Infiniti Q50 Forum banner
1 - 20 of 26 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #1 ·
Hey what’s up. I purchase FI CBE and looking for lower downpipes. I live in Cali, so strict regulations don’t allow me to purchase FI lower downpipes. I was thinking on getting AMS 3” LDP, but I been reading threads that it’s better to get a 2.5” LDP to match my 2.5 “ CBE.
Will the HP gains be less or equivalent if I get a 3 inch AMS or HKS 2.5inch?
Anyone have this type of setup (Fast intentions CBE and AMS LPD or HKS) ? If so are gains equivalent to getting the Fast intentions lower downpipes?
I’m trying to get the most HP/torque without a tune. I got intakes, heat exchanger. I greatly appreciate anyone helps. Thanks!
 

·
Premium Member
Allen, Texas
Joined
·
541 Posts
I have a set of AMS 3” LDP sitting on a shelf - I had them installed with my FI CBE for nearly 2 years w/o and issues (tuned and/or with a JB4.)

With stock turbos the delta from 2.5 - 3” is less noticeable than with upgrades turbos - then the 3” pipes all the way back seem to yield the highest dyno numbers (tuned with fueling upgrades and all the other FBOs.)
 

·
Registered
Joined
·
2,629 Posts
You'll be fine with the 2.5" diameter LDPs considering you're not planning major upgrades upstream, such as bigger turbos, higher-flow injectors, etc. The 2.5" LDPs will not be a choke-point in establishing the most gains from your planned bolt-ons.
 

·
Super Moderator
Newport, Oregon
Joined
·
12,827 Posts
Don't you have to pass an inspection? The state may not care for the fact that you removed the secondary cats and replaced them with LDPs that are un-catted.
 
  • Like
Reactions: SocaliridiumQ50RS

·
Registered
Joined
·
488 Posts
I'm gonna install Gavin Newsome as my LDP.
 

·
Registered
Joined
·
2,629 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #7 ·
I have a set of AMS 3” LDP sitting on a shelf - I had them installed with my FI CBE for nearly 2 years w/o and issues (tuned and/or with a JB4.)

With stock turbos the delta from 2.5 - 3” is less noticeable than with upgrades turbos - then the 3” pipes all the way back seem to yield the highest dyno numbers (tuned with fueling upgrades and all the other FBOs.)
What gains did you achieve with FI CBE and AMS LDP?
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #8 ·
You'll be fine with the 2.5" diameter LDPs considering you're not planning major upgrades upstream, such as bigger turbos, higher-flow injectors, etc. The 2.5" LDPs will not be a choke-point in establishing the most gains from your planned bolt-ons.
Thank you, so I should should consider getting HKS 2.5 LDP over AMS 3 inch LDP?
 

·
Super Moderator
Newport, Oregon
Joined
·
12,827 Posts
Thank you, so I should should consider getting HKS 2.5 LDP over AMS 3 inch LDP?
HKS LDPs for the Q50 are no longer being made but there are a few around for a ridiculous price. Concept Z Performance has a few left at $900. I bought a pair from them a year and a half ago for $389.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #10 ·
HKS LDPs for the Q50 are no longer being made but there are a few around for a ridiculous price. Concept Z Performance has a few left at $900. I bought a pair from them a year and a half ago for $389.
Forgot to mention, I have the q60 red sport 400. And thanks! Ill look around to see what options. If I can’t find any, I’ll go with AMS
 

·
Super Moderator
Newport, Oregon
Joined
·
12,827 Posts
Forgot to mention, I have the q60 red sport 400. And thanks! Ill look around to see what options. If I can’t find any, I’ll go with AMS
If you want a resonated LDP, AAM and PPE make them. I'd recommend resonated but if the possibility of drone doesn't matter to you then just about anyone's LDPs will do.
 

·
Super Moderator
Newport, Oregon
Joined
·
12,827 Posts
I have some ams ldp ready to sell if any of you are interested pm me
How about placing an ad in the Classifieds instead of trying to sell it here?
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #14 ·
If you want a resonated LDP, AAM and PPE make them. I'd recommend resonated but if the possibility of drone doesn't matter to you then just about anyone's LDPs will do.
I prefer non-resonated. I can’t seem to find any 2.5 inch lower down pipes. Can you refer me to a link or couple brands?
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #15 ·
HKS LDPs for the Q50 are no longer being made but there are a few around for a ridiculous price. Concept Z Performance has a few left at $900. I bought a pair from them a year and a half ago for $389.
Do you know any 2.5 inch LDP? I been trying to search for some online, but only seem to find AMS 3 inch, HKS but expensive 895?
 

·
Super Moderator
Newport, Oregon
Joined
·
12,827 Posts
  • Like
Reactions: IridiumRS400

·
Registered
Joined
·
2,629 Posts
Call me deaf(t), but when I had my Q with FI LDPs and resonated CBE, I didn't experience any drone, except for what I call a "passing frequency" under load in the 2-2.5k rpm range. It would only occur if I was light on the throttle going up a hill, for example. Otherwise, pick any legal/not-so-legal highway speed, and this FI combo didn't drone. Maybe it's due to the wall thickness of the FI piping? Smoothing their internal welds? Just sayin'...
 

·
Registered
Joined
·
114 Posts
Call me deaf(t), but when I had my Q with FI LDPs and resonated CBE, I didn't experience any drone
good to know the resonated CBE cuts down on the drone. That will be the set up I get. I was on the fence about resonated or non resonated, but I really don’t want drone.
 

·
Registered
Joined
·
488 Posts
My FI CBE is almost ready to ship to meeeeeeeee. I have nothing to add to the conversation just wanted to share my joy.
 

·
Super Moderator
Newport, Oregon
Joined
·
12,827 Posts
Call me deaf(t), but when I had my Q with FI LDPs and resonated CBE, I didn't experience any drone, except for what I call a "passing frequency" under load in the 2-2.5k rpm range. It would only occur if I was light on the throttle going up a hill, for example. Otherwise, pick any legal/not-so-legal highway speed, and this FI combo didn't drone. Maybe it's due to the wall thickness of the FI piping? Smoothing their internal welds? Just sayin'...
With the resonated FI CBE, I had a slight drone at 2.2K RPM. After adding the HKS LDPs, the drone was gone...as much as I could tell with my poor hearing, anyway.
 
1 - 20 of 26 Posts
Top