Quick SAFC Tuning Question

[pointblank9957]

OK I am turboing my 4g64 powered Eclipse this summer, and I have a question to make sure I'm understanding the concept right.
Injectors are SFI 650cc's which should be good to around the 300hp range.
4cyl & arrow Up
I set the LTP to around 20-25% and HTP to around 40%, then I rev to the according rpm, and get my wideband reading to around 12.5-14.7:1 while keeping my EGT below 900°C and 0 knock? Seems too easy to be right

 

[WES_393]

While I can't help with the exact settings of the SAFC, here's some things to consider.

1. Your injectors are High-Impedence, so you'll need a resistor box to run Low-Impedence injectors.
2. Your stock injectors are 275cc, not 450cc like a turbo DSM. So 650cc injectors may be 44% larger than stock 450's, but they are 136% larger than your current injectors.
3. You don't have a knock sensor from the factory.
4. You want your wideband to read around 14.7 at idle/cruise and around 10.5-11 at WOT. You might be able to go leaner at WOT, but I wouldn't until you have a knock sensor.
5. While the SAFC can control fuel (to an extent), it can't control ignition timing. And on top of that, the SAFC controls fuel by lowering the airflow signal which generally causes the ECU to increase timing.

What I would suggest is swapping in a turbo DSM ECU, preferably a Flashable ECU or one with DSMLink.
http://www.dsmtuners.com/forums/articles-tuning-ecu/424084-turbo-ecu-spyder-gs.html

 

[pointblank9957]

While I can't help with the exact settings of the SAFC, here's some things to consider.

1. Your injectors are High-Impedence, so you'll need a resistor box to run Low-Impedence injectors.
2. Your stock injectors are 275cc, not 450cc like a turbo DSM. So 650cc injectors may be 44% larger than stock 450's, but they are 136% larger than your current injectors.
3. You don't have a knock sensor from the factory.
4. You want your wideband to read around 14.7 at idle/cruise and around 10.5-11 at WOT. You might be able to go leaner at WOT, but I wouldn't until you have a knock sensor.
5. While the SAFC can control fuel (to an extent), it can't control ignition timing. And on top of that, the SAFC controls fuel by lowering the airflow signal which generally causes the ECU to increase timing.

What I would suggest is swapping in a turbo DSM ECU, preferably a Flashable ECU or one with DSMLink.
http://www.dsmtuners.com/forums/articles-tuning-ecu/424084-turbo-ecu-spyder-gs.html

The SFI are high impedance, I made sure I bought HI's so I wouldn't have more junk under the hood . As for size, I'm just going by Curt's advice, 450's are the bare minimum for a 4g64T. I'm wondering if I could just wire in a knock sensor since the 64 ECU is almost identical to a 63 minus fuel maps. The 64 ecu leans out the mixture drastically at wot, so I may need to compensate. Would a 63 ecu bolt right in with the harnesses?

 

[WES_393]

While 450's are the bare minimum for a turbo setup, the SAFC has it's own limitations. I'm not sure what those limits are, but 136% seems pretty drastic. It even says on Curts page

If you installed 450cc injectors in place of the stock 275cc ones, you'll need to lean out your SAFC considerably (if you still have the stock ECU)

Not trying to be a downer, I'm just being realistic about the capabilities of the SAFC. And I'd say 90% of problems people experience with DSM's are directly related to tuning. Either not enough tuning equipment, or a poor tune in general.

To my knowledge, the Spyder GS ECU doesn't support a knock sensor. Installing a turbo ECU isn't very complicated, the link I posted abvove has all the info you need.

 

[pointblank9957]

While 450's are the bare minimum for a turbo setup, the SAFC has it's own limitations. I'm not sure what those limits are, but 136% seems pretty drastic. It even says on Curts page Not trying to be a downer, I'm just being realistic about the capabilities of the SAFC. And I'd say 90% of problems people experience with DSM's are directly related to tuning. Either not enough tuning equipment, or a poor tune in general.

To my knowledge, the Spyder GS ECU doesn't support a knock sensor. Installing a turbo ECU isn't very complicated, the link I posted abvove has all the info you need.

What if I returned the 650's for 440's or 500's? Considering I'm in highschool, I don't exactly have a lot of cash to play with just yet for DSMLink.

 

[Mischif]

A safc can adjust the airflow signal by 50% + or -. With that said, you don't want injectors that are more than 50% larger than stock. So you could run a maximum injector size of 412.5cc. So 390's would probably be your best bet. Theres a few tricks you can do to allow you to run bigger injectors, but they make the a/f tuning process a pain in the ass and require adjustments of the safc almost daily. You can lower your fuel pressure to lean everything out on a global scale. Wouldn't go lower than 30psi as your base pressure. You can also add small holes(one at a time) like just a hole or vacuum nipples or hose to your intake pipe before your turbo but after the air flow meter. That will increase the amount of unmetered air. Basically your engine is sucking in the same amount of air but the air meter is seeing a lower signal and puts in less fuel. But these are bad ideas if you dont want to have to constantly be monitoring your wb and want something you dont have to worry about adjusting all the time. So run 390's or find a better tuning option than that safc.

Your real problem is going to be your timing advance. N/A's are programmed to run alot more timing than a turbo car is, both during cruise and wide open throttle. So if you keep your stock ecu your going to be running some very dangerous timing numbers for a turbo system. I would suggest you get a logger and log the timing on the car before you turbo it. With that stock ecu your going to want to run really low boost or else its gonna detonate ALOT from the high timing. Another reason you should probably pick a better tuning solution than the safc.

 

[clipto]

Save up sell safc buy ecmlink. Sorry your trying to use old technology get decent power out of your car. 300whp on your setup will require more then safc. Are you even logging? Do you know how much knock timing your car has. Safc is only for real real basic setups. Tune right you won't be disappointed. Hell even a burned Eprom chip or black box ecu is cheaper solution to ecmlink and will actually be tunable then safc. Other wise just adjust the safc Best you can with your wide band and hope it don't go boom.

 

[bigbird94]

Is selling the car for a gsx an option? By the time you boost and tune it you will have more money into than what it is worth, IMO. The turbo 4g63 is a MUCH better engine. Adding a turbo to a car that isn't engineered for is usually a bad idea.

 

[pointblank9957]

Is selling the car for a gsx an option? By the time you boost and tune it you will have more money into than what it is worth, IMO. The turbo 4g63 is a MUCH better engine. Adding a turbo to a car that isn't engineered for is usually a bad idea.

it is not an option.
and the reason behind it is that the extra long stroke produces MUCH more torque than a 4g63

 

[Breezio69]

Lol to the reason why you cant use a 4g63...

Im sure you'll make much more torque at your safe 8-10 psi on the 4g64 with 400cc injectors... meanwhile, while the 4g63 takes on 20-30 psi daily with stock guts and hx40's hanging off the front....

Thats the new silliest thing ive heard on here.

 

[pointblank9957]

Lol to the reason why you cant use a 4g63...

Im sure you'll make much more torque at your safe 8-10 psi on the 4g64 with 400cc injectors... meanwhile, while the 4g63 takes on 20-30 psi daily with stock guts and hx40's hanging off the front....

Thats the new silliest thing ive heard on here.

8psi to 8psi, yes, yes it will make a lot more torque.