Just dyno'd DC headers..yikes..lol
 

Well, I just got back and....well...if i just go by the dyno alone i'm worst off than before..LOL. but there is hope. (again i'll scan the graph and post them up asap)

my mods before-Stillen duals, motordyne 5/16 iso thermal, k and n intake, kjr pulley:

basically my best peak #s last time were 241.97whp 219.25lbs tq. now my peak #s are 242.70whp and 220.57lbs. of tq. but it gets worse. looking at the curve it looks like this:

3.0-3.5K rpm= +0whp +0 tq
3.5-4.0K rpm= +3whp +5 tq
4.0-4.5K rpm= +2whp +3 tq
4.5-4.8K rpm= +3whp +3 tq
4.8-5.0K rpm= -3whp -3 tq
5.0-5.5K rpm= -5whp -5 tq
5.5-6.0K rpm= -6whp -6 tq
6.0-6.1K rpm= -3whp -3 tq
6.1-6.2k rpm= +1whp +1 tq <---peak power

then it kinda just dies from there. Am I surprised? not too much. i was hoping i wouldn't have to tune to squeeze out power but looking at the a/fs it looks like i'll have to.

that's where there is hope. my last dyno without the headers showed an a/f ratio at 13 flat straight across till 4.5-5.5K where it bliped to 13.8 than came down to 13 flat again.

now with the headers i'm running really lean showing almost 14s across the rpm range! :eek:

i think that's where i can squeeze off more power. a good tune. i richen up a bit back to 13s-13.5 and i'll be seeing the power that i'm supposed to.

so waste of money? i don't think so. it just reaffirms what i already know. a good n/a set up needs a tune. during everyday driving at part throttle i do notice a difference in tq. it's not like i don't like my headers...it's just now i'm going to have to tune to get the most out of them. plus the car does sound more throaty.

see you all in a couple of weeks for my tune + dyno!:icon38:

Was ECU reset before dyno? Even if it was, it would probably be better to let the ECU learn the mod before dyno'ing. Not saying you don't need to tune, or wouldn't benefit from it, but it may not be as bad as it seems right now.

I've had the mod for about a week and driven it for about 200 miles.

You are right. A before and after dyno would be helpful.

what do you mean? i do have a before and after dyno. i just need a scanner to scan the darn thing and post it. tlkaed to tadashi from technosquare to do a reflash. problem is is that he is only open on weekdays (and obviously i work on weekdays). he also said if we were to do it on a weekend that he can only flash it wihtout a dyno b/c he's got no guys to work on a weekend..he'll tune the a/f by 'sniffer' (i think that's what he said)? i wouldn't do that...i need to see the a/f curve and tune accordingly. maybe a greddy EU...i'd love for a utec but i'm married and $ for my car is limited...lol.

i left a message for shawn at church automotive but no response.

just keep trying until you get shawn on the phone, he's a great guy but for some reason they are really bad about returning phone calls.

Just got my dyno scanned...
 

here's the dyno....notice how lean i am throughout the band after the headers and that i actually lose more power than i gain. time for a tune...

i think this is the first baseline vs dc header. i haven't seen one on these boards from an independant source yet. :icon38:

looks like your car goes a little funky around 5400rpm. I'm interested in seeing what a tune will do for you

hopefully the lackluster power is due to not having enough fuel. i hope to richen up and see power thoughout the band when i do a tune. it's very hard to get an appointment at technosquare because i work on the weekdays (the only time they are open). i can send my ecu out but since i live in socal i would want them to tune accordingly with a dyno or mobile afr sensor.

what year motor do you have?

03' VQ-35DE 287hp...

i was thinking maybe my ecu needed to adjust...but i doubt it. i had the headers a full week before the dyno with some wot runs here and there.

I dynod the TS headers on my G35 and found the same results...

did you ever get to tune it tony?

You guys need to realize one thing, Z/G's hate mods! If you mod your car you have to tune it. The headers got you in the 14's A/F range so in order to compensate for that you need a tune. Just get a UTEC and call it a day.

Utec
 

This is exactly why i'm going to do test-pipes, headers, and UTEC at the same time. I can't wait!

Which is before and after? Red or blue?

umm...dyno runfile.04 would be before (red) and dyno runfile.07 would be after (blue). it basically stops making more power than the last dyno after 4.5-4.8K rpm and starts losing it. :(

Decreasing the air:fuel ratio with a tune will be interesting.

i agree....i think that's where i'll see some power.

No. I eventually had to remove them due to a leak.