Infinity Design E9x M3 air intake system

[RG m3]

Originally Posted by M3SQRD

Wow. That’s one way to scare potential buyers away from buying other brands of CF plenums. If making claims that the majority of other brands of CF plenums on the market have had velocity stack failures is posted to the forum then supporting images and/or references to failures needs to be included. Also, if velocity stack failures are so widespread then where are all of the threads on the forum supporting his claims? This is the first time I’ve heard of this. There have been other types of failures but velocity stacks? No two CF plenums use the same velocity stack mounting scheme yet all have failed

Failures have happened, that's well known, maybe not with all brands, I don't know. It's not that the velocity stacks themselves break, it's that they detach from the pIenum bottom. I imagine Salman is very well connected in this industry and might know more than we do. See this thread:

https://www.m3post.com/forums/showthread.php?t=2185627

[M3SQRD]

Originally Posted by RG m3

Failures have happened, that's well known, maybe not with all brands, I don't know. It's not that the velocity stacks themselves break, it's that they detach from the pIenum bottom. I imagine Salman is very well connected in this industry and might know more than we do. See this thread:

https://www.m3post.com/forums/showthread.php?t=2185627

I work on spacecraft composite structures for a living. So far I’ve only been able to find velocity stack and CF-to-aluminum ring (secures the velocity stack to the ITB) bonded joint failures on the Eventuri CF plenum design. It’s not surprising that the Eventuri velocity stacks have separated from the plenum due to its poorly designed bonded joint that’s subjected to primary adhesive peel loading (weakest load path for an adhesively bonded joint). Using a large blob of adhesive to create a generous radius adds zero peel strength. The metallic ring that secures to the ITB is a single lap shear joint with practically zero bond area. The CF plenum is subjected to structure-borne random vibration from the engine rpm, thermally-induced loads due to CTE mismatch as well as secondary inertial and acoustic loadings. I doubt they performed any type of dynamic analysis to predict loads and then used the predicted loads in structural analyses to show their design can withstand its structural loading environments.

[RG m3]

Originally Posted by M3SQRD

I work on spacecraft composite structures for a living. So far I’ve only been able to find velocity stack and CF-to-aluminum ring (secures the velocity stack to the ITB) bonded joint failures on the Eventuri CF plenum design. It’s not surprising that the Eventuri velocity stacks have separated from the plenum due to its poorly designed bonded joint that’s subjected to primary adhesive peel loading (weakest load path for an adhesively bonded joint). Using a large blob of adhesive to create a generous radius adds zero peel strength. The metallic ring that secures to the ITB is a single lap shear joint with practically zero bond area. The CF plenum is subjected to structure-borne random vibration from the engine rpm, thermally-induced loads due to CTE mismatch as well as secondary inertial and acoustic loadings. I doubt they performed any type of dynamic analysis to predict loads and then used the predicted loads in structural analyses to show their design can withstand its structural loading environments.

You work in composites so you know a lot more than I do, that's out of my depth, I only report what I read! I guess doing all those tests takes a lot of time and money, so maybe that wasn't done, who knows. Yes, so far the problems only seem to be with the original Eventuri design. I have their updated plenum which bolts the throttle adapters to the velocity stacks with special vibration resistant lock nuts to avoid this problem. I think they learned from their mistake and did a thorough update. Hoping it holds up over time.

[M3SQRD]

Originally Posted by RG m3

You work in composites so you know a lot more than I do, that's out of my depth, I only report what I read! I guess doing all those tests takes a lot of time and money, so maybe that wasn't done, who knows. Yes, so far the problems only seem to be with the original Eventuri design. I have their updated plenum which bolts the throttle adapters to the velocity stacks with special vibration resistant lock nuts to avoid this problem. I think they learned from their mistake and did a thorough update. Hoping it holds up over time.

I bet they are using nylon lock nuts? Nylon lock nuts can’t be used in spacecraft/space due to nylon high rate of outgassing in a vacuum. Either Nord-lock SS wedge-lock washers or wire-lock nuts/bolts. Third option is something called Vibra-tite which is a gummy coating you put on a portion of the threads on a fastener (it is different from loctite). However, a properly designed bolted joint should not lose preload under reversing (dynamic/cyclic) loads.

FYI, the Partee CF plenum uses bolted-on velocity stacks. Their full CF design is nice but I couldn’t stand their version with the Lexan window which they no longer make.

[RG m3]

Originally Posted by M3SQRD

I bet they are using nylon lock nuts? Nylon lock nuts can’t be used in spacecraft/space due to nylon high rate of outgassing in a vacuum. Either Nord-lock SS wedge-lock washers or wire-lock nuts/bolts. Third option is something called Vibra-tite which is a gummy coating you put on a portion of the threads on a fastener (it is different from loctite). However, a properly designed bolted joint should not lose preload under reversing (dynamic/cyclic) loads.

FYI, the Partee CF plenum uses bolted-on velocity stacks. Their full CF design is nice but I couldn’t stand their version with the Lexan window which they no longer make.

This is what Bilal from Eventuri told me this week regarding the nuts they use:

"Also we are using Aerotight lock nuts which don't come loose under vibrations like the traditional nuts do."

