I NEED Boost... Opinions puh-lease

[Nexus1155]

:brokenhe art:

Look at it this way, whats the power output of a GT25 @ 12psi compared to a GT35. The difference is astronomical.

[sleey0]

Nevermind....

[Nexus1155]

nononono be lucky i am not tamago and i won't yell at you and i'll try not to go too in depth. I am going to show you what I mean. You are not allowed to build a turbo kit until you understand this. Basic I am sure you know, air + fuel + spark makes combustion and power. Doing something to allow air to flow into the engine more = more air+more fuel+spark = more power. Now if you take a turbo/supercharger and start forcing more air into the engine you will get alot more power.

http://www.atpturbo.com/root/maps/im...8rsturbine.gif

Pretty much identical turbo other than the area/radius of the housings. If you follow any pressure ratio on that given map you will see the larger housing will always be pushing more air through the engine.

Depending on if you want it for low end boost or more high end, something even in the same family of turbos can be dangerous to your engine if you do not size it properly even a GT25 and you end up cranking up the pressure one day by a little bit your engine might blow. Even though these engines ae only like $50 a pop.

[why?]

well maybe $500 a pop, but still dirt cheap engine wise.

[cdydjded]

Sitting in my warehouse, $350 delivered, 55000 mile
IMG00597.jpg

[Nexus1155]

SEE $350 DELIVERED and thats a pretty good condition one as far as i can tell. Can't beat that

[cali yaris]

50... no.... 500...no....... 350....... BINGO

LOL

[cdydjded]

www.car-part.com is a gold mine!

[Freedan]

350 for an engine!? Wow.

Might have to visit the local junkyard and find an engine that I can tinker with if it's that cheap.

[Focus_Sh1ft]

Build update...

Been having problems getting the car to run properly with the FIC hooked up after I wired up the cam and crank wires. Turns out I had to drop the mago- wires on each, then just TAP C20-121 with both magi- wires. Why I had to do this when others didn't... I dunno.

Anyways, I first threw in a map pimp my yaris gave me just to see if my AFR would respond correctly, and possibly use as a base map for tuning. For whatever reason, nothing happened. Watching my wideband, the AFR continues to hold around 14.7 with no notable changes. I drove around a bit and pushed the engine to make sure. I'm going to do some logging and see if I can figure it out.

Was wondering what injector response time I should be running. Brian, Carlos, if you could chime in that'd be great.

[Focus_Sh1ft]

Alright so tuning... I just don't understand how changing values on the fuel map is honestly going to work. By doing that I'm setting up the STFT and, therefore, the LTFT to be wayyyy off... I feel like the O2 sensors need to be manipulated to get an accurate and reliable tune. Also - while driving it seems like they just lean the car right back out to 14.7 even when additional fuel is being added. This is due to closed loop though, right? When I change values during idle I can watch the wideband go richer, then quickly get corrected back to about 15. So I'm assuming I need to leave everything out of boost untouched, then figure out a way to force the car into open loop when I'm boosting. Then I can adjust fuel without having the O2 sensors interfering, right?

So it's either force the car into open loop at around 15 PSIA, or manipulate the O2 so closed loop is forcing a richer AFR than 14.7. I feel like the latter is what I have to do, because the car begins boosting while in closed loop.

UGH.

[pimp my yaris]

Your thinking is spot on. But you can do this with the maf. clamp when in the boost. OK first, when in closed loop [ie: normal driving] Your AFR will always be 14.5 to 15:1. This is actually good as it maintains low emmisions and good gas mileage. What we want is to clamp the MAF. at the correct voltage so when in the boost the computer will stop adding fuel and the FIC takes over. I still need to get this MAF max voltage on a normally aspirated Yaris. Also the most important AFR reading U need is when under heavy exceleration [IE: foot to the floor]. This is when Im trying to get that 12:1 zone AFR. The factory ECU flips to open loop at around 80% load or higher. Under that U should see 14.5 to 15:1 on the wideband. Their is no point to make the FIC control fueling all the time unless we are road racing or only driving a track car. I have already altered the map a little to help keep fuel trims more inline. What is your AFR when wide open and under boost. I know its difficult to answer but it should not go leaner then 13:1. Also in the map I gave you I clamped the map at 3.1 volts when in the boost and at above 3800rpm, if I remember correctly. Its still a work in progress for me too. I am happy I dont have any excessive rich or lean trouble codes.

[1.5ty]

Your spot on with everything but way are you looking for a a/f of 12.1 I know how to use aem standalone but not fic and when I tune with that with a boosted car max power falls around 11.2-11.5 a/f

[pimp my yaris]

This is the first car I have worked on tuning. The factory (non boosted) open loop AFR was 12:1 to 12.5 to 1. I just tryed to keep it in that range. I dont have a dyno. Everyone here seems to have a different opinion on the best AFR range to run.

[Focus_Sh1ft]

Ok good I was wondering how you were running something other than 14.7 under closed loop but you're not. I took your map and made a couple changes according to where my car enters boost, and I also moved the MAF clamp to a lower RPM and changed it to 2.9 (my max value out of boost approximately).

The problem I was having yesterday was that I was entering boost and was still stuck around a 14.7 AFR. Even by 5 PSI I wasn't getting any richer. I'm not sure why... I'll watch closed/open loop more closely today and see where it switches. I may have actually been using a map yesterday that didn't have a MAF clamp... can't remember. That could be the issue.

AFRs confuse the hell out of me because there's a lot of conflicting information online... I was under the impression I needed an 11.5ish AFR at all times on an FI engine, but that's only really needed during boosting I reckon?

[Focus_Sh1ft]

Well I had a crummy last two days lol. Car died because of battery terminal corrosion, then I went to go replace a coolant adapter and had the wrong one. Good thing is that I finally know the exact size thread I need so I can stop battling this stupid tiny leak.

Anyways, I've been toying with the FIC the last couple days and setup a MAF map. I put it in voltage mode and am using the MAF as the reference column. I then set all the rows to mirror the incoming MAF voltage. This way, MAF in = MAF out. However, at 2100 RPM and 2.81 volts, I've clamped everything beyond those values at 2.9V. This appeared to be the max N/A voltage reading I was obtaining. Not sure if this will work, as I haven't had time to try it yet.

Brian - if this works we won't need a MAF map. In fact I don't see why this wouldn't work. Anyhoo, I started throwing a MAF map together in case this fails, but it's been a real PITA so far...

[Focus_Sh1ft]

Alright.. Would like to talk about open loop. Hopefully some of you here will have some info for me.

I've yet to see my car enter open loop unless I am letting off the throttle entirely. How hard do you need to be pushing a car to enter open boost, WOT? Because I do my driving in the 1k-3.5k range and rarely hit WOT. Is there some sort of difference between a manual and automatic that I don't know about?

[1.5ty]

Open loop and close loop it controlled by temp when you start the car in the morning when it's cold that's what they call open loop after it's warm and that's what they call closed loop