Who's running rich? Not me!!!!!

[Brian MP5T]

Why not get a standalone and just plug in whatever A/F you want??

 

[GAspeedProtege]

I'm thinking cost is the main reason.

 

[Brian MP5T]

I understand, however if you think about it like this...

Engine $3000.00...Wouldn't it be better to spend this money correctly the first time than have to blow a motor and then still be left with the same problem??

I'm not saying it will blow or anything, just it would be alot easier to get exactly the A/F you want and also get control of so mant diferent items. No Flash problems, no fuel cut, no rev limiter...

 

[DSMConvert]

well for an individual that is just getting into cars, yes I would suggest just blow the money and buy the stand alone...but you must remember that any new progress made for the MSP or any car for that matter is going to require taking acceptable risks. This is of course assuming that these risks are taken by knowledgable individuals who are able to push the limits of the engine without damaging it. I mean we can all just sit back and buy whatever comes off the assembly lines, or we can use our own ideas and knowledge and build new products and make new adaptations. For example the foglight brackets for the MSP, or the SAFC installation...these were all fabricated and tested by joe schmos who did their research and took a calculated risk...Personally I feel this is exactly why the large part of the MSP community is being taken advantage of by the large companies...I mean give me a break 1200 bux for exhaust, 300 for a DP....makes ya think if we dont start making progress on our own, then who is? ok thats my preacher bit...im done...

 

[igdrasil]

Thats very true...

This is how one friend here managed to boost 17psi daily on a stock motor and internals in his 1st gen protege, daily driven, kicks 11seconds on the tracks using only 93octane fuel and not break it...

...testing and testing... breaking a lot of motors, up to finding the best setting.

 

[DSMConvert]

ok just finished my first whole tank of gas...before the valve i was getting a consistent 23mpg...now im up to 26mpg(this is city driving), under pretty much the exact same driving conditions. On the performance end I def. have a noticable pull past 4K, where I used to have barely anything. Haven't thrown anymore cels so Ithink I have it tuned to the maximum variance for the ecu to still cooperate..overall this was more of a b**** than I had originally planned it to be(tuning wise), but then again I'm very happy with the final results thus far.

 

[murph1379]

Now, I really don't know that much about engines, but I have a friend with an STi that does. I was talking to him about some of the things people are doing to the MSP like this and the unichip thing, and mentioning that you were trying to correct the "rich" state of our A/F ratio... he told me we're really not running very rich, and that there's a reason turbo 4's run rich. He says the combustion temps are lower with a richer mixture, which is safer for the motor. By leaning out the mixture, we're increasing combustion temps, and straining our motors, aside from the internals dealing with more power.

I have carbon all over the inside of my exhaust, but he's got it all over his bumper as well, and he's getting a whopping 9mpg in his car. (I get about 21mpg)

Have you guys heard about this before? Could this be something to worry about with this solution or the unichip?

 

[TooleBox]

I have carbon all over the inside of my exhaust, but he's got it all over his bumper as well, and he's getting a whopping 9mpg in his car. (I get about 21mpg)

I used to get carbon all over my rear bumper, trunk deck and spoiler... i bumped the boost to about 7.5psi and now it is only inside the exhaust tip... If i drop it back to stock boost it goes all over the place again

 

[Riles]

He says the combustion temps are lower with a richer mixture, which is safer for the motor. By leaning out the mixture, we're increasing combustion temps, and straining our motors, aside from the internals dealing with more power.

That's why you don't want to run too lean, and thats exactly why Mazda and every other car company on the planet tune their cars to run rich. It's hard to hit the a/f perfectly, and the car companies would rather be wrong on the wrong side than replacing engines under warranty.

So, yes- running richer does make for cooler engine temps, but there is a target engine temp for engines to make optimal power without threatening the internals, and running rich makes it too low (and running too lean makes it too high). Every attempt at leaning out the MSP tries to bring the temps to that perfect temperature.

On a side note, somebody posted that the only way to change a/f ratios was to alter the 02 sensor signal. This is wrong- you can also change the a/f ratio via the maf signal. Just thought I'd throw that out there.

 

[igdrasil]

Ask me...All my blown engines were caused by leaning out the fuel curve.

I have even overboosted running rich and the engine handles it.

Everything goes wrong leaning out the fuel curve.

 

[DSMConvert]

hmm your friend with the subbie is a little presumptious...not all turbo 4s run rich, in fact the msp is the first turbo 4 I've run across that does run rich...well extremely rich anyways. every other turbo 4, well any turbo for that matter, that I've come across has been slightly rich, but not to the point of hesitation, this would include, nissans, porsches, toyotas, mitsubishis, etc. He is correct about the engine temp though, but I need to add a little to it before it is a completely true statement. the EGT(Exhaust gas temp) is the pretty much standard gauge for temp. tuning an engine. run too cold and you loose mpg and hp, run to hot(over 1400C) and you melt pistons and fuse iron and aluminum. The stress on the engine isn't directly caused by the heat, but rather the rapid expansion of gases and pressure due to the heat. Hence why hotter temps give you more hp. Idealy you want to run stoic, 14.7:1, but as stated before its better to run slightly rich than lean. I, myself, have tuned numerous turbo cars and in my experiences an engine is more likely to go due to piston ring failure at high boost than it is to go b/c of too much "heat" stress. I strongly suggest that this type of tuning only be done by individuals that are highly knowledgable about engine management. My purpose in this is not to suggest that every owner who wants more power should do this, but to inform the more advanced tuners that this is a realistic way of gaining more hp without damaging the engine. I say this timidly, as any modification in the area of increased boost is sure to shorten the life of an engine, but if done correctly and carefully can be appropriately managed. So far the car is still running great, mpg is up 3-4 miles and there's a noticeable gain in power in the upper rpm range. Still trying to get time to get to a track or dyno to see the performance gains, but with gas prices the way they are I'm happy with just the mpg update. As far as the only way to change the a/f ratios. there are several ways to change the ratios within the variance range of the ECU, if you want to change the ratios outside the variance, then yes you will have to modify the o2 in addition to either the maf or fpr....but just modifying the maf will help you none outside the variance range, as the o2 sensor will rat you out in a heartbeat...