1. Not sure about the smog pass. they are 200 cell CATS versus a oem CAT which has about 600 to 800 cells. you may or may not pass. I dont have do worry where I live.

2. wait for the Dyno results, Pre and Post install results will be posted here in the next 2 weeks.

3. they advertise little cabin drone. but I will post those results as well. and I have a little solution for that as well if it is needed.

4. yes, its lighter you are getting rid of the boat anchor in the rear of the car. the system you are talking about with all 4 sport CATS is 20LBS lighter. even lighter if you delete the rear CATS.

stay tuned

UPDATE

I know a few people are following this thread. I'm on a plane tommorow. and have the Base line dyno scheduled for Friday July 3. Will post vid results. Then should be able to intall Full NHP following weekend.

results coming soon

thanks

Update parts are in (pics)
 

going to dyno tommorow. (pre-install numbers)

Unwrapped parts. Excellent quality. welds look great. good penetration. heatshields on the mid pipes and the mufflers. gaskets for everthing included.

http://i80.photobucket.com/albums/j1...ey/header2.jpg
http://i80.photobucket.com/albums/j1.../midpipes1.jpg
http://i80.photobucket.com/albums/j1...y/muffler2.jpg
http://i80.photobucket.com/albums/j1...y/muffler4.jpg
http://i80.photobucket.com/albums/j1.../mujffler3.jpg

i'll be anxious to see the results!!!

you have an S - my car is only a 2.7L base - 217hp...so whatever gains you see - i'll have to expect less.... lets hope you see massive gains!!

are you doing any kind of ECU flash or just bolting on the system? is your system the entire thing - headers/midpipes/muffler?

The parts look high quality and the tubing diameter is noticeably larger than stock. Definately interested in the results.

Pre-Installation Dyno Vids & Pics
 

Dynoed Today on a Dynapack, so there would be no questions about variables. there are no tension straps, no rollers, wheel spin, deflection etc.....

Dynapack info:
http://autospeed.com/cms/title_The-Dynapack-Dyno/A_0930/article.html

Video Results of my stock 2003 Boxster S:

http://s80.photobucket.com/player.swf?file=http://vid80.photobucket.com/albums/j179/ryancausey/boxterfinal1.flv&fs=1&os=1&ap=1
http://i80.photobucket.com/albums/j1.../dynosheet.jpg


Looking at back on Dyno in 2 weeks Full NHP installed.

:matchup:

can't wait for the results!!!! thanks for doing this - i'm sure I"m not the only one anxious to see the results. I'd also like to hear how it sounds. :)

aside from dyno numbers - I'd be interested in your subjective impressions as to how it seems to drive/perform - seat of the pants observations.

1. I am doing this at a 1 step at a time approach. (yes I will be altering the ECU maps, custom tuned. but later) The reason is I want to know as well as others whether Porsche has detuned the boxster through the exhaust or the ECU or quite possibly both. (Porshce did not want Boxter's threatening there 996 owners).

2. Yes, 1st stage is strictly bolt up exhaust that should determine if flow is restricted anywhere.

3. Yes it is Full NHP exhaust as follows:

Headers:
Equal Length primary piping, mandrel bend
Racing merge collector for primary piping
42mm primary piping vs. 36mm stock piping
200 cells sport catalytic converters vs 800 cells factory
2 inch exit pipe vs. 1 3/4" stock exit pipe

Mid Pipe Bypass pipes:
Completely removing rear CATS
50mm versus 40mm diameter

Exhaust:
304 Stainless Steel this muffler is a straight through pipe design
there are no internal baffles

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.

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.

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

Ed

:D

nothing wrong with the car it runs great.

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

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

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.

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

Hmmn, very interesting.

Take it back after a few hundred miles and see what happens. Where is your AFR data?

Topless,
Around 190 at the wheels on a dyno jet is about the max one can see without induction work. I have gotten 200 on my dynojet with an enhanced induction arrangement, totally discarding the stock 2.5 plenums and runners as well as the throttle body.

Even with a camshaft change (read as 4 different cam sets designed by me) won't make much more power at all (just move the power up) over 190 at the wheels..

My daily driver 2.5 test car is now at 194 with a bone stock exhaust system..

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.

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

The average HP I see from any Boxster S is 223, average TQ is 210.

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

Your engine is rated at over 250 flywheel HP.. If his dyno is that stingy, it's inaccurate. These engines generally lose a max of 15% to the drive train as RWHP.

Find a dynojet, the numbers from unit to unit are near exacyting and the industry standards are set on dynojet units.. Thats why I bought one instead of a dyna pack..

I have engines tested in either of my engine dyno labs, install them into the car and generally see a 13-15% difference from flywheel HP to RWHP consistently.. Thats how I know our numbers are spot on.

yes, i think its kind of strange the guy that dynoed right after me was around 40 hp under what he is used to seeing. that would put me exactly on the average you said you see for an S. 223 hp. i'll look for a dynojet.

thanks

I would....there is usually just a 1-3% difference between dynoes so there is something else going on. I've heard the dynapac's are stingy, but your hp #'s are similar to what early 2.7L engines put out, not even close to 03 S power. The huge drop in the middle of your torque curve is very strange as well. The TQ curve should be nearly flat.

re-dyno
 

update:

Going to change the plugs and re-dyno on a dynopac (roller dyno). will also have AFR's this time as well.

Hope I can get it in before 7/19. out for work after that.

Later

Cool.. I consider the AFR data more important during this evaluation than the HP output... But then again, I average HP numbers before I even look at peak numbers, because peak is so very worthless unless you drive around at above 5,252 RPM ALL THE TIME.

