Don't laugh... Plastic Intake Manifold ???
#11
10-06-2009, 09:40 AM
But its harmless and fun, and yes, from time to time, trial and error is the mother of invention, but mostly its fruitless effort in reality, but in the mind's eye, its "l33t Yo!"
#12
10-07-2009, 06:53 PM
I wish I was brave enough to alter the headers of my car- But I just wouldnt know where to start.... Let me know how the Ebay headers work- I'm very curious.... I was looking at them a while back but i chickened out i guess.
#13
10-07-2009, 10:08 PM
Porting and polishing plastic manifolds
Sorry been a way for a minute but in response to my earlier post. By the way I do see the humor in your post and I take it in Gest but what i have found is that generally those millions of dollars of research have gone into some engineers pocket and generally enginners all think inside the box. Now I don't have any formal schooling to speak of on cars or any proper knowlege on engine therory. All i have is a decade or so of building motors for race cars and street cars. and believe me I don't know everything and don't claim to know everything. The fun part here is you have an intake manifold you can screw with and try new things. just as an example that somehow all this miollions of dollars of research missed was if (only good for headers) but you can weld a flat plate in your headers dialed in to a very certain degree depending on the motors there was anywhere from 3-5% power increase. just by welding a simple plate inside your header. I know it's weird that some backwoods boys without a big fancy shop could figure this out but it happened. So back to what I was saying is that on our intake manifolds for our race car we would port and polish the intake then match our heads and gaskets so there was no way for the air to slow down. then at the bootom of the intake manifold we would just roughin up the runner not even a lot but it would disurb the air just enough to help it mix with the fuel. We had good results with it. Then I read that article about adding material it was on Race bikes agaian unproven bu the therory was sound and by starting off with the normal size runner then making it a little bit smaller at the end effectivly sppeding up velocity you could cram more air into the cylinder. Were not talking about a great deal either way, changing thinngs minuetly could alter the performance of the engine.
Side note is that i am not saying that anyway is right or wrong and most of what we have done has been off of our racecars with v-8's sometimes big block sometimes small blocks. And for our cars could be for better or for worse all I know is that nothing ever changes if you don't think outside the box.
Side note is that i am not saying that anyway is right or wrong and most of what we have done has been off of our racecars with v-8's sometimes big block sometimes small blocks. And for our cars could be for better or for worse all I know is that nothing ever changes if you don't think outside the box.
All of this has some merit. The biggest difference from the above experience and yours is that roughing up the last bit of the runner in a carbureted Chevy is to keep turbulance and thus keep the fuel suspended in the air. On an injected car, the best thing you can do (assuming you have stock cams and compression ratio, meaning that you can not take advantage of alot more airflow) is to smooth and match ports. This is critical at the back side of the valve seats, and around the guide. You may be able to achieve lesser results in the manifolds.
More gains can be had by optimizing the exhaust to scavenge at your peak torque rpm through your peak hp rpm. This will net you a nice driveable car.
Open the ports too much and velocity slows. Which negates the ram air effect.
So much for porting 101.
Next lesson: camshaft design theory.
Good luck..
#14
10-08-2009, 11:09 AM
ALL right guys. I'm working slower due to the cold here in Chicago (and my wife nagging that I spent all summer playing with my car) so it's not all clean and I don't have pics to share. I will say that in the end I'll probably wind up with a freshly cleaned Intake manifold with roughed exhaust ports and phenolic spacers that will give me a minoot gain but it'll be hopefully more than I started with. Most of it will be in my head so I can sleep better at night.
I will say that I installed a lightweight stubby antenna and the gains were impressive. LOL
I will say that I installed a lightweight stubby antenna and the gains were impressive. LOL
#15
10-09-2009, 12:48 PM
Senior Administrator
Join Date: Feb 2005
Location: Lotsa places, currently Metro D.C., USA
Posts: 13,574
Sorry been a way for a minute but in response to my earlier post. By the way I do see the humor in your post and I take it in Gest but what i have found is that generally those millions of dollars of research have gone into some engineers pocket and generally enginners all think inside the box. Now I don't have any formal schooling to speak of on cars or any proper knowlege on engine therory. All i have is a decade or so of building motors for race cars and street cars. and believe me I don't know everything and don't claim to know everything. The fun part here is you have an intake manifold you can screw with and try new things. just as an example that somehow all this miollions of dollars of research missed was if (only good for headers) but you can weld a flat plate in your headers dialed in to a very certain degree depending on the motors there was anywhere from 3-5% power increase. just by welding a simple plate inside your header. I know it's weird that some backwoods boys without a big fancy shop could figure this out but it happened. So back to what I was saying is that on our intake manifolds for our race car we would port and polish the intake then match our heads and gaskets so there was no way for the air to slow down. then at the bootom of the intake manifold we would just roughin up the runner not even a lot but it would disurb the air just enough to help it mix with the fuel. We had good results with it. Then I read that article about adding material it was on Race bikes agaian unproven bu the therory was sound and by starting off with the normal size runner then making it a little bit smaller at the end effectivly sppeding up velocity you could cram more air into the cylinder. Were not talking about a great deal either way, changing thinngs minuetly could alter the performance of the engine.
