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Performance Intake Manifold

11K views 22 replies 12 participants last post by  twowheelin  
#1 ·
I was wondering if they make any performance intake manifolds. Do they have any made for our car that are bored out and polished, or do we have to do it all ourselves?
 
#2 ·
#3 ·
you can use this to polish your intake manifold http://www.autogeek.net/motplaspol.html

and maybe this to port/bore it http://www.sears.com/shc/s/p_10153_12605_0...20070921x00003a

:slap:[/b]
That might be one of the worst responses I've ever seen on these boards to a legitimate question.

Front1ine, an intake manifold from the 6s has been donated to a company (forgot which) by Sheldon of Mazmart here on the boards to get something going for you guys. It may take quite a while for this to happen though, so patience certainly is required.
 
#4 ·
you can use this to polish your intake manifold http://www.autogeek.net/motplaspol.html

and maybe this to port/bore it http://www.sears.com/shc/s/p_10153_12605_0...20070921x00003a

:slap:[/b]

Speaking of this, say someone has thrashed their plastic intake manifold from consistantly taking it off and puting it back on. How much would a new one cost? Is this a just ask Tiffany or Mazdamart question?

If I buy a new one, I am definitly going to sand out and polish the inside of my old one to try to ever so slightly increase the volume of air that it can hold. Then of course make some gaskets, look for CEL's, and dyno. It is amazing how this car reacts to small changes in Air/Fuel/Timing changes.
 
#5 ·
That might be one of the worst responses I've ever seen on these boards to a legitimate question.Front1ine, an intake manifold from the 6s has been donated to a company (forgot which) by Sheldon of Mazmart here on the boards to get something going for you guys. It may take quite a while for this to happen though, so patience certainly is required.[/b]
Sorry I have had enduser delight all day and needed a good laugh I wasted 20 min of my life on the phone with a lady who kept unplugging the pbx instead of my router so I have to keep calling her back and I keep asking her wtf is up with the phone
Speaking of this, say someone has thrashed their plastic intake manifold from consistantly taking it off and puting it back on. How much would a new one cost? Is this a just ask Tiffany or Mazdamart question? If I buy a new one, I am definitly going to sand out and polish the inside of my old one to try to ever so slightly increase the volume of air that it can hold. Then of course make some gaskets, look for CEL's, and dyno. It is amazing how this car reacts to small changes in Air/Fuel/Timing changes.[/b]
they are not cheep best look at a junk yard
 
#9 ·
Anywhere from $60 (Silvers Auto Parts USA-ME(Orono) 1-888-666-2124) to ~$100 in varying spots ( www.car-part.com is great)
 
#10 ·
I ordered my new one and I am going to start modding my old one. Carbconn.com helped me do some measuring and we marked the areas where we can remove some plastic to create more volume. What is also interesting is that the ends of each of the 6 inlets into the engine dont match up perfectly to the block. The ends on on the intake manifold are smaller in diameter than the blocks opening. I will take some pictures when I am done, and they are also going to make me some gaskets for it as well.

Should be interesting and fun.
 
#12 ·
How hard will it be to do this? Also, how long will it take you think?[/b]
Front 1ine, If your talking about the plastic one, its not hard but it may take a day. You will have to be very delicate if your using a dremel, you dont want to punch through. I will am going to take it easy with my old one on the porting.

The sexy metal version.... is going to take a while to have it made.


DJQuik1, 84FordMan, & MR Tea Just for clarification... What is the overall benefit to having a larger intake manifold on the V6? More power possible?

Thanks
Matt
 
#13 ·
DJQuick1, 84FordMan, & MR Tea Just for clarification... What is the overall benifit to having a larger intake manifold on the V6? More power possible?[/b]

This is where things get REALLY complicated.The intake manifold will actually change where the powerband comes into play.Usually longer runners means more torque.A couple of good examples come to my mind are the Corvette L-98 engines vs. the late model LT-1 engines

The big difference between the engines were cam profiles,intake design,and .5 difference in compression ratio.Yes they had different cooling systems to compensate for the LT1's higher compression,but here is a comparison.






Here is an example of how horsepower makes a major difference in how fast a car can accelerate, in spite of what torque on your backside tells you. A very good example would be to compare the current LT1 Corvette with the last of the L98 Vettes, built in 1991. Figures as follows:




EnginePeak HP @ RPM Peak Torque @ RPM
------ ------------- -----------------
L98 250 @ 4000 340 @ 3200

LT1 300 @ 5000 340 @ 3600


The cars are geared identically, and car weights are within a few pounds, so it's a good comparison.

First, each car will accelerate or push you back in the seat with the same force - at least at or near peak torque in each
gear. One will tend to feel about as fast as the other to the driver, but the LT1 will actually be significantly faster than the
L98, even though it won't pull any harder. If demonstrated with the formula, we can begin to discover exactly why the LT1
is faster.

Horsepower * 5252
Torque = -----------------
RPM


If we plug the numbers in, we can see that the L98 is making 328 foot pounds of torque at its power peak (250 hp @
4000), and we can infer that it cannot be making any more than 263 pound feet of torque at 5000 rpm, or it would be making
more than 250 hp at that engine speed. In actuality, the L98 is probably making no more than around 210 pound feet or so at 5000 rpm, and most drivers would shift it at around 46-4700 rpm, because more torque is available at the drive wheels in the next gear at that point. On the other hand, the LT1 is fairly happy making 315 pound feet at 5000 rpm, and is happy right up to its 5500 rpm redline.

