aftermarket intake manifolds?

[P8ntBalla]

does anyone make intake manifolds for 2gs?

 

[SOURCE1064]

Venom, I am getting an Extrude Honed one from www.roadraceengineering.com. The intake flows very well on the 2G and it will be much better if you get it Extrude Honed. pluse it cost less than a new intake manifold such as the venom one.

 

[L2RTSiAWD]

Magnus makes one. Polk Performance makes one. Venom Makes one. Or like Source said you can get your stock one extrude honed.

Later,

 

[IPT]

I just say a polk one last weekend. All I have to say is the insides look PERFECT. His blends from the plenum to the runner are Amazing!! I am really impressed by it. The only thing I had to complain about is that it only had 4" long runners. It is kind of on the short side for the street, but it will make power up top.

Also when talking about the runner length the problem with the 2G's is that the fire wall is closer to the motor then in the 1G. That limits the lenght the runners can be.

 

[RocketDSM]

I Extrude Honed mine (through RRE) and I love it. When I got it back it was mirror smooth inside. The port volume was HUGE. Problem, as is typical to my style of shooting myself in the foot, I didn't get the head ported. I HIGHLY recommend getting that done first or at same time. I know that those surfaces not matching is robbing a good deal of intake velocity.

 

[Polk]

The only thing I had to complain about is that it only had 4" long runners.

I have a few designs with different runner lengths and plenum sizes.

Polk

 

[IPT]

Polk. I talked to you about intakes awhile back. Question... What is the longest runner that you can get in a 1G and a 2G?? What is a good length for a "street" car??

 

[NDgsx]

Don't get anything from venom, their products NEVER fit right at all.

 

[IPT]

I just saw one a couple of weeks ago and it seemed OK.

 

[96TalonAWD]

what will happen if i put a port IM on my 2g and dont port the head?

 

[BatmanGSX]

Guys, comparing an extrude honed stock manifold to an aftermarket one with a different design is a flawed comparisson. The extrude honed stocker should behave more or less like stock with a little more power. A new design will behave totally differently. Different runner lengths and plenum sizes totally effect the power curve. Shortening your runners is like going to give you more top end power and less low end torque. I forget how plenums work... I think smaller means more top end power, same as short runners, either way, you get the idea.

An aftermarket intake manifold is going a big step toward a specific goal, it's not your average "more air = good" mod. It can change the character of the vehicle same as cams or a turbo.

 

[IPT]

As some one explained it to me.. The Plenums change throttle response. Not sure on what bigger or smaller do for you.

 

[Polk]

Batman is pretty much on the right track.

The runner lengths are a big key to where the power will come on. On the short runner intakes the 2.3 and 2.4 motors love them. They have a bit more displacement so it is not as hard to create velocity with a bigger motor.

The Plenum is another key to building the right intake. A good rule of thumb is to keep the plemum at least 115% of volume of the displacement of the motor.

Another thing is that our heads 1g in particular flow a ton of air unported. It does hot have a huge amount of velocity but a ton of air. The factory intake is a BIG restriction on these heads. The intake does help create a little more velocity but chokes the head down on the higher lifts. Now you can put a good tuned sheet metal intake on a stock head with lets say a small 16g. The lower end will hardly suffer to any at all but the mid range to red line will come alive. This is due to the fact that you are now speeding up the air charge (velocity).

Now lets say you have to of the same heads. One has a port displacement of 160cc's and the other has 180cc's. Now the one that has 180cc's may flow 20% more flow than the 160cc head due to it being larger. Now you take the smaller head and port it. You don't worry so much on size but on the shape. Now you take and flow the smaller head that cc's out to a 175. It is still smaller and is still down 3% flow from the bigger head. You then dyno the two heads with on the same car. The smaller head makes not only better power, but has a lot better power curve (flat) as well. That is how important velocity is. Bigger is not always better.

If anyone has any questions you can always reach me at the shop. I don't mind helping anybody out. Even if they don't spend a dime with me. Just want to see everyone go FAST.

Polk
(501) 847-RACE

 

[IPT]

You are the man!! Thanks.

 

[HighPsi91]

Extrude honed intakes give very little performance gain per dollar. Someone reported a 1% increase in flow over stock on a flowbench. That hardly seems worth the cost.

Aftermarket intakes are proven to make more power over stock however its important to chose one that will improve torque in the rpm range where you will be operating. Choosing an intake that has the potential for big peak HP numbers seldom helps performance where it counts. Thats why it is good to call a guy like POLK who can tailor a manifold per application. I am not trying to plug POLK but he is one of the only guys I have seen that has different runner lengths available.

 

[dsm_illicious]

STR Makes one for about a g.

 

[KenTSIII]

screw the big name companies.. they could care less about performance... only thing they care about is looks. IE the Venom intake mani is junk!

 

[dsm_illicious]

yah...personally, i'd take the stock manifold and get it honed, ported, and polished.

 

[RocketDSM]

Biggest thing I like about extrude honing the stock mani is that I get better flow (even just a little) and it doesn't look ANY different for a cop or referree to through a hissy over. ANY third party mani would raise flags and I would never hear the end of it.

