the extra air that the lex afm can offer stock.. then tune it with the safc2 
remember, you are trying to get the most air/fuel u can in there at a good ratio.
remember, you are trying to get the most air/fuel u can in there at a good ratio.
as far as i know that is not correct. i believe the safc2 just controls the amount of fuel/air. you would also need to be able to adjust the fuel pressure to keep up with said increase of fuel delivery and increased injectors. forgive me if im wrong.
You could do it that way... but you'll have a restriction in front of the turbo, and it'll take a whole lot more tuning than just upgrading to the lexus. The FPR is not necessary, but really helps when tuning to avoid fuel cut, and getting a nice crisp idle.
Another concern is when you don't do the lexus AFM and install the 550's to tune with the stock AFM you'll be taking out (in theory) 27% of your fuel across the board.. which will realllly screw up your timing (according to rumor, it will advance it) and make you very likely to detonate and blow your motor. Don't listen to people/shops who don't know OUR cars and OUR ECU's and ASSUME that all of their car information/logic will carry over. While most of it will a lot won't. You know what they say.. when we assume it makes an ass out of u and me.
In theory the reason you'd go with a lexus and 550s is because you wouldn't have to tune at all. Unfortunately this isn't always the case, as usual it makes you run on the rich side. By leaning it out it will put you even further away from fuel cut.
Another concern is when you don't do the lexus AFM and install the 550's to tune with the stock AFM you'll be taking out (in theory) 27% of your fuel across the board.. which will realllly screw up your timing (according to rumor, it will advance it) and make you very likely to detonate and blow your motor. Don't listen to people/shops who don't know OUR cars and OUR ECU's and ASSUME that all of their car information/logic will carry over. While most of it will a lot won't. You know what they say.. when we assume it makes an ass out of u and me.
In theory the reason you'd go with a lexus and 550s is because you wouldn't have to tune at all. Unfortunately this isn't always the case, as usual it makes you run on the rich side. By leaning it out it will put you even further away from fuel cut.
