Question for Mapping Experts

hombre

Nitrous
Joined
Dec 31, 2006
Messages
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I'm of the opinion that with forced air induction the individual cylinder maps should be identical (F1, F2 & F3). My reasoning is that with FA induction, the difference in cylinder flows is negligible. I've equalized the "L" tables in my IC SC tune with excellent results, but at this point am still using slightly different "F" tables for each cylinder. I'd be interested in others' opinions on this.

It would be ideal to run a Motec ECU, with a wide-band Lambda sensor in each header pipe. The Motec has full closed loop control capability for each cylinder, allowing real time A/F tuning in each cylinder throughout the RPM range.
 
That's sounds about right. You figure when you do any sort of custom fuel mapping anyway you are not making changes to individual cylinders but to all at the same time. So if one cylinder in particular is running lean or rich you really wouldn't know.

I can't explain the differences between cylinders in the stock maps other than it's done to meet emissions and noise standards.

So are you saying when you get your exhaust made there will be a bung for each cylinder? I wonder if the Motec would use the IACV to control idle?
 
That's sounds about right. You figure when you do any sort of custom fuel mapping anyway you are not making changes to individual cylinders but to all at the same time. So if one cylinder in particular is running lean or rich you really wouldn't know.

I can't explain the differences between cylinders in the stock maps other than it's done to meet emissions and noise standards.

So are you saying when you get your exhaust made there will be a bung for each cylinder? I wonder if the Motec would use the IACV to control idle?

Pig9r, I was told by a very knowledgeable fuel injection tech that the differences in the individual cylinder maps were an attempt to compensate for the horrible variation in cylinder fill caused by the stock log exhaust manifold.

Yes, my custom exhaust will have a O2 bung for each cylinder, and equal length headers. The Motec has IACV capability, as well as the capability to control an electronic boost valve for the supercharger (or turbo application). Only big drawbacks to the Motec are price and fabrication of the wiring harness.

Speaking of idle control, starting a SC R3 in cold weather is a real eye opener to the stepper control and ECU fuel control. She fires up WAY RICH (10.5 A/F) and stays that way at 800 RPMs for about 2 full minutes. Then when warm, she revs to 1200 RPMs, and leans out to 13-13.5 A/F and drops to 800 RPMs... smooth as silk. Back when naturally aspirated, the idle A/F swing wasn't nearly as pronounced.
 
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Frigging LOG

Hombre:

On another thread we talked about aftermarket mufflers and such and my comment was that no matter what mufflers you put on the naturally aspirated engine, the most degrading component of the exhaust system was the exhaust manifold itself.

Your term "LOG" aptly describes it. It's a frigging log. I couldn't find the right words to describe it. From now on, I'll refer to it as a frigging LOG

Now, every time I look at it, in my warped mind, I'll envision a chrome shrouded log.:D
 
About a replacement ECU, couldn't you get away with wiring it directly from the factory ECU plug or each individual wire? The wiring diagram shows each connection to the stock ECU (about 50 of them).


I thought I read somewhere that the turbo came with an replacement ECU, is that correct?
 
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Connecting to the stock input/outputs could be fairly simple, but the Motec has many more (such as the multiple Lambda inputs) that have to be wired in as well. It's a suitable Winter project. ;)

I don't know if the Turbo kit comes with a new ECU... but doubt it at the price given. The TTS Supercharger kit DOES NOT come with a new ECU... only a very crude tune.
 
exhaust temps

hombre,
do you have access to a pyrometer? if so, then find the coldest pipe and adjust low side[all 3 cylinders] to this. then look at bottom of torque band and adjust to same. then go to 2 to 300 before top shelf fall off and do the same. this should get you close till you acquire and install motec.i'm assuming you've already synchronized throttle bodies....and are going to adjust with tune boy.delete o2 please.

p.s. when are you going to paint her? this winter?

greg:D;)
 
I'm presuming that you guys aren't aware that the snowmobile sport has produced some really neat and fairly inexpensive dataloggers. I haven't been looking at them lately but 3 years ago you could get a datalogger that gave continuous EGT as well as a bunch of other parameters like actual crankshaft speed, acelleration parameters and instant playback for time frames up to one minute. Most of the dataloggers have multiple EGT inputs for continuous monotoring of each cylinder and with the advent of EFI on sleds, they monitor the AF ratio too.
 
hombre,
do you have access to a pyrometer? if so, then find the coldest pipe and adjust low side[all 3 cylinders] to this. then look at bottom of torque band and adjust to same. then go to 2 to 300 before top shelf fall off and do the same. this should get you close till you acquire and install motec.i'm assuming you've already synchronized throttle bodies....and are going to adjust with tune boy.delete o2 please.

p.s. when are you going to paint her? this winter?

greg:D;)

Excellent advice, Goodfellow! I have a radiation pyrometer (infrared thermometer) in the lab, so this will be simple with the heat shields off the head pipes. Yes, I've already balanced the throttle bodies with some help from Pig9r, and use the O2 delete.

Let me state here and now, that I find the level of technical advice on this forum to be way higher than the other forum, which has descended into nothing more than a cesspool of personal insults. I greatly appreciate the help found here.

My R3 will be custom painted this Winter. All the black CF will remain unpainted, while the tank and upper fairing get painted black with "Blue Ice" flames. Might overlay some blue ice flames on the CF too. :D
 
Hombre:

We insult each other here too. Our saving grace is we all get together in the summer and apologize face to face for our misgivings.:) From what I can ascertain, the difference between 'there' and 'here' is the level of discretion exercised by the posters and overseen by the moderators who have a low tolerance for adverse interaction. Having said that, I've been spanked more than once for stupid remarks.

Speaking of summer, are we gonna wait until after the New Year to make plans for next years shindig or what? I see Raymond is conspicuously absent again.
 
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