Bought a lower plenum on eBay *Pics added* *Dyno added*

[Sentientbydesign]

Here are some more work in progress pictures.

These aren't done, but they're getting there. I need to go look for tools. Hand sanding is a PITA.



I plan on taking more material off of the top of the front intake runner. I will also be smoothing out the lip on all 3 and polishing everywhere else (except between the right and left runners).

Here are some shots of the untouched side



And an overhead comparison

[toddnos]

nice work,,i may do the same...i wonder what can be done to the piece between lower plenum and heads???

[Sentientbydesign]

Not sure. I've only seen pictures of it so far, haven't actually removed a lower plenum to see the other part in person.

I would assume it could also be polished out. It would probably be much easier since that part is straight versus curved like the runners.

[Sentientbydesign]

Update:

I went to Harbor Freight, Sears, and Lowe's trying to find some sort of flexible sanding device to get into the intake runner because doing it by hand both a pain and also beginning to be hazardous to my health (more about that in a little bit).

When I got to Lowe's (Last place I checked), I just decided to walk in with the lower plenum for sizing. My initial thoughts were to rig up a drill with a flexible shaft and some sort of fabric sanding disc or (my father mentioned) steel wool.

Lowe's didn't have any flexible shafts. Actually, only Sears did and it was about 9" long with a quick connect at the end (I variable sized collect/chuck to place a mandrel in).

So I spent some time in Lowe's and finally settled on the flexible shaft dremel attachment. I initially saw this at Sears and didn't think it would work because the handle at the end of the shaft is rigid and I needed something that would be flexible to get through the plenum bends. I figured out, based on crude measurements, that the rigid handle was small enough to fit into the runner.

So I bought it, a flap wheel sander (120 grit), and some of those barrel shaped sanding things (also 120 grit, should have gotten 60 though).

-The good and the bad-

The Good:

>Most of the runner sanding is done!!! I've got one runner that I left untouched for my own comparison and there were a couple of places that I missed yesterday.

>Flap wheel worked well- I wish it was a little more flexible, but it still did the job. I found out that moving it around slowly with minimal pressure produced the best results.

>>>Ice Cream truck passed by while I was working- Most of you probably can't relate to this, but Mexicans have their own style of popsicles. They're called paletas. They come in just about every flavor imaginable in both milk and water varieties (think cream vs juice). I've been trying to get a rice one for the past month or so and the only place I can get the good ones is from ice cream trucks or from the "Paletero man".

http://farm1.static.flickr.com...7.jpg

This guy is actually selling Helados which are basically ice cream, not paletas.

Anyways, the rice popsicles are sweet and milky (not quite creamy) with a bunch of cooked rice, and in this case, raisins in it. I was soooo happy that I bought 3 of them (just barely had enough cash lol).

On to the BAD:

>>>Sanding the plenum by hand was horrible. I confirmed last night, that even light sanding would kick up the aluminum particles and dry out my throat within a few minutes. I actually got a couple of migraines last week and I attribute them to the dry air and the aluminum dust.

>With any rotating tool, you get wander and kick. The kick portion wasn't so bad because it's just a light sanding. The wander was a different situation.

The seem line was the hardest to sand down because of it's thickness. While trying to do so, I found that I was taking A LOT of the adjacent wall material of while trying to sand the seem down. Pressure needed to be applied both down on the seem and a counter-force was needed to make up for the flap wheel's tendency to roll in the direction of the rotation.

I figured this out kind of late and I think I may have modified the plenum a little more than intended. I don't see it significantly affecting performance.

>Another issues was getting the right texture. Quick sweeps with the flap wheel made a coarse texture. Slow light movements made a much better texture.

>>The 120 grit wasn't coarse enough to take off the textured portion on top of the runners. I think I went through 3 of the sanding bands (barrel shaped thing) and only barely touched half of the top of the runner. The 60 grit did a much better job at this.

Plans:

>I need to finish off the tops of the left side.

