Jump to content
LegacyGT.com

2.5 LGT Header Mod to Fit 2.5i


Recommended Posts

LOL and this is only one of like 5 threads that i alone have started :lol:

 

 

Well to bring you way up to speed a 100 % bolt on UEL header for the 2.5i platform is in production should be on sale in April it will bolt up using stock sensor locations and mid pipe

 

Mike @ rallisport hasn't been able to get this project underway due to business and life event. Sorry for the delay. :(

Link to comment
Share on other sites

  • 4 weeks later...
  • Replies 372
  • Created
  • Last Reply
Waiting for the dyno...
06LOB2.5i MT, JDMRSB, GYTTs, HPS, LGT Mufflers & Leather Wheel, SubiMomo Knob, Inalfa Moonroof, Clutch Switch Bypass, DeDRLd, DeChimed, & Straight Headrest.
Link to comment
Share on other sites

  • 7 months later...

So this thread comes full circle today. I'm currently waiting in the showroom at Mach V getting my LGT manifold baked and TIG welded to mate to my sto k mid pipe. Video and pictures to follow with LGT stock cans, stock y pipe and stock LGT manifold.

 

I drove it to the shop with open headers and it wasn't that loud cruising only loud when I had to take off from a stop. After this mod I'll add AVO y and center pipes with 60 series delta flow out the rear and that will be it.

Link to comment
Share on other sites

Finished up the chop and weld along with the rear extension (via Casper extension) and front AFR sensor.

 

Can't be happier :) And there is no need for a video b/c it doesn't sound any different than a stock LGT. BUT i wanted that in the first place so when I add my CBE it wont be as loud as last time with the MagnaFlow CBE.

 

 

In fact it is MORE QUIET than the stock manifold :eek: Yeah i was shocked LOL all you hear is the engine but it is more toned. It is tough to explain the exit note it deep just like a stock LGT.

 

I moved the AFR into the collector where the up pipe used to connect and I moved the gray O2 sensor just behind the the second cat pointing upward to protect from direct water spray from the road. There is tons of clearance for the filter but I haven't tried to fit the stock splash tray but if it wont clear im not going to worry about it.

 

I am very happy with the job Mach V Motorsports did and I am 100 percent certain it will be perfect once i add the CBE :)

Link to comment
Share on other sites

So ive driven about 100 miles and no CEL's, no drop in MPG, no drop in acceleration, no issues.

 

The acceleration in 5th gear is improved greatly i can get on it in 5th at 2000RPM and get up to speed quickly. The car also pulls in 4th and 5th better from low RPMs.

Link to comment
Share on other sites

What length did you use for the Casper O2 sensor extension? And is moving the AFR just a personal preference or was it necessary?

 

I got the the 36" extension to give myself options as I wanted to go 05 setup at first then custom 06+ and finally Stock LGT. The extensions from casper all cost the same $32.00 so you might as well go the longest one. The AFR didn't move at all I placed the O2 bung in the modified LGT manifold in the same location it would have been on the stock 2.5i manifold. I did this to ensure no change in reading due to exhaust gas temps (which would be affected by moving it further downstream.

 

I have to do an oil change Friday and I will take some up close pictures to show you where the new rear O2 is located and the bridge piece that connects the LGT part to the 2.5i pipe. Now i have a bolt on UEL solution that isn't loud, doesnt throw CELs and can pass emissions should I ever have to do that.

 

Lastly my job is neat the extensions are sheathed and tucked away and the TIG weld on the Cast Steel is classy.

Link to comment
Share on other sites

I bet it sounds nice.

 

 

I need to start researching a way to do this to my 2.5i now that I have an exhauast on it.

 

Def this is not a hard mod it is just people have been deterring 2.5i-ers from doing this citing reasons such as: you lose low end power, there are no gains, you suck, you're and ass-hat, your mom, etc :lol: (seriously people give these reasons why you shouldn't try this)

 

This UEL setup was 5x easier than my first attempt and much cheaper. This cost me:

LGT manifold - $60 shipped

Vibrant 2.25" SS Flange 3 bolt flange: $21

Casper Extension: $37

2 O2 Bungs : $4

Cut/Weld Job: $180

 

$302.00 Total

 

My last UEL setup cost over $700 (parts and $350 labor charges)

 

I have done the trial and error for you and anyone else wanting to venture down this path. in the end the LGT conversion is the best in my honest opinion. The stock manifold converted to UEL and the Borla replica are both lesser in my book.

 

As far as logic and power go the exhaust gases have a shorter and less restricted path to exit the cylinders (you eliminate one cat and over 3.5 feet of tubing versus the stock 2.5i manifold.)

 

Also you don't need to add O2 spacers or O2 simulators or tune to keep the CEL away your secondary cat is equally as efficient as the primary and is the exact same spec.

 

Hind sight is 20/20 and 3 years ago I wish i did this UEL mod instead of the myriad of others. You can't beat the simplicity and functionality of this version of the UEL mod.

Link to comment
Share on other sites

You can refer to this thread:

 

http://forums.nasioc.com/forums/showthread.php?t=2076358&page=4

 

Im pretty sure the process is very similar on a Legacy. GEE-OTTO can probably confirm this.

 

Yes the process is NO different except the impreza boys have a louder exhaust due to the single exit exhaust, our dual mufflers help keep things classy. :)

Link to comment
Share on other sites

Your making me want to put my ravspec spoiler on hold for a while and put a WTB thread up for an exhaust manifold. :lol:

 

If it's as easy as one cut, one weld I think I'm going to jump on this.

 

Close but one cut two welds (the flange to extension and extension to manifold)

 

When I say extension I mean 4-5 INCHES of pipe :)

Link to comment
Share on other sites

Also guys I will be getting a GS Hi flow cross pipe to add to the mix http://www.grimmspeed.com/images/product_images/crossover_v2_600_5.jpg

 

This will work well with my GS extra thick cross-pipe to manifold gasket I already have. This pipe gives the turbo guys BIG gains:

http://www.grimmspeed.com/Dynos/dyno_pnp_exh_mani_vs_pnp_exh_mani_larger_xover1.jpg

 

Now im N/A but im thinking it never can hurt to allow gases to flow more freely.

Link to comment
Share on other sites

Where exactly is this crosspipe located? And do you think it would have similar effects to a cat-back exhaust - drop in low-end, gain in high-end?

 

 

That cross goes here on my car:

http://img842.imageshack.us/img842/1307/photo7sy.jpg

 

So ill swap the stock for the GS piece :)

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.




×
×
  • Create New...

Important Information

Terms of Use