Alright, I went to see my family in Ottawa and finally got a chance to get a good normal 3 hours 15 minutes drive with the XLR8 J-Pipe installed. Here are my impressions and more importantly, some numbers:

Facts:
1) Outside temperature was around 16 Celcius;
2) The drive occured during the afternoon;
3) There was numerous construction sites throughtout the drive but I didn't need to stop, only slowed me down;
4) Cruise control was set at 70 mph for 70 % of the drive, excluding Ottawa and Montreal ;
5) Average speed was 65 mph;
6) My usual drive gave me between 26-26.3 MPG before installing the J-Pipe.

Results:
1) My average MPG went to 27.7 MPG, so its a 5 % increase in FE during highway trips;
2) Passing power in 4th in increased upto the point that I can easily pass cars if my RPMs are around 3000+, no need to dwnshift in 3rd anymore;
3) FE stayed the same for city driving, around 16-16.5 mpg (I use the Takeda intake, which caused a loss of roughtly 1-1.5 mpg in city driving).
4) I now have a growl around 1 500-2 250 RPM when moving the car after a stop or near-stop, which I think is quite annoying. This is the only minus so far.

I would like some thoughts of the other owners of this mod. We could have a good, dedicated thread to facts and impressions.

I hope it will be useful to many people!

Have a great day!
-YetiTL

 

i never really watched my mileage, but i drove from Toronto to Montreal a few days ago, always going above 120-130 km/h, got 536 km on the tank with the gauge reading more than a 1/4 tank remaining. At that rate 700 km was possible.

The growl at low rpm i love, the car needed more sound, maybe yours sounds different but i enjoy mine. Passing power has changed, i love 1st gear light throttle, the car doesn't take time to get into it's "groove" just goes.

can't wait for cat back

 

I have the Takeda plus the J-pipe and high flo cat. I must admit that the growl when gunning it is probably too addicting. I love cruising with what sounds like a stock exhaust only to gun it and litterally turn heads. This has lead to an obvious drop in fuel efficiency due to lead foot. However, I wouldn't trade it for the world. I want to add the cat back, but I don't really want a louder exhuast, especially at cruising rpms.

 

Oh man...I used to LOVE that growl...lol.

Nice write up though....not sure how many people that are actually modding are overly worried about fuel economy though. Once I start modding...thats generally something I dont even pay attention to for the most part. But good points made and good information!

 

The cat back is now up for sale!!! It will be available to ship within 1-2 weeks.

http://store.excelerateperformance.c.../i-399077.aspx

 

That's wonderful news Josh! Do we have a sound clip or something to have at least an impression of how it sounds?

I love your choice of design! It looks quite stock, only nicer! Kudos to you!

 

Well I understand totally what you mean but I wanted to give all the info I gathered, the pluses and the minuses. And I agree with you on FE. It's quite nice actually since I drive this car 50/50 city/highway so the increase FE of the J-Pipe will counterbalance the FE penalty of the Intake netting me only increased power. That sounds like a fair deal to me!

 

Good point and good information frankly....very thorough writeup!

 

Silly question... Does using a aftermarket J-Pipe cause factory warranty issues?

 

If it's proven that it caused damage to your car, then yes. But I can't see any reason the J-pipe would pose any problem: no sensors around and make in 304 stainless steel with appropriate gaskets...

 

Not to change the focus of this thread, but you said you had a loss of fuel efficiency with the Takeda intake??? I would think the opposite should be expected

 

Well, with the ECU monitoring the AF ratio, if you pull more hot air, the ECU will pour more gas to maintain the AFR. I can say that after a year of driving with the intake my MPG improved for 1 week with the intake then it went down to around 16-16.5 MPG (from 17.5-18 MPG city driving in S mode).

And no, I don't stomp more on gas with the intake, I'm not 18 yo anymore. I stomp on the gas before the intake...

We have a semi-cold air intake from the factory with the air coming from around the radiator so it might explain a bit why I see a MPG decrease with a SRI. But I'm no mechanic and you shouldn't pick my writings as a holy text...

 

Where are all the reviews?!?!?!? I really want to get this mod, but I want to hear some more real world impressions first. Come on guys, let's see some input

 

Do those thermal spacers and gaskets really make a difference?

Do they really work?

 

Yes they do make a difference. It isn't going to throw you back in your seat but every bit of power counts. On most J-series motors it makes about 5 whp and 5-8 wtq.

 

Nice review, thanks for posting. You seem to have really tried to keep it objective, which is refreshing!

 

where did you pick up the headers?

 

The exhaust manifolds are built into the heads on the J37. What he has is our j-pipe and high flow third cat.

http://store.excelerateperformance.c.../i-349736.aspx

http://store.excelerateperformance.c.../i-349577.aspx