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When it comes time to tune a car, most simply rock to the dyno tuners, hand the key over and leave it at that. Most of the time youre happy with the result. But chances are, you are not getting the true potential out of your engine. Most tuners simply use a wideband sensor shoved into the exhaust and monitor collective AFRs. While this works, it is not nearly as effective as running one sensor per cylinder. Gains of HP and engine longevity i beleive are almost always had with one sensor per cylinder.

I doubt that any inlet manifold distrubutes air evenly across each cylinder and hence we have the potential for each cylinder to run different AFRs. In addition, fuel injectors never flow exactly the same adding to another source of AFR variability. Youll often hear that cylinder number 4 goes on 4 cylinders and that is simply because I would say the inlet manifold almost always forces more air into this cylinder.

So if you can afford it, get four sensors in there and get the maximum engine power and safety.

Or you can go about it another much cheaper way. Simply fitting EGT sensors to each exhaust runner and getting them all to run the same temperature aiming for your 12 AFR or less if youre running big boost.

I will be posting some results in a few months of my experiences and gains with such a setup (I went the 4 EGT sensor route).

If anyone can add info it would be great. Also, I used Exhaust gas technologies sensors. Are there any cheaper ones out there on the market which are as good?

Innovate have released a cpu that logs 12 wideband sensors but beware, its expensive.

Look foward to your replies.

whilst i agree, the cost of the "tune" can often really crank up. especially if you want each cylinder plotted for egt. it takes more time, more resources and more work which costs the customer in the end. for a track/race car it sounds worthwhile, and for some people if you are tuning your carself then it makes sense.

but for the average jo blo who has XYZ ecu and just wants a good power tune with safe afr's then its more work and more cost.

most people can justify $500 ish on a tune, but even that is fair bit.

Obviously there is potential for serious damage using the average a/f ratio but as mentioned its out of reach for the majority.

On a 6 cylinder for example individual cylinder a/f ratios could be 12,9,12,12,15,12. One cylinder is dangerously lean and another is stupidly rich but the single o2 sensor will read the average of them all which would be smack on 12:1.

Most people on here prefer bang for buck and simplicity i.e bolt in fmic kit, exhaust, straight swap injectors and fuel pump, bolt on high flow turbo and a PFC (plugs in with a base tune).

To do what you are saying would require the manifold to be removed, drilled, threads welded on and then purchase of the O2 or EGT probe. What did the EGT probe cost? And then a gauge. Then the tuning process will be be prolonged as they go through one cylinder at a time.

This will be a significant larger amount of money for the total tuning process and frankly its a gamble 98% of people are willing to take.

I dont think its a case of people not knowing about it but more of not willing to spend the money for it. Plenty of cars run around just fine using a single average a/f ratio.

For informations sake, when my car was tuned he used a infra red thermometer and just pointed it at each runner to make sure there was no large variance.

Edited by FATGTS-R

When i see 400rwkw + RB26's tuned with nothing more than a sniffer in the exhaust, none of which lean out, none of which shit pistsons etc etc etc.

I think its enough to say that its a not a warranted cost, and especially not for the common mans application.

When i see 400rwkw + RB26's tuned with nothing more than a sniffer in the exhaust, none of which lean out, none of which shit pistsons etc etc etc.

I think its enough to say that its a not a warranted cost, and especially not for the common mans application.

I agree, but I started this thread for those who would like/can go one step further. There's no denying there's an advantage and for the competitive, every bit of torque and HP counts. That said, EGT sensors dont cost 1000s of dollars. For a few hundred you can have a system setup on a 4. If you get your car tuned by someone, then it shouldnt be much more expensive. The engine is a linear device and once you have a few load points tuned with respects temperature for each cylinder and overall AFR, youre away. Its not as expensive as you make it out to be. However, as I said, totally agree, for the average joe who just wants to fang his car, its not worth it, however for the competitive its something you shouldnt disregard. You mention a 400rwkw rb26, I know I would have my AFRs spot-on for an engine of this calibre, not only for power's sake, but reliability though you claim these engines are reliable with one sniffer, I wouldnt take the chance.

This is not a motec system, just four EGTs with analogue faces, not that expensive.

what brands are u using?

The brand i use is Exhaust gas technologies. BTW (sorry for not replying to your first thread).

http://www.exhaustgas.com/ProductDetail.as...tID=&RepID=

I just log with my lm1 innovate kit, but you can simply use the analogue faces or simply monitor voltage 0-5V with any instrument. If your a gun with jaycar stuff, you could get wawy doing this cheap. The sensors are the expensive bits costing 48 each american. Ill be in the states soon :P

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