Stock turbo with RC550 Injectors & 3 Bar Map

[Monty]

Since i`ve got the injectors and the Map i`m thinking of fitting with the stock turbo to see what i can ring out of it, going to use a in car bleed valve and already have a the fuel cut clipped and do a dyno run before and after. Eventually I`ll fit a EBC which can be programmed for max boost aka overboost.

Just wondering what the chances are that the engine may go Pap!!!

Also thinking of fitting an Air/Fuel ratio gauge like this ONE to keep an eye on the mixture. Looking at the instrustion it can be connected to the stock O2 sensor

Since i want to go closed loop i`ve bought a stainless boss so i can fit and O2 sensor but need to have that welded in to the Stiffy 1st

Does the Elan Scan give readings of AF mixture? and what Ratio should i be looking at at full throttle?

What do you guys think?

[tigerdog]

Whether or not you'll pop the engine depends on just how big a leak you put in the wastegate air pressure line. Smaug boosts to 16.5-17 PSI (1.13-1.17 BAR) and hasn't destroyed himself... yet.

Elanscan will show Fuel/Air ratio and will correctly report boost with the 3 Bar MAP sensor if you change a value in the m100aldl.ini file (usually in your windows user directory under "application data".)

To make it easy, I've created two versions of the file. Under Windows2000 or XP, copy the correct version for your MAP sensor to c:\Documents and Settings\username\Application Data folder (where username is your Windows login username) and rename it to M100ALDL.INI. Then open ElanScan and you should see correct boost numbers.

[racerstev]

To be safe go with a seperate wideband air/fuel ratio gauge. If you clip the fuel cut even a little too much you can
lean out and go lean. It took me a few pulls to set mine right. You may want to back off the timing a few degrees untill
you get it all dialed in.

Are you sure you need the larger injectors to max out the turbo? I was at 1 bar last year ans the air/fuel was still pretty
rich.



Steve

[Monty]

Doug, thanks for the zip files but i`ve only used the ES a couple of times and that was years ago so need to learn up on logging etc.

Steve,
I have no idea what the difference is with wide and narrow band, whats the benifit going wide band? If i go wide band then i`ll have to fit a 2nd O2 Boss On the Injectors, all i know is that Alan said that the AF goes to lean with the stock injectors at 1bar hence why he won`t do a chip anymore than 0.9bar.

the cost is another question as a wideband are £150 a EBC are £200+ and since i`ve got the basic kit for Maries turbo upgrade should i just save the money to put towards the Garrett turbo

The reason i wanted to try this is

a. i have the injectors, MAP, O2 sensor and incar MBC already.
b. Years ago Dico`s beast was running on a BBR kit (stock turbo) and the stock boost gauge was maxed out, more investgating we found that the BSV was completely by passed so the wastegate would not open so turbo was maxing out. We attached my turbo gauge and dico reported back it was hitting 1.4bar
c. i`ve always believed the stock turbo can do more than 1bar
d. gives me something to do

[steve matthews]

Monty, no that is not correct.
On the Fed. engine running at 14.5 lbs. boost you are still pig rich 14 to 15 to 1.
Steve -w- stock injectors and turbo.
With the new Fed. down pipe we obtain the same H.P. from above with 1 to 1.5
less LBS. boost. AFR. still pig rich.
I would like Allen to make me a chip that can use that extra AFR.

Check Dyno reports on Fed. Down pipe thread.

Steve

[Monty]

2 Steves lol

What i may do is stick to the stock injectors, fit the 3 bar MAP, O2 sensor and fit the AFR gauge and see what it reads then maybe stick her on a dyno but 2 runs is £70

Whats the optimal AFR?

[lotusgirlmarie]

Just to be clear. 14.1-1 is the optimal A/F ratio refered to as stoichiometric. If you see 15-1 your lean, 13-1 your rich. The first number is air the second is fuel which should always be 1. Always strive for a little rich as you will be less likely to burn a valve or worse, a piston. The downside is leaner mixtures provide more power because the burn hotter and more completely. they also burn up engine components at a faster rate.

