Yep they are really nice cars for sure. Haven't driven an auto, only the manual

 

How did the auto syncro rev match work out on the downshift. Pretty trick stuff.

 

It's a weird feeling to be able to do it. I can't find any practical use for it on the street, but on the track it probably is different

 

Been using the car alot in the past few weeks, and loving it. The only thing I'd really like to work on is bringing the IAT's down during. I've got a vented hood which I am sure is helping, but there is definitely a sweet spot for the temps. The sensor is mounted in my plenum (post throttle body), on the front of the passenger side. When temps are over 120F, you feel the engine get lazier. Yesterday was insanely muggy and got up to the high 80's. At highway speeds, temp settle at like 115-120F depending on how much you're on the gas. But during lower speed cruising, traffic, etc where the throttle is barely cracked open, they get up to the 140's and 150's pretty easily. Obviously things are best when you can keep temps at ambient, so I'll have to give some thought as to what to try.

The new rear we did with the 4.3 final drive is fantastic - it suits the character of the engine perfectly, but still remains civil enough to use on the street. It was a long and expensive road to get it all together, but I am really glad I stayed with it.

 

Definitely put all the mileages you can on that rear end, get your money's worth.

As far as the intake temps, I've been working with my friend on his DSM trying to get the same thing taken care of. Basically you want a inlet and a outlet in your engine bay to move as much air as possible when the car is moving. Also do you have a open airfilter or do you have a heat shielded or enclosed unit?

We began our testing with a heat shielded element but no air inlet in the engine bay. Then we took one headlight off and the change was dramatic. The air temp and heat soak changed as much as 20 degrees.

So basically now we are doing a combination of ram-air through the headlight and a inlet scoop on the hood to try to move as much air through the box as possible.

 

currently it consists of

V2 duct
HKS 200mm filter
some metal heatshield thing I found on ebay for $20







the hood is vented in 2 spots



crappy pics, sorry

 

mmm nice

 

I would do 2 things. Get a fully enclosed element that is sealed with the hood. Then get the mines type bumper duct. Im sure you would have cosmetic reason not to go with it. but you would need a direct path for the air to enter and exist the enclosed element to make it work properly. Whether or not a different shield would help, you can test it by using the stock airbox and monitor the intake temp and heat soak during idle. Chances are it'd be 5-10 degrees cooler at 30mph than the open element.

 

Nice setup. I have the Nismo V2 bumper, so I will also be using that duct. I am likely going to install a Titek/Varis style duct as well.

 

How do you accurately tune this? Wouldn't the A/F run lean up top, at speed, since you can't simulate speed on a dyno?

 

you don't "tune" this is observed. The goal is to get as close to ambient temp as possible when cruising and eliminate too much heat soak when idling. You will need a tuning software to monitor this accurately however.

 

I'm not being clear.

The modifications to the intake that you suggest affect the IAT at idle, but most critically to the A/F and power, at speed w/ higher RPMs. When going 110mph (hypothetical speed at which negative pressure is created by the duct), the duct would elicit a ram air effect complimented by reduced IAT due to the sealed system taking in colder ambient air, creating a denser charge and forcing more air through the system while in motion.

My question is, how do you tune for that spike in intake charge at higher rpms/speed, due to the ram air and ambient air, when the car is sitting motionless on a dyno with fans?

I would think that a normal dyno tune would start to run slightly leaner because it is not accounting for the ram air/ambient temps. Additionally, there should be a few more hp to squeak out w a real time tune; it is base on observed conditions at high speed/WOT.

 

Tuning for additional power from the benefit of the air-box setup is perhaps secondary to actually having the set up and able to obtain relatively ambient air on a dd. However if you would like to tune for the newer setup...there is always road tune. And yes we did observe the air temp dropping as much as 5 degrees during wot pull but our primary goal was simply to get the proper ambient temp for IAT so the ecu boost level matches the actual on the dsmlink.

 

Here's what I did for mine (on my 330Ci)

My MAF is 3.5 inches. I got a 3.5 to 4 inch 90 degree elbow. Used a BLOX racing velocity stack and filter. Gutted out my stock airbox. Let's me keep the stock airbox for a little insulation, plus I get more filter area and a velocity stack. I'm considering doing something similar on my wife's Xterra.

I also have some tubing running down to my air duct, similar to the M3.

I'm going to dyno it soon to see how it does over just a better drop-in filter.

It's not a Z, but I'm trying to get my buddy to do something similar to his 350. I can't see why it's wouldn't be better.

 

problem with a stock airbox is I dont use the MAF anymore, I run MAP based now

and yeah, I'm not doing a bumper duct

we'll play around with some setups though...I think you're right that a fully sealed box with as big a filter as I can fit is step #1

 

Yeah I don't know if you have too many options as far as the ducting for the air inlet if it's not on the bumper it'd have to be on the hood if not either one then maybe a long tube and have it sit just behind the side vent on your bumper, if there is room.

 

Kwame and I were just talking, and he has his bumper here that has a duct in it already (Zerosun). Maybe one of these days, we'll do a quick swap, and see if temps change significantly; at least then we'll know if we're going in the right direction. I think the key to my old setup (Gruppe-M) working so nicely was that the filter was alot larger, and it was in a housing. Then again, that measured temps at the MAF, so they are bound to be less, and recover alot quicker too since it doesn't have to wait to go through the plenum like it does now

 

The way you have the sensor I was thinking could also be affected by the plenum's own temperature, since the TB has the coolant running through it and the plenum sit atop the motor. I feel as though the reading you have is overly high for the true incoming air temp but rather the air temp prior to combustion heated by all radiant sources. Just a thought I guess, ultimately you are measuring new setup vs old any improvement would be nice.

Also forgot to mention, the first setup we tested on the dsm was with the box only, which did minor improvements, it is only when the headlight was removed that helped the engine air escape and the intake was actually sucking in colder outside air.

 

Paul, he blocked that off when he went to the throttle cable setup.

 

Oh ok...I guess we'll have to see just how your bumper with the duct changes the temps. Although you guys will still need an enclosed airbox with the opening at the duct.