FORUMS
- 5
|
|
![]() |
![]() |
![]() |
|
![]() |
BMW Garage | BMW Meets | Register | Search | Today's Posts | Mark Forums Read |
![]() |
|
BMW 3-Series (E90 E92) Forum
>
DIY: Downpipe (DP) installation for E90 335i (1/3)
|
![]() |
|
DIY: Downpipe (DP) installation for E90 335i (1/3)
Published by jahwerx
12-29-2007 |
|||||||
|
|||||||
|
|
|||||||
|
|
|||||||
|
#1
By
jahwerx
on
12-29-2007, 05:10 PM
|
||||||||||||||||
|
DIY: Downpipe (DP) installation for E90 335i (2/4)
Getting Access
6. Using a 10 mm wrench, remove the hose mount which attaches to the passenger's side of the steering rack (this makes getting access to the nut on the top of the steering rack easier and generally provides better access. 7. Using a 16mm wrench (I used a 5/8” which works perfectly – for some reason they decided to “skip” 16mm in my set!) and the E12 Torx Socket, loosen both the driver and passenger's side nut/bolt. Remove the passenger's side nut and bolt completely. 8. Using the T25 Torx driver, remove the first heat shield bolt, located right next to the passenger's steering rack boot 9. Pivot the steering rack toward the front of the car as far as it will go - about 1 inch. (no Picture) 10. Using the T25 Torx driver, and short handle socket, remove the second and third bolts. For reference, the picture shows the driver bit in one of the bolts. 11. Heat shield removed. |
|||||||||||||||
|
|
||||||||||||||||
|
#2
By
jahwerx
on
12-29-2007, 05:12 PM
|
||||||||||||||||
|
DIY: Downpipe (DP) installation for E90 335i (3/4)
Removing the downpipes. For reference in this DIY there is a “forward” and a “rear” downpipe referring to the pipes that correspond to the forward and rear 3 cylinders banks.
12. Mark the O2 sensors. Picture shows the front sensors, mark the rear as well. Break the front sensors loose with the 7/8” wrench, then unscrew them by hand. I waited until the pipes were off before removing the rear O2 sensors – easier access. 13. Using the 13mm wrench, loosen the clamp connections for both downpipes. Remove the bolts and set them aside. 14. Moving to the rear of the car, spray the bolts attached to the cat-back generously with liquid wrench or WD40. Let it soak a bit – I have less than 5000 miles on my car and they are pretty rusty. Use a 12mm wrench to remove all 4 bolts. 15. Moving further back, I found it much easier to uninstall the DP's by removing the muffler brace. (Use the E10 Torx socket) 16. Using the 12mm socket, remove the nuts on the hanger for both DP's. This picture shows it fully “uninstalled”, since the downpipes should literally “fall out” now! Notice the rear O2 sensors still installed. 17. Using the 7/8” wrench, remove the rear O2 sensors. (I popped out the brackets – makes it much easier) No picture – see step 16. 18. Your car is now modified with a VERY short 3” exhaust. (I have a video of me starting the car with no exhaust – stupid funny ... LOUD!) |
|||||||||||||||
|
|
||||||||||||||||
|
#3
By
jahwerx
on
12-29-2007, 05:14 PM
|
||||||||||||||||
|
DIY: Downpipe (DP) installation for E90 335i (4/4)
Install the new DP's
19. Comparison shot of the old and new. 20. Take both clamp connectors and loosely place them on the turbos 21. Connect and tighten the REAR O2 sensors. 22. Position the “rear” downpipe and “hook” the clamp connector into its final position. 23. Align the hanger bracket – note the notch and the holes. This is the “critical” connection to have aligned, since the fitment to the cat-back is dependent on this. Inset the smaller of the bolts included in the kit into the hole and hand tighten the nut. 24. Now go back to the turbo, and thread the bolt back into the rear clamp connector. Make sure the orientation of the clamp connector is in the same position as it was taken off (refer to the picture for step 13). This will ensure that you can do the final “clamp down” with the wrench. Install the front “rear” O2 sensor and tighten. 25. Install the other “front” DP in the same manner as the rear. Since all connections are still loose, this should be an easy process. This picture shows what everything should look like, right before you insert the bolt into the front DP clamp connector. DO NOT tighten either of the clamp connectors yet! 26. Using some pressure and 2 13mm wrenches, “push to seat, hold, and torque” the hanger bolts into position for both DP's. These are the first 2 bolts to tighten down completely. Now look at the end of the DP's and they should look just like this picture – aligned to the catback! 27. Re-use the gaskets from the uninstall, and loosely attach the muffler. 28. Go back to the turbos and tighten the rear and front clamp connectors. Reinstall and tighten the front O2 sensor (not shown in picture). 29. Using 2 13mm wrenches, tighten the DP bolts at the catback connection. (no photo). ALL FITTINGS SHOULD BE TIGHT NOW! 30. Ensure that all O2 wiring clips are back in place. (No more pictures from this point) 31. Reinstall the muffler bracket in the rear. 32. Reinstall the heat shield. Do the 2 “PITA” bolts first. Rotate the steering rack back into its correct position and reinstall the third bolt. 33. Reinstall the steering rack. Remember to tighten BOTH sides. 34. Reinstall the hose mount. At this point (and no earlier) you can opt to test drive the car to make sure everything is good. Listen for exhaust leaks, etc. 35. Reinstall the 2 hanging brackets. 36. Reinstall the the engine cover. Congratulations! |
|||||||||||||||
|
|
||||||||||||||||
|
#8
By
BoostedBMW
on
12-29-2007, 05:49 PM
|
|
That is an EXCELLENT write-up! Thanks for taking the time to post this up.
Now i'm wondering how raspy catless downpipes would make my CP-E exhaust sound.... hmmm. |
|
#10
By
BoostedBMW
on
12-29-2007, 05:52 PM
|
|
#14
By
jahwerx
on
12-30-2007, 09:04 AM
|
||||||||||||||||
|
I'm going to leave the OEM exhaust (at least for the time being), so I can't speak to the whole "turbo-back" experience.
I do notice a slightly more raspy sound on start-up when I have the door open. When I'm in the car, with doors closed and windows rolled up, I barely notice a difference in sound (which in good IMO). I'd suggest finding someone with DP's installed, and do a quick cat-back swap to see the difference. cheers |
|||||||||||||||
|
#15
By
jahwerx
on
12-30-2007, 09:27 AM
|
|||||||||||||||||
|
Quote:
The fitment was nearly perfect. There could have been a tiny bit of misalignment around the turbo fitting, but not anything that the clamp connections couldn't handle. Its too early early to tell if there will be long-term implications of not having a flex fitting near the turbo joint (like the OEM DP's), as others have pointed out on other threads. I really do think that would have make sense at the cost of a couple horsepower perhaps? Lots of temperature gradients down there meaning lots of metal wanting to deform... BTW: I've owned a previous Ultimate Racing product before (turbo kit for S2K), and all their fabricated parts for that never gave me any issues over 3 years of installation. There is a thread out there (with pictures) of someone who needed their UR pipes cut and rewelded because of fitment issues, but I don't think root cause was determined (bad manufacturing v. bad install) Hope that helps! - Josh |
||||||||||||||||
|
#17
By
jahwerx
on
12-30-2007, 03:07 PM
|
|||||||||||||||||
|
Quote:
(there is a TON of space up there - heh heh) |
||||||||||||||||