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Discussion Starter #1 (Edited)
So my mk3 has been on the road for over a month now after a dreadful 3 years and im happy to say all is well... nearly. The engine is a 6m crank, stock rods, forged Je .020 oversized pistons, all new seals, bearings, arp hardware, new oil pump shimmed, new squirters, ect. Went with an 80mm Titan mhg and arp studs.

Now my engine builder told me that because my compression ratio (8.57:1) is higher than stock (8.4:1) I shouldnt run boost higher than 14psi until I go standalone or run methanol to be safe. Does this all make sense? Will a .17 difference in the CR really make that much of a difference?

I am planning on stepping up from stock boost this summer. What I have done so far is a full 3" exhaust system, 3" intercooler with 2.5" hardpiping, 60 trim ct26, cone filter, full flow thermostatically controlled oil cooling system, oil catch can, j-tube delete, Walbro 255.
What I have not installed is an Apexi Safc2, HKS evc, 550cc injectors, lex maf, afpr, Still need to buy a wideband and rewire my knock sensors before I can do anything with these parts.

Who here has done an Safc 2 with an ebc that has a high boost and low boost setting? How do you tune it for each or is it just one tune for both?
What boost levels should be safe for my build? Im thinking maybe 10psi for low boost setting and 13 for high.
Am I missing anything here to complete this upgrade?
Is this a safe setup for street use?
Any and all recommendations, tips, and questions are encouraged, thanks!
252222
 

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its a complicated question.

physically: you motor has strength to live at 5-600 whp on the stock connecting rods. people have taken oem bottom end and held that much

electronically: your oem computer + 550 + lex + Safc is a primitive way to run this engine. add the word antiquated as well. and not the most reliable due too so many old components (wire harness / 30+ year old ecu with caps that could fail).

on top of the handicap of the cars oem stuff, the real Achilles heel is the timing control and strategy of they cars stock ecu. when you add the larger AFM and balance with 550 injectors, you are telling the car "hey your getting way less air" so it give a very small injector pule, which works well with those much larger injectors. what goes wrong is the car thinks "less load" and advances timing.

so you would think, hey this car has a cps that allows me timing adjustment. instead of running 10 deg factory spec ill retard that to 5 degrees so im safe.

well the cars ecu is actually listening to the knock sensors, and advancing timing until it hears knock. it then remembers this info and alters its timing maps with this new info

so no matter what you set your cps at (within reason) the ecu always finds the true max timing and it finds it with a god dam sledge hammer because it brings the motor into knock and pulls back

now its not doing this knock learning only in boost. actually its the opposite (I would suspect, if it acts like gm systems of similar vintage that I was trained on decades ago). the car learns the knock point under light load / light acceleration and then builds out the high load ignition table based on the learned knock points. again I suspect. we know the cars stock ecu does this with fuel trims, records o2 info at low loads and builds out the high load table, it makes sense the knock table is similar

so long long story short, you really want a stand alone to max that baby out. then you can run pump gas with that turbo all the way up to 20 psi and maybe more, provided you can control timing

also, if you can run higher octane you can piggy back with a bit more margin of error. I mix 1 gal of 110 race with 3 gal premium. I don't hear any knocking, see any on the plugs ... but want to try det cans sometime to make sure. personally my car has lived years, a few dozen 1/4 passes and countless street pulls on the piggy back setup.

Im hitting 15 psi on a 56 trim billet 11 blade, but I have 440s and somewhat insane fuel pressure to get more out of them (and some other things, like no afm due to map conversion)


if you get a stand alone you don't have to understand the cars old oem stuff (wiring, sensors, joy of fuel trim boost cut and ecu resets) and can just learn more useful things : how to wire, install and tune a modern ecu.
 

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@madisonMK3 thanks for the detailed info ^^ Here's a question. Is there any benefit, or is it even possible, to run a standalone ECU with an OEM engine setup?

My reasoning would be just more stable and modern "avionics" as it were. A comparison for me would be that B-52s airframes are still in service, but all of the technological gear has long since been updated.
 

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Here's a question. Is there any benefit, or is it even possible, to run a standalone ECU with an OEM engine setup?

My reasoning would be just more stable and modern "avionics" as it were. A comparison for me would be that B-52s airframes are still in service, but all of the technological gear has long since been updated.
Yes. you remove all the limits programmed deficiencies that @madisonMK3 alluded to.

you will now be able to hit mechanical limits (turbo, fuel injectors fuel pump etc).
 