Side note is that i am not saying that anyway is right or wrong and most of what we have done has been off of our racecars with v-8's sometimes big block sometimes small blocks. And for our cars could be for better or for worse all I know is that nothing ever changes if you don't think outside the box.
Side note is that i am not saying that anyway is right or wrong and most of what we have done has been off of our racecars with v-8's sometimes big block sometimes small blocks. And for our cars could be for better or for worse all I know is that nothing ever changes if you don't think outside the box.
I agree 1000% with the spirit of EVERYTHING you said. Speaking of spirit, you seem to have channeled Smokey Yunick !
I wish you luck.
P.S., when you do get around to welding that vane into the intake track, consider giving it a profile similiar to an airplane wing. If it DOES work, and you make a grillion-dollars off of it, all I ask is that you give me naming credit by calling it the "Jazz-Deflector"
#16
10-30-2009, 12:04 AM
If you want to make hp faster just do what i did to my 2.8 and alter the TB to make both TB plates open at the same time when you hit the accelerator. That will make your car accelerate faster and when you driving on the highway get 2-3mpg more. youll probably get better results than trying to do what you had in mind and best of all its a free modification.
#17
10-30-2009, 12:38 AM
If you want to make hp faster just do what i did to my 2.8 and alter the TB to make both TB plates open at the same time when you hit the accelerator. That will make your car accelerate faster and when you driving on the highway get 2-3mpg more. youll probably get better results than trying to do what you had in mind and best of all its a free modification.
#18
10-30-2009, 12:56 PM
https://www.audiforums.com/forum/sho...d.php?t=141129
here you go man, i started a thread about it. I dont know much about audis since ive always been a MOPAR guy but i just got my first Audi and THIS mod does work VERY NICELY.
I looked through other AUDI-VW sites and didnt find anyone doing this so i hope you guys try it and have good results as well.
if you deside to try the mod give me some feed back on the Thread.
Tony.....
here you go man, i started a thread about it. I dont know much about audis since ive always been a MOPAR guy but i just got my first Audi and THIS mod does work VERY NICELY.
I looked through other AUDI-VW sites and didnt find anyone doing this so i hope you guys try it and have good results as well.
if you deside to try the mod give me some feed back on the Thread.
Tony.....
Last edited by MUNDO_AUDI; 10-30-2009 at 01:12 PM.
#20
12-04-2009, 04:28 PM
With respect to the idea of trying to ram-funnel the air as was done on a race bike, remember the difference between that engine and the street car engine you're working on. On the race bike, due to weight and other factors, they're going to have a limit to the size of the runners they're willing to fit on the intake manifold. And that engine is built to scream, wide-open throttle, for most of its operating life. At the RPM a race bike engine turns, the ports are open for VERY, VERY short lengths of time, so the funneling helps to maximize airflow into the engine.
On your street motor, you see nowhere near those revs, and your airflow characteristics are already suited very well. Hogging out the runners may help the car, but not at a near-stock state of tune - they already are capable of flowing way more air than your engine is demanding. Even a stage 3 build on an S4, to produce 500hp or more, doesn't take into account the idea of enlarging the runners out of necessity. And the guys with 300awhp on their 1.8Ts on here are largely doing it with stock manifolds as well.
At way higher boost, like a couple guys here are running, making power numbers that are just silly, enlarging the manifold would probably net some pretty good gains. A K03 turbo needs none of those, and likely won't even notice them - the best I'd bet you'd see is a SLIGHT decrease in spool time. You have to remember the applications of the engines you're comparing - what works for one's design intent doesn't necessarily translate to another engine with another purpose, even if the theory is sound on its own.
As for the theory of roughing the runners for turbulence, it does help - atomized fuel being injected into the intake air charge can be swirled and mixed more thoroughly by having an amount of turbulence. Again though, the gains from that aren't likely to be apparent on a near-stock tune for the street.
On your street motor, you see nowhere near those revs, and your airflow characteristics are already suited very well. Hogging out the runners may help the car, but not at a near-stock state of tune - they already are capable of flowing way more air than your engine is demanding. Even a stage 3 build on an S4, to produce 500hp or more, doesn't take into account the idea of enlarging the runners out of necessity. And the guys with 300awhp on their 1.8Ts on here are largely doing it with stock manifolds as well.
At way higher boost, like a couple guys here are running, making power numbers that are just silly, enlarging the manifold would probably net some pretty good gains. A K03 turbo needs none of those, and likely won't even notice them - the best I'd bet you'd see is a SLIGHT decrease in spool time. You have to remember the applications of the engines you're comparing - what works for one's design intent doesn't necessarily translate to another engine with another purpose, even if the theory is sound on its own.
As for the theory of roughing the runners for turbulence, it does help - atomized fuel being injected into the intake air charge can be swirled and mixed more thoroughly by having an amount of turbulence. Again though, the gains from that aren't likely to be apparent on a near-stock tune for the street.