92sc250tt

What is the best ECU/Piggyback to use for the GS400/430? I'm looking to tune my 99 GS400, and don't know what to buy. Any suggestions? I'm just looking to tune it N/A for now. I'm possibly going to turbo it in the future.

kdick91

It reaaaaally depends on what you're looking to do. For something super simple that will work with basic intake and exhaust, the piggyback from SRT does the job. It doesn't include any flexibility whatsoever. Picture it as a 'canned' tune. If you're going to turbo it at some point, stay away from this. Alot of people on here get away with using the Apexi SAFC for boost and N/A applications. Basically, it wires like any other piggyback but tweaks the MAF signal (iirc) to command more fuel. I also would not ever recommend this because it does not allow you to edit timing which is a very big deal. But, the factory timing is pretty conservative so you can get away with using it. If you want comprehensive control with VE tables, timing tables, target AFR tables, data logging, and closed-loop enrichment capability I'd recommend the Split Second FTC-1. Whereas the SAFC (and the like) 'add fuel' for an RPM range (using plus and minus values), the Split Second can use VEs and ARFs, so it allows for a bit more precise tuning. The heavy-hitter though is that the FTC can control timing and do closed-loop enrichment. Closed-loop enrichment is really only needed if you have boost, but if you're boosted, you will know wether or not you need it.

Really boils down to your needs, budget, and application. Hope this information helps!

Kyle

92sc250tt

Thank you! That is exactly what I wanted to know. Do you happen to know what part number it is that you are supposed to use for the GS? I looked on their website, and the one that seems like would be the best fit looks like PN# FTC1-017B. Is that correct?

kdick91

I do believe that one is correct. I spoke with Split Second a while back and they mentioned that they might have something that would better suit the VVTi 1UZ. Unfortunately, they never got back to me and I didn't call back as I am still putting a bunch of other stuff together for the supercharger I'm working on. Definitely contact them before purchasing, they will know better than I. I'm glad someone else is interested, this will make things much easier for me. If you'd like to discuss finite details, please feel free to do so in the thread I started or continue here. I just ask that you don't PM me so that others can find this information when needed. I wish you the best of luck and really look forward to hearing about your progress. What wideband will you be using and how are you planning on mounting it?

92sc250tt

I've been very happy with my AEM digital gauges in my S2000, so I'll most likely continue with them in the GS. As far as mounting goes, I'm not really sure. I want the gauges to be clean, as it is a luxury car. At the same time I want them to be visible, so I'm not really sure what to do.

vwynn

iTrader: (4)

if youre serious about booost... go with a standalone.. it gives you more options for tuning and overrides the stock ECU

with a piggyback you are using the tuning module to trick your ECU into thinking its doing something else. From what ive read it starts to mess up when VVTI decides to relearn itself to counter what the piggyback is telling it to do.

that being said. im on a piggyback cuz its cheap lol

kdick91

Sorry, I should have been more specific. I meant where are you mounting the actual O2 sensor? From what I've seen it look like the driver-side manifold directly above the flange in the collector is the only option. The factory narrowbands are mounted upside down and, unfortunately, you cannot mount a wideband upside down (condensation will collect in them and cause premature failure).

As far a gauge mounting, most people use the ashtray in the center console and I probably will too.

I have to agree with vwynn as well. Standalone is your most versatile option for permanent implementation. As far as VVTi releaning itself, I've never heard of it causing issues, but I've never looked that far down the road. The way you have to 'tune' these cars really does suck. I come from the GM LSx world where it's as much as plugging in to the OBD and editing real time 18x18 fuel and timing maps. It's the best haha. But on these, everything you do is just 'tricking' the stock PCM (as in telling it there is more air than there actually is to get more fuel and intercepting reluctor signal from cam/crank to adjust timing). I really hate that it is like that, but there aren't any options unless you go standalone.

92sc250tt

Who makes a standalone for the GS400? I haven't seen one. I'm running full standalone on my S2000, and would love to do the same with the GS. I'm pretty new to Modding the GS, but not to Modding cars, or Lexus in general. I had a 1JZ SC 300 before the GS, and currently have a 546whp S2000. I worked as a Tech for Lexus for 6 years, so I know the car pretty well.

kdick91

I know people have ran AEM, Adaptronic, Perfect Power, etc. You really have many options!! You may want to explore Google though as it's more popular with people who have swapped in a 1UZ. You *may* lose features like VVTi, cruise control, traction, ABS, etc.

tom steele

i had the split second unit and aem afc neither work for long stock ecu fight them need stand alone if you want to get serious

BoostdIS3

I don't mean to bring up an old semi dead thread, but has the consensus changed on which standalone ECU is best to run on the SC400/430 cars?

NorthStyle

iTrader: (16)

From what I remember reading, most people use the AFC Neo and have a WOT tune made up as the factory ECU will eventually overwrite any "day-to-day" driving tune. But, those are mainly guys running I/H/E.

For the ones running SC/TC... most likely stand-alone or whatever the manufacturer provides would be my best guess.

BoostdIS3

These seem popular around here.

https://www.clublexus.com/forums/clu...onic-ecus.html

Thoughts>?

gsean400

Im still really really confused as far as tuning goes for these cars. Can someone clear something up for me.. So when u use a piggy back the cars ecu re-learns itself and basically erases the tune. When that happens do u have to retune it? And when people say they are fighting their ecu what do u guys mean exactly? What is happening

NorthStyle

iTrader: (16)

From everything I've read//been reading, that's basically it: the ecu will eventually overwrite the tune, with the exception being WOT settings since 99% of drivers rarely stay there for more than a few seconds at a time.There's an older post where one of the guys who got his dyno'd previously had it re-dyno'd and showed the results. I'll post it if I can find it.