Zer0 Cylinder

there's some type of valve inside of the vdi isnt there? whats it do during all of this?

Icemark

I have a bunch of pictures of it all torn apart, but I'll take some pictures in the next day or so of it all together.

Icemark

Yes, there is a rotary valve inside the middle intake system that is the main part of the VDI.

Zer0 Cylinder

does the valve have to be taken out or what? and ill take any pics you'll give me, zerocylinder@aol.com

88IntegraLS

That sucks! If I had heard about it I would probably have signed up.

Preventing IM heat soaking is one of the least recognized power adders. Engineers know about it, which is why modern car co's are starting to use fiber reinforced nylon IM castings, and competition design teams use carbon fiber. I wish I had a pic of my school's formula SAE car's CF mani. It is beautiful. Imagine the dark weave seen on high dollar CF body panels . . on an intake manifold. It's not there for looks; Carbon fiber is a horrible conductor of heat, like fiber reinforced nylon.

Zer0 Cylinder

88integra, what have you done to yours to prevent the heat seaking?

Zer0 Cylinder

WTF IS UP WITH THIS SITE????

but anyway, 88integrals, what have you done about heat soaking on your rx7?

RETed

Actually, it's not as bad as you think.
Maybe the CF/epoxy matrix might be a bad conductor, but base carbon actually conducts electricity pretty well.
Don't believe it?  Take a a mechanical pencil lead and read resistance - it's not that bad.  Graphite is another form of carbon.



-Ted

88IntegraLS

Ha, not much. The car's sweet spot for power is right after it reaches 160*, basically when it reaches operating temp for the first time. The fuel mixture is right on, the exhaust manifold has not been radiating heat upwards onto the intake manifold for very long, etc. and the engine is a beast. Then, after about 20 min, it feels a little neutered. It doesn't feel like it pulls nearly as hard. I have verified this on my Gtech, to the order of about .1 G in first gear (.65g before heatsoak vs. .55g after)

Recently, I plumbed a duct from the passenger side bumper inlet and routed it to blow cold air at the lower intake manifold. So when I am driving at speed, air comes through the tube and cools off the intake manifold somewhat. I have verified this by putting my hand on the manifold before the mod, and of course it burned. After the hose job, the area of the manifold that was in direct flow of the hose was mildly warm to the touch. The areas around that spot were warmer, but not burning hot like before. The car also doesn't feel as neutered after driving at speed for a while vs. messing around in traffic.

I'm sure that part of the reason it feels so slow when it has been warm for a while is because I get numb to the power and handling, like a coke addict developing a tolerance for the drug.

Icemark

You might try a 4.5K resistor inline on the Grn/Orange at the AFM. That drops the air temp that the ECU thinks it is "seeing" down about 50F.

Often when the engine heats up the stock ECU backs down timing because of the heat soak to the AFM, rather than the actual air temp or manifold change. To top that off Mazda built in about a 2K tolerance to the actual temp reading.

Zer0 Cylinder

88integra......post some pics of your setup if you can...

Icemark

Pictures of the engine finished for those that want to see:

andrew lohaus

very nice!!! but why did you keep (and even reroute) the accelerated warm up bypass hose? i asume you kept all the emisions and TB stuff because you are in cali, or was that just a personal choice?

Icemark

If you note, in this pic:

actually the AWS valve is not even electrically plugged in.

Yeah, its just a CA emissions thing. They look at the sticker on the hood, and all the vac routing on it must be there. I am sure I could probably remove it, but it doesn't make any real difference when its not even hooked up.

The BAC is still there though. Funny it also has a bit of AWS operation when starting as well.

The 1st set of throttle plates are gone from the ported TB as well, just the end of the rod there filling the hole, but no check valve or throttle plate controller.

and the Yellow soleniod valve instead of being for the EGR is now for the VDI.

so its pretty minimized for a CA car.

RXONMYMIND

Damn, & I was just impressed he new where to find the weatherstrip for the vert...Now there's this car wax will give you 25hp gains.....

projekt

how is the VDI operating exactly?

why do you still have the air snorkel if the box isn't sealed?

Zer0 Cylinder

looks nice.

Icemark

air snorkle is just for air flow from in front of the rad. I figure it doesn't hurt air flow and might help a little at higher speeds. Of course the hole that the FMIC tube used to go through (when I had the 13BT and FMIC in the car) is also right in front of the air filter as well.

I wired a RPM switch (yep I am working on one of those, for sale on my website soon as well), anyway I wired a RPM switch at the ECU in the pass floor panel. I actually cut the EGR lead off of the ECU harness and hooked that up to the RPM switch.

So at 5200 (+/- 50) it sends the electrical signal to the EGR solenoid. However the EGR soleniod is now getting input air from the air pump, and the output feeds to the VDI actuator. Note how a couple people who have done the S5 intake on the S4 motor, have wired the VDI to open at 5800, but according to my testing (and the factory shop manual) that is way too late. I also played with 4800 and 5000 and found those too early.

The nice thing about that set up, is the minimal underhood re-wiring. Since I did not have the S5 hard lines, I simply routed a feed line from the ACV over to the driver's side (runs right behind the alt) and to the former EGR solenoid.

Again, this makes it harder for a non FC specialist to tell that the smog systems have been modified.

88IntegraLS

I'm not sure if this is directly relevent to this discussion or not, but I support your decision to go ported N/T instead of turbo. Someone let me drive a TII this weekend (my first experience with one), and while it was adequately fast when it was in boost, it lacked the snappiness and predictability of my current FC. It still handled well and was fun to drive, but in a different way than my 2400 lb street ported NA. The TII felt more like a GT cruiser, while my current NA feels a little more like an actual race car (louder, harsher, quicker to react, predictable power band).

Icemark

That is exactly why I went back to non-turbo!

I am glad someone else understands how the two motors feel and influence the balance of the car.

projekt

my car is just slow and heavy

wozzoom

*Ahem* Whose finger is that? I belive that finger belongs to me.

It's amazing...I shut down my old website almost 4 years ago but all the content and pictures are still out there!

wozzoom

If you can put up with the annoying pop-ups from tripod, I have a pretty detailed write up on this modification with pics:

http://wozzoo.tripod.com/Info/89Intake.htm

Originally I didn't have the S5 hard lines, so I modified the S4 lines to fit with the VDI intake. It's not as hard as you think.

Second time around I had the S5 hardlines and the job was way easier. I'd strongly recommend using the S5 vac spider.

Icemark

Hmmm I most have posted the wrong picture....

I could have swore that is my finger, and my paper towel, and my funky orient style carpet that use to be on my garage floor.

I'll have to look through my Harddrive, I know I took a picture just like that.

wozzoom

Nope. That's my freaky deformed index finger. (I chopped the tip off with an axe when I was 12 years old) 17 stiches.

I'm just having fun! I think it's kind of cool that people actually read and saved pics from my old website.