Planet-9

987.2 CR exhaust on 987.2 CS

Add to repair workspace

New repair projectOpen repair workspace

Original source

6 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCH987.2 CR exhaust on 987.2 CS

Leading reported evidence

Use slightly thicker pipes (7mm difference vs base/s)

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion
As you probably know Cayman R catback uses slightly thicker pipes (7mm difference vs base/S) from headers to mufflers.
Original post Read captured discussion
987.2 CR exhaust on 987.2 CS

Read full discussion summary

Leading evidence: 'Use slightly thicker pipes (7mm difference vs base/s)' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Use slightly thicker pipes (7mm difference vs base/s)' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.

Read captured replies

1 matching discussions · 6 captured posts examined · 1 partial discussions

Frequently discussed actions (1)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Use slightly thicker pipes (7mm difference vs base/s)

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion
As you probably know Cayman R catback uses slightly thicker pipes (7mm difference vs base/S) from headers to mufflers.
Original post Read captured discussion
987.2 CR exhaust on 987.2 CS

Coverage and how to read this overview

Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

6 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

Planet-9: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T105141Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1Original post

Please correct my interpretation, but from what I've read here it seems that strictly upgrading the exhaust (catback) yields only slight gains (~10 hp) because the main bottleneck is in the headers. Has anyone installed Cayman R exhaust on a Cayman S? And in the future if one were to upgrade the exhaust manifold to one with 200 cell cats, would the Cayman R catback become the bottle neck? I guess my question is, how much attainable power in such setup ?

POST 2Original post

First of all, 10HP is not a slight gain! Second, upgrading Cayman S with Cayman R catback will not give you 10HP. I've recently upgraded my Cayman base with Cayman R (Carnewal GT modded) mufflers and power gain is not really noticeable. Maybe a slight increase at lower end or maybe it just seems that way because its louder (sound is the main reason I wanted the Carnewal mod). As you probably know Cayman R catback uses slightly thicker pipes (7mm difference vs base/S) from headers to mufflers. If power is your main goal, upgrade the headers to catless or 200-cell ones, since the main bottleneck on a 987.2 is in the headers. In fact there are two cats in each of the two headers, so getting rid of them or replacing them with one hi-flow cat will yield improvement. There are no cats in the mufflers of 987.2 cars, hence they will not be bottlenecks for any upgrades.

POST 3Original post

I agree with everything you said. I still have a question. Let's say I were to upgrade the catback with a Cayman R which is 7 mm thicker as you said (55mm vs 48mm). If my math is correct, this would allow for about 31.3% more flow if the other bottleneck(s) (headers) were to be freed up. My question is: Would the Cayman R catback accommodate a free-er flowing exhaust manifold (not catless but say 200 cell)?

POST 4Original post

I am pretty sure it would accommodate 200-cell headers. In fact I am looking for such a set myself Take a look at this post by Cayman guru Gert : https://www.renntech.org/forums/topic/47683-987-2-exhaust-system-explained/

POST 5Original post

Thanks for the link, great info. " I've recently upgraded my Cayman base with Cayman R (Carnewal GT modded) mufflers" - I'm confused, I thought you just said you're looking for a set? Also what is the exhaust pipe diameter on the base Cayman?

POST 6Original post

I meant to say I am looking for a set of 200-cell headers

This is a source reference. Confirm exact model applicability in the original material.