Originally Posted by john370z (Post 45829)

Hi all again. I have raced my wife over 20 times. She in the 335 and me in the z. I can even beat her off the line but at this altitude she is dominant. I would guess at 60 mph she has almost 2 car lengths and the gap isn't widening as fast but it is widening. The torque on the 335 is amazing. I have installed K&N drop in filters but nothing else. Her car has the same. After driving the z almost 2000 miles I have some more observations.

As far as the engine, the 335 is much quieter and seemingly in better tune. I prefer a peaky engine and the 335 is not that. In fact is has more pull at lower rpm than at higher. I prefer the z tranny (7 sp auto) to the 335 6sp auto. I like the relationship the z has between the two. The 335 has so much torque that is does not have to downshift to accelerate well where the z does.

I like the brake feel better by a little on the z. The 335 are a bit grabby and are difficult to modulate.

The suspension is softer on the 335. I prefer the z's suspension tune over the 335. Although on a long road trip they both will get old...the z will get old faster.

I have come to like the z stereo. It had the presence of good bass, great treble, but lacks mid-range. I have chosen to slightly fade the stereo towards the back by two ticks to add a little more rear sound fill. Center balance leaves the rear speakers silent. The 335 has a better stereo, but they charge for it. I think the stereo alone is a $1350 add on for this year 335 model. Was in a premium package when I bought it.

Looks. Even my wife loves the z more. The wheels make it. The 335 wheels are set in and don't give off an aura of performance. Whe ncomparing the two in looks....my wife who has won 20 out of 20 races laughs at me saying "all show and no go". I grind my teeth, but remind myself that it is my duty to keep her happy...even if I have to loose to her all the time.

Loving the discussion!

Originally Posted by serge (Post 47718)

I lived in Colorado Springs (6,000 ft. altitude) and I'm pretty familiar with the negative effects of thin air on engines, specially NA ones. Someone stated on a previous post that at 5000 ft., a NA engine loses 3% power. Wrong. It's 3% every 1000 ft., equaling 15% power loss. As an example on how bad altitude is, my bolt-on Evo used to run 11.9 @ 115 mph at sea level, but was only able to manage a best 12.8 @ 108 at 5,500 ft (Denver), almost a full second and 7 mph slower.

The reason why your 335 is faster than your Z at 5,000 ft. is because the 335s ECU compensates for altitude with extra boost, around 2psi. My best friend has a modified 335 with Procede tune and he runs faster at altitude (Tucson, 3000ft.) than sea level. So, while your Z is losing about 15% of its power (285-290bhp "after taxes"), your 335 is basically keeping all its original power, which is believed to be around 320-330 bhp "tax free". There're plenty of posts on e92.com from owners with stock 335's "destroying" more powerful NA cars like the C6 Vette (LS2s), 911 CSs or SRT8s at >4000 ft. altitude. The 335s boost compensation feature does miracles on the 335 at high elevation.

Nevertheless, even though it may not be the faster car around the block, I'll be getting a 370Z as soon as I get back from my deployment ;)

Originally Posted by ianthegreat (Post 47964)

Are you sure his 335i is running faster at that 3,000ft? You are right, the ECU does adjust accordingly. The ECU is having to accomodate the altitude, but higher boost does not equal more power in this situation. For example, a FMIC actually drops the amount of boost required to produce the same amount of power.

On a side note, my buddy is coming into town with his 370z. We'll be heading out to the houston raceway park in baytown -- I'll try and post some vids.