What is stock A/F. Should it be around 12.5 or closer to 13? Or were you at 13 because the ECU was adjusting for your other mods?

 

The a/f ratio should be exactly 12.5 for our tuned ECUs, as the timings are set for that very mixture and because those timings are aggressive, you don't wanna deviate from the perfect 12.5 ratio.

Gurgen

EDIT: the stock AT sedan a/f is 10.5. Sucks doesn't it!!! While others (Z's, coupes, mt sedans) are around 12.x. THat's why the Sedan is badly detuned!!!

<P ID="edit"><FONT class="small"><EM>Edited by gurgenpb on 12/17/03 09:08 PM.</EM></FONT></P>

 

Anyone else install a Stillen Sedan Exhaust? Impressions?

DaveO
2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU
Street Edge TC / Stillen Exhaust System

 

Mine comes in on Tuesday the 30th. I'll be sure and post after I've had it installed.

[size=1]'03 AT Sedan | Brilliant Silver | Willow Leather | Sport | Premium | Aerokit w/Spoiler | Nav | Injen CAI | UR Pulley | Tein Flex w/EDFC | Stillen Rotors | Cusco Sways | TS ECU Upgrade[/size=1]

 

Great news Don!

I'm looking forward to your impressions. I sure like the increased torque, hp and of course the sound.

DaveO
2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU
Street Edge TC / Stillen Exhaust System

 

Hey DaveO, mine's going on a roundabout route. Stillen > Avalon Racing in NH > me in NY. It left NH on Monday.

___________________________________
2004 | 6MTs | Diamond Graphite/Graphite

 

I've had mine on for 5 days now and the ECU is fully adjusted. There is no question there are torque and HP gains. They are real. Wanted to dyno this week, but no slots available due to holiday. But will do next Tues to see how she does.

 

Can't wait to see your results!!!

 

Gurgen and whoever else has it installed, how do you think it will sound with no other mods? My 6MT sedan is completely stock right now, but you guys got me interested. I'm not really after HP gain, just making it more fun to drive (the improved sound alone seems like a +10 fun factor). Also will there be any other adjustments I have to do, and will I void the warranty or anything?

 

The exhaust will NOT void your warranty, while the sound will still be the same as it was on my car- the sound from the exhaust, that is. My engine makes more sound because of the intake.

Gurgen

 

Anybody found that the Stillen exhaust caused unsafe A/F ratios with the stock ECU? I have the MT Sedan, with only the K&N drop in.

 

No the Stillen did not seem to change the A/F from my testing.

Gurgen

 

gurgenpb - your and Karl's comments re: a/f and ECU re-learning have me somewhat confused. You echo what I have been told elsewhere, specifically that the Stillen exhaust installion will not result in any appreciable change in a/f readings - particularly on the 6mt (I know the 5at ECU is slightly different and the a/f, in theory, should be impacted a bit more). If this is the case, then it seems safe to assume that dyno testing on a 6mt immediately after the install should render valid results, i.e., there will likely be little to no benefit gained by waiting a period of time for the 6mt ECU to re-learn? And, any minor compensation made by the 6mt ECU is not likely to even make a difference on the dyno results. Make sense?

I have scheduled my install and dyno at the same time for before/after testing. Because I believe most large a/f changes stem from intake, rather than exhaust, system changes (excepting headers), my plan was to base the validity of any actual gains plotted on the consistency of the before/after a/f readings, i.e., if the a/f readings remained within + or - 0.5 or so, then that difference was negligible enough so as not to have any major skewing impact on the total gains under the curve. The shop doesn't limit to any pre-determined number of pulls, rather, they continue until two pulls are within a specific range, small enough to be considered valid. So if it takes only a run or two to compensate, I'll be covered.

I figure if the a/f readings remain relatively unchanged on the after pulls, any HP and TQ changes could be compared objectively and the difference would offer definitive and valid results. The decision was in part driven by the fact they could do the exhaust swap with the car right up on the dyno. So since it's already up on the machine and all ready to pull again right after the exhaust swap, I figured why not give it a try and see what happens. I realize that may not be perfect but, if it works, this will be alot cheaper and more convenient than having to come back in a week. It also eliminates any weather and humidity variables, etc. which could have an impact on the results. If it doesn't look right, hey, I can always go back.

So, does this sound like a reasonably good plan, or would a week of ECU re-learning time before the "after" pulls for my 6mt actually be best? Any feedback is appreciated. Thanks.

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

 

Adding to the above question - would it make sense before the after pulls to do the Basic ECU and Idle Air Volume Learning Resets as outlined in the FAQs and DIY board? The rest don't appear to apply for 6mt.

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

 

Doug,

IMO, a full ECU reset and some run time after your exhaust system installation would be best. Stillen's exhaust system significantly increases exhaust gas scavenging and therefore the cylinder "charging". The ECU needs to adjust for the increased air/exhaust gas flow. Even with the TS ECU upgrade, my car is still adapting. I should have followed my own recommendation. The old "do as I say, not as I do" remains true in this instance.


DaveO
2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU
Street Edge TC / Stillen Exhaust System