So, in a drag race the cars would launch more or less together. The L98 might have a slight advantage due to its peak torque
occurring a little earlier in the rev range, but that is debatable, since the LT1 has a wider, flatter curve (again pretty much by
definition, looking at the figures). From somewhere in the mid range and up, however, the LT1 would begin to pull away.
Where the L98 has to shift to second (and throw away torque multiplication for speed), the LT1 still has around another 1000
rpm to go in first, and thus begins to widen its lead, more and more as the speeds climb. As long as the revs are high, the LT1,
by definition, has an advantage. It is better to make torque at high rpm than at low rpm, because you can take advantage of gearing


The L-98's intake had twice the runner length as the LT-1's.

So it will take someone with engineering skills and a good understanding of camshaft profiles to sit down and design a manifold that will be streetable and provide a better power range for current modifications.


Why do you think there is a enormous amount of small block chevy aftermarket intakes with certain advantages and disadvantages out there.


The intake will be the biggest headache out of all the mods for the car,but the VVT will be of some help with compensation of design differences if we can control it(HURRY UP SNIPER). :yesnod: :laugh:
 
#14 ·
Great Explanation D.


But i have a lil' question may be contridictive or stupid but. with porting......more rather port matching the Upper Intake manifold with the Lower and and actual head ports.........that doesnt increase actual runner length, correct? that icreases plenum volume, right?

if this is the case. the porting shouldnt change the Powerband, it should just in theory and hopes increase the power and torque availible in the same powerband, Correct?

Now, if we were to add a plenum spacer-

IE- the spacer used in the 350z's...........now that would create the effect of longer runners and incorporate the change in powerband you just explained, Correct?

so my general conclusion is that doing a simple Port match will only give more where we already have, not change where we have it?

am i correct in my thinking.........of course there is more to it than that, but simply in this, would i be correct in my thinking?

Plenum Volume and Plenum(runner) Length is different, correct?
 
#18 ·
QUOTE (The Great NY @ Apr 21 2008, 05:53 PM) index.php?act=findpost&pid=1329234
Great Explanation D.


But i have a lil' question may be contridictive or stupid but. with porting......more rather port matching the Upper Intake manifold with the Lower and and actual head ports.........that doesnt increase actual runner length, correct? that icreases plenum volume, right?

if this is the case. the porting shouldnt change the Powerband, it should just in theory and hopes increase the power and torque availible in the same powerband, Correct?

Now, if we were to add a plenum spacer-

IE- the spacer used in the 350z's...........now that would create the effect of longer runners and incorporate the change in powerband you just explained, Correct?

so my general conclusion is that doing a simple Port match will only give more where we already have, not change where we have it?

am i correct in my thinking.........of course there is more to it than that, but simply in this, would i be correct in my thinking?

Plenum Volume and Plenum(runner) Length is different, correct?[/b]

Theorethically port matching will reduce turbulance, which is always a good thing. I'd say less turbulance will tend to increase air speed, hence more torque. I port matched mine, and smoothed and tweaked it in several spots, 18 months ago. Bumping my tb out 5mm in combination with this mod and the EGR tube trim provided noticable gains.
 
#20 ·
Didn't notice it before, but how the hell can you trash the upper intake manifold from just removing and reinstalling it. Shit I believe I still hold the record for number of times I removed it and I never damaged it once in anyway.

Anyway as to designing intake manifolds and what the gains would be.. impossible to know. Intake manifold design is literally automotive black magic. There is no specific formula. There are mathmatical equations to help you get in the right ball park, but then add in real world factors and suddenly the theoretically perfect intake manifold is pure garbage.

Any company looking to design a respectable unit creates numerous one-offs and dynos them all to find out what works best. Edelbrock, Gale Banks Engineering, Bullydog are just a few that immediately come to mind in which I have seen their plastic test castings before making the real metal units.

The opening and closing of the intake valve creates a scavenging wave similar to that found in exhaust headers. This creates a suction like force in the intake manifold, drawing even more air and fuel into the combustion chambers. Then add into the fact that the 3.0L doesn't have just ONE set point in timing in which the intake valve opens and closes, thanks to variable valve timing, but two or more points. So keep this in mind when modifying the intake manifold, you may end up causing an irreversable flat spot in acceleration.
 
#21 ·
QUOTE (djquik1 @ Jun 13 2008, 04:01 PM) index.php?act=findpost&pid=1368962
Is anyone still interested in this still.I have another company that is interested at tackling this project in the next few weeks.[/b]
I am definately interested!

Can you give us some details?
 
#22 ·
Interested for sure, considering we're getting a quality product. But yes, more details would be great.
 
#23 ·
QUOTE
Plenum Volume and Plenum(runner) Length is different, correct?[/b]
Yes, they are different, but the longer the plenum length, the greater the volume. (if the tube size stays the same....) There is a huge amount of engineering that goes into the intake to get the most HP/TQ from the engine at a given fuel consumption. The actual cost of making the part is probably about $50. The cost of making the part wrong is $millions$ lost in the market because your engine is underpowered or gets crappy mileage. (or both :()