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How can I tell if I'm running lean?

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Old 07-31-02, 09:53 PM
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How can I tell if I'm running lean?

Ok first off I am not very good w/ cars. I know the basics, thats about it.

BUT....

I am pretty sure that my cats are clogged. I want to replace w/ downpipe and midpipe. I just don't want to be running lean! ( I have a t2, so this will also increase boost) Is an FCD the only thing I need? I figure that would be a bad idea though, they have the fuel cut off for a reason, and I would guess that it is there to keep you from running lean. BTW this is with stock exhaust for now, so maybe that will help keep it from making too much hp (for the time being)

Also while I'm at it...

Is there a *cheap* way to make my engine run richer? I can't afford expensive mods like a new computer.
Old 08-01-02, 02:36 AM
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hitting fuel cut is bad for your car. unless your engine and turbo are in really good shape, you probbably wont hit fuel cut. i have an 87T2 with a DP/MP and TID mod. and i'm getting about 7.5-8psi. so not quite hitting fuel cut. the best thing you can do for your fuel system without spending a lot of money is to re-wire your fuel pump. www.1300cc.com/howto/how2/rewire.html
Old 08-01-02, 02:55 AM
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you will probably be ok if you keep the stock catback, mufflers and intake.
Old 08-01-02, 02:59 AM
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I hate to say it man ... but Fast + Turbo rotary != Cheap



Old 08-01-02, 05:34 AM
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Adam, you really think that? When I compare the amount of work that has to be done to a turbo rotary versus a turbo cylinder engine, you can stretch your buck A LOT farther with rotary. Am I overlooking something?

Steve
Old 08-01-02, 06:08 AM
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turbo rotary+ fast == patience and tuning
Old 08-01-02, 03:45 PM
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Originally posted by MtnRacer
Adam, you really think that? When I compare the amount of work that has to be done to a turbo rotary versus a turbo cylinder engine, you can stretch your buck A LOT farther with rotary. Am I overlooking something?

Steve
Yeah...Youre missing some common sense.


Throwing exhaust+intake on a T2 = Dead engine unless you add some fuel and tune it some.

With a piston motor on the other hand ( like countless DSM's ) you just throw it on there and call it a day.
Old 08-01-02, 03:46 PM
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Originally posted by darkwaveboi
turbo rotary+ fast == patience and tuning


Exactly....And tuning = $$$
Old 08-01-02, 08:46 PM
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how much more head room will rewiring my fuel pump give me?

Funklord, how much rwhp are you putting out?
Old 08-01-02, 09:13 PM
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You don't need to get up to fuel cut to lean out, about a year ago my car was leaning out way before the fuel cut point and yes it broke the rear housing and all three rear apex seals plus the rear of the turbocharger. You will hear a loud knocking noise comming from the engine. That means the car is extremely lean. Get an msd fuel pump and a mallory fuel pressure regulator.
Old 08-01-02, 10:15 PM
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how can I monitor my mixture... is there a guage or something that can do that for me? how much for one?
Old 08-09-02, 09:00 AM
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All fuel/air mixture gauges are ****.
Old 08-09-02, 08:43 PM
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Are the ****?


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Old 08-09-02, 10:38 PM
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Originally posted by nonameo
how can I monitor my mixture... is there a guage or something that can do that for me? how much for one?

EGT or A/F gauges ... having both is not NECESSARY, but i guess if you can afford both, it can't hurt either.

don't know the prices - but i'm sure they will vary with quality.
Old 08-10-02, 02:29 AM
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Originally posted by diabolical1



EGT or A/F gauges ... having both is not NECESSARY, but i guess if you can afford both, it can't hurt either.

don't know the prices - but i'm sure they will vary with quality.

An EGT will NOT monitor A/F ratio ( which is what he asked... ).

If you use an EGT in conjunction with a wideband O2 ( like on a dyno or something ) to find out what your EGT's would be at XX A/F mixture, you could get a pretty good idea of when youre running lean. Increased EGT's = Leaner mixture.

However, if you truly want a REAL way to monitor A/F, you need to get a wideband system.
Old 08-10-02, 11:46 AM
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would an A/F gauge be a good investment , and were would you hook it up?
Old 08-10-02, 01:47 PM
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Originally posted by Mephis
would an A/F gauge be a good investment , and were would you hook it up?
In the stock location is where you would hook it up. Good investment...depends on who you talk to. It seems like unless you run a Wide Band, there's no point...
Old 08-10-02, 05:00 PM
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http://www.autospeed.com/A_0618/P_3/article.html
Old 08-10-02, 06:42 PM
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I would like to know what the general concensus is? What is the best setup for accurately determining your ratio? Would a combination of EGT and A/F meter be sufficient? Barring a huge expense like a wide band, Could an effective system be setup for under 600 bucks. ....also is there a better o2 sensor to try?
Old 08-10-02, 07:35 PM
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Narrow band is narrow band whether its got a heater on it or not. Buy the wideband or go to a tuner and use his. Just my opinion. Don't have either myself.
Old 08-10-02, 07:37 PM
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can you actually buy a wideband? and at what cost?
Old 08-11-02, 01:11 AM
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What about this?

I know its o2 but maybe better than the analog.

http://cgi.ebay.com/ebaymotors/ws/eB...tem=1850161117
Old 08-11-02, 02:42 AM
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Originally posted by nonameo
What about this?

I know its o2 but maybe better than the analog.

http://cgi.ebay.com/ebaymotors/ws/eB...tem=1850161117

I didnt read anything from the seller, but AFAIK, all A/F gauges work the same. They just read voltage from you O2 sensor and then give you an idea of how rich/lean youre running.

Basically, an A/F gauge is only as good as the O2 sensor.
Old 08-11-02, 06:35 AM
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i have never dynoed my car, but i'm pretty sure my RWHP is really crappy for the mods i have. i think its because my engine is old and has low compression, which would also by why i'm only getting around 8ish psi when i should be getting more like 10 with severe boost creep. oh well, at least this way i dont have to get an FCD and bigger injectors and stuff until later. but my car is too slow.
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