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Thanks Ave. Would be interesting to know stock as well. Glad you're pleased with the HKSs.
 

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I had the MR LDPs with stock exhaust for about 6 months. Absolutely no change in sound. Didn't quite feel a noticeable difference on the butt dyno though like I do with LDPs + catback.
Good to hear, yeah while I would like to install a FI CBE I just do not have the funds to spend on that right now. I was also contemplating installing a Y-Pipe, you think this would be worth it? Not sure if the mid pipe is just as restrictive.
 

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2017 Q50 Red Sport 400 RWD
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Good to hear, yeah while I would like to install a FI CBE I just do not have the funds to spend on that right now. I was also contemplating installing a Y-Pipe, you think this would be worth it? Not sure if the mid pipe is just as restrictive.
My opinion is all CB or nothing. Some may be higher quality than others and the sounds will be different but I think any aftermarket CB will give you about the same power increase.
 

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My opinion is all CB or nothing. Some may be higher quality than others and the sounds will be different but I think any aftermarket CB will give you about the same power increase.
So are you saying that just replacing the LDP's will not improve throttle response/power unless I also have a CBE?
 

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So are you saying that just replacing the LDP's will not improve throttle response/power unless I also have a CBE?
I think replacing the LDPs can be beneficial. I was referring more to the CB itself. I wouldn't do pieces of a CB, I'd recommend all or nothing. I don't know the measured gains of doing only LDPs but that's how I ran for about 6 months.
 

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I think replacing the LDPs can be beneficial. I was referring more to the CB itself. I wouldn't do pieces of a CB, I'd recommend all or nothing. I don't know the measured gains of doing only LDPs but that's how I ran for about 6 months.
Okay, yeah I was referring to the Y-pipe because I though that the diameter of the Y-pipe was the same as the LDP's.
 

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Sup InfinitiQ50.org! I’ve been inactive for a while. Hope everyone is doing well. My RS is at 68k miles strong and it looks like I may end up buying the car out at lease end, since I’ll be way over mileage lol. Since my car will be passing the powertrain warranty mileage soon, the mod bug has hit me again.

So far though, these get the Avedis seal of approval.
Thanks Avedis. Your seal of approval has influenced my recent purchase lol. I ordered the HKS LDPs from ConceptZ the other day. They should be here tomorrow. Hopefully I’ll get them, and the AMS Intakes that I ordered too, installed tomorrow evening.

Are you looking for a how-to for the LDP? AMS and Fast Intentions have published DIY's that are pretty in-depth on their website.I was going to do one until I saw how comprehensive their instructions were.
After reading their install instructions, I was hesitant on performing the install myself too. But, after watching the install instructions that ConceptZ provided for the AMS LDPs, it doesn’t seem that bad. See video below.

 

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After reading their install instructions, I was hesitant on performing the install myself too. But, after watching the install instructions that ConceptZ provided for the AMS LDPs, it doesn’t seem that bad. See video below.
I installed the FI LDPs & CBE with the help of my buddy's 4-post Bendpak lift. The biggest challenge is removing the studs/nuts from the stock secondary cats to the exhaust/turbo manifold. When I went to loosen the nut (one on each side from the top), the exhaust stud/nut is angled towards the firewall, and I almost rounded-off the driver's side nut. After I loosened it, it took several turns to remove. I thought initially that it was stripped, but what actually happened was the nut AND stud came out together. This occurred on both sides.

In addition, it was a challenge to remove the pigtail connector of the rear O2 sensor from the mating harness (passenger side), as the transmission intrudes on the space to get a hand on the release tab.

Otherwise, it was a fairly straight-forward install.
 
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I installed the FI LDPs & CBE with the help of my buddy's 4-post Bendpak lift. The biggest challenge is removing the studs/nuts from the stock secondary cats to the exhaust/turbo manifold. When I went to loosen the nut (one on each side from the top), the exhaust stud/nut is angled towards the firewall, and I almost rounded-off the driver's side nut. After I loosened it, it took several turns to remove. I thought initially that it was stripped, but what actually happened was the nut AND stud came out together. This occurred on both sides.

In addition, it was a challenge to remove the pigtail connector of the rear O2 sensor from the mating harness (passenger side), as the transmission intrudes on the space to get a hand on the release tab.

Otherwise, it was a fairly straight-forward install.
Thanks for the heads up! I believe I’m prepared enough...
90296


Luckily I have a RWD model, so space to unclip the passenger side’s oxygen sensor shouldn’t be too tough... hopefully.
 

