Hey guys,

This last weekend I got around to installing the catless downpipe from MarioKart here on the forums. He was super helpful and responsive and got the dp out to me quickly.

Install was a learning process of what needed to come out and how to take things out. It took me about 4 hours to install. If anyone is looking to do this job and has questions please feel free to ask I'd be more than happy to walk you through all the steps. It is a very easy process.

I got everything installed and tightened down. I was even able to use the oem heat shields without a fight. Everything reinstalled smoothly. On my first drive I had rattles and clunks. The rattles I have come from the heat shields on the downpipe. I removed the upper heat shield and they almost completely disappeared. I then removed the lower heat shield and the rattles went away completely. The clunk was not part of the heatshield. The clunk came from the driver side hanger. It looks like it's just a little too low and hangs about ~1/2" above the subframe. With the engine movement it contacts and that's where my clunk comes from.

I'm looking for ideas on how to solve this issue. The only option I can think of is to take the dp to a local machine shop/tig welder and have it cut and rewelded so I have additional clearance. When I look at the hanger on the car I should be able to free up another 1" without issue.

Are there any other options that you guys can see? Any adjustments I can
make to make more clearance?



And for your viewing pleasure here is the dp fresh out of the box. It is a thing of beauty and after I put a couple heat cycles on it, it really got some nice coloring started.

 

What year is that going on and what do you use for the CEL?
Have you tried to bend that hanger a bit before taking it to a shop?

 

I have a 2016 F55. This DP has, what I've used on previous vehicles, to defeat cel's built in. I can get a picture tonight but the bungs are spaced further away from the dp and there is a perforated piece of metal in the bung to limit exhaust gasses getting to the sensor. From my experience this setup will give the sensors the temperatures they're looking for and not throw a cel.

I tried to bend it lightly but I didn't put any muscle behind it. Also I'd have to change where the bend is on the hanger instead of making the bend tighter or looser. The hanger contacts the subframe in the middle of its bend.

I couldn't stand the noise so I'm back to the stock downpipe until I get this sorted out. I wish I got some more pictures but the 4 i snapped all have the same angle.

 

Damn that easy to swap back out for the stock one lol.
I would try heat, a wrench and a vise and bend it but I'm cheap and want to do it myself.
Might as well take it to a metal shop and put a marker for the guy where you want it tacked at.
What exhaust do you have paired with it? Is the sound insane or bearable?
Website for the downpipe?
Sorry for all the questions but I'm looking into a DP for my 2011 with magna flow.

 

I can get this install done in an hour now that I've done it once and got everything figured out.

I might try heating and bending but mariokart is going to give me a call tonight so hopefully i can get this sorted out.

I ordered this directly through mariokart here on the forums. It is matched up with the stock exhaust right now. exhausts for the F55 are slim pickings. I'm sure if I give it a little more time more options will come up.

The sound is amazing! I couldn't be happier with how it sounded. My pops are twice as loud and the exhaust might be 10-20% louder. Not a huge change. I love the additional exhaust and engine/turbo sound though. That's why I'm excited to get it back on.

 

Why don't you go for custom exhaust? I bought a Maganaflow muffler and had my local shop cut and bend pipe to go straight from the dp to the muffler. Sounds like a beast but I want the stock dp replaced for better flow. The magna flow set up cost $125 for the muffler and like $80 for the piping.

 

I like to know what sound I'm getting before buying an exhaust. I've run magnaflow mufflers in the past and have the general idea but I've gotten spoiled with so many youtube video's showing me the specific sound I'll get.

 

Cool, good luck with he search and be sure to post up a clip when its all together.

 

Holy ****.. Finally someone else.. I had the exact same problem.. Had the helix guys install it.. They bent the hell out of the hangers to make it fit w/out hitting the subframe.
As for emissions, it's passing all readiness monitors so i can pass Inspection... But I'm taking it off cuz it's screwing with my JB4. I'm overboosting...boost safety is 20psi but I'm hitting 25psi.

You running a JB4?

 

Did bending the hanger fix the fitment? What's your year and model? Did you let Mariokart know about the fitment issue? I spoke with Mariokart last night and he told me that he had not heard anyone else run into fitment issues and I asked if he had it on an F55 before. He had not, and asked if I would rent him my downpipe to double check fitment against his jig. He seemed genuinely concerned and wanted to fix the problem.

I have a WMW tuner on the way and a forge intercooler installed right now. Otherwise no JB4.

