Dyno results-headers, intake, bypass pipes

[crios]

When driving, can you feel the gain of 29.69 HP? Seems like a lot of gain.


Fabspeed bypass pipes - Claim +8HP gain
EVO intake - Claim +7HP gain

This leaves about 14HP...where would you say that gain came from?

Maxspeed headers with 100 cell cats - ?
CHI muffler?


PS...what exactly is this Chi Muffler mod?

[Adam]

Originally Posted by crios

When driving, can you feel the gain of 29.69 HP? Seems like a lot of gain.
Fabspeed bypass pipes - Claim +8HP gain
EVO intake - Claim +7HP gain
This leaves about 14HP...where would you say that gain came from?
Maxspeed headers with 100 cell cats - ?
CHI muffler?
PS...what exactly is this Chi Muffler mod?

The headers are what gave him the biggest gain. The stock exhaust manifolds pretty much suck.

[23109VC]

questions:

on a 2.7L - would headers make much of a gain?

are the cheapo chinese headers any good or b/c they lack cats do they suck?

what about the maxspeed setup that have the hi flow cats built into them? i have fantasized about just buying that whole setup -0 it's like $2000 - but i bet it woudl sound AWESOME and if I picked up 15hp or so - all the better. i only have 217 stock on my 2000 - but on such a light car - that much gain would be definitely felt.

or i can just sell my boxster and put that 2000 dollars toward a NEWER car with a 3.2L!!!!

[jhandy]

23109VC, this is what I would do...

Buy the Max speed headers ONLY if you have CATS on the headers as the standard setup.

The cheap China knock offs will give you a CEL and a huge headache if you have CATS in the headers.
Also I have read the the china headers can set fire to your car because the are NOT ceramic coated and get red hot, and they get real close to the Power stering lines. then bam, no more car.
So wire the hose away, wrap the headers, and that is the best you can do.

Or just pay the 600$ for the maxspeed,
Then, go to a muffler shop that you trust and ask them to build you a cat delete pipe, maybe 100$ in cost, the problem is that it illegal for them to do this because it deletes the CATS and Obama gets mad at that. I suppose you could just take off the pipes and have them fab one from that.
Then get a drill and drill out the muffler like a previous post. The muffler DID NOT add any HP, or it was so small I could not tell. The advantage is the sound and the loss of about 40 LBS.

so you could have a safe and effective set up for 7-800$
The intake added a few noticable HP but what a pain in the rear to install. Never will I do that again.

James

[blue2000s]

Did you have a wideband hooked up when you did the dyno run? It would be good to see where your afr is to make sure that power you're making is safe.

[jhandy]

Air fuel was a little rich actually. I attached the printout.

To those who know this kind of thing,
Why did I loose HP and Torque in the middle, The dyno guy said that it was because it was running rich and told me to replace the 02 sensors, and that might help.

[blue2000s]

Originally Posted by jhandy

Air fuel was a little rich actually. I attached the printout.

To those who know this kind of thing,
Why did I loose HP and Torque in the middle, The dyno guy said that it was because it was running rich and told me to replace the 02 sensors, and that might help.

Can you rescan that so the scale shows?

If I were to venture a guess at your AFR plot, I'd say that either the stock map gets rich at high RPM/load for longevity (which is likely) or the exhaust mods have altered VE enough that the DME isn't metering correctly anymore. Either way, the car should be tuned if you want to really make the most power.

Oxygen sensors are only used at low loads and under steady state. They won't effect the AFR at WOT.

The dip in torque looks like the change-over point for the varioram system to me. It looks alot like 944boy's dyno run.

http://986forum.com/forums/attachment.php?attachmentid=9781