i posted this in another post, but hope to get some more speculation here:
these are my observations:
1. the coupe and sedan differ by 20 hp due to exhaust
2. coupe: when modded with exhaust, gains hp (not sure how much)
3. sedan: when modded with exhaust, gains 20 hp.
1+2+3=with aftermarket exhausts, sedan is still behind coupe in hp/tq numbers. my question is why? and can we milk it for some more at the sacrifice of dB and perhaps some droning?

G35S 6MT
Technosquare ECU
350Z Springs & Struts
6-wire ground kit

 

.. the coupe may come with 20 more horsepower..but it is heavier than the sedan.

 

The coupe might have a slight advantage on the intake side. Maybe even a tuning advantage on the ECU (ignition timing, fuel maps). Perhaps it has more aggressive cam profiles, too. Who knows?

'03 G35 5AT Sedan, Garnet Fire/Willow
Staggered 18" SSR GT1/Bridgestone PP S03's
Eibach Springs & Anti-Sway, Stillen 2-pc B Brakes
Stillen SS Cat-Back Dual Exhaust System

 

no no, misunderstanding. im not asking what the difference is between the coupe and sedan. I think that is has pretty much been discussed to death. the intake is actually the same. ecu tuning is the same for the 6MT sedan and the coupe. only the auto has different ECU. so between the 6MT sedan and coupe, the only difference is the exhaust. oh yea, as for cams, only the 350Z has different cams from the G's.

G35S 6MT
Technosquare ECU
350Z Springs & Struts
6-wire ground kit

 

I hypothesize as the number of mods increases on each model, the performance of the two get closer and closer. At some point, the sedan, which weighs less than the coupe, should out-perform the coupe. With the differences in OEM parts successively neutralized with one aftermarket part replacement after another, this is a logical conclusion, is it not? If so, the question is: Which combination of mods will, once installed on both the sedan and the coupe, enable the sedan to consistently outperform its two-door counterpart?

Is that what you mean?



'03 G35 5AT Sedan, Garnet Fire/Willow
Staggered 18" SSR GT1/Bridgestone PP S03's
Eibach Springs & Anti-Sway, Stillen 2-pc B Brakes
Stillen SS Cat-Back Dual Exhaust System

 

According to the part numbers and shop manuals the cams are the same for all Gs and all 350Zs regardless of transmission type... at least for the 2003 engines. There's 4 part numbers 'cause there's 4 camshafts.


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

 

yes bullseye. i suppose that is pretty close to what i mean. except i supposed that the exhaust would be that aftermarket product. which is why i am curious as to why this is not true. so, the only hypothesis i can come up with is that the sedan aftermarket exhausts are still not making max gains becuase of sound dB issues.

G35S 6MT
Technosquare ECU
350Z Springs & Struts
6-wire ground kit

 

nuttyprof: Really? The ECU ignition timing, fuel maps, etc. for the 6MT sedan and the 6MT coupe are the same? From where did you receive this information and how was it verified? That is very interesting. I was under the impression that the coupe had a more aggresive timing. Thanks.

04' G35S 6MT Ivory Pearl, Willow, Premium

 

Front and center, first thing that needs to be driven from our thought process is any manufacture claims on hp gained, use ONLY independent dyno's. If a suitable independent dyno doesn't not exist, work to urge that one be done or even do one yourself if you have the system in question, don't be sucked into dubious manufacturer claims. The 350Z sport magizine exhaust shoot out was very eye opening in that respect.

By Infinti's own admission the Coupe get's a performance muffler. Plus we can surmise that the sedan's large premuffler vs the coupe's smaller premuffler doesn't help the sedan either. So, yes the oem sedan system is more restrictive than the coupes and it's logical for sedan system's, if done right, to show more gains than on the coupe, you are "uncorking" more.



"All that's necessary for the forces of evil to win in the world is for enough good men to do nothing.”
Edmund Burke

G35 6mt

 

dklau, it should be correct that the only difference is the exhaust, but im not completely sure. then next time i see Tadashi from TS, ill ask him about it. hes sure to know. until then....

G35S 6MT
Technosquare ECU
350Z Springs & Struts
6-wire ground kit