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Sure is a pretty clean engine bay.
I'd skip the LEX AFM and S-AFC route personally. I've been there and done that and it works, but man there are so many better options these days.

To answer your question though, the stock ECU timing curve has been shown to be incredibly aggressive. I was running Sunoco brand 110 octane fuel full time in my car, making 600-650hp. That lasted for a few years before I started getting HG leakage again.
 

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Discussion Starter #7
@madisonMK3 thankyou for the insight and detailed info, I had no idea the ecu would be playing with the timing that much.
Now im not quite looking to "max this baby out" as I am very young and shouldn't have that much power to play with just yet. Honestly at this point I would actually like to understand more of the stock setup with all the sensors and fuel trims with the efi fuse and what not before I decide to ditch it. That being said, I will go standalone in the next year or two but im just not ready for that big of a step.
I was more looking for a comfortable 350whp to play with this summer and then step it up to 400 or so next year. If I do it in increments I can get used to the power and have more control of the car for when I really get up there.

@T6Rocket It was taken off to get cleaned and painted, will go back on when done.

@MK3Brent Thankyou, thats what I like to hear haha. I know there are better options but this just seemed like the way to go for so many others for a long time. So to run this setup a little safer I should be running high octane? Currently im on 91.
 

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So to run this setup a little safer I should be running high octane? Currently im on 91.
Always run the highest octane you can at the pump, in my opinion. (Alternatively, you could also look into a water or alcohol/meth injection system.)
And I'd keep the power levels in the 450-500's if you want it to last. (Assuming you step up the injectors and all necessary fuel support.)

Just from my personal experience. I know others will disagree.
 

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@WhiteMk3Turbo

Honestly,

If you do not have emission testing in your neck of the woods, forgo piggy backs and run a standalone. It will save you headaches long term.
 
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At 8.57 CR and if you are running Candian petro 94 octane, I wouldn't worry about problems until 20 PSI. Getting to 20 PSI is going to be challenging without a bunch of piggybacks. Stock computers are probably the best at pulling timing on the first detection of knock. I know for sure my 2jz always knocked on stock ECU at 14 PSI on cali 91 octane. When it pulls the car is gutless, and you know right away. Adding 35% E85 to my tank made the car night and day. Same with my 7m on only 11 PSI.

The issues with standalone computers are most neglect knock control, or it's simply just isn't anywhere near as robust as the stock tuning on the stock ECU. However, the benefits of all the other controls outweigh this.
Using piggybacks will allow you to get to more boost, and more timing reduction with that boost via the stock computer, (you'll make more HP but torque at peak will prob be the same). The problem is the mess you create wiring wise by adding the boost control, boost cut defender, fuel computer and yada yada.. In the past I've been using Emanage's to great success, the issue was they were limited on inputs as well. With the EMB and EMU only having 1 or 2 inputs for external sensors, and a lot of wiring to split off and redirect signals.

I've now graduated finally (15 years later) to a PNP standalone form Perfecttuning. It's really a magical unit IMO since it includes everything you would want and gives the ability to expand to whatever you want later. Most importantly, it removes the restrictions of a boost from the stock ECU while allowing you to keep safety like adding a boot cut again at the desired area.

In my case, I made an ultra-clean install since I only needed to steal power for the two sensors I'm using (flex-fuel, boost solenoid) and to do this i made a mini jumper harness. keeping things really clean and tidy above the glove box.

Edit Don't have a pic of the one power wire I stole, but here's another of the ABS wires I stole to activate traction control for the standalone (feature obviously the mk3 never had) If I want to go back to stock, I just remove my connector and depin the 4 wires and put them back in the stock terminal.

See the pic below.
 

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Discussion Starter #11
@MK3Brent I have an afpr, fresh fuel filter, Walbro 255 and 550 injectors, what should this setup be good until, and should I upgrade the fuel rail feed line for 400hp?

@figgie No we do not have emissions testing up here in Ontario anymore. Standalone is out of my reach this year, maybe Ill have to put up with some headache for a bit.

@ZaZZn Im thinking ill do 94 for the weekend on a high boost setting at maybe 12psi and then 91 for the weekdays on a low boost setting at 8-9psi. Also I though E85 was only safe for cars modded to support it. How does it mix? Im okay with making a mess of stock wiring as when I go standalone ill make a new wiring harness.

