S-AFC Fuel Management, 7afe options Options

[[Freemantle]]

I've recently acqiured a '95 ST as my new daily driver after some unfortunate mishaps with my previous vehicle (Honda Prelude). I've been a Honda kid since before I could drive, but I refuse to just give up on this car because it is "a 110 hp Toyota".

That being said, the Celica feels like it has no aftermarket when compared to anything I've driven prior. As a non-typical Honda guy, I'm all about keeping the car stock looking and using some shade-tree mechanic work to turn out some surprising numbers. I've got a T25 off a fresh rebuild and I'm ready to make this car a little more ballsy. I've done plenty of reading, I just have one issue.

The 7afe seems to have nothing as far as fuel management is concerned. I refuse to use an FMU (Boost dependent rising rate fuel pressure regulator) as "fuel management". It appears that the best kind of fuel management I am going to get is using the AFC hack, where I will use oversize injectors and dial them down with negative values with an AFC. Here are my questions.

A) How does the 7afe ECU respond to boost? The AFC will do nothing to correct ignition, it will just keep the car from seeing boost to dial down the map position (decreasing pulse duration to dial down the oversize injectors from choking the car).

B) Has anyone done this before?

C) What injectors fit the 7afe that can be easily obtained? What is the cc/min rate of stock 7afe injectors?

Thanks for your time.

[Dr_Tweak]

Good stuff. Of course I'm sure you know to use check valves on the MAP sensor line. Other than that the strategy you have in mind will work just fine. Do keep in mind that the ECU tends to advance the timing when you lean it out with the SAFC, so an MSD Boost Timing Master is a good addition.

Also the Greddy eManage will control both fuel AND timing, so check into that.

It has been done before a few times, search around and there's even a how-to guide here.

[nik]

,Jul 25, 2005 - 5:47 PM]A) How does the 7afe ECU respond to boost? The AFC will do nothing to correct ignition, it will just keep the car from seeing boost to dial down the map position (decreasing pulse duration to dial down the oversize injectors from choking the car).

B) Has anyone done this before?

C) What injectors fit the 7afe that can be easily obtained? What is the cc/min rate of stock 7afe injectors?

Thanks for your time.
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Just a quick question why dont you like FMU? i used one for quite a few months and it worked fine but i wanted more control then i started boosting 10psi+ so i went the greddy e-manage + profec E-01 good control for a piggy back ecu.

A) not at all if you have a 94-95 st you can manually retard your timing if you have 96-97 then you need a msd retard timing unit etc. As for fooling the ecu into seeing no boost check my how to there is a check valve set up that works great and is cheap to make.

B) i think there is how to install a safc in an st

C) 4age high imped 290cc injectors as for stock injectors there like 90cc or so not sure off hand just check your chilton book or call toyota


EDIT: here is the link http://www.6gc.net/index.php?action=howto&itu=128

This post has been edited by nik: Jul 26, 2005 - 11:49 AM

[[Freemantle]]

Thanks for the input, I didn't knwo the GReddy E-Manage worked for our application. I've never toyed with that interface before, just AEM and Hondata/Uberdata.

I don't like the FMU because it dosen't take engine speed into account. Consider that an engine spinning at 6000 rpms @ 10lbs is getting nearly the same amount of fuel as an engine spinning at 4000 rpms @ 10 lbs. That means that you have the option of running pig rich in the middle of the powerband, or leaned out up top. A 12:1 FMU will most certianly do the former, giving you that "JDM y0" backfire when you're not even getting on it.

I have personal experience replacing head gaskets (and worse) on FMU managed cars. I've seen 2 D series and a B series bite the dust from FMU complications.

Again, thanks for the help, E-Manage sounds like a great idea. Timing control FTW.

[Dr_Tweak]

,Jul 26, 2005 - 10:13 PM]Thanks for the input, I didn't knwo the GReddy E-Manage worked for our application. I've never toyed with that interface before, just AEM and Hondata/Uberdata.

I don't like the FMU because it dosen't take engine speed into account. Consider that an engine spinning at 6000 rpms @ 10lbs is getting nearly the same amount of fuel as an engine spinning at 4000 rpms @ 10 lbs. That means that you have the option of running pig rich in the middle of the powerband, or leaned out up top. A 12:1 FMU will most certianly do the former, giving you that "JDM y0" backfire when you're not even getting on it.

I have personal experience replacing head gaskets (and worse) on FMU managed cars. I've seen 2 D series and a B series bite the dust from FMU complications.

Again, thanks for the help, E-Manage sounds like a great idea. Timing control FTW.
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While I certainly agree with you about using a piggyback over an FMU, you are not totally correct with what you said here. While an FMU does not take engine speed into account, that is a moot point since the ECU *does* in that it lengthens the pluswidths as the engine speed increases. The FMU provides higher pressure under boost conditions, which will increase fuel by a percentage all across the board. (In other words, more fuel will be spraying out at a higher RPM since the ECU is ordering longer pulsewidths, while it will be spraying less at a lower RPM.)

Bottom line is, an FMU can work quite well under low boost on engines using return-line fuel systems. Anything above 6 or 7 psi, or on engines with deadhead fuel systems, a piggyback at minimum is a must.

-Doc

This post has been edited by Dr_Tweak: Jul 26, 2005 - 10:22 PM

[nik]

you got it doc

[playr158]

another great deal for the money is the prs4 standalone unit.....which could potential be cheaper or more expensive then the greddy-emanage......note to run the e-manage you must by this and that attachment ect.....this and that sensor... the prs4 retails for 849$ and it will also adress your map sensor question because you can tac a 2.5bar map sensor for an additional 90$....... but standalone isn't for everyone especially if your under 10psi...its just a option....

[[Freemantle]]

Thanks for all the input, this has definately showed some aftermarket potential. This setup isn't going to be serious, (not much more than 8Psi on a junkyard turbo, hell - I paid $1800 for the car) so I doubt that a full stand-alone will be my avenue.

I can most likely get a secondhand e-manage unit for a decent price. If not I will most likely run the S-AFC and use my old PLX wideband from my old car's turbo setup and dial in the fuel for saftey reasons.

While timing control would be a huge power benefit as well as saftey, I'm not really looking to take home any tropies with this car, just give it a little pep and make it move like somthing besides "a girls car" (does every Celica owner get dissed with this?).

As far as the Dr's comments, you are correct in the sense that the injector duty cycle is greatly increasing, but the pulse duration per rotation is not increasing in a sense that will accommodate the increased density of each intake stroke. If you have it and you love it, then more power to you. I'm not saying that it will surely blow up your car, or that it should never be done, but past experience tells us that anyone on boost has a tendency to get bored and push the FMU system well beyond its limits. I'd be lying if I said that I didn't want this 7afe to put down 225whp, even if I fully know that isn't feasable with improvised fuel management.

Speaking of horsepower, what kind of engine (or wheel) horsepower do 7afte owners experience at low boost on stock internals? I'm not sure how responsive this car is to boost, and I want to size my injectors properly. I saw the post with the 240cc injectors listed, they just seem.... small compared to what I am used to using. Any larger alternatives? MKIII supra injectors perhaps? Thanks for bearing with me, I'm trying to dig up the Toyota ghetto-fab secrets.

EDIT: I'm having a tough time sourcing a manifold. Any suggestions? Do all "a" heads have the same port size?

This post has been edited by [Freemantle]: Jul 27, 2005 - 4:06 PM

[nik]

7AFTE DYNO
this power was made on stock internals and 10cc bigger than stock injectors
http://www.6gc.net/forums/index.php?showtopic=21152&hl=

for turbo header
www.jgstools.com

or custom

or the b-series conversion in short cutting the exhaust flange off the b-series header and rewelding the 7afe flange to it.

[[Freemantle]]

7AFTE DYNO
this power was made on stock internals and 10cc bigger than stock injectors
http://www.6gc.net/forums/index.php?showtopic=21152&hl=

for turbo header
www.jgstools.com

or custom

or the b-series conversion in short cutting the exhaust flange off the b-series header and rewelding the 7afe flange to it.
[right][snapback]317501[/snapback][/right]

Those are great numbers! 10cc over stock? This is pretty amazing to me. I'm so used to working with 450cc injectors. I take it you are compensating with fuel pressure and blocking boost to the 7afe ecu with a missing link or check valve system?

[nik]

7AFTE DYNO
this power was made on stock internals and 10cc bigger than stock injectors
http://www.6gc.net/forums/index.php?showtopic=21152&hl=

for turbo header
www.jgstools.com

or custom

or the b-series conversion in short cutting the exhaust flange off the b-series header and rewelding the 7afe flange to it.
[right][snapback]317501[/snapback][/right]

Those are great numbers! 10cc over stock? This is pretty amazing to me. I'm so used to working with 450cc injectors. I take it you are compensating with fuel pressure and blocking boost to the 7afe ecu with a missing link or check valve system?
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the sorry ment 10% more flow they were venom injectors but i would go atleast 365cc injectors. and check valves on the ecu

[playr158]

i've heard shady things about venom.....

i'd suggest a nice set of RC saturated injectors

[nik]

i've heard shady things about venom.....

i'd suggest a nice set of RC saturated injectors
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venom worked fine for me but yea i would go with RC over them