designing and building manifolds.

[GalantVR41062]

Originally posted by awd4bangr
Cremco doesnt have a web site. Dont know the phone number any more. Try Quest Dex or something similar.

Not to piss on anyones parade but I've not seen or heard any original ideas in this thread. At some point in the past 10 years or so all of this stuff has been designed, built, and didn't make the final cut for one reason or another.

I don't know how long some of you have been around DSM's but some of the shops that are sometimes forgotten have spent lot's of time and money designing, building, and dyno / track testing so many different intake manifolds and exhaust manifolds it's hard to keep count.

Keep this in mind when you try to reinvent the wheel.

Also up until recently, a 12 second dsm was fast....
so maybe the wheel doesn't need to be re-invented, just re-evaluated...
just a thought....

 

[JET]

I have never seen anyone try an idea like the one I had. If you have I would love to know who it was. I have been into DSM's for 9 years, so I am no newbie

 

[awd4bangr]

Jet -

I have seen some pictures from the land down under of a design very similar to yours a few years back. It was on an Evo II. I'll see if I can get them again.

 

[autronicDSM]

If all of those designs were already tried how come everybody only makes sheet metal intake manifolds? Velocity stacks increase the air flow so I'm suprised that nobody makes manifolds for our cars with these. I'm sure somebody could tried that few years ago but the cost of it maybe was too high for an average DSMer? Anyways, I've been around these cars for only 2 years if that makes a difference. I'm a college student and just recently decided to fabricate my own stuff. I thought that thread was very interesting and educationl and I picked up few things from it and hopefully I'll be able to build something that's better than Magnus or BJ's manifold (fingers crossed).

Besides, I don't think it's possible for everybody to know what's going on in every DIY guy's garage.

 

[awd4bangr]

Originally posted by autronicDSM
If all of those designs were already tried how come everybody only makes sheet metal intake manifolds? Velocity stacks increase the air flow so I'm suprised that nobody makes manifolds for our cars with these. I'm sure somebody could tried that few years ago but the cost of it maybe was too high for an average DSMer? Anyways, I've been around these cars for only 2 years if that makes a difference. I'm a college student and just recently decided to fabricate my own stuff. I thought that thread was very interesting and educationl and I picked up few things from it and hopefully I'll be able to build something that's better than Magnus or BJ's manifold (fingers crossed).

Besides, I don't think it's possible for everybody to know what's going on in every DIY guy's garage.

The answer to your first question is simple. They work better than the other designs that were built and tested.

Velocity stacks have been applied to some of the aftermarket intake manifolds for DSM's. Cost for the average DSM customer isn't the factor when most people design the manifold. Making power at higher RPM's is the priority. If you look at the times people put up and what they use for an intake manifold, you'll see more without velocity stack type designs.

As for building a better mouse trap than Magnus or BJ you need to specify whats wrong with those designs and then figure out how to make them better. Could you make them better on the low end? Probably but then why not just use the stock part? Could you make something better in the mid range and top end? Again the answer is yes but you'll need to do some extensive testing with those products and then yours.

If you're just wanting to build your own manifold that's fine and I'm all for it but be ready to make several and spend a lot of time testing to get something that works.

When I chimed in on this thread it wasn't to tell anyone they are wrong for wanting to do this. I read all of it and noticed nothing new, nothing that hasn't been done already. The reason you don't see any of those designs around is due to the fact they didn't work very well.

 

[autronicDSM]

By better I mean making more power, either low, mid or high rpms (i would prefer low to mid). I remember when I bought my car few years ago I only found one company that was making manifolds for our cars. And it was way overpriced, it was $1100-1200 range. After that came cheaper Venom manifold and then people like Magnus and BJ's started to make their custom ones. