singyau78

First off, I'm looking for no more than 400rwhp on my sc300 92. I've gather pretty much everything to complete the swap, but 1 major concern is the ecu shutting off the car during boosts over 12psi. I've heard the sc300 stock ecu can't handle over 12psi. What can I do in this situation? I don't plan on using any expensive electronics like aem, or fcon stuff, but I may consider buying the s-afc if neccessary. I've heard that the gm 3bar map sensor would take care of the issue of increasing the fuel pressure psi without the ecu shutting off. If so, how do you install this 3bar map? I know it's installed and attached on the ecu harness as a few wires are neccessary to be used from that harnest. As for the afm, which is on top of the intake filter pipe, do we have to remove that? I've heard that the ls400afm would swap over perfectly, but that 25% extra airflow seem to cause a whole mess of trouble as far as fuel issue goes. I don't want to mess with that. Please help me in anyway you can.. Much appreciated!! thanks guys.

Lex Luthor

I would suggest doing a whole lot more research before taking on this project. Let me help get you started:
1) Sounds like you're referring to fuel cut, it does not exist on these cars since they are not turbocharged from the factory, regardless the ECU never 'shuts off' under any circumstances.

2) You will need some sort of fuel mgt at the least, not necessarily the 'expensive electronics' as you call them, but you will be very limited with just an S-AFC.

3) A MAP sensor won't and can't alter fuel pressure on it's own, it simply senses manifold air pressure. In deference to what you said re: this and the MAF, sounds like you're referring to the difference between an airflow meter and a speed density metering system....i'm not one of these automatic 'use the search engine' ppl, but it will help you greatly since you seem to only have a crumb of knowlege when properly turbocharging a Lexus coupe is more like a seven-course meal.

Hope that gets you started, nothing is more important than doing the proper research and then taking the time to do it right. Good luck.

singyau78

Thanks for helping out anyway. I sort of get this problem now. The only reason others were able to use the 3bar map was because they were using the aem system. Would that be right? Anyhow, if the 3bar map won't work, would you be able to suggest any alternatives? Again, I'm looking for no more than 400rwhp. thanks buddy.

singyau78

You know what? I was in a rush at first to read through your reply and respond to you. I just now realized that you said the ecu would not shut off under any circumstances. That's funny because I've heard from a lot of people that once the pressure hits above 12psi, fuel cut occurs, or even the vehicle shutting off. They even say that the stock is at around 6-7 psi. I've heard that the ecu had to be fooled from seeing too much boost. I'm not exactly sure which psi they're referring to though. If you are right, the main concern is having the proper air fuel ratio then after the turbo is completly installed. Let me make it clear to you that my goal again is no more than 400rwhp, or 350 to the wheels would also do with the use of a 50shot nitrous dry. I'm replacing the head gasket to the twin turbo gasket. I will be running a turbonetics na-t kit, and included would be the t04e .70 turbo and manifold, oil return lines, supra tt side mount intercooler and piping, hks blow off valve, jackson racing fuel regulator, 6 rx-7 460cc's injectors, s-afc, supra tt fuel pump. That's all I can think of for now. It's complete though. I really would appreciate the help from you and others as well. Thanks again.

singyau78

Again, thanks for your care and concern on this matter. First off, I will be using 460cc's from a second gen rx-7, and heard from several others that if you don't use at least 550cc's, you'll blow your motor with the ls400 afm. Secondly, if Lex L. says that the sc300 ecu won't shut off the car, or fuel cut from higher boost levels, I wouldn't have to worry about the ls400 afm then right? Why don't I just use the existing sc300 afm. Also, I've heard that people switch over to the ls400 because it extends the fuel cut to a higher psi, somewhere in the 20's or something like that. How hard is it to acheive 400rwhp? I'm also a little confused when people say too lean is bad, and too rich a better than lean. What's going on there? I've also thought to myself that using the ls400 afm would increase the airflow +25%, and with more fuel in additional to that, would be the way of obtaining more hp. Correct me if I'm wrong.

aliga

iTrader: (147)

Are you j0hnnyboi? If so, Im not helping you. I take all my info back. Its funny how you switched your name up, trying to get help after disrespecting me before.

http://www.supraforums.com/forum/sho...hreadid=152027

Fred Smith

Find out more about fuel injection systems, and how they work. Specifically, the role a MAF plays, and the role a MAP plays. Then find out how the ECU detects and shuts down with overboost. Also learn more about turbocharging a car. Corky Bell's book would be a good start.

DaveGS4

iTrader: (2)

Yes he is.