Single turbo setup for GS400?
11-05-09, 05:17 AM
#16
Rookie
Join Date: Jun 2008
Location: Az
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
I've turboed quite a few cars and two trucks that never came with a factory option. I hope I don't come across as too much of a ****, it's not my intention really but if you have to ask you shouldn't do it. Read as much as you can. Not just on this board. You will learn more about tuning on other sites. What starts out with a few psi will turn to power greed. AFR, timing, compressor maps, ect are just the basics of DIY. Then as someone else mentioned the trans. I know this is a Lexus board but I would look into a 03-05 E55. Super charged 5.4, crazy torque and bullet proof trans, plus big brakes.
11-05-09, 04:26 PM
#22
Lexus Champion
Certainly the HARDEST thing about FI is the ability to correctly tune the air/fuel ratio AND the ignition timing.
The Cartech FMU does a reasonable mechanical job on cars with return fuel systems. The SAFC and tuning devices like it mearly adjust the MAF signal causing a change to the fuel map. Problem is the stock ECU will try to correct the "modification".
IFAIK no one makes a device that allows the stock ECU to be modified or tuned internally. Shame. It would be usefull to have an interceptor type device that takes the stock sensor signals and modifies them causing the stock ECU to make the changes needed. Until we have something like this we will be limited to low boost applications that can be tuned with SAFC type devices or go with a complete stand alone which creates a whole bag of new problems.
I am still thinking about a SMALL pair of turbos mounted low at the stock manifold outlet position. 3-5psi boost run efficiently is 20-60+% power increase.
The Cartech FMU does a reasonable mechanical job on cars with return fuel systems. The SAFC and tuning devices like it mearly adjust the MAF signal causing a change to the fuel map. Problem is the stock ECU will try to correct the "modification".
IFAIK no one makes a device that allows the stock ECU to be modified or tuned internally. Shame. It would be usefull to have an interceptor type device that takes the stock sensor signals and modifies them causing the stock ECU to make the changes needed. Until we have something like this we will be limited to low boost applications that can be tuned with SAFC type devices or go with a complete stand alone which creates a whole bag of new problems.
I am still thinking about a SMALL pair of turbos mounted low at the stock manifold outlet position. 3-5psi boost run efficiently is 20-60+% power increase.
The following users liked this post:
djr48312 (10-18-21)
11-06-09, 10:44 AM
#26
i keep reading that all over this forum, but have yet to experience that myself. i street tuned my 98 gs400 with an innovate lm-1 (2 bungs welded into each pipe after cat) to an afr of 13.3-13.5 @ WOT using an safc-II. my afr's are rock solid after driving on it for 3 months now, and even after my battery died and i installed a new one. under WOT conditions i think its safe to say the ecu does not try to re-learn. (goes to preset maps) under part throttle conditions, the ecu maintains a steady 14.7 afr....which most deffienetly is a learning condition.
im not sure what would happen under boost though...i would ***-u-me, that if the setup was making boost at a part throttle condition, the ecu would still achieve a 14.7 afr, which we all know is bad news. at WOT the safc is more than adequate. im not sure how the ecu would react under boost as this is the 1st maf car ive ever owned....that part is still a mystery to me.
im not sure what would happen under boost though...i would ***-u-me, that if the setup was making boost at a part throttle condition, the ecu would still achieve a 14.7 afr, which we all know is bad news. at WOT the safc is more than adequate. im not sure how the ecu would react under boost as this is the 1st maf car ive ever owned....that part is still a mystery to me.
The following users liked this post:
djr48312 (10-18-21)
11-10-09, 12:00 PM
#29
Maybe something was up with his tune that day?