1.6 dohc turbo (New pics added)

Nubira2.2 · Post by **Nubira2.2** » Thu Sep 13, 2007 2:14 pm

i dude ...
first remember to size the turbo for the engine and HP goals
second size the fuel system for ur HP goals

i use a DTEC-FC to control fuel and in works well
in my fuel system i only have 450cc injectos with OEM fuel pump

good luck

jidasas · Post by **jidasas** » Thu Sep 13, 2007 6:42 pm

Thanks, I have my turbo...it's big for 4psi but later I'm gonna build the bottom end and head stronger and run more like 20 psi...probably within the next year. I was told the turbo is good to about 300 hp, but I've seen an eclipse running one almost exactly like it and it was pushing 420 hp. So, it may be a little big but I'm gonna try it and see...if it has too much lag or I don't like it I can always spring for a new one when I do the next phase.

As for fuel system, for the 4psi I was just gonna go with the 2.0 injectors-should be good I think.

So, Was the dtec easy to tune with? I hope to be able to do the basic tune myself and only have to pay for a few hours on the dyno that way.

Thanks so much for the advice! I know it's taken me forever to get this far...but I will get it done.

Jimmy

exist3nce · Post by **exist3nce** » Mon Sep 17, 2007 3:37 pm

I would be careful with those injectors, even tho they are for the 2.0L they still aren't that big. My Optra 2.0L injectors are only 20 lbs / hr which is somewhere around 200 CC. Pretty small.....

jidasas · Post by **jidasas** » Mon Sep 17, 2007 9:36 pm

You think I would be able to tune a set of ~350's down enough to run the 4 psi without running really rich at lower rpms?

Jimmy

Nubira2.2 · Post by **Nubira2.2** » Tue Sep 18, 2007 7:47 pm

my basic tune with the dtec 4psi and 450cc is ...
-45% @ idle
-42% @ full boost and thats about 11.3:1 AFR
i still have plenty of fuel

exist3nce · Post by **exist3nce** » Wed Sep 19, 2007 10:28 pm

jidasas wrote:You think I would be able to tune a set of ~350's down enough to run the 4 psi without running really rich at lower rpms?

Jimmy

No you probably won't be able to lean it out enough with a piggyback unit to get it to a nice stoic 14.5 AFR for cruising and idle. Sure you will have plenty of fuel for boost, but you probably will run rich the rest of the time too.

jidasas · Post by **jidasas** » Thu Sep 20, 2007 12:48 am

So, I would be best running the 2.0 injectors at least until I get ready to turn up the boost.

Update too...I picked up my other block today.

Jimmy

Nubira2.2 · Post by **Nubira2.2** » Thu Sep 20, 2007 1:57 pm

exist3nce wrote:
No you probably won't be able to lean it out enough with a piggyback unit to get it to a nice stoic 14.5 AFR for cruising and idle. Sure you will have plenty of fuel for boost, but you probably will run rich the rest of the time too.

sorry i don't agree

my car has stoich idle with my DTEC-FC piggyback using 450cc injectors and by the moment
@ 4psi

remember our cars are OBDII
and use O2 sensors to messure the close loop AFR
if it is too rich it will lean it back to 14.7:1

my car runs the same MPG before and after turbocharged

exist3nce · Post by **exist3nce** » Thu Sep 20, 2007 2:28 pm

Nubira2.2 wrote:
sorry i don't agree

my car has stoich idle with my DTEC-FC piggyback using 450cc injectors and by the moment
@ 4psi

remember our cars are OBDII
and use O2 sensors to messure the close loop AFR
if it is too rich it will lean it back to 14.7:1

my car runs the same MPG before and after turbocharged

Are you sure its running stoich during idle and cruising? Do you have a wideband O2 to verify this? Most piggybacks can't trim out more than -50% of fuel. And yes I know full well our cars are OBD2, and that the O2 sensors might be able to trim out the rest of the fuel. However if it has to start trimming alot of fuel it will start throwing CELs. I tried it, and on my car it gave me CEL and limp mode.

Also a question to nubira2.2 and jidasas, have you, or are you, planning to implement something to prevent the O2 sensors from trimming out the fuel at partial throttle boost regions?

jidasas · Post by **jidasas** » Thu Sep 20, 2007 11:21 pm

I thought about running the o2 sensor slightly outside of the exhaust flow and using the dtec with a wideband o2 sensor to control the fuel. I think the sensor running outside of the flow should keep the computer from fooling with the fuel much at all.

Jimmy

Nubira2.2 · Post by **Nubira2.2** » Fri Sep 21, 2007 8:11 am

exist3nce wrote:
Are you sure its running stoich during idle and cruising? Do you have a wideband O2 to verify this? Most piggybacks can't trim out more than -50% of fuel. And yes I know full well our cars are OBD2, and that the O2 sensors might be able to trim out the rest of the fuel. However if it has to start trimming alot of fuel it will start throwing CELs. I tried it, and on my car it gave me CEL and limp mode.

Also a question to nubira2.2 and jidasas, have you, or are you, planning to implement something to prevent the O2 sensors from trimming out the fuel at partial throttle boost regions?

yes im sure

yes i verify it @ the dyno

in the future im planing to instal a 2bar map sensor that will read pressure so that when it reads positive pressure @ partial throttle it will calculate the correct fuel also will ease the tuning
as for the O2 i try not to boost when cruising always watching my EGT

Post by **PrecisionBoost** » Sat Sep 22, 2007 5:01 am

What are the specs for your turbo?

GsiTurbo also had to install the 2.0L injectors before boosting the engine above 4psi during break in...... there wasn't enough fuel cut even with his adjustable fuel regulator turned down.

I can't remember what he's using..... I think they are 550cc injectors..... which are fine for big horsepower numbers but the car idles very rough.

jidasas · Post by **jidasas** » Sat Sep 22, 2007 9:43 pm

I believe my turbo has a .58 a/r on the turbine side but I havent measured anyof it yet. If I find it's bigger than that I'm probably gonna just get another one...probably off a wrx subaru.

jimmy

jidasas · Post by **jidasas** » Sat Sep 22, 2007 10:59 pm

ok I tryed to calculate my a/r of the turbine side and came up with .66 so I assume it is somewhere between .63 and .68.

For the compressor...it is...about .68? It is a weird turbo. I have no idea how well it will work if at all. I do know of one person running one on a 1.8 liter and he gets full boost at 3700 rpm I believe....but he's running 16 psi. I do know that for 4 psi it will be only on like a 48% efficiency...it won't reach over 70% until I push the boost past 14 psi...if I am write in estimating the approximate compressor map.

Jimmy

Nubira2.2 · Post by **Nubira2.2** » Sun Sep 23, 2007 5:08 pm

with the TD04HL
u will reach 70% with less psi
and for a 1.6 it will be fun