I have run into situations where the downpipe can cause an overboost situation if the wastegate can't compensate for the change. Those fixes involved swapping some springs in the wastegate though. I have read about a few other people running tuners that had overboost issues as well. I don't know if they were running a downpipe or not. I will try to find those posts.

 

yes, bending it fixed it...but i'm telling you i bent the hell out of it. well, the helix guys did. feel free to give them a call and ask them.
as for me telling him, i sure did...and he said the same thing...installed on 10 cars and noone had an issue. the downpipe may be good one, but the hanger design straight up sucked.

i'm completely blaming the downpipe on my overboost. with lack of back pressure, the turbo spools up too quickly and the tuner can't keep up with the boost safety. i was running on MAP2 on the JB4 for months and never once overboosted. the moment i installed this, i overboosted. i'm actually contemplating setting my boost safety to 17 and maybe that will keep me closer to 20.

also, if you have an intake as well with the downpipe, you may trigger a CEL like me. i got a P0171 (system lean). now i don't know what is causing this but i can only assume that with the new intake, and the O2's reading improper values due to lack of cat, it's screwing up the ecu and eventually trigging the CEL. if you have an OBD Monitor, keep an eye on your STFT and LTFT...my LTFT started creeping up slowly. note: the LTFT is ONLY when on idle. the moment i accelerte it zeroes out. all the more reason to say that the intake combined with the downpipe is messing with the O2 values.

P.S. i'm a 2014 2-door S (f56)
P.P.S my next step is to remove the DP and leave the stock cat on. 2 reasons...1) should be able to put the intake on again...2) i can move up to MAP2 on the JB4 and not worry bout overboosting. combine those 2 and i'm pretty sure i can pull more power than the DP alone. i may just have to wait until a proper tune can tweak my fuel trims accordingly with a de-cat.

 

What is the diameter of Mario's DP? 3"? I hope I won't be having the same problems with the Milltek + JB4.

 

BadakVT : I think it is 2.5" but I would have to measure it when I get home tonight to make sure.

MarcoPolo: Well I am very happy that it is only a hanger that needs to be adjusted and not a flange or the pipe. Still a little worrisome that we were told the same thing about no other fitment issues.

it's also disappointing about the overboost that you're getting. Adding a downpipe really isn't that big of a change in general and I especially wouldn't think that removing 1 of the 2 cats would make that big of a difference. At least I know what to expect. Thanks for the heads up on that.

 

So it took me a lot longer to get back to getting the downpipe on than I thought. Mainly because it got dropped off at the vinyl shop for a week. Here's a quick pic for you guys.



I did get the downpipe on this weekend. For some reason I thought the downpipe hanger was a solid bar. DUR...(way to look at the open end of it walkingdrunekn) So I got the downpipe back on the car and used a box end wrench to bend the hanger. It was very easy and non-complicated. I used a small offset wrench that I slid over the hanger. That gave me the leverage to slowly bend to exactly where I needed it. I also got all the OEM heatshields back on and I have zero rattles or knocks to speak of. Overall I love the result of the downpipe and love that it is a bolt on application. I'm dissapointed that the fitment was off, especially with MarcoPolo reporting the same.

Overall good weekend. Got the car back on Friday from the shop. I got the downpipe on Saturday and the WMW tuning box on Sunday. This little car is becoming a beast!

 

good job. small suggestion...get yourself an OBD2 reader and start logging your car. personally, i'm using an OBDLINK LX with the OBDLINK app on my android. it allows me to graph specific readings live. then monitor your boost (manifold absolute pressure). the WMW tuning box is probably like any other tuning box in that it just adds more boost. question is, are you seeing the added boost or a lot more.

i'm on the JB4 and i was set to see no more than 20Psi yet i was hitting values of 25Psi. may not be a bad idea to find out what your'e supposed to be seeing and monitor it. if you get more than you're supposed to, question would be is the extra amount safe or dangerous. again, i dropped down to map1 and so my overboost values have been controlled. this is why i want to take it off. i can bring myself back up to map2 and keep my boost values controlled.

 

I have one of the bluetooth obdII reader and I use Torque on my phone. I haven't logged anything yet but I was going to do exactly what you said and log first, see where I'm at, and then maybe turn it up to stage 2.

 

Hello I see you have tips for installing the MarioKart DP. I have 2016 F55 manual with JCW pro tuning/exhaust with Dinantronics module. I have upgraded turbo, forge IC, and DP I want to do over a weekend. Thanks