Porsche has had my car since Monday (AC service) I get home from work today (Friday) "hey your car's ready". Not sure if I can get this done before 7/19. If not it's going to be another month. (out of town again, for work). I could just bolt up the exhaust, but I want to do this the right way. and from what every one has said about the Dyno sheets, something doesn't look right. which is why I insist on re-dynoing it.

This could take awhile. oh well, :cheers:

UPdate waiting again
 

Ok, It didn't get done. I'm out of town again. return Aug. 15. It will be dyno'ed upon return on a roller dyno with AFR readings. Then NHP exhaust will then be installed and re-dynoed on same dyno. Sorry for the wait. But I feel an accurate baseline is needed so we can know what effects of the NHP setup is going to give us. Please hang in there. THANKS

here is a quote from the person who dynoed right after my on the same dyno:

"Yeah I thought yours seemed a little low even for a stocker.. but as they said that dyno is stingy. Dunno, mine dyno'd 90hp and 50ftlb down from last time.. but .. different style dyno, different conditions"

So yeah I'm gonna find a different dyno.

later

Nhp Install Update....nhp....is....installled!!!
 

Following has been installed:

5w-40 Castrol Syn

6 new Interpulse Plugs

NHP Full Exhaust installed

I can not tell specifically from driving on HP gains. I can say the back end broke loose like it never has before.

To me the sound is fine. if it gets to lound in the cabin all you have to do is go up a gear and it instantly quiets down to nothing. this is acceptable for me. but I also don't us the radio much.

try to dyno next weekend.

Old Beru Plugs

http://i80.photobucket.com/albums/j1...usey/berus.jpg

Long term update - probably a solid 8,000 mi on a full NHP exhaust on our '99 with sport cats. Cats started throwing a CEL about 2,000 mi and had to add o2 sensor extensions to fix the CEL. After the last track weekend, there's a rattle somewhere in the tip or mufflers, looks like their heat shield is coming loose.

O2 sensor extensions
 

Did you buy the O2 sensor extensions? or did you make them yourself?

I could have made them, but I was lazy and just ordered them from FVD.

Did a quick search on google just now, there are cheaper options. Here's one I found:

http://www.tuneralley.com/megan-racing-mechanical-o2-sensor-extension-p-73047.html

are the headers on the 99 the same as an 03? do you have 4 02's?

NHP exhaust status update
 

NHP exhaust is fully bolted up.

Headers with sport cats, bypass mids, Exhaust.

Bolted up and fit perfectly. no leaks from headers or mids.

All four muffler clamps that connect the U pieces from the Mids to the rear exhaust LEAK!. THERE SUPPLIED CLAMP IS GARBAGE, and you re-use 2 of the OEM sleeve clamps which also leak. $2k the exhaust should not leak anywhere.

Next: they guarantee no CELS because all 4 O2's are reconnected. Wrong, after about 100 miles. now throwing a CEL, going to check it tommorow OBII scanner. almost sure it is going to say O2. will see.

Can't wait to here there explantion for the exhaust leaks. Gd dmn ridiculous.

Trying for DYNO with AFRS this FRIDAY. DPT tuning Chesapeake, VA.

:cheers:

Just a thought- can you reuse the factory u-pipes and clamps? That way, you could at least guarantee no leak. Maybe the aftermarket u-pipe diameter is a little bit smaller than OEM, which causes the leak?

2K3_Boxster_S:

I just recently bolted up the same system on my 2.7. Since the only parts to be reused were the double sleeve clamps, and mine tightened/loosened like crap a couple of years ago when I put on my first aftermarket muffler, I opted to install new ones. They are part # 996-111-110-01 that list for $32.50 and I was charged $22.24 by my local dealer. Do your double clamps have the wedges in them? Did you remove them? My new clamps didn't have them installed but the old clamps did I believe. Removing the wedges allows the clamps to be torqued down tighter and is in the instructions for the mid-pipe installation.

I did use the clamps NHP supplied from the U-pipe to the muffler. Again, I removed the wedges in the clamps and torqued them really tightly. I don't believe the instructions mention removing the wedges on these clamps but I did so anyway.

I've driven my car ~ 220 miles (including 70 miles this morning) and thus far no leaks and no CEL. I hope my luck continues.

I hope you get your problems sorted soon and I like many other are looking forward to your dyno results. My un-calibrated butt dyno tells me there is a marginal gain from the exhaust and BMC filter I installed on my 2.7. I believe I need an ECU flash to really feel the benefits and that is down the road.

Best of luck and let us know how it all turns out.

Boxtaboy,

I believe the u-pipes are slightly different and therefore not interchangeable.

http://i143.photobucket.com/albums/r...n0529/032a.jpg


ddb

that is an expensive system for only "marginal" gains.

i've watched the youtube videos..they sound cool... but it's almost $2000 for that system and if all it does it "sound" cool and leak and throw CEL codes..no thanks.

I bolted up a used pedro muffler - bought from another member here - for about $150 and it sounds pretty good. not as good as the true aftermarket sy stems... but for $150 it was the best bang for the buck...

It's my understanding that any exhaust / intake mod will give you a marginal gain, if you're lucky. Some will probably cost you power.

In all fairness, any system, regardless of cost, is likely to leak or throw CEL, especially if not installed correctly.

Like I said, the real benefit will come when the DME is reflashed.

I'm sure your muffler mod sounds great! Probably better than mine.

:cheers:

ddb

It takes several "Marginal gains" to add up to something of significance.
Even on our much larger engines we only see marginal gains from the current systems on the market.

I've been working on a development especially for our engines for several months now, because it has been clear to me for many moons that the sound and look are the most important characteristics of the current systems on the market.. Neither of these things are primary objectives for my engine program where effectiveness is paramount.

I see people spend 2K+ to make 2-5HP or even lose 20 HP with a certain system. A simple 200.00 crank pulley can easily give 10HP, but it doesn't add sound or isn't shiny.