Wow. Nice work! I'm really curious what the outcome is.

Are you going to custom fab some form of a plenum to join the elbow to the runners?

 

Yep, the stock plenum would no longer fit because of the modifications over the leftmost runners so they are not sitting in tight corners. Should be starting the plenum building in earnest tomorrow if everything goes as planned. It will be mated to the TB with 3.5" aluminum pipe that is identical in ID to my 3.5" intake and LR MAF.

I am still not sure what the final plenum volume will be, but I roughly estimate around 50% more than stock.


On another note, I just finished polishing the runners with some MSC industrial supply bore polishers and cross buffs (with 8" shank extension). I do not consider myself skilled enough yet with porting to guarantee that I can evenly port and taper each runner, so I am just polishing to avoid ruining what could be a great manifold. In order to limit myself from porting the runners by accident, I did not remove 100% of the casting marks, but instead made it smooth and even across each runner.

 

oh ok i see what ur talkin bout now.......sillly me.......im thinkin of spliting the elbow in half gut it out then re weld it together......do u think that it will work......and the same thing with the plenum except just gut it out and re weld it on

 

Look at the outside of the elbow, then visualize it in your head a little bit. You won't get a round single-flow elbow.

 

yeah i see......where did u get ur 3.5 tubing from.....i might go that route also is there a way to bypass the coolant lines that go into the plenum and the elbow??

 

I got a 180 degree bend of 3.5" aluminum pipe for ~40 bucks on amazon. Should be enough to make both my elbow and intake piping.

The PCV system can be fully vented to atmosphere and the coolant lines can be barb connected together (coolant bypass comes with NWP spacers). You also need to retain vacuum lines for evap and brake booster afaik. I know brake booster is required, but I haven't considered disconnecting evap.

 

whats the thickness of the tubing that you got.....

 

3mm, or about 1/8th of an inch.

 

well so far this is a sweet design........i just got some new tools today to start working on my spare intake manifold..........ima going to cut the top of so i can get easier access to the runners and the ledge thing to make it a ssim then im going to re weld it tight and weld up the coolant lines.......then im goin to steal your idea except im going to use 3 inch tubing, cause i found some laying around in my garage....but yeah im going to start work on it 2moro......cant wait to see your final product

 

Good luck. Make sure you are able to tig weld if you'll be welding cast aluminum.

 

Today I did some final touching up on the runners, built the plenum out of poster board, then used that as patterns to cut it out of aluminum plate. Also made a venturi to transition the elbow into the plenum. I will be pulling my stock IM off the car tomorrow to mock this new IM up as we weld it together and make sure everything fits precisely without wasting any space. I calculated the total volume to be between 240 and 280 cubic inches, which means it should be roughly 110-130% of the engine volume (3.5L or 213CI).

 

yeah i got access to a tig......we got one at school.......shouldnt be to big of a pain......but yeah yours is looking real nice......cant wait to see the out come

 

i thought sparks was a red head???... anyways im all in... im loving this... coupled with a working 3" MAF and cams i dont see why it shouldnt make peak power in the 7K's

 

I am a red head, the guy with the broken leg is my welder friend.

The MAF and intake will be 3.5", around 82-83MM ID. We'll see how it works. I'd like to see peak power around 6500-6800 then a nice, flat curve out to 7500-7800ish.

 

Well my plenum design came out perfect, pretty much as big as possible with the size constraints. There is about 1/4" of space over the rear coil packs, 1/2" between the elbow and firewall (NWP torque link and ES mounts keep engine still enough for no worries here), and around 3/4" between the plenum and the hood.

Still making vacuum fitting bungs (the holes in the back are for brake booster and evap) and the TB flange. Then a ton of cleanup and finishing touches on the outside.

 

good work man!!!

 

damn that looks awesome, ima start on mine soon, thanks to the lovely weather i wasnt able to start on it

 

I hope it's good enough, this was a TON of hours and still isn't done yet.

 

Looks great. I have a question though, would there be any gains to rounding the front edge of the plenum? I'm just curious about the capacity vs flow turbulence.

 

stupid question but is the engine cover gonna fit?? also i think u should mass produce this thing if u get some good gains with it

 

Ha! You do notice that I cut off all the engine cover mounting bolts? I haven't had an engine cover on my car in a long while. Don't plan on ever putting it back on. You'd even need a custom strut bar or none at all with this sucker on.

Mass production implies volume, and we'll be able to reproduce this much faster and cleaner than the prototype, but would still be tons of hours. If there are gains, I may gauge interest, but the amount of hours would require a pretty hefty price tag. We are considering, however, doing "high end" SSIMs by cutting the plenum in half, doing a perfect grinding and polishing job on the shelf and polishing the runners (not possible without plenum cut off) then welding it back together. Just more than you can accomplish without cutting off the plenum.

