[warpeacelove]

Never had any issue with the Dinan inlets, it is a simply install or seek a professional installer for assistance.

[Revan]

Originally Posted by warpeacelove

Never had any issue with the Dinan inlets, it is a simply install or seek a professional installer for assistance.

The installation isn't an issue. It's the reports of leaks and cracked seama that has me concerned.

[warpeacelove]

Originally Posted by Revan

The installation isn't an issue. It's the reports of leaks and cracked seama that has me concerned.

Gotcha. Had mine for roughly about 1.5 yrs without any develop defects.

[pbonsalb]

Seems like the ones made a year or two ago were good. The reports of problems are from ones installed in the last 6 months.

[Advantage]

I received replacement turbo inlets from Dinan late last week. Dinan is standing behind their product. I haven't had a chance to even open the box yet but plan to look them over and install them this weekend. I will be following some of the advice provided "pbonsalb" in this thread. Thanks again.

[Revan]

Thank you pbonsalb for such a detailed post. I checked with a flashlight and sure enough, I have holes by the PCV and metal band. I will call Dinan in the morning.

[NCRob]

I purchased and installed mine in January. So far so good I guess. If I’m not getting a CEL should I assume everything is functioning correctly?

[SatinblkF90]

So, I went through 2 sets of Dinan inlets, got them back in 2021 when they first came out. Cel I got was a crankcase pressure too low code, using ISTA bmw scanner tool.

Literally tried everything to figure it out, must of reinstalled them 10+ times and never got the cel to go away. Everything was installed right, everything tight. Even did a smoke test and saw no leaks or anything. Got my tuner to just “code out” the CEL and have been driving ever since without any issues. I will check to see if by now they are lose by the crankcase connection as per the video above, and if they are I am just going back to OEM and being done with these once and for all, enough is enough with poor garbage quality control on these inlets.

[pbonsalb]

Since the crankcase vent recirculation connects to the inlet tube ports, I agree a leak there is likely. I noticed thin carbon or gaps there and added epoxy to seal.

[SatinblkF90]

Originally Posted by pbonsalb

Since the crankcase vent recirculation connects to the inlet tube ports, I agree a leak there is likely. I noticed thin carbon or gaps there and added epoxy to seal.

Right, so technically even though I coded it out I should still have that CEL. Do you think I’m fine driving around this way? It’s been a long time and no issues so far.

I even took them off and installed same inlets on my friends m5, left them on for a few days. He drove it 500 miles+ and no cel came on his then as soon as I put them back on mine, I get CEL. Seems like some cars it’s more sensitive to trigger a sensor than others, very weird.

I figured in that case then it’s not a real problem I have to worry about, but if it’s loose after some time by crankcase connection like the video above, it’s not even worth fixing anymore as overtime more issues may come up, over a mod that literally is only for sound and no power- at that point it makes a lot
more sense I just go back to stock inlets and be done with it. The joys of aftermarket sh!t when it comes to engine bolt ons…

[pbonsalb]

Dinan did dyno testing that showed power gains of as much as 22 rwhp in the rpm range with peak gains of 11 rwhp. On a modded car with raised boost, the gains could be greater. I bought them for that reason, not the sound though they do add to the induction sounds. Great mod along with secondary or both downpipes for both power and sound. I can hear the turbos whistle now as they spool. Probably there is no consequence from the crankcase leak, but the suction from the inlets does help pull the crankcase gas out and it is well known that too much crankcase pressure can cause oil leaks. There is also the risk that a little in filter air is being sucked into the turbos through the leak. Still, I would guess the CEL is more emissions related since the PCV system is part of emissions, than a real problem. But if it was my car, I would fix them myself or send them back to Dinan for replacement.

[SatinblkF90]

Originally Posted by pbonsalb

Dinan did dyno testing that showed power gains of as much as 22 rwhp in the rpm range with peak gains of 11 rwhp. On a modded car with raised boost, the gains could be greater. I bought them for that reason, not the sound though they do add to the induction sounds. Great mod along with secondary or both downpipes for both power and sound. I can hear the turbos whistle now as they spool. Probably there is no consequence from the crankcase leak, but the suction from the inlets does help pull the crankcase gas out and it is well known that too much crankcase pressure can cause oil leaks. There is also the risk that a little in filter air is being sucked into the turbos through the leak. Still, I would guess the CEL is more emissions related since the PCV system is part of emissions, than a real problem. But if it was my car, I would fix them myself or send them back to Dinan for replacement.

A replacement was already done and made no difference. Both times, for both sets we tried the same inlets on 2 different f90s and in both cases only mine triggered the CEL while the other one did not.

I am going to say then it’s definitely just emissions related which is not a real problem, and my car for some reason was just being more “sensitive” about it, it seems. The mechanic also came to the same conclusion, I just hope it won’t result in any actual issue. Already driven over 10k with cel coded out and it’s not caused any leaks or issues of any kind.

