OK guys, bear with me.

Car - 98 GS400 with srt/exhaust/headers etc. ( I do not have the headers yet but this is for when they arrive and are installed.)

I do not believe the ecu from the SRT is doing the job correctly, so I plan on installing and getting an S-AFC2 tuned to work with the new headers, exhaust etc.

I will wire the S-AFC2 in myself but here is where I am confused.

If I remove the SRT ECU and replace it with the S-AFC2 is the car still going to run ok because the SRT ECU has been removed. For instance, it would be just like installing the SRT intake without installing the ECU, which would make the car run badly/not at all.

So then I was wondering if I leave the SRT ECU in and wire in the S-AFC2 after the SRT ECU. But this doesn't seem to make a lot of sense as I would technically be tuning something that is supposed to be tuning something else

So, if I remove the SRT ECU and put in the S-AFC2 will the car run ok long enough to tune the S-AFC on the dyno or no?

Also, if I remove the SRT ECU and start the car I am going to get a CEL right? And then I have to try and get the damn code cleared!!

So what is the best way to do this?

Jonny

 

Does anyone know if the SRT ECU does anything else besides air\fuel?

 

I am guessing that is all it does. What else does an intake do besides increasing airflow? (This is a question not a statement!)

Jonny

 

I don't have any good experience to share Jonny, but perhaps you should arrange for a flat bed to get the car to a tuning shop once you have the SAFC2 in place. My theory is that driving it with no tuning won't be good because I believe the car will think it's getting less air than it is because the flow rate will appear slower to the MAF due to the larger pipe than stock. This would cause the car to deliver less fuel than is needed which would cause detonation? Maybe I've got it totally wrong and it will just run rich, in which cae you'd be fine.

Plenty of better educated and experienced than I can chime in here... just my $0.02

 

You never know... especially with the large increase in HP it provides... that's why I was asking...



not the intake... the ECU

But that is probably it.

 

Been there done that, The SRT ecu and the SAFC do the same thing. The difference is that the SRT is preprogramed with a fixed setting. The SAFC gives you the abillity to adjust the AF to your specific car and setup.

If you remove the SRT ecu and install the SAFC and tune it at the same time, you will be fine. The trick is that you will need to know how to tune the SAFC for your car, without a wideband I dont know how you will do this succesuflly.

 

Your car will be fine. There is nothing special about the SRT intake. It's just a tube will some paper at the end. If you are really worried, reset the ecu after you take off the SRT piggy back.

There are people here running centrifugal superchargers here with the stock computer. If their cars haven't exploded, your car won't explode either as a result of a metal tube.

 

i've heard taht w/o the SRT ECU, the car can cut out because of the amount of air going through the huge pipe and not enough fuel to compensate. Not sure how true that is, but that's what i heard.

Edit- well now that some more people have chimed in, im sure you'll be ok. guess i heard wrong

 

Thats true it will cut out if you dont have something to readjust the AF mixture ie the SAFC

 

Like Morris said, it can work just fine and once tuned probably even better. The key is to get a "base" map into the SAFCII that is good enough to let your car run long enough to get to the dyno. It will probably run pretty bad until you get it tuned, but it will work. W/O a wideband it's going to be difficult unless you cheat by using someone else's settings.

 

Can you guys explain what you mean by wideband? Won't the guy tuning the S-AFC be using this? Sorry, I am a little lost.

I will be doing the install at the dyno shop so the car can go straight in to the dyno.

Thx,
Jonny

 

Jonny if you go down this road do it all at the same time, I know from experience your car won't run with with just the intake and no ECU.

 

Yeah, I plan on installing it outside the shop - but then I don't know if as soon as I remove the SRT ECU whether the car will run well enough to tune the S-AFC??

Jonny

 

well i went from srt piggy to greddy emange using the same wires pretty much

and so far so good

there really is only one wire you cut when installing srt piggy

so if you removed just be sure to reconnect that and you will be golden

until you get the safc or greddy

 

Johnny,

I am guessing that the S-AFC will probably use the same wires that the ECU uses. On the S-AFC you only cut one wire also. I need to do some research on it and compare the 2 wiring diagrams.

Also, I need to know which setting the GS400 uses on the S-AFC. Is it Karmann?

Jonny