I guess those are some type of aerospace grade nuts.

I'm with you on the Partee plenum, the one with the Lexan wouldn't appeal to me at all as I am an OEM+ kind of guy.
I'd rather stick with a company that has a known reputation when it comes to customer care.

[CamasM3e93]

Originally Posted by M3SQRD

I work on spacecraft composite structures for a living. So far I’ve only been able to find velocity stack and CF-to-aluminum ring (secures the velocity stack to the ITB) bonded joint failures on the Eventuri CF plenum design. It’s not surprising that the Eventuri velocity stacks have separated from the plenum due to its poorly designed bonded joint that’s subjected to primary adhesive peel loading (weakest load path for an adhesively bonded joint). Using a large blob of adhesive to create a generous radius adds zero peel strength. The metallic ring that secures to the ITB is a single lap shear joint with practically zero bond area. The CF plenum is subjected to structure-borne random vibration from the engine rpm, thermally-induced loads due to CTE mismatch as well as secondary inertial and acoustic loadings. I doubt they performed any type of dynamic analysis to predict loads and then used the predicted loads in structural analyses to show their design can withstand its structural loading environments.

Yeah, I was going to say that….😏

[smokinjoe64]

Regarding the Infinity Design bespoke air filter, a few questions/considerations since little detail on their site:

• Single use or Reusable?
• Dry or oiled?
• Maintenance [process or 'kit']?
• Replacement price?
• Recommended replacement interval?
• Part availability for replacements?

Given bespoke filter design, considering long-term availability and support for key consumable with the 'investment' in-mind...comments?

[smokinjoe64]

Originally Posted by M3SQRD

I work on spacecraft composite structures for a living. So far I’ve only been able to find velocity stack and CF-to-aluminum ring (secures the velocity stack to the ITB) bonded joint failures on the Eventuri CF plenum design. It’s not surprising that the Eventuri velocity stacks have separated from the plenum due to its poorly designed bonded joint that’s subjected to primary adhesive peel loading (weakest load path for an adhesively bonded joint). Using a large blob of adhesive to create a generous radius adds zero peel strength. The metallic ring that secures to the ITB is a single lap shear joint with practically zero bond area. The CF plenum is subjected to structure-borne random vibration from the engine rpm, thermally-induced loads due to CTE mismatch as well as secondary inertial and acoustic loadings. I doubt they performed any type of dynamic analysis to predict loads and then used the predicted loads in structural analyses to show their design can withstand its structural loading environments.

Share M3SQRD sentiments, that with 'similar' knowledge and experience with multiple composite types and processes for both commercial and military applications [flights controls, jet engine power plant systems & more].

To produce 'relatively' complex geometries, with compound curvatures along with tight tolerancing reliably and consistently, this typically requires significant capital investment, development, and testing...meaning time & money.
[material system, process selection, inspection, prototype testing].

My take from years of development experience there's likely fundamental root causes and factors aside from material system selection...
Build Processes:

• Hand or manual lay-up - Extremely operator dependent
• Bonding - Autoclave, Resin Pressure Molding and others [compatible with/material selections]
• Nondestructive Inspection (NDI) - Proper methods, equipment, use to identify defects like cracks, voids, or material variations.

Based pics observations alone, raises questions regarding production units long-term robustness for intended operating environment, build consistency, along with likely 'workarounds' [i.e. 'random/excess' internal epoxy applications].

Certainly not bashing, since when one decides to purchase/install aftermarket components that experience dynamic loads/forces WE knowingly accept more risks than OE. These issues are by no means unique to Eventuri or similar suppliers.

And so it goes with aftermarket ==> Forces in tension...

> Speed to market
> Cost
> Quality
> 'Trade-offs'

...thoughts, comments?

[smokinjoe64]

Originally Posted by CamasM3e93

Yeah, I was going to say that….😏

[a5m]

Originally Posted by smokinjoe64

Regarding the Infinity Design bespoke air filter, a few questions/considerations since little detail on their site:

Single use or Reusable?
Dry or oiled?
Maintenance [process or 'kit']?
Replacement price?
Recommended replacement interval?
Part availability for replacements?

Given bespoke filter design, considering long-term availability and support for key consumable with the 'investment' in-mind...comments?

Filter is oiled. Replacements can be bought here:

https://www.infinityautodesign.com/p...ent-air-filter

Salman had mentioned they're made in France I believe? By some company that he highly regards and considered the best. I believe he suggested the K&N Filter Cleaning Kit so it is serviceable.

I would've preferred a dry filter, but he was adamant oiled was better. From my research it seemed they filter and flow better too, but it could've been they filter better and flow the same or the difference is negligible. I don't remember off hand.

[smokinjoe64]

For those considering importing automotive parts from UK these days see below [ie Infinity Design].
Fully prepared to order this week until discovered ID no longer fulfills from US resellers/warehouse, now solely direct UK importing.

IMO, a nasty consumer tax for no good reason...'tariffying' & nonsensical!

An AI inquiry:

[smokinjoe64]

Originally Posted by smokinjoe64

For those considering importing automotive parts from UK these days see below [ie Infinity Design].
Fully prepared to order this week until discovered ID no longer fulfills from US resellers/warehouse, now solely direct UK importing.