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Thanks for the heads up! I believe I’m prepared enough...
View attachment 90296

Luckily I have a RWD model, so space to unclip the passenger side’s oxygen sensor shouldn’t be too tough... hopefully.
That should do it! lol. Good job. And like Iridium said, be prepared to take some entire studs, not just nuts.
 

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Sup InfinitiQ50.org! I’ve been inactive for a while. Hope everyone is doing well. My RS is at 68k miles strong and it looks like I may end up buying the car out at lease end, since I’ll be way over mileage lol. Since my car will be passing the powertrain warranty mileage soon, the mod bug has hit me again.



Thanks Avedis. Your seal of approval has influenced my recent purchase lol. I ordered the HKS LDPs from ConceptZ the other day. They should be here tomorrow. Hopefully I’ll get them, and the AMS Intakes that I ordered too, installed tomorrow evening.



After reading their install instructions, I was hesitant on performing the install myself too. But, after watching the install instructions that ConceptZ provided for the AMS LDPs, it doesn’t seem that bad. See video below.

I hope the HKS LDPs meet your expectations. You will hear the difference at WOT and my butt dyno says more low-end torque than just the JB4 and CBE alone. I didn't have any problems with the installation as I had it done at a shop here. LOL! I did ask if the mechanic had any problems breaking the upper bolts free and the manager said that they came apart with no issues. FWIW.
 

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Hey All. New to this forum. I just had the HKS LDPs installed with an existing REV9 Cat. Around 2k rpms I get this passenger side floor board knocking and sometimes when I turn a corner left or right too. Any thoughts? Theres no way that it's like the crackles and pops within the resonators right?
 

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Hey All. New to this forum. I just had the HKS LDPs installed with an existing REV9 Cat. Around 2k rpms I get this passenger side floor board knocking and sometimes when I turn a corner left or right too. Any thoughts? Theres no way that it's like the crackles and pops within the resonators right?
Could it be the cross brace over the exhaust tunnel? I don't know why the knocking would start now only after the LDP install but just ruling everything out.
 

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Sounds like something is loose or hitting the cross brace. Get it up on a rack and have it checked out.
 

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Discussion Starter #115
@ChicagoBlu its your y-pipe hitting. I had this issue on a previous exhaust. The right fix is to realign the the downpipes to create the clearance. The easy fix is to mallet a dent at the point of contact to create some separation. Your car, the decision is yours. Best of luck either route and good luck!
 

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I installed the HKS downpipes last night. What a headache! I’ll never willingly install downpipes on my cars again lol. I did the install by myself and used jackstands.

When starting the car it sounds slightly louder then it did with just the FI resonated CBE until the electronic waste gates closed and then it was no different than before. Cruising at a steady speed, I detected no difference in the cabin and didn't hear any drone, even around the 2200 RPM range where I could detect a slight resonance before. When I drop it down a couple gears with the paddles, the auto-rev matching sounds cool and when I punch it, the sound in the cabin is really sweet. I like it. More testing to do but my first impression is positive and I don't see any reason to take them off.
I concur with your statement above.
 

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Did you happen to obtain weights of the HKS DPs before install?
I weighed them last night during my install.

OEM LDP, Passenger-Side: 8.2 pounds
OEM LDP, Driver-Side: 8.2 pounds

HKS LDP, Passenger-side: 5.6 pounds
HKS LDP, Driver-Side: 6.2 pounds

I shaved off a whopping 4.6 pounds with the HKS LDPs! :cool:
 
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I installed the HKS downpipes last night. What a headache! I’ll never willingly install downpipes on my cars again lol. I did the install by myself and used jackstands.



I concur with your statement above.
Come on EQ50, it's not too bad! What's the hardest part? Breaking some of the nuts (studs!) loose? Taking out the O2 sensors. Tough but doable. Once the large OEM DPs are out, it's eaier to work with the slimmer aftermarket DPs. Congrats, good job.
 

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If you do anymore work underneath the car, you need QuickJack:

90324
 

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I installed the HKS downpipes last night. What a headache! I’ll never willingly install downpipes on my cars again lol. I did the install by myself and used jackstands.



I concur with your statement above.
Why do you think I had a shop swap them out? I saw what was involved in accessing and removing the upper bolts and figured it was worth $180 to me to have a service tech do it with a lift.
 
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