its funny how a 5 year old thread still doesnt give us any info about horsepower an torque gains!

 

And we probably won't get a straight answer, at least one that isn't disputed, for quite some time. Most people that install headers have a CAI, after market exhaust, after market y-pipes, etc. My point is headers are a great foundation for a NA build and most people can't accurately gage gains or are not willing to dyno after just a header install.

 

It is also funny the obsession with numbers, horsepower and torque. As many have stated, there is an increase in both as determined by different methods. There is an increase in drivability as well as mileage. The instal is easy and the price is not terribly high. At what "magic number" does the modification become worthwhile?

If every 2JGE car was to be dynoed before and after header installation there would be just as many different numbers just like how every 2JGE motor has different hp/torque numbers when stock. What was the ambient temperature, what weight and type of oil was being run at the time, what type of trans fluid was being run, what drag did the accessories have on the motor, how well was the motor broken in....these are just some of the variables.

The performance increase offered by just a header installed could be accomplished by removing all the extra stuff in the car (spare tire, tools, passenger seat, etc) and aside from the labor involved is "free". Does that make it worthwhile?

Point blank: almost every performance mod done to a car will have different results on every car it is done to. Not every mod will increase the hp/tq numbers but may increase drivability and/or mileage. On the flip side, many mods increase the hp/torque but hurt drivability or mileage. "Do this mod and you'll increase peak hp by 15 but the car will be much slower off of the line because of the weight increase" <-just as an example.

Regarding the header swap on my GS300:
1) better drivability
2) increase in mileage
3) easy instal
4) inexpensive
5) slightly better performance

 

Well said. A video of interior and exterior noise levels would be amazing!!

 

how much louder is it? I do not want the car to be louder at all, just wanted to improve my MPG and some performance also.

 

With just the header the noise increase is almost inperceptable. Very very small increasse in noise output.

 

sweet, i have a cat back flowmaster exhaust, the tone is not loud at crusing which is what I like, so i might just install the headers.

 

I'd keep the stock mid pipe on to help things stay quiet and to keep some low end tq. Just make sure that you don't have exhaust leaks. It can be common when you mate an aftermarket header to a stock midpipe.

 

I did dyno my gs , after and and before . I had 11 hp and 5 tq gained with just the headers the srt intake gave another 13 hp and 14 tq by also replaceing the stok mufflers with some aftermarket ones it also gave me some power Not alot. I have some sound clip


http://youtu.be/BXPxUbHE13A

 

Nice. Can't wait to start on my exhaust mods.

 

nice pix. looking into replacing sensor 2 bank 2 but cant find it.

 

I'm surprised no one here has mentioned using a spark plug non-fouler for the O2 sensors. I used them for my SRT-4 neon and my Evolution when I replaced the catalytic converter. Neither car threw a CEL, and it seems a lot simpler than having to wire stuff into the ECU. They are $3 bucks at Auto-Zone.

Looks like this

 

The one in this pic is using two.

 

they are talked about....just not in this thread

post # 17 from here

https://www.clublexus.com/forums/gs-...eader-gs3.html

my opinion of this is i wouldnt personally do it....removing the O2 sensor from the "stream" effectively makes it worthless and its essentially not monitoring anything which is why it doesnt ever throw a code....which then doesnt help you if you have some unseen engine issue which is what the CEL is trying to tell you but again just my $0.02

 

Maybe I did not read thoroughly enough or I just simply do not understand what an o2 simulator does, but I thought that the o2 simulator removes the the two o2 sensors that are in the place of the catalytic converter from the car's system. IE: the o2 simulator tricks the ECU into thinking that the sensors are still there and functioning and that a catalytic converter is still in place. I could be wrong though, just trying to learn.

Based off this question and OPs response, seems like the o2 sensors no longer do anything.