AcquaCow
12-12-2006, 01:03 AM
This is a pic of AaronWRX's completely stock '05 STi (I didn't baseline) vs my '04 with K&N Typhoon and a 3" Stromung catback. No engine management yet.
http://dave.oc7.org/images/dyno/stockvscatbackandintake.gif
It's a bit rich between 3500 and 4900, you can sorta feel it on the road...
Guess it's time for some EM and a tune to really smooth it all out.
I should probably get a downpipe and midpipe before then no?
-- Dave
AcquaCow
12-12-2006, 01:13 AM
Max boost?
Dunno, no gauges yet.
My roomate's AP said 14.8 with the stock catback, so I'll have to check again with the new catback.
-- Dave
520hpsti
12-12-2006, 01:17 AM
nice numbers. must be fun to drive!
FraudulentNeon
12-12-2006, 07:27 PM
May not want to compare numbers from different days and cars. Especially with a 50% difference in humidity.
SQC120
12-12-2006, 07:40 PM
May not want to compare numbers from different days and cars. Especially with a 50% difference in humidity.
teach a noob.
does humidity make a huge difference? (i am assuming yes)
how/why? what kind of difference?
nhluhr
12-12-2006, 07:40 PM
SAE correction accounts for that difference. The difference, by the way, is a whopping 5% engine output.
Relative Hp for dave's run: 104%
Relative Hp for Aaron's run: 99%
teach a noob.
does humidity make a huge difference? (i am assuming yes)
how/why? what kind of difference?Yes, higher humidity means less power. This is because the humidity is actually gaseous water dissolved in the air. So for a given volume of air, if you have a lot more humidity in it, that means less of the rest of the components of air (most importantly, oxygen). So more humidity = less oxygen = less power.
You can plug in various atmospheric conditions to this SAE Conversion calc to see what kind of hp difference you can expect from various levels of humidity:
http://wahiduddin.net/calc/calc_hp.htm
micropro_wright
12-13-2006, 12:08 PM
Nice graphs...some of the only ones that actually label each curve, and are readable...A/F chart is nice addition .
Wonder where the power came from, I have seen a number of posts where cat back only did not add much, if any. 30 hp incr is a nice bump....
AcquaCow
12-13-2006, 01:37 PM
Nice graphs...some of the only ones that actually label each curve, and are readable...A/F chart is nice addition .
Wonder where the power came from, I have seen a number of posts where cat back only did not add much, if any. 30 hp incr is a nice bump....
Yeah, we definitely think it looks a bit high for the mods I have.
When I get a downpipe, i'll have to check the stock cat's for any kind of modifications...
The car certainly doesn't smell catless and it doesn't shoot fire between shifts, so I dunno where the power is coming from.
I do have the breather hoses bypassed and not bolted to the IC, but I don't think that adds any power.
Injectors/turbo are both stock and I'm running stock boost.
We'll see.
-- Dave
AcquaCow
12-16-2006, 12:05 AM
I installed a boost gauge tonight to check on the boost levels...
It never even hits 15psi...so I'm still running stock boost. *shrug*
That's still an odd amount of power.
-- Dave