Tuning My Gt-r

[Slim Mat]

Hello,

I installed my new Power FC last weekend(R32 GT-R), went for a drive, monitored everything, seemed ok, so I left it in for the week. Unfortunately it developed a miss by Thursday morning. The injection map is set too rich for town driving and as a result it fowled the spark plugs. Old ECU back in, quick burn out the highway sorted that.

Not really keen on driving 700kms to get my car tuned, since I live in the country, so I would like to have a go myself. I know that doesn't sound very wise, but I think I have a pretty good idea on what needs to be done.

I would like to know how everyone else messures their air:fuel ratios. I can use that to set up the injection map. It's not as simple as using the O2 sensors because they produce a varying voltage depending on what the ECU sets as the A:F ratio(closed loop).

Or I could messure the precise air flow and set it using that, but I need some idea on voltage tables so that I can compare the air flow meter voltage and set a corresponding injection value. For eg: if the MAF sensor reads 1 volt, that might equal 1kg of air so I would set the injection value on that load point of the map to X.

Could someone post up their own methods of tuning their cars, I know that there are a few people that claim they have done it. Let me know what else I need to do. Or if someone knows a member(I can't remember their names otherwise I might message them) could you put me in touch with them.

[paulr33]

you need a wideband sensor to measure af ratio - not a standard 02 sensor, they are narrow band which is slow and 0v to 1v

a wideband is nice and fast and 0v to 5v which is much more accurate and linear - around $400 ish

youll need some understanding of afr's, exhaust temps, ign timing, fuel injection, and general tuning

there is lots of documentation out there and some tools that can help - also be sure to note if you do it wrong or make a mistake you can kill the engine

so if you cant fork out the cash for rebuild or arent prepared to then you should reconsider - its a given risk, yes but a few wrong settings can be fatal

last but not least have a read of the powerfc faq to learn most of the common things and how to tune it

http://paulr33.sauvic.com.au/docs/powerfc-...powerfc-faq.htm

[Slim Mat]

Yeah thanks Paulr33.

I have read just about all of the FAQ before doing anthing, it's awsome, thanks heaps for it. I understand most of it. I know that too high combustion temps(too lean) and I'll melt a piston and other such stuff. I just finished a basic engine management course, so I learnt a fair bit on that sort stuff, timing, mixture etc, just don't know how to measure and set it all properly yet.

How do I use a wide band sensor and where can I get one?

Are there any other threads on the forum that you know of that might assist me?

And as a general rule, to set ignition timing, you would try to advance it as far as possible at all load points without producing too much knock, is that right?

And for injection it would be as close to 14.7:1, until exhaust temp(combustion temps) get too high and then richen it up a bit, so under the highest load points of the map? Also to provent knock.

[paulr33]

wideband sensors can be set up in a few different ways

you can have a temp sensor up the exhaust muffler (external) or you can install it in your dump pipe(s) next to the factory ones

you want the wideband sensor as close to the exhaust outlet for accruate representation so im not sure how u would do it on a gtr with twin dumps

perhaps somewhere near the cat or just after the cats it joins up? but somewhere there

then youll need a wideband guage or digital box - www.wb02.com.au has some good kits - techedge i believe is the one you are after

some are cheap and some are expensive with logging etc etc. if its your own car its probably best to install it in the dump pipes

the idea with ign timing is to run as much as possible but keep it under safe knocking or detonation levels

i basically kept upping the timing on mine until knock hovers around the 10 mark ish and leave it there

this gives the car a crisp & gives fantastic response but thats just for light cruise - i didnt do any high load ign tming - be careful with this (get a tuner to do it)

and youll need the dyno to ramp up 4th gear and touch the end of the map (180km+ area in 4th) so not suitable for the road

the afr's you can lean out on light cruise (make sure you disable 02 feedbackl while tuning) and again get a tuner to do max load afrs ( need dyno)

from memory my afrs on light cruise are somewhere near 15.5 to almost 16 i think - again too high and youll melt valves etc

[paulr33]

this is what i used when i did my car

as you can see its a temp wideband sensor

this might be more suitable

i dont see the need for a perm installed 02 sensor

http://paulr33.skylinesaustralia.com/photo...ar/IMGP1207.JPG

http://paulr33.skylinesaustralia.com/photo...ar/IMGP1208.JPG

http://paulr33.skylinesaustralia.com/photo...ar/IMGP1209.JPG

[Slim Mat]

Thanks Paul. I found your DIY tuning thread as well, having a read through it.

Why should the feedback on O2 sensors be disabled for tuning?