>I also need to think of how I plan on smoothing out the inside of the runners once they are all rough sanded. I'm not sure if there is a higher grit flap wheel or not. A polishing cloth and some polishing compound might do

>And I need to figure out if I want to do any actual porting at the openings. I'm leaning towards not doing it, but we'll see.

More pictures will probably be up tonight or tomorrow.

Stay tuned!!!

[BrandAidDesignG35]

Looks awesome! I think you're doing a great job man! Super duper write-up!!!

The paletas sound amazing... like frozen rice pudding or something ...

I know you should be wearing a mask to avoid those migranes Did someone forget about safety? KEEP US POSTED DUDE!!!! You da man!

[Sentientbydesign]

I wore safety glasses after hearing about Noah's last incident, but I kind of skimped on the mask because I didn't think the aluminum would go airborne.

Surprisingly, I didn't have any problems while using the dremel, only while hand sanding.

Thanks for the support!!!

Think of a thinned out, frozen, rice pudding!

[BrandAidDesignG35]

Sounds sex You have my VOTE!!!!

[eZg001]

Maybe all that particlized aluminium will add to the conductivity of the

BLUE WIRE GROUNDING KITS

you are supossed to be working on

j/k

[Sentientbydesign]

Maybe all that particlized aluminium will add to the conductivity of the

BLUE WIRE GROUNDING KITS

you are supossed to be working on

j/k

Wire won't be in until today at earliest (this was mentioned in one of my numerous emails lol). UPS estimated delivery is actually tomorrow.

I spent most of last night finishing an FX35 AWD kit, so .

[eZg001]

I guess I got confused on whose delivery was coming tomorrow

I was surprised, and am still being surprised, that the Computer in my G35 is STILL getting used to the intake's new MREV2 and 5/16 spacer that I put on this past Saturday.

I wonder if you will have to 'Reboot' (reset...refresh...whatever the correct term) your car inbetween dyno tests when you put on your individually ported and polished lower collector?

[Sentientbydesign]

I wonder if you will have to 'Reboot' (reset...refresh...whatever the correct term) your car inbetween dyno tests when you put on your individually ported and polished lower collector?

I'm glad you mentioned that. I'm going to call the shop doing the dyno and see if they have anywhere I can open it up. Why? You ask? I'm going to do an ECU reset, then open it up, then dyno.

Swap out plenums and repeat.

The theory here (and maybe someone can correct me) is that reseting the ECU puts everything back to the factory default. Doing a couple of WOT runs should tell the ECU what I'm looking for---Max performance.

I just have to be careful about reproducing the same procedures for both runs.

[Sentientbydesign]

More Pictures from Sunday:

Here's the Upper Texture. Still contemplating how smooth I want this:



Collector is pretty smooth. I'll probably leave it this way. I don't see it benefiting flow to polish it out to a shine.



Here's the inside of one of the runners. You can see along the right side where the flap wheel made it's own slight indention. I will be going over this again to smooth out the sand marks.



Here's a comparison from the bottom side. The sanded runners still need a little work, but they are significantly smoother (to the touch) than the one on the bottom of the picture.



This shot shows the finish of the output side pretty well. I'm still going to do a light manual sanding on it.

[Tampa G35 Sedan 6MT]

SBD... your work is getting better and better! DJ

[zozoka1212]

Wow nice. So have many hours of labor? I would of give up for sure if I had to do it by hand. for you .

zozo

[Sentientbydesign]

I think I spent almost as much time looking for tools as I did working on the thing

I think about 2-3 hours went into sanding out the insides and part of the top. Different accesorries would have sped up the process, but I was using my father-in-law's dremel (which I bought him lol). I have a whole set of attachments in storage

For somebody else (after I do the write-up), you could probably do the whole thing in 4-5 hours.

Additional tools could cut that down a little too. I'm taking small layers of material off of the front runners versus using an angle grinder and taking it all down in a few minutes.

[Jacko3]

For some reason, the ECU of the G-35 takes longer to adjust with intake modifications than it does with exhaust modifications. I don't know why. For intake modifications, it might take as long as a month or more for the ECU to reset itself. For exhaust modifications, it might take as little as 2 weeks for the ECU to adjust.

