anyone intalled NHP full exhaust??? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Topless · 07-03-2009, 11:48 PM

Yikes! Looks like a huge hole in performance at 4300 rpm. Low numbers for a Box S also. Bad MAF??? Spark plugs?? I have seen a lot of Boxster dyno results. Something looks very wrong here.

stateofidleness · 07-04-2009, 02:01 AM

i know nothing about dyno's and such, but 186hp on an "S"?
I thought my MY00 stock 2.7 was rated at 210hp... is yours low, or is mine high?

seems like the S should be putting out a lot more, even a stock one.

edevlin · 07-04-2009, 03:33 AM

Interesting stuff, keep the dyno sheets comming....

Ed

2K3_Boxster_S · 07-04-2009, 08:03 AM

Quote:

Originally Posted by stateofidleness

i know nothing about dyno's and such, but 186hp on an "S"?
I thought my MY00 stock 2.7 was rated at 210hp... is yours low, or is mine high?

seems like the S should be putting out a lot more, even a stock one.

its horsepower to the wheels, not what the engine can make. Those numbers put my car around 250 hp.

2K3_Boxster_S · 07-04-2009, 07:57 AM

Quote:

Originally Posted by Topless

Yikes! Looks like a huge hole in performance at 4300 rpm. Low numbers for a Box S also. Bad MAF??? Spark plugs?? I have seen a lot of Boxster dyno results. Something looks very wrong here.

nothing wrong with the car it runs great.

2K3_Boxster_S · 07-04-2009, 08:05 AM

Quote:

Originally Posted by Topless

Yikes! Looks like a huge hole in performance at 4300 rpm. Low numbers for a Box S also. Bad MAF??? Spark plugs?? I have seen a lot of Boxster dyno results. Something looks very wrong here.

go put your car on a dynapack and lets see whats going on.

Topless · 07-04-2009, 08:38 AM

Here is another dynapack run with a bone stock Boxster S for comparison.
http://i4.photobucket.com/albums/y144/bisimoto/DeSnorked986S.jpg

Do you see what I mean about your cars hole at 4300 rpm(down to 140 ft lbs)? Peak performance is much lower on your run also. I am not here to burn you down. I just figure if you want to get a good baseline run before tuning your car it should look similar to other stock Box S runs to be valid. Looking at your numbers I suspect a fouled/contaminated MAF.

Topless · 07-04-2009, 09:09 AM

Here is another run with a well tuned 98 Boxster spec car. The motor is a stock 2.5L crate motor that was recently installed. This run was under ideal conditions on a cool morning at sea level. These are the best results I have seen with a stock 2.5L. Note the big fat torque curve at 4500 rpm. This car sings.

http://www.boxsterspec.com/uploads/monthly_01_2009/post-49-1232326727_thumb.jpg

2K3_Boxster_S · 07-04-2009, 08:45 PM

Quote:

Originally Posted by Topless

Here is another dynapack run with a bone stock Boxster S for comparison.
http://i4.photobucket.com/albums/y144/bisimoto/DeSnorked986S.jpg

Do you see what I mean about your cars hole at 4300 rpm(down to 140 ft lbs)? Peak performance is much lower on your run also. I am not here to burn you down. I just figure if you want to get a good baseline run before tuning your car it should look similar to other stock Box S runs to be valid. Looking at your numbers I suspect a fouled/contaminated MAF.

hmm. yes I see what you are saying. your dyno sheet drops at almost the same exact point. not nearly as drastically though 10Lbs i think. I'm also looking at a difference in the Rpms and Mph, don't think that matters though. If its a plug or MAF you can not tell by driving the car. Plus shouldn't you get a CEL if it was the MAF?

Jake Raby · 07-05-2009, 06:48 AM

Quote:

Originally Posted by 2K3_Boxster_S

hmm. yes I see what you are saying. your dyno sheet drops at almost the same exact point. not nearly as drastically though 10Lbs i think. I'm also looking at a difference in the Rpms and Mph, don't think that matters though. If its a plug or MAF you can not tell by driving the car. Plus shouldn't you get a CEL if it was the MAF?

There are lots of issues that can reduce output without throwing a CEL.. some of these are MAF issues, others are fuel pressure or fuel injector related and even issues with catalytic converters.

Or a low power engine may have an impending mechanical issue... I haven't ever seen a healthy Boxster S engine that didn't make at minimum 205HP at the wheels.. That engine was very tired with near 30,000 track miles on it.

Adam · 07-05-2009, 11:46 AM

183 hp and 177ft/lb at the wheels? Something is definately wrong with the car or the way it was dynoed. This 2003 S at fabspeed dynoed 229 hp and 203 ft/lbs at the wheels...bone stock.

http://www.fabspeed.com/Boxster.html

2K3_Boxster_S · 07-05-2009, 08:57 PM

Quote:

Originally Posted by Adam

183 hp and 177ft/lb at the wheels? Something is definately wrong with the car or the way it was dynoed. This 2003 S at fabspeed dynoed 229 hp and 203 ft/lbs at the wheels...bone stock.

http://www.fabspeed.com/Boxster.html

Not saying that your wrong, but what kind of dyno? every dyno is not the same. this is on a Dynapack the owner said it is very stingy. here is a video of a guy that dynoed right after me. It's a ford merkur (iron block) on 25 psi to 30 psi (boost creep) and he is used to seeing well into the 300 whp. Well, he didn't even get close. I'm just saying every dyno is and will be different. i'm considering re-dynoing somewhere else. maybe the way it was set up or just this dyno. the car is definitely not driving like 183 and 177.

this car makes well over 300. not on this dyno.

http://s80.photobucket.com/player.swf?file=http://vid80.photobucket.com/albums/j179/ryancausey/M2U00194.flv&fs=1&os=1&ap=1