How much power can you squeeze out of a 986 Boxster S?

[jaykay]

Originally Posted by Gelbster

987 Airbox +986 MAF tube+986 MAF sensor is no problem on my 986 S . The airbox is not critical within reason. Boxster CAI systems have no real airbox at all.
987 v 986 Air box

Yes my point exactly...

[neil_b]

Part 3 of my real world Boxster mods is now up

We talk about the ECU remap and go back to the rolling road to get the final horsepower figure

https://youtu.be/Rf_iv6nyr1g?list=PLNKrPMJBU7WhWJWDcSdS4BFK2d182oHP V

[neil_b]

Thanks for all the feedback guys. Will reply to all your comments tonight.

[neil_b]

Jaykay, the original 986 MAF and tubing we kept.

[neil_b]

Hi Gelbster, Check out part 1. we talk about fitting the 996 throttle body and plenum.

[heliguy]

Originally Posted by neil_b

Part 3 of my real world Boxster mods is now up

We talk about the ECU remap and go back to the rolling road to get the final horsepower figure

https://youtu.be/Rf_iv6nyr1g?list=PLNKrPMJBU7WhWJWDcSdS4BFK2d182oHP V

What other videos do you have planned?

[Gelbster]

Neil = Congratulations on having the guts to publish the results of going back to the stock ECU map.Many of us are tempted to buy expensive mods but there is seldom any independent evaluation like yours.
A proven gain of 25hp would have been worth paying a lot for ! You got it by returning the ECU to the stock map !
Your videos have great credibility and value - an unusual combo on the Internet !Well done and thank you for sharing.

[PaulE]

Thanks for the update. Just to summarize and make sure I have it right, are these the final modifications after round 3? -

Sport Exhaust with Euro exhaust manifolds without catalytic converters
987 airbox with 986 MAF
996 Throttle body and intake plenum
Underdrive pulley
Stock ECU Map

Do you have and if so can you share the RWHP graphs from the dyno sessions? If not, is there a conversion factor that was used to arrive at the engine HP figures quoted? I'm not doubting you or poking holes at what you've accomplished, which I think is great. I'm just trying to understand.

For a US spec 2003 Boxster S, what would be the equivalent exhaust upgrade? For example, headers with catalysts and secondary cat delete pipes?

[The Radium King]

seems odd that it is running rich like that. some thoughts ...

you are hard on the throttle on the dyno, so the car is going straight into high load operation - should be at 12 to 12.5 afr (on the graph you can see the ecu start at stoich and then richen the mix asap)
trims don't matter, as the ecu doesn't use the low load trims at high load - just a maf reading and a lookup on the fuel map
your idle trims look ok (rkat +/- 4%) but uncertain how long you ran with the new flash before you logged them (ie, enough time to adapt)?
do you have low load trims (fra should be 0.7 to 1.32 - ie not a %)? this will tell you if your maf is doing its job (because it is all you have when the car goes open loop at high load)
did you log your 02 sensor data to compare it to what the dyno guys were reading? i think it is jake raby who has some interesting posts on this forum about the inaccuracies of wideband o2 sensors when placed in the tailpipe the way the dyno kids do it.

otherwise, if you are looking to go the final step, consider a 987 maf holder and 2004 anniversary edition tune (your car is an 03/04, yes?). the 987 holder mates properly to the airbox, has a flow straightener, and allows you to keep the intake at a larger diameter. the larger holder requires a different tune, but using an AE flash keeps it all OEM (and a 5 minute job for your dealer). porsche may have snuck a few additional hp into the AE tune as well. fyi, a 2000 S car should use a 996 tune of the same year (drive by wire, larger maf holder). dunno about a 2001 or 2002 car as porsche was transitioning from 7.2 to 7.8 ecu and i'm not sure what works with what. 03/04 can't use a 996 tune however as the 996 went to variocam+ in 2002, but the 03/04 had updated cams and a 7.8 ecu so can't use anything 2002 or older.

[edc]

In the UK the Anniversary is rated at 266 vs 260 of the late S.

[jaykay]

I have ...shall we say experienced these results as well. Fellow forum member Heiko had the same modifications on his 2000 S as I did but with a stock tune. His car felt like it had 911 levels of power where as mine felt very lack luster moving towards higher rpms. The main difference was the generic re map on mine. It seemed to be fine with a stock configuration....but it felt like successive modifications (74mm tb ) didn't seem to jive with it.

I have since moved;I will be pushing back the stock file once I can an internet connection close the car again........or perhaps a dealer might oblige.

A great video Neil!!