NAZTY97

Since the last posting of this issue:

1) has anyone with a SC400 successfully had installed and dyno tuned a SAFC??? If so,..can you post preferrably a scan of the dyno run before/after.

My concern from previous posts were about the ECU retarding the timing and undoing the work of the SAFC. Someone said Lexus ECU's do this.

From my experience,...everyone keeps saying lean out the mixture to get more horses,... that's not entirely true. I owned a SAFC when I had my Z and actually watched the whole process of install and tune. First,... at least for a NA motor,.. Justin at ProTech in Austin ( pretty knowledgeable guy ) said that the optimum ratio for safe and complete combuston was 14:1. When they did my A/F initial run on the wideband,.... my stock ECU was overly lean down low,... overly rich throughout the middle, and lean again in the upper rpms.... my dyno sheet showed that by virtue of a big dip in power where the ECU was running too rich,... He only tuned the SAFC to lean/richen the A/F ratio to 14:1, not to run it leaner than that all the way across. I gain 24hp and 25ft/lbs in the 3-4K rpm range and only 8hp at redline,... but the majority of my driving band of rpm had been raised in the 20hp/trq range and that was just from correcting the ratio to keep it consistent. Not over leaning. Actually I got a gain in the areas he added fuel to,... so that's my experience. I figure if you're running it at 14:1,.. the ECU shouldn't adjust timing.

Any ideas?

xBlkGs430x

here is the deal, i have the safc in my sc4, i've had it for about 6months, i just put a apexi rev meter in as well, the rev meter by the way is ver acurate, and the safc is great. ever since i got it i've taken it out a couple of times and put it back in, i can tell a difference between the stock and safc, i took it out for a week to mold it in the sun visor and when i put it back in i could feel a much better defference, i did not dyno it, b/c there is not a dyno place arround, but i would recomend it to all sc4s, i have not had any negative experince with it, both safc, and rev meter were very easy to install, it was $$ well spent.

MadMaxSC400

Actually leaning the mixture at high RPM is exactly what you're supposed to do. The dyno tuning proved this... and the timing on my reprogrammable is held to the proper level by the computer in the upgrade module. Same with the mixture. The SAFC gets set and stays where it's put, and the computer will adjust up and down as it sees fit. I never dyno tuned my SAFC, because I started using the ECU upgrade.

Frankinaustin

What is this thing and how much does it cost? Can you send me to a web site to learn more?

xBlkGs430x

http://www.apexi-usa.com/electronics_safc.asp

NAZTY97

I know the SAFC is not for timing,.. what I was saying is someone here said when the ECU detects the leaner mixture, it retards the timing ( I don't see how the ECU would know being the signal is altered, but just a statement made in a previous thread that I was investigating ).

Leaning the mixture is relative,....if you lean it out too much, you end up with detonation, so there is a limit, and actually when my A/F ratio was richened, I gained more hp at that rpm.

By the "seat dyno" doesn't mean much of anything to me because, for 1) you don't know what your base hp/torque was vs your after. 2nd) you don't know what your initial A/F ratio is, and isn't constant or consistent. Mine was all over the place in stock configuration, and actually causing a loss in power. Yes, I could have had it ran leaner, at what cost,... melted pistons? That's what guesswork will get you, and no two cars are identical. I had intake/exhaust/SAFC/underdrive pulleys to net 198/177 rwhp/trq, where another car only had intake and was doin' 192rwhp, and the median rwhp for that car was 177ish. So him tuning his SAFC definately should not have been based on my findings.

I guess when I buy another one, I will be the first to actually put this thing on correctly and I will post the dyno initial runs vs the final pass. I will probably do the intake and exhaust at the same time.

I will post my dyno sheets from the Z so you can see how erratic the stock ECU fuel map can be and how it can actually create power loss by simply running too far out of either extremity.

Ali Hammed: do you have any pics' of your installation/location of both the SAFC and rev meter?

xBlkGs430x

i was looking into the greddy e-manage, is it the same type of thing as the safc, or different, could i have it in my sc400 with the s-afc anyone have the greddy in a sc4

NAZTY97

I looked at it, and the guys at the shop said the SAFC was better in the fuel management regard, plus they didn't have prgms for our cars yet,... so, not YET worth the money for us.

I'd say, get the Apex ITC, it allows you to manipulate the timing to maximize the SAFC,...you have to dyno tune/install this or is bang, bang, boom to your engine.

healerhand

I just got my tech person install SAFC last night on my TT LS400 Setup. I will let you know what happen.

NAZTY97

...but damn,.. you got those darn turbo things,....so, I can't really see how it'll affect the V8 NA engine, but if you do your initial run w/ it inactive get a run after everything else is tuned, then run it through the 8 or 9 passes to tune it and print that sheet off,... that shows the true gains.

MadMaxSC400

I opted for the chip because the timing definitely can be tweaked for HP too. I don't think there's much point in an SAFC on an N/A V8, and my friend Leo, VP of Weapon-R certainly didn't think so. My setup as listed on my sig yielded rear wheel numbers of 200/221 hp/tq, and that was on questionable gas (my previous run a month earlier was 222whp). If I can get my hands on the dyno sheet again I'll post a copy of it.

healerhand

My Timing is control via MSD DIS 4 ignition. I have an extra one, that is why i am using it. The MSD will control timing and Increase ignition.

NAZTY97

MADMAX:
Why do you say that?? I got 24 additional usable hp on a N/A V6 and 25ft/lbs,.. why wouldn't I expect better gains on the V8??

Also,... if the stock ECU is erratic in A/F mixture,... why wouldn't it be wise to make it linear and more optimized?

An ITC inline with a SAFC accomplishes what a chip does, and IMO does a better job simply because it's tuneable to the car, not a one size fit's all application. ( most of us don't live near weapon r to drop by and get our chips tuned to our cars,... mileage, cost, time, labor... expensive ) I think,.... if you took your chip off of your car and put it on mine,.. I'm certain we'd get different numbers, and if you put it on yet another car,... it'd get different numbers,....your stock configuration may take better to the enhancements of the chip vs another car's configuration and stock performance. True, you may not get the rev limiter or top speed limiter removed,... but for fully tuneable timing and A/F ratio, for the $$$, I don't know a better way to accomplish that.

Stand alones cost 3X's the cost of both together as a package, and still require dyno time and tuning ( labor $$$$ ). A chip is good start,... but even if I had a chip,... I'd still add an SAFC to tweak it to better performance. A lotta Z and Supra drivers do it, chip and SAFC/SAVCR. Very few people deal with the ITC because I guess not many people know about it and how it works.

healerhand

I think the Stand Alone is the best, but the price will kill a lot of people. Secondly, not too many Stand Alone computer would support the 1UZFE engine.

MadMaxSC400

Because it's two totally different motors with very different computers. I know it's not as effective, because it's been proven with people who've tried using the SAFC. The dyno numbers just aren't all that big, mabybe 10 hp gain.

Quote:

Also,... if the stock ECU is erratic in A/F mixture,... why wouldn't it be wise to make it linear and more optimized?

The stock ECU is not erratic in A/F mixture. If you're seeing that in your car you need to clean or replace your MAF and check the wiring, the SAFC does not replace the signal from the meter, it simply changes the amplitude of the signal it gets from it.