I have all my pieces ready to go, afpr, safc2, hks evc, lex maf, 550s and an AEM wideband to tune. Knock sensors fixed and Im ready for this upgrade, thinking this weekend. Any advice?
 

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My rule of thumb was no more than 80% of the fuel injector. So 440hp should be fine. (I dyno’d 564hp on RC 550s once. But wouldn’t want to leave it there. )
 

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I would do it in stages. there is a lot of room left in the 440 injectors with the AFPR and taking fuel pressure up a bit. provided your injectors are good / have been cleaned and checked recently. stock rail flows 400hp easy with the oem regulator gone and afpr installed.

meaning you could just install the wideband 02 and SAFC to start (plus afpr). you will then have the ability to lean the car out / see how it runs stock

my bet is its absolutely piggy fat rich at WOT. so you can then pull fuel (scale the afm signal down ) only at WOT and take that 10:1 or richer and get it to 11 or 11.5 : 1

that alone will give you a lot of headroom. Im running 440's, fuel pressure set 10psi above factory spec, 56 trim billet (ct26) pushing 15 psi and im just under fuel cut

But, I have the ability to ramp my boost up from spring pressure -->> 15 psi via an electronic boost control. if my turbo came on too early , say 10 psi at 3500 rpm.....I can hit fuel cut easy. but with boost rolling on (from 7psi spring to full 15) after 4000 rpm I don't hit fuel cut.

but, I would not risk switching fuel. can't be much more per Gal (or L haha) to risk it

x 10 if you throw those 550's in there. those force you to drastically scale the afm signal (hence the lex housing). this makes timing way to advanced and really not save without premium fuel

btw I would say im @ close to 350whp on the 440's. best quarter mile 13.3 trapping @110 --have not been on a dyno
 

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Discussion Starter #14
@madisonMK3 so you are saying to do the lex maf but stick with the 440s? I have no Idea the condition of them but I could run some injector and fuel system cleaner in my next tank and hope that does something haha. Makes sense not to switch the fuel back and forth, she probably wouldn't like that too much.... So I guess this weekend Ill be switching over to Petro Canada 94, it sits around 1.25/1.30$ per L, compared to 91 at around 1.15/1.20$ per L.

So far I have my HKS EVC boost controller installed and im running 9psi and I just finished getting my AEM wideband installed so now I got afpr, safc2, lex maf??

I don't want to run high fuel pressure because that just sounds like trouble to me. Also don't want to push these 33yo injectors I have so maybe ill start off really light on the boost.
 

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Upgrade the injectors. Period. Don’t fuss with 30y/o injectors. Get a nice set of RC550 or bigger injectors and start there.

if you’re interested, you could send them to RC and have them tested. That’d be cool to see. How do factory Toyota 440 cc/min injectors perform. :)
 

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@MK3Brent I have an afpr, fresh fuel filter, Walbro 255 and 550 injectors, what should this setup be good until, and should I upgrade the fuel rail feed line for 400hp?

@figgie No we do not have emissions testing up here in Ontario anymore. Standalone is out of my reach this year, maybe Ill have to put up with some headache for a bit.

@ZaZZn Im thinking ill do 94 for the weekend on a high boost setting at maybe 12psi and then 91 for the weekdays on a low boost setting at 8-9psi. Also I though E85 was only safe for cars modded to support it. How does it mix? Im okay with making a mess of stock wiring as when I go standalone ill make a new wiring harness.

I have all my pieces ready to go, afpr, safc2, hks evc, lex maf, 550s and an AEM wideband to tune. Knock sensors fixed and Im ready for this upgrade, thinking this weekend. Any advice?
afpr 150, safc 2 150 , evc 200, lex afm 150, wideband 200 = 950 the PNP standalone is 1250 and comes with the wideband. EMU Black is even cheaper at 1000 or so.
Pump in Ontario is much better than Cali.... I used to run 17 PSI on my stock CT made 307rwhp /406 tq used to drop to 14 psi by redline. I used to run 20 on my 2jz's on pump no problem with my aristo and mk4 as well. The biggest problem you are going have with your setup is you are going to fight boost cut nonstop. SAFC is really stupid on the mk3 because it adjusts the AFM signal. Which adjusts fuel map and timing.