Perhaps we could start a table of MAF sensor voltage. It would make tuning so much easier, for anyone on the forum. Do get what I mean by my description in the topic post?

[paulr33]

cos if 02 feedback is on while you are tuning the FC will adjust and lean itself out to stoich or the 02 feedback co-efficient value in the FC

in theory - it will auto correct what you set on the INJ map in closed loop - so have it off to see the true numbers

[Duncan]

wide band o2 sensors from these guys - they are cheap and have interchangeable options

http://www.techedge.com.au/

start at $383 - bloody cheap and a local product

[Guilt-Toy]

i got sick of people asking me what that thing is in my exaust pipe so it has its own home before the cat now.. much more accurate for low throttle imho

The techedge stuff www.wideband.com is the best you can get in australia in my opinion. buy one from there. the after sales SUPPORT is second to none.

this is what i used when i did my car

as you can see its a temp wideband sensor

this might be more suitable

i dont see the need for a perm installed 02 sensor

http://paulr33.skylinesaustralia.com/photo...ar/IMGP1207.JPG

http://paulr33.skylinesaustralia.com/photo...ar/IMGP1208.JPG

http://paulr33.skylinesaustralia.com/photo...ar/IMGP1209.JPG

[STATUS]

^^ i like the innovate gear http://www.innovatemotorsports.com/ ( i personally use a LM-1) from rocket industries as it has plenty of add-ons and the LC1 is cheap too

and Guilt-Toy yeah your right in the tailpipe is no good for idle etc....

more info http://www.titanmotorsports.com/lmdiairame.html

[Gav]

Another recommendation for the Innovate product.

I now have an LC1 with an XD16 gauge. Integrates very well with the Datalogit and is a permanent install install now with a single USB port for logging all information. The online manual is quite detailed in how to install and integrate with the Datalogit and the forum gives good advice for any problems (I had none and all worked first go).

[Slim Mat]

Thanks to all the others that left responses and recommendations. I might have to get on to you about some more info soon.

Some of that gear looks pretty hardcore serious. I want to get to that stage, but at this point I just have a standardish motor and that looks like a rather big jump with extra controllers and stuff. Bit over the top for a standard car, maybe a little to exy as well for now when I won't see that much gain.

Then again, if it's the absolute only way of tuning my PFC is guess I'll have to go that way. Is the same sort of gear the most tuner workshops use? Obviously the have tailpipe jobbies(portable styles).

[Guilt-Toy]

and Guilt-Toy yeah your right in the tailpipe is no good for idle etc....

more info http://www.titanmotorsports.com/lmdiairame.html

I find that in the tail pipe is okay for small exausts its only when you have it going into a massive cannon where it can give you lean readings on idle and soft cruise.

Thanks to all the others that left responses and recommendations. I might have to get on to you about some more info soon.

Some of that gear looks pretty hardcore serious. I want to get to that stage, but at this point I just have a standardish motor and that looks like a rather big jump with extra controllers and stuff. Bit over the top for a standard car, maybe a little to exy as well for now when I won't see that much gain.

Then again, if it's the absolute only way of tuning my PFC is guess I'll have to go that way. Is the same sort of gear the most tuner workshops use? Obviously the have tailpipe jobbies(portable styles).

I would honestly go for the wideband.com range with the green display (looks cool) Dyno workshops will have one attatched to their dyno and alot of them have a portable device to test the car with on the street as well.

I drive around with mine hooked up all the time and i allways watch it, it saved my engine once already as the fuel pump started to fail and i picked it up straight away because it was reading lean mixtures on boost so then i introduced the bosh 044 pump which fixed my fuel issue.

Its a good tool to have and it can be moved easily to other cars to check the afr's.. i got one before i got any other toy or device for my car once my engine was built because i was sick of hireing one.

[Gav]

Thanks to all the others that left responses and recommendations. I might have to get on to you about some more info soon.

Some of that gear looks pretty hardcore serious. I want to get to that stage, but at this point I just have a standardish motor and that looks like a rather big jump with extra controllers and stuff. Bit over the top for a standard car, maybe a little to exy as well for now when I won't see that much gain.

Then again, if it's the absolute only way of tuning my PFC is guess I'll have to go that way. Is the same sort of gear the most tuner workshops use? Obviously the have tailpipe jobbies(portable styles).

A datalogit and simple wideband set-up really isn't that expensive and is pretty straight forward to setup. It also helps you fine tune areas of the maps that will never be seen under dyno conditions.

Drop me a PM next time you come up to Perth and I'll show you my setup.

Gav