I've rebuilt turbo engines, mostly Honda, that failed because the were lean and melted a hole through a piston crown. Not fun. Learnt my lesson and studied well to avoid that again.

[Doug]

Marie, how much of that is due to Honda not making turbo engines? Are they really stout enough for forced induction or have these been purposefully built up? Acura RDX is the only US Honda turbo I can think of ....

[lotusgirlmarie]

I used to build and race turbo Hondas. Mostly the B16 ,H22 and B20 series engines. The internals a very strong to begin with. Welding in a block guard to deal with the open deck design further reduced flex in the cylinder walls allowing higher cylinder preassure if you wanted over 1BAR. Pistons in the standard engines could handle up to and a little over 1BAR of boost. Connecting rods were good to 1.5BAR. In some of the higher compression engines you were very limited as to boost levels. The internals aren't very different from the Isuzu or Toyota for that matter. The issues are the same. AFR, knock, ping and detonation.

[abmunro]

This is AFR gauge i bought.


It also gives an output to my Haltech ECU..


http://cgi.ebay.co.uk/AEM-Digital-Wideb ... 82ff0f719b

[tigerdog]

What i may do is stick to the stock injectors, fit the 3 bar MAP, O2 sensor and fit the AFR gauge ?

I wouldn't recommend using stock injectors with 3 Bar MAP. If you fit stock injectors with a 3 Bar MAP, you'll inject a lot less fuel than the engine needs.

The reason that 3 bar gets paired with 550cc injectors is to keep the AFR close to stock. The 3 Bar MAP puts out less voltage at a given boost, so the ECU thinks the engine is getting only about 70% as much air as it really gets. The ECU therefore tells the injectors to squirt less. The 550cc injectors squirt more than the computer thinks and the whole thing (mostly, kind of) balances out.

If you try to use a 3 Bar sensor with stock injectors, your handy gauge should tell you the engine is much leaner than it needs to be. Hopefully it tells you this before it self-destructs due to detonation. Of course, you were looking for something to do, so an engine rebuild should keep you busy for a good long time.

[Monty]

Guys,thanks for your advice.

So i need to learn how to use ES correctly and how to log files. Then go with thy bigger injectors to make sure that poor Pinky doesn`t run lean.

Is it worth going to the expensive of fitting a wideband sensor or should i just rely on the ES and does the ES give live readings on the AFR?

It`s all a learning curve

[tigerdog]

Elanscan does report AFR within the limits of the narrowband sensor. Not sure how quickly ES and the stock sensor react, though.

[GeoffSmith]

Is it worth going to the expensive of fitting a wideband sensor or should i just rely on the ES and does the ES give live readings on the AFR?

A wideband sensor would behave completely differently to a narrowband sensor. I think the ECU may get confused as the signal would be a continuous voltage rather than oscillating between 0V and 4V.

Elanscan does report AFR within the limits of the narrowband sensor. Not sure how quickly ES and the stock sensor react, though.

I think ES is reporting back the AFR that the ECU has calculated based on the many input parameters.

[Monty]

if i was going to fit a wideband (with AFR gauge) i would still need the standard O2 sensor for the ECU to run closed loop so will need an extra O2 boss welded to the Stiffy I`ll need to work out where to place that, can the wideband be placed further down the Stiffy (down pipe)?

[racerstev]

Alot of the wideband systems have both a 5 volt output and a narrow band output.
So all you need to do is put the wideband sensor were the stock narrow band goes and run a
wire from the wideband controller to the narrow band input of the stock ecu.

The system I have does not have the narrow band output so I just welded a bung in farther down
the downpipe.

Steve

[Monty]

The system I have does not have the narrow band output so I just welded a bung in farther down
the downpipe.

Steve

I may do the same but the other way round ie the stock O2 at the top and the wideband lower down, will having the wideband sensor lower down the system effect the reading?

[addict]

if u fit a air fuel ratio gauge / autometer are good using a narrow band reading it will just say lean or rich all the time
if u fit a wide band lamda it gives u a stable reading unless u burn oil the it will feck up in no time .