 

[NosLaser]

Selecting an intake manifold goes much further than one that looks pretty, or has smooth runners. MUCH further. Let's first take a look at the primary function on an intake manifold, and a look at what's going on inside the engine. An intake manifold works opposite of how an exhaust manifold works, I'm assuming of course you know that, but I'm setting up here. Why do you have a plenum on an intake manifold instead of just having the intercooler pipe branch off into 4 equal length, equal diameter runners that bolt right to the head? The problem with no plenum, or small individual plenums is this. You must first understand that the intake valves are going to be opening and closing rapidly, so if air hits a closed intake valve, it is going to bounce back towards the IC pipe in this case and try to shoot all the way back into the intercooler, or the closest low pressure area. (you are going to have high pressure in the runners, and obviously in the cylinders) The reason for the large plenum is to provide a low pressure area for the air to "bounce back" to. All of this happens at the speed of sound, and is known as the 3rd harmonic affect. The way you "tune" an intake manifold is to provide a plenum that is just right, so that when the air hits a closed valve, it bounces back into the plenum, and then bounces back again and hits an open valves this time; and this will give you a ram affect. Now, some people will say "the engine is already boosted, so you are already 'ramming' air into the engine" but you know what? More is ALWAYS better. The other part of the equation that will be difficult is determining runner length. The way to determine runner length is to take the number 84,000, and divide it by the rpm you desire to have peak horsepower. The way to "cheat" another couple horsepower out of his equation is to divide it by the rpm RIGHT BEFORE peak HP. After that equation is complete, you must measure the distance from the opening of the intake port, to the back of the intake valve. Let's use easy numbers. Let's say you want to make peak HP at 7,000 rpm. 84,000 divided by 7,000 is 12. You will need a 12 inch long runner to make peak HP at 7K rpm. Now, that is 12 inches of TOTAL runner distance. You must subtract from that number (12) the distance you measured from the opening of the intake port to the back of the valve. Let's say that distance is 6 inches. Therefore, in order to make peak HP at 7K rpm, you need a 6 inch intake manifold runner. Now, to determine the proper size of the intake plenum, you need to make it at least twice as large as the total volume of the cylinders. Take a look at the intake plenums on the turbocharged indy cars. It's HUGE!! When it comes to plenum size, you can almost say the biggest that will fit under the hood will be the best for performance. These tiny plenum big runner intake manifolds really don't fullfill the reason why you would change the intake manifold anyway! It's like spending money to have some pretty looking chrome thing under your hood. I haven't seen the Polk intake manifold, but can give my opinions as I call it. The Magnus intake manifolds suck in my opinion. Ever notice their cars make no torque? This comes from two things. They run the cars too damn lean, and the intake manifolds kill low end power. Those cars have to rev out to like 9500rpm to make any horespower. Not very feasible in a street car. I'm not God's gift to cars, but I guarentee you give me a Magnus built car, and I will make more horsepwer, and much more torque with it. The Venom manifold is about the best aftermarket one available (again, I haven't seen the Polk) and even that one isn't that great at all. I hope this helps a bit, and I'm really not here to bash shops. I could care less which name is on it. Remember, form FOLLOWS function, not the other way around.

Regards,

 

[HighPsi91]

Ohh Boy...

 

[KenTSIII]

NosLaser,

Mind showing me a few FAST cars running the venom inatkes? I know of a few people that had them & said they actually hurt their performance.. and actually gained HP by going back to the stocker. Marco has ran 10.0s w/o nitrous... so that tells me that he know's what he's doing.

 

[rdrkt]

I don’t know what Aslan's deal with Marco is. I remember about 6 months ago when he though he thought he found the holy grail cure for crankwalk and he emailed Marco offering to fix the motors that he couldn’t. Even though Marco has been a pioneer in trying to identfy what causes crankwalk.

I find it laughable at best that you think you could do better than him.

Originally posted by Polk
The runner lengths are a big key to where the power will come on. On the short runner intakes the 2.3 and 2.4 motors love them. They have a bit more displacement so it is not as hard to create velocity with a bigger motor.

Originally posted by NosLaser
The Magnus intake manifolds suck in my opinion. Ever notice their cars make no torque? This comes from two things. They run the cars too damn lean, and the intake manifolds kill low end power. Those cars have to rev out to like 9500rpm to make any horespower. Not very feasible in a street car. I'm not God's gift to cars, but I guarentee you give me a Magnus built car, and I will make more horsepwer, and much more torque with it. The Venom manifold is about the best aftermarket one available (again, I haven't seen the Polk) and even that one isn't that great at all. I hope this helps a bit, and I'm really not here to bash shops.

You know that they run a 2.4L motor right?

Until you come close to what some of these guys are doing why don’t you back off with the comments that you can do better. Ok?

 

[GSTBoostin]

Look on turbo magazine's new issue with the galant 4g63 dyno testing, venom manifold gave 19.2 more if i recall right...not sure where in the band that is but hell if it still pulls down low its damn with the 5-600 bucks

 

[KenTSIII]

That whole artical has inflated #s... mind telling me how a stock car that came w/ 195hp at the crank put down 195hp to the wheels.. even through the AWD drivetrain?