Hi

Has anyone got one of the new Invidia Q300 true dual cat back exhaust (http://www.z1auto.com/prodmore.asp?m...st&prodid=3531) or G200? Are Invidia exhausts very easy to install and fit - ie no problem with hangers or clamps etc (are Invidia a very good quality make - ie up there with the likes of HKS, Greddy etc)? A lot of the true dual exhausts with x-pipe advertise impressive gains from just a bolt on. The Q300 which I like the look of says this exhaust will get 20+ wheel hp. What does the "X-Pipe" actually do - it is better having one than not?

I thought any initial exhaust gains get cancelled out by the stock ecu and you see no power increase - can anyone confirm what the case is, any dyno's before and after? I live in the UK but assume my ecu is exactly the same as the US? Also will I see a loss in power low down the rev range in sacrifice for higher end power with fitting a true dual exhaust or is it an increase in power right through the band (my car is totally stock)?

Thanks for any info and help.

 

basically exhaust and intake with no tune is good for sound and nothing more...ecu is pretty restrictive and will compensate for whatever mods basically and tune u back or go way lean ive heard...basically though like i said for sound and looks with no tune..

 

i am not sure that's true. i have saw several dynos with mods and no tune that show gains.

 

i agree most likely ur gonna pick up maybe 10hp or so to crank with intake and exhaust after ecu adjusts, but i have seen losses as well as no gains...different combinations work better than others, but really without a tune u are not benefeting much if any performance wise imo..
does sound good though

 

No need to tune for exhaust. There should be a gain without tune, depends on piping size and how exhaust designed.

X-pipe is good option for exhaust, there is gain shows and many people are happy after they added Xpipe on their TD exhaust system.

Hope this help.

 

Where in the world did you get that info?

 

Then better stay with the OEM exhaust unless you just want an exhaust that sounds different.

 

wouldn't their be gains if you reset the ecu and let the car relearn everything?

 

A search of this forum will yield multiple dyno plots showing gains of various modifications. Some show more than others, some show less. My searching, for HR specific modifications, if I can generalize, showed that HFC's were good for 6-10 hp, dual exhaust good for 6-12 hp, and K&N drop ins were good for 1-2 hp, all on stock HR motors without flashing the ECU. As they say, your results may vary. The mods tended to lose a little power below 2500 rpm, and add power above 2500 rpm. The Injen dual intake appears to add about 10 hp at high RPM's, and not lose power down low. Reflashing the ECU after the mods were done added about 10 hp, pretty much throughout the range, though not quite as much below 3500 rpm. I've not reflashed my ECU yet, and I believe there is noticably more hp with my current mods. The car certainly spins the tires much easier, and wheel hop has become an issue (need suspension mods...). I plan to visit the track soon, and hopefully will see more scientific evidence, though I did not visit the track before the mods....

 

Good searched. HR motor loves breath, surprised HR motors shows good gain with dual exhaust as well. Wish mine was HR lol

Have fun at track

 

Wait so the dyno sheet shown on the invidia website, you must get a retune or a piggyback to get these gains? Same with the plenum spacer?

 

NO

 

 

The numbers represent before/after installing the performance parts; no tuning was done. Basically the company slapped the part on and dyno'd the car...

 

most of the time, the gains promised by the manufacturer is not the real gain that you're going to get

they just happened to advertise the BEST result that they have gotten themselves, but not the average/probable gain that it might yield

 

Yea you reset the ecu then dyno. The car will lose power after a few hundred miles.

 

Stock ECU constantly compensates for various conditions like temperature, atmospheric pressure, quality of gas, what it has learned in the past itself, etc, etc. On any given day, the results will fluctuate and produce variations in outcome if you were to dyno the car every day. Add to that the fact that dynos register behavior induced by a driver, which in itself can also vary from run to run. On top of that, dynos themselves have margins of error and will vary in readings. Results will vary and it's important to remember that.

As far as ECU 'learning' things, the ECU does not learn around increased flow of air. More oxygen means more fuel which means more power assuming other factors remain fairly constant. If you add a well flowing intake and exhaust that improves flow, you will make more power. The hard part is to quantify when something is actually working better then the OEM component. If I were evaluating an intake or exhaust, I would start by logging my MAF output to see if my flow got better, not go to a dyno and do 10 pulls to stroke my own ego. If I see consistent improvement in the rate of flow (g/s) at the same RPM range, I know I am making more power. That's me and I haven't really seen people talk about this at all. Seems like everybody gets hung up on the bragging rights of how much horsepower their car makes off mod X.

 

So we drive SRT-4's now huh.

 

just keep in mind manufacturers advertise peak gains, not gains at peak...... meaning, it might have an increase of 10 hp at 2700 rpms and might not make a single HP more where your car makes it peak HP

 

OMG, so true. That's how the 07 is so much faster than the 06 and only makes 6 more hp at peak. AHHHHHHH I got it.