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but in a fuel injected motor the computer will compinsate with the proper O2 sensor simulator.
Just to be clear, there are 2 wide band O2 sensors before the cats, this tells the ECM how to adjust the A/F ratio on each bank real time. These cannot be simulated. The second set of O2 sensors are simple ones that tell the ECM if both front cats are working properly or not. These can be simulated.

DEWFPO
 

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Learning alot here guys, thanks.:bigthumb:

I was speaking to Gadget at URD and I was considering doing CAI, Y-pipes, a cat back exhaust and the Doug Thorely headers; however, I was scared off when he said that without any cats the exaust may sound "raspy". He suggested I wait until they finish up their FJ project, which will have all the aforementioned + the URD MarkII supercharger and the X1, and see how that one sounds with the SC in it. I wound up just getting the CAI, Y-pipes and a new cat back exhaust. I will probably try out the X-1 depending on how things feel after all the air flow mods. He did not mention anything about torque loss, so that is another interesting thing to consider on this.
 

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Discussion Starter #25
So for now, should I just use some flowmaster cats and a high flow mulffer. I also have the URD 5 band O2 similator. That way I don't get any check engine lights. I'll get the sound I want and a lil power increase without losing torque. All I need now is a snork for some cold air. I won't be doing that for a while cause I just lost my job yesterday.
 

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Great info here gusy, thanks.

I was thinking of teh DT long tubes but after reading all this I am happy I didn't go with them as I want all the low end torque that I can get.

What are the options to increase the low end torque on a 2010. I got it stock as of now with only the 08 TRD Cat back on it.
 

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What are the options to increase the low end torque on a 2010.
Unfortunately there are not many, but the good news is the 1GR-FE is a pretty strong engine even in stock form.

In an ordinary gasoline engine, the things you can do to increase low-end torque are: 1) use a cam with longer exhaust duration, 2) stroke it (use a crankshaft with more offset for longer stroke), 3) raise the compression ratio, and 4) tune the exhaust (smallish exhaust valves, smallish exhaust header and pipe diameter, and tuned length for scavenging).

But with the 1GR-FE and its variable valve timing, it already does a pretty good job and there is no aftermarket for different cams (too complex of a system, and not enough market for it). Likewise, stroking it is not an option without a custom crankshaft (+$$$). The compression ratio is already 10.5:1, you could bump it more by shaving the heads (or stroking it) but you're going to start having other problems (cooling, etc.) at compression ratios much higher than that. Finally, tuning the exhaust (which gives the least amount of benefit of all these things, and then only in concert with a longer-duration cam) is difficult because again there are no aftermarket valves or headers designed for low-end torque - it would all be custom work.

The 1GR-FE is a fair masterpiece of engineering, and produces nearly twice the power of same-displacement Toyota truck engines of just 20 years ago, at way less weight, and with way better fuel economy. It's so good as it is that it's not worth the time and money required for the minimal improvement you'd get to tune it or hod-rod it in my opinion.
 

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Totally agree with you on this.

I am happy with this engine and even more happy with the new 2010 version. Can't say I really notice the power difference as I have bigger tires on it but I do notice the improoved fuel economy.

I waslooking at getting a URD MAF calibrator for it, what are the comments on this or the UNICHIP. Can't afford the X1 so lets leave that for now.
 
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