The dyno is nice and all, but I tested the 100-200kph times on and off on stage 2 with 23-24psi on 93 so quite aggressive of a tune (over 700whp) and they did not improve the times by even 0.1s difference, overall average on all runs were identical times as stock inlets. Maybe they do add 11whp but it’s not enough difference to actually be measurable by a dragy or anything? Might just be too small to see. Based off the times it seems they don’t. They are a good sound mod, plus I also noticed the throttle response/turbo spools a bit faster so they do also add faster response time, and likely some low end torque. Still good, and hope to not have to switch them out for stock but if they are getting looser over time and building up more issues (I still have yet to check this) it’s not worth it for such a marginal improvement in how it drives/sounds.

[warpeacelove]

Originally Posted by pbonsalb

Dinan did dyno testing that showed power gains of as much as 22 rwhp in the rpm range with peak gains of 11 rwhp. On a modded car with raised boost, the gains could be greater. I bought them for that reason, not the sound though they do add to the induction sounds. Great mod along with secondary or both downpipes for both power and sound. I can hear the turbos whistle now as they spool. Probably there is no consequence from the crankcase leak, but the suction from the inlets does help pull the crankcase gas out and it is well known that too much crankcase pressure can cause oil leaks. There is also the risk that a little in filter air is being sucked into the turbos through the leak. Still, I would guess the CEL is more emissions related since the PCV system is part of emissions, than a real problem. But if it was my car, I would fix them myself or send them back to Dinan for replacement.

That test was performed for the entire system (CAI + Inlets) which showed power gain as aformentioned. But, we can't claim any power gain for the Dinan inlets Alone besides the accoustics.

[pbonsalb]

Originally Posted by warpeacelove

That test was performed for the entire system (CAI + Inlets) which showed power gain as aformentioned. But, we can't claim any power gain for the Dinan inlets Alone besides the accoustics.

I don’t read Dinan’s description that way. Rather, to me, it appears the intake does not add measurable horsepower at stock power levels, while the inlets do add power. But I also agree 11 rwhp peak added to roughly 570 rwhp peak will not show up in testing. The biggest bang for the buck is a tune. Inlets and downpipes add less but do add power. At some point it becomes noticeable in acceleration times and as the boost goes up, reducing restrictions helps more and more.

[SatinblkF90]

Yes I remember reading directly from dinan themselves that it starts to make a “measurable” difference only from 1000hp+ builds, but before that it’s negligible. So, even on stage 2 they basically just add sound and increased throttle response. Still not bad for the price, as long as they actually work without all the BS.

[warpeacelove]

Originally Posted by SatinblkF90

Yes I remember reading directly from dinan themselves that it starts to make a “measurable” difference only from 1000hp+ builds, but before that it’s negligible. So, even on stage 2 they basically just add sound and increased throttle response. Still not bad for the price, as long as they actually work without all the BS.

Those inlets are comestically appealing, creates faster spooling and produces some bit of more spunk in terms of acceralation, and they're a lot better than some of these expensive CAI's.

[SatinblkF90]

Originally Posted by warpeacelove

Those inlets are comestically appealing, creates faster spooling and produces some bit of more spunk in terms of acceralation, and they're a lot better than some of these expensive CAI's.

Yup, not a measurable difference but can feel and hear that quicker turbo spool/sound which most CAI don’t do as well, that’s why I got them in the first place. Combined with BMC high flow air filters the car has instant throttle response in sport+ mode and the turbos kick in sooner and harder on power delivery.

[F9T]

Had a crankcase ventilation CEL that the dealer could not figure out at first. Finally found cracks in the Dinan turbo inlets. Hoping to get replacements ASAP.

[SatinblkF90]

Originally Posted by F9T

Had a crankcase ventilation CEL that the dealer could not figure out at first. Finally found cracks in the Dinan turbo inlets. Hoping to get replacements ASAP.

Was it anything saying crankcase pressure too low or too high like mine did?

[F9T]

Originally Posted by SatinblkF90

Was it anything saying crankcase pressure too low or too high like mine did?

I am not sure as the BMW dealership did not share the specific codes with me. I have a request into Dinan to get replacement turbo inlets under warranty. Hopefully that goes through smoothly and I get my defective ones replaced. Only problem is that Dinan is telling me that labor is not covered which is disappointing since the labor costs almost as much as the inlets themselves. I am also concerned that I will have the same issue with the replacements since this seems to be a common manufacturing defect.

[SatinblkF90]

Originally Posted by F9T

I am not sure as the BMW dealership did not share the specific codes with me. I have a request into Dinan to get replacement turbo inlets under warranty. Hopefully that goes through smoothly and I get my defective ones replaced. Only problem is that Dinan is telling me that labor is not covered which is disappointing since the labor costs almost as much as the inlets themselves. I am also concerned that I will have the same issue with the replacements since this seems to be a common manufacturing defect.

Yup I replaced mine and still had same code come back on the replacement set as well. It was well over a year ago and since then just had it coded out by the tuner.

No issues since, and I believe it’s just emissions related that some cars are sensitive and trigger it, but not a “real” problem with the car.

[F9T]

Originally Posted by SatinblkF90

Yup I replaced mine and still had same code come back on the replacement set as well. It was well over a year ago and since then just had it coded out by the tuner.

No issues since, and I believe it’s just emissions related that some cars are sensitive and trigger it, but not a “real” problem with the car.

Interesting. I did not get a CEL for a few thousand miles after having the turbo inlets installed. Only got it recently and then discovered the cracking, so I imagine that is the cause of my CEL.