Possibly. I doubt much. Many of the aftermarket or custom plenums like this have the front edge squared. For example, the SFR manifold for our cars.

 

yeah i saw that, just felt like asking a stupid question.......but yeah that thing is pretty tall

 

Nice work sparks, that looks as good as the SFR one, minus the chrome.

 

I honestly didnt think you would get this far this fast. Not because I doubted you or the welder's skill, but because most projects end up unfinished or take years to complete on the org. So thats just what I naturally expect now. I hope this shows gains the way I'm thinking it will.

 

The SFR one is just polished aluminum. I will be spending some time cutting down the extra metal and making it look nice (as possible) on the outside, but won't be polishing it as it will be coated with thermal dispersant (which happens to be black) and it won't matter. The volume is probably 50-60% more than the SFR one!

Thanks... yeah when I set myself on a project and have the funds to complete it, it goes obsessively fast. I've been losing sleep to keep up with class work and put 10-12 hour days into this the past week.

Currently we are waiting on some small stuff to come in the mail and giving him some time to work on a major art project for some hospital in the mean time. Should be completely finished next week or so depending on arrival time of the finishing touches.

I am tempted to just go test it out with stock cams at the local 1/8th mile vs the vias delete to get some initial results before the dyno after cams and supporting mods more towards april, but not sure on that yet.

 

please do that

 

I'm inclined to think it may not gain much with only a 7100-7200ish rev limit and stock cams. However, others have shown great gains with a SSIM after full boltons... so I guess it's worth checking out. The SG intake did see large gains on a totally stock car, after all.

 

Just ordered the stock gaskets for the UIM and TB from courtesy... Will use those in order to make fast manifold swaps at the track/dyno for testing.

 

hey anyways i was wondering what cams would you suggest for the street, im looking at finishing up my lil ssim project the new headers, and a tune......maybe some juice, idk right now though......

 

Any of the 260ish duration mid 10 lift cams would be fine for a daily driver street car. I was trying to hold out for some BC3s or JWT C8, but found a set of BC2s for extremely cheap and had to jump on it.

 

damn, i cant believe how fast you are moving on this. Nice work!

 

thanks, any idea on where i can get some

 

I don't think you'll see anything impressive with a stock cams either actually below 55k it will most likely be worst. Between the runner diameter and lenght then plenum volume it does not seem the best for your current setup but I still would like to see how it does 65k + and if your mph goes up at the track.

I think this will really shine when you start to turn the motor at 8k

 

For used, my350z forums engine classifieds. I watched almost daily for a few months before my cams showed up. I paid for them around 30 mins after the thread was started and there were 5-6 other posts within a few hours wanting to buy them... gotta be quick.

Otherwise, just search around online. The brian crower S2s can be had around 910+shipping new now, then you have tomei and JWT that are also well respected. Tomei makes some 264s, JWT S1/C2 are good choices. Just do your research and take your time. Look at the my350z NA build section.

Yeah thankfully I stay above 5500 when i'm at the track (even launch at 6k) so it's very possible i'll see some nice gains. Since I already ordered the gaskets and the local 1/8th mile does TNT every sunday + is only 20 mins away... I'll be sure to try it out and see what happens.

 

thanks again

 

Got the vacuum fittings finished today. Will be finishing up the elbow and TB flange on Wednesday or Friday of next week, then possibly testing it that Sunday if I find time to get tuned on it ahead of time and the gaskets come from courtesy nissan in time.

 

This will be the "super short" 3.5" intake that will be tested against a length-tuned one. Notice I trimmed the MAF so that the couplers can cover most of the surface. The engine side has a 3.5">3" reducer.

 

sparks this is some good ish man... i wish i could experiment like that... i dont mind the ride having down time for something like that

 

I've had almost 0 downtime. So far, just 8 hours one day when I took off the vias deleted stock IM in order to test fit the "custom" one while building the plenum.

The hardest part about it is either having the tools, ability, and design or knowing someone with them. Luckily, I have some of the ability and tools, most of the design and my friend has the rest.

For the next project, I'm probably going to make aluminum underbody trays for the engine bay and rear bumper area (like krazy6 did with tape) also. If the prototypes look good enough, may actually see if the community wants to buy them. If they work well, would be looking at gas mileage and trap speed increases

Or, if the intake manifold doesn't work out... I have other ideas to make one that will work out already cooking in my head.

 

if u see gains i'd be willing to buy this.... also the same with the underbody tray... as long as its removeable.... gotta make it fit with AE lip Stillen lip and stock bumper gluck with that