Does anyone have pics of the lower intake manifold? I am doing some port work on a throttle body and upper and lower intake manifold. Does anyone have pics of where it is, is it a pain to get too? I have a Hanes manual and will see if I can find it in there but was wanting members feedback.

 

It right below the upper portion of the intake manifold. It's 2 piece design...

 

I'm not sure why you would want to port the intake manifold anyway, unless your supercharged or turbocharged. If anything I'd say replace your throttle body with one from a pathfinder & open up the upper intake maniflod to accomidate for the larger thottle body diameter but thats it...

If your boosted then I would do the throttle body swap anyway & have my upper & lower intake manifold extrude honed to make it as wide & smooth as possible on the inside of the manifold...

 

I wouldn't port anything either. Years ago I remember seeing dynos for extrude hone work on the upper and lower intake manifolds. The lower manifold gained zilch, but the upper manifold gained about 4 peak hp, but about 8-10hp through the midrange and that's what counts.

You really need to know what you're doing when porting because it's very easy to FUBAR the flow characteristics. It's say extrube hone the upper manifold and call it a day.


Dave

 

The 2000 lower intake manifold is ported and polished about an 1/8 of a inch where it bolts to the heads

 

Most gains that come from any kind of porting need to be done to the cylinder heads anyway, so just leave the manifold be? Besides if you do want to port the heads your gonna need a bench flow to make sure that each cylinder is flowing within a certain % of each other. Keep in mind that most port matching alone doesn't make that big of a difference. What doe's increase power is reducing the amount of flow lost through the valves? And unless you are a pro at porting then you will not know if you need to make the air turn more sharply into the cylinder of if a more direct approch is the best way to go. Leave this kind of work up to people you do it on a daily basis. Here is something else to ponder? Some vehicles heads are already so well designed that porting them will actually take away performance then increase it...

 

This is more for fun than really looking to get big gains. Basically my design for the max is what Dinnan did to the M5 (S2- Ditched stock air boxes for CAI, ported throttle body, Shortened the intake runners and ran larger diameter velocity stacks (which I will not be going to quite that extreme - for everyday driving I preffer the low end grunt of longer runners), Suspension, Exhaust, ECU), keep the original characteristics but make minor changes to give an overall better ballance. I already have the suspension, minor visual enhancments (clear corners, larger lighter wheels that resemble stock SE, red/clears, chrome gauge rings) ECU, now I just want to work to improve the flow into and out of the engine, all while keeping it as cool as possible to keep my engine happy. The max is not going to be my modified car, only my daily driver.

I will definatly not be doing the port work myself, and as far as the upper, lower intake manifolds, throttle body and CAI those were about $100.00 shipped total. I am ceramic coating everything to keep intake temps down and increase flow, that is the main goal.

I figured that I would port the throttle body and the inlet of the intake manifold while it was out. I don't plan on porting the runners (as I have heard on some Sentra forums that too much porting can mess up your air fuel ratios's), only the throttle body and inlet to the manifold (I had thought with the surface area of the runners (the diameter of all the ports combined) compared to the surface area of the throttle body, that the throttle body is not adequate in size to feed those intake runners all that they could handle.) I don't expect to see significant gains, I just want to feed the engine a little more. I also for now have a Y-pipe which I figured would increase flow a tad more too, I plan on getting Cattman headers when the Y-pipe goes, and full exhaust to finish it off.

The reason I am not going for the pathfinder throttle body is for a couple of reasons. One it is way to expensive, if you can find a used 2001 pathfinder throttle body for around 200.00 you are doing very good, (I bought my OEM 96 throttle body used for 20.00 shipped here) My main cash flow is going towards the DSM. The second part of that reason is because there are issues with cruise control and the adapter plate. I am just finishing the max up as a daily driver the way I think Nissan should have built the max (web page up soon) I have a 91 DSM AWD that is the fast car, this is just for fun and to see if I could do it better than Nissan without loosing the original qualities of a maxima. Third, to port match the intake manifold to the 70mm throttle body I have heard is really stretching the manifold thin on the inlet, I think porting mine a few mm will give me the same gains NA, which I do not expect to be significant.

So what I am thinking I will do is port the throttle body, port match the inlet to the upper manifold then ceramic coat the CAI, throttle body, and upper and lower intake manifolds and call it a day (I want my Nissan breathing as much cool air as possible. I also wanted to clean all the gunk out of my manifolds that has collected for the past 90,000 miles, this is an easy way )

Let me know if you have any other thoughts. Regarding the port work that will be done by a proffesional, it is on the buddy deal so if you are comparing cost to gains don't worry about that. Just having cleaned ceramic coated manifolds will be like it was just ported with all the crap that has collected in my old ones. If you think that the throttle body is large enough to feed the intake manifold all it can handle let me know.

 

Good, I wouldn't do much more then that. A good tool to use for the porting would be a brake or cylinder hone. You have probably seen them before they have 3 grinding stones & you can hook it to a cordless drill or air powered prefered. It will work good because it will keep the round shape on the inside of the throttle body perfect & it will also make sure that the throttle body & the intake are exactly the same diameter. Also good idea on coating the part's it should help keep the intake tempatures down quite a bit. Good luck!!!

 

Are you talking about ceramic coating the internal of the manifold or externals? I wouldn't put anything on the inside of the manifolds because that stuff isn't very reliable in terms of sticking and it chips off easily. Personally, I wouldn't even bother ceramic coating the manifold because the whole point of ceramic coating is to keep heat IN and not to stop heat soak. Headers are ceramic coated to keep the exhaust gases hot in an effort to increase exhaust velocity. The coating also does a decent job at keeping the external areas of the pipe slightly cooler. An intake manifold is bolted straight to the scalding hot engine block. Once the block heat soaks, the manifold will heat soak regardless of the coating or even ice put on it. With the coating on the intake manifolds, it means the manifolds will hold the heat in longer and not dissipate as quick as OEM. Honestly, I don't ever remember reading about anyone ceramic coating an intake manifold.

If it was my car, I would extrude hone the upper manifold, hand polish the TB and lower manifold, and sinter the throttle blade bar. Ceramic coating the CAI isn't a bad idea, but I can tell you that even on 75+ degree days, that CAI pipe stays nice and cool to the touch. A 4th gen with an extrude hone upper manifold, JWT ECU, CAI, y-pipe, B-pipe, along with some nice lightweight 16s would be a killer street sedan. It's 0-70mph would be amazing for NA. With that setup and a good track you would be looking at lower 14s at 96+mph or basically BMW 540 performance. Who can argue with that?



Dave

 

I thought ceramic coating the outside of the intake manifold was common?

I'll look into extrude honed but I bet it is going to cost me. The person that did the extrude honed intake manifold, did they have any throttle body modifications, did you hear of any difficulties as far as air/fuel, did they have to use a SAFC?

 

Coating the inside of the manifold is possible & will help smooth out the inside because it will fill up the porus area's & help to level thing's out inside. We were disscussing the option off extrude hone or not. Extrude hone is the way I would go, but you can coat the inside of the manifold & not have to worry about it flaking off & getting into the engine. If I could ever figure out how to put pictures from my hard drive on here I would show you some pictures of coated manifolds. Maybe you can give me some advise on how to do that..... Remember from my hard drive not from a website...