[Jacko3]

Nate:

Good idea! However, once you open up and/or reset the ECU, you will need to give the ECU time--a few days or even weeks, to fully adjust. The same applies when you do the swap. results won't be accurate if you dyno as soon as you reset the ECU.

[Sentientbydesign]

Nate:

Good idea! However, once you open up and/or reset the ECU, you will need to give the ECU time--a few days or even weeks, to fully adjust. The same applies when you do the swap. results won't be accurate if you dyno as soon as you reset the ECU.

Unfortunately, the alternatives are:

A) Don't reset the ECU. I think this provides an unfair bias because the ECU will have adjusted for the stock plenum.

B) Just reset the ECU before each dyno run. While this may provide "equal" parameters for each plenum for comparison purposes, I think it limits a realistic dyno comparison. That's why I want to reset the ECU, then give it some basis to start adjusting parameters (a couple of WOT runs around the parking lot).

If you have a better suggestion, I'm all ears.

[G_whizz]

Geez Nate...you have the patience of a Saint!!

[Jacko3]

Nate:

I would go with option two----no other way around it once the ECU is reset---it may provide a better set of results so long as you go WOT enough times in a few days with the new plenum.

[eZg001]

so.........did you make it to the dyno yesterday?

[Sentientbydesign]

so.........did you make it to the dyno yesterday?

Barely, I spent all of Friday night finishing the plenum. Still wasn't completely done, but all of it was improved over it's original self.

When I woke up, I remembered that I needed to change my oil. Just finished break-in and I was at the recommended oil change interval. So I headed over to Walmart for some M1 and a filter.

Got back...blah...blah...blah and I had 1.5 hr to get there. Google maps said 1hr 21 mins in perfect traffic (up to 3:10 for traffic). I ran into SOOO many traffic "blocks" it wasn't funny. I was swerving through traffic the whole time trying to maintain 75-80.

Got there at 12:38 for a 12:40 dyno. Luckily they stopped for lunch. I let her cool down a little and they did the baseline. 279 peak hp for the first run, then they sprayed down my plenum because I was getting knock. 283 peak for the second pull. Tq peaked at 250, but the curve looked horrible (interesting compared to the dyno dynamics which gave me a fairly even curve).

I ended up having to make and install an FX35 grounding kit right after my first run and had just shy of 2 hours to swap plenums. In the process, I bent my fuel line (metal on). Lost a plenum bolt. Lost a little flesh. and realized that WE ALL need to invest in an oil catch can. Damn was that messy!

The results for the second dyno are hard to understand. Peak HP went up after a couple of runs. The graph showed me loosing some hp in the mid range, but also picking up huge tq where I had deep valleys from the first run.

I think the lower plenum needs more work (got some advice from another guy there), plus I need to go with a smaller spacer. The blox is hurting more than it's helping I BELIEVE.

I didn't have the money, but I'm thinking about getting the Uprev Osiris. It's like the Cobb, but allows for custom maps NOW (not when cobb feels like it). And it stores the maps in the ECU, not on a piggy back system.

Normal price $650 with tunes. Yesterday's price $500 with tunes

I'm asking for it for Xmax. lol

I'll scan and and post up the dyno sheets later. Got to get to breakfast.

[toddnos]

plus I need to go with a smaller spacer. The blox is hurting more than it's helping I BELIEVE.

nice numbers on that lower plenum!!im gonnalook for one myself to grind on.

i was told that by a friend not to buy the 5/8 spacer, because it hurt power..i did not listen...like i said i believe the kenetix upper to be superior to that spacer.my friend always recomends the motordyne spacer kit.

[BrandAidDesignG35]

Awsome, I think with a little work you should have that beast fine tuned to perform

What are your thoughts on the blox now? Do you believe it is creating a loss in air pressure, neccessary to push the air into the lower plenum? In theory, it would make sense, perhaps you need a CAI to get more air into the manifold quicker...

What are your thoughts on adding a dual intake to your car? Thinking something like this to add to my fujita tube, my filter needs to be cleaned/replaced anyway, thinking about adding something like this below.