IMO, a nasty consumer tax for no good reason...'tariffying' & nonsensical!

An AI inquiry:

UPDATE
Decided to order and received Infinity Design CF intake.

Initial impressions, pics, and comments posted here to reduce duplication

[smokinjoe64]

A member posted the ID intake makes contact, rubs the hood and suggests PPF application.

> Any ID intake owners observe a 'rubbing' issue?

[smokinjoe64]

Originally Posted by smokinjoe64

A member posted the ID intake makes contact, rubs the hood and suggests PPF application.

> Any ID intake owners observe a 'rubbing' issue?

Quick Follow-up
After some 'spirited' driving and rips - - confirming no hood rubbing of CF intake or plenum

[2manyMcars]

Infinity is previewing their 2026 S65 Carbon Plenum to to marry with their S65 Carbon Intake. So now they will have complete intake to throttle body carbon for both the s85 and the s65.

Having enjoyed the full csl intake plenum sound on the e60 m5, (it’s good to have friends), I’m finally going to be able to finish my s65 project with the Infinity carbon plenum.

It’ll be worth the wait for the design, the build quality, and the finish, especially for those of us who already have the Intake and have been waiting for the complete system.

Infinity Design S65 Carbon Plenum 2026

[a5m]

Originally Posted by 2manyMcars

Infinity is previewing their 2026 S65 Carbon Plenum to to marry with their S65 Carbon Intake. So now they will have complete intake to throttle body carbon for both the s85 and the s65.

Having enjoyed the full csl intake plenum sound on the e60 m5, (it’s good to have friends), I’m finally going to be able to finish my s65 project with the Infinity carbon plenum.

It’ll be worth the wait for the design, the build quality, and the finish, especially for those of us who already have the Intake and have been waiting for the complete system.

Infinity Design S65 Carbon Plenum 2026

Whoa interesting! I wonder if there will be any gains.

[smokinjoe64]

Originally Posted by a5m

Whoa interesting! I wonder if there will be any gains.

Regarding ID gains [vs OE], my 2¢ & experience...

> CF Intake - Definitely + larger 'closed system' [~10 HP claimed]
> CF Plenum - Slim to none detected

However, CF plenum + CF airbox pairing illicits a pleasurable 'double eargasm'
Configs tried:

• ID airbox & OE plenum - Noticed performance bump/gain
• ID airbox & PR CF plenum - Butt dyno says more improved throttle response

Curious...after all this time awaiting ID CF plenum design, looks like Eventuri V1 with all carbon ports and stacks ...maybe CAD illustration doesn't show material definition.
Nevertheless, another great AM supplier with another option for e9X M3 on-going support.

Long live the S65!

[2manyMcars]

Originally Posted by smokinjoe64

Regarding ID gains [vs OE], my 2¢ & experience...

> CF Intake - Definitely + larger 'closed system' [~10 HP claimed]
> CF Plenum - Slim to none detected

However, CF plenum + CF airbox pairing illicits a pleasurable 'double eargasm'
Configs tried:

ID airbox & OE plenum - Noticed performance bump/gain
ID airbox & PR CF plenum - Butt dyno says more improved throttle response

Curious...after all this time awaiting ID CF plenum design, looks like Eventuri V1 with all carbon ports and stacks ...maybe CAD illustration doesn't show material definition.
Nevertheless, another great AM supplier with another option for e9X M3 on-going support.

Long live the S65!

Indeed, it’s a quality addition. And yeah if you put it together with the intake you’ll be getting your engine bay visual fix and “eargasm” which lets be honest by the time youve done everything else with tunes and test pipes, exhausts and coilovers, all that’s left is the subtle touches that bring a smile to our faces when we blip the throttle and get that grin that you just can’t explain and your wife always rolls her eyes at!

Sal @ Infinity is gonna offer a more modular system with choices, there’ll be short straight velocity stacks, as well as larger than stock curved stacks, two lid designs, the whole thing will be serviceable and customizable. It’ll be a nice compliment for anyone who has the intake already. Or anyone who just wants a solid well designed carbon plenum. Cheers!

[play2lose]

Just to let future buyers know, I received an import duties invoice for my purchase of the intake in Sep2025. It came out to $122 via FedEx. I purchased from extreme powerhouse.

[vlo41662523]

My import fees were 98.25
Around Black Friday , ID intake was a few hundred off from xph

[smokinjoe64]

Originally Posted by play2lose

Just to let future buyers know, I received an import duties invoice for my purchase of the intake in Sep2025. It came out to $122. I purchased from extreme powerhouse.

Also purchased Sep`25 from Extreme Powerhouse [w/ free shipping from UK].
Import tax & tariff fees $99 via UPS

[Herofmine]

Originally Posted by vlo41662523

My import fees were 98.25
Around Black Friday , ID intake was a few hundred off from xph

Originally Posted by smokinjoe64

Also purchased Sep`25 from Extreme Powerhouse [w/ free shipping from UK].
Import tax & tariff fees $99 via UPS

How long did it take to arrive?