[Barryng]

I have had my new 2019 Base manual transmission Boxster for just a few months and I am satisfied beyond already high expectations with this wonderful car. However, like many things in life, a lot is not enough and I would certainly like more low end get up and go. Although my Boxster is light years more satisfying than my previous Z4 (also manual transmission), I perceive the Z4 3.0si had more torque around 2,000 RPM or so than my Boxster and I feel, in responsible city driving, I am usually one lower gear than I was in the old Z4 to get the RPM up and feel a more satisfying throttle response. Whereas 2nd gear was previously satisfying when slowing for a corner, I now frequently find I have downshifted into first. I am not suggesting I am leaving rubber when turning a neighborhood corner but I am saying the same throttle response at low speed now seems to require higher RPM. I don't think I am feeling turbo lag (although it sometimes feels like that), I think the four cylinder Boxster engine just likes being at a higher RPM than the 6 cylinder BMW engine.

The local PCA has an excellent monthly magazine called the Kassette and this month's issue has a full page advertisement (in the form of an article) about IPD intake plenums and all the magical low end performance gains they provide by optimizing flow. So....

-Has anyone installed an IPD intake plenum upgrade?
-What is the cost of doing this?
-Are the performance gains worth the cost and effort?
-Is it a good assumption this mod will void the warranty on my brand new car?

With respect to performance gains, I upgraded the intake manifold in a BMW Z4 a number of years ago. The gains were not dramatic but certainly noticeable to an extent that I had no regrets about the cost and effort of doing it. The gains in the Z4 case were most noticeable at high RPM (>3,500) but in the case with my Boxster I am looking for a low end gain around 2,000 RPM.

 

[msacks]

To my knowledge, no one currently makes an IPD Plenum for the 4-cylinder engine on the 718, they’re only available for the older generation flat-six. Having said that, I could be completely wrong, so any of you senior members out there feel free to correct me on this.

 

[Andros X Thomson]

IPD said they would release it once development was complete. That was more than 2 years ago. I too am waiting to see what they come out with.

 

[Barryng]

Thanks for the responses. I also read some articles indicating the plenum only upgrade did not really provide much of an increase in power. So, I guess the lack of an appropriate plenum and what I read puts a hard end to this potential adventure.

 

[Fosgate769]

A plenum is going to help alot more on a N/A engine vs a boosted one. Not that it wouldn't do anything but probably not worth changing. Haven't looked at gearing on a Z4 but it could have just been geared a bit shorter.

 

[cipher]

You’re probably better off switching to a higher flow down pipe.

 

[BzzzBom]

IPD is considering making a plenum for the 718 flat six engines

 

[vosadrian]

Turbo engines respond very differently to NA engines for both intake and exhaust manifolds. Both of which are at much higher pressure then in NA engines. This being the case, the turbo itself becomes the dominant aspect to performance rather than the manifolds. As long as the manifolds can flow enough (minimum restriction) with low enough volume as to not cause response issues (caused by taking longer time to build up pressure for a high volume) , it is all about the turbo. In NA engines the intake and manifold designs can be used to tune localised pressure peaks and troughs to enhance flow in RPM ranges to enhance performance.

It is worth noting that a flat engine with a single turbo is one of the worst setups for turbo performance as the volume of the manifolds is necessarily high as there is a long distance between the sides of the engine that need to come together in a single turbo, which increases manifold volumes and makes it difficult to get any type of tuning going between cyclinders. This is worsened with the typical flat 4 firing order which has cylinder on the same side firing in succession. Flat 6 firing order is much better for this, but most flat 6 engines go to twin turbo with each turbo doing 3 cylinders with smaller manifolds which works great.

 

[BzzzBom]

That’s why I was only considering the normally aspirated flat six engines such as the ones in the 718 GTS 4.0 or GT 4. IPD may be working on a plenum next year for these engines.

 

[JazzCatGab]

@Barryng I have a 2019 base Cayman and I try to avoid 2,000 RPMs at all costs because it is like what Gertrude Stein said about Berkeley, "There is no there, there." It means I go around tight corners a bit fast, although I can get pretty close to 2,250 RPMs and still have a weak but doable response. One other thing you can try is staying in 2nd gear, rounding the corner and after the apex, clutching and goosing the gas a bit, and then release the clutch as the RPMs start coming down. That might give you enough torque to avoid juttering.