[Sentientbydesign]

Awsome, I think with a little work you should have that beast fine tuned to perform

What are your thoughts on the blox now? Do you believe it is creating a loss in air pressure, neccessary to push the air into the lower plenum? In theory, it would make sense, perhaps you need a CAI to get more air into the manifold quicker...

Data is inconclusive. Part of that is my fault because I didn't have the time to do the ECU, Throttle, and Volume learning before each of the runs. I finally did it after the 2nd dyno on my way home and the car seems more responsive, but that's a poor indicator of true performance. I'm tempted to go back and do a 3rd run with the ECU adjusted to the new specs, but I'm not sure if I'll have that opportunity.

Quote »What are your thoughts on adding a dual intake to your car? Thinking something like this to add to my fujita tube, my filter needs to be cleaned/replaced anyway, thinking about adding something like this below.

[/quote]Hmmm. That's a hard one. Completely dual intakes like the HR motor would definitely help, but I'm not sure that having dual cones at the end of your fujita is going to make any gains.

There would have to be some sort of evidence that the filter was impeding flow enough to warrant adding a second filter.

As this point, some sort of EM will probably be my next mod. We can bolt on all we want, but realistically, without data, it's all "Butt-dyno" lol.

Dyno Sheets will be up shortly.

[Sentientbydesign]

Here's the comparison dyno:



I did some photoshopping to it for ease of understanding and to clarify a couple of errors.

Here are a fewthings to consider when looking at this data:

1) I was NOT able to reset the ECU and Volume learn before each run. Timing and some unforeseen circumstances negated that option.

As such, the mod was not able to show it's true potential.

2) The front runners were only taken down slightly (less than 1/8"). This was due to time constraints and improper equipment.

I will probably be grinding those down soon and retesting

3) In order to have "equal" comparisons of the two plenums, I got the plenum very hot on the second run. They cooled it down slightly with water (on both the baseline and plenum mod runs).

4) The original plenum was VERY oily from the PCV system. I did some light cleaning before running the modded plenum.

5) Most of the vehicles dynoing had knock issues and the ECUs were retarding timing. I believe this is what caused some of the uneveness on the TQ curve.

6) The Blox spacer likely is not helping me much due to it's excessive size.

[BrandAidDesignG35]

Nice work, it seems interesting to look at the chart, you lost nearly 10 whp with the plenum... yet gained 8lb/ft tourque... hmm...

Also notice the dips in the baseline were so oposite on the plenum mod run? Where the baseline goes down, the modded plenum run yeilds good improvements, so essentially, you've smoothed out the power curve.

That said, it is unfair to compare this test as being fully true, as you mentioned without the throttle position sensor relearn, ECU reset, etc, etc, the test will never be completely accurate.

Keep us posted on your work, Nate

[BrandAidDesignG35]

So, OK, I just looked at your charts again, and I want to point out 1 more thing to you.

I'm not sure, but I bet you'd see higher numbers in the upper 5-6K rpm range with a CIA... Maybe your polishing has changed the air intake pressure to each cylinder or something If you had a new intake, you may find you'll be able to get more air into each port of the manifold.

[BrandAidDesignG35]

One final SBD, do you know why golf balls have those dimples in them?

Maybe this can be true for manifolds as well? Perhaps that bumpy texture you've worked so hard to smooth out has actually played a negative role in your plenum tune?!?

My Speculation Backed by intuition, not fact or knowledge.

[toddnos]

One final SBD, do you know why golf balls have those dimples in them?

Maybe this can be true for manifolds as well? Perhaps that bumpy texture you've worked so hard to smooth out has actually played a negative role in your plenum tune?!?

My Speculation Backed by intuition, not fact or knowledge.

yep, a lot head porters will create that dimple effect on the roof of the port. think air ballbearings moving the other air along faster...its a proven technique.also thats why certain portions of the plenum are rough and some areas smooth. i dont believe just polishing to do anything but disturb the intake air...porting and dimpling would be what i would try and achieve.