Basically, here's how it goes 14 PSI on the stock turbo = around 1500-1550 HZ on the AFM output. This is where you see FCO... When you add boost and SAFC in the mix it goes like this.

17PSI = 1650 HZ from AFM, you'll need to pull 5% signal from AFC, go to 20 psi and you need to pull maybe 10%. Upgrade the turbo and it gets worse because it flows more air and have even higher HZ numbers. Remember the stock computer stopped adding fuel at 14 PSI and you are tricking it everywhere else and adding fuel via fuel pressure and or bigger injectors. Basically, it's a shit show of messing around. It can be done, but there are so many better ways of doing it now days. The manage is only like 150-300 used. I know Rob in Toronto was parting out and has my old manage blue which would be perfect for your use. That way instead of pulling fuel at 14 psi you clamp the signal at 14 PSI then add fuel directly driving the injectors longer with the emanage.
 

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its a complicated question.

physically: you motor has strength to live at 5-600 whp on the stock connecting rods. people have taken oem bottom end and held that much

electronically: your oem computer + 550 + lex + Safc is a primitive way to run this engine. add the word antiquated as well. and not the most reliable due too so many old components (wire harness / 30+ year old ecu with caps that could fail).

on top of the handicap of the cars oem stuff, the real Achilles heel is the timing control and strategy of they cars stock ecu. when you add the larger AFM and balance with 550 injectors, you are telling the car "hey your getting way less air" so it give a very small injector pule, which works well with those much larger injectors. what goes wrong is the car thinks "less load" and advances timing.

so you would think, hey this car has a cps that allows me timing adjustment. instead of running 10 deg factory spec ill retard that to 5 degrees so im safe.

well the cars ecu is actually listening to the knock sensors, and advancing timing until it hears knock. it then remembers this info and alters its timing maps with this new info

so no matter what you set your cps at (within reason) the ecu always finds the true max timing and it finds it with a god dam sledge hammer because it brings the motor into knock and pulls back

now its not doing this knock learning only in boost. actually its the opposite (I would suspect, if it acts like gm systems of similar vintage that I was trained on decades ago). the car learns the knock point under light load / light acceleration and then builds out the high load ignition table based on the learned knock points. again I suspect. we know the cars stock ecu does this with fuel trims, records o2 info at low loads and builds out the high load table, it makes sense the knock table is similar

so long long story short, you really want a stand alone to max that baby out. then you can run pump gas with that turbo all the way up to 20 psi and maybe more, provided you can control timing

also, if you can run higher octane you can piggy back with a bit more margin of error. I mix 1 gal of 110 race with 3 gal premium. I don't hear any knocking, see any on the plugs ... but want to try det cans sometime to make sure. personally my car has lived years, a few dozen 1/4 passes and countless street pulls on the piggy back setup.

Im hitting 15 psi on a 56 trim billet 11 blade, but I have 440s and somewhat insane fuel pressure to get more out of them (and some other things, like no afm due to map conversion)


if you get a stand alone you don't have to understand the cars old oem stuff (wiring, sensors, joy of fuel trim boost cut and ecu resets) and can just learn more useful things : how to wire, install and tune a modern ecu.
I'm very interested in learning the specifics of how the stock ECU works. Do you happen to have any resources I could read?
 

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^^ The learning of a modern ecu" is a slippery slope for me. I'm most interested in keeping it stock, but, in light of 33 years now, I see at some point in the near future where that won't be possible without the car just becoming a museum piece. At that point though, you cross over into the modded realm from which there is no return :)
 

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haha yes when you turn the boost up, free things up (exhaust, downpipe) there is no going back. add electronics so you can tune things and record data from the car, and its the same way....you just want more and better stuff. Im cool with 100% stock exterior including sawblades, but why are you not pushing 300whp at least is a supra man come on ;)

I'm very interested in learning the specifics of how the stock ECU works. Do you happen to have any resources I could read?
lots and lots of good info in this thread:

 

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Oh I totally agree. What comes to mind is the B-52H. Flying 50+ years, it had be completely modernized with the latest technology to keep it relevant and lethal. Still looks basically the same from the outside. What I run into these days also is every Honda, Challenger, and Range Rover wanting to race me at lights :ROFLMAO: I'd like to at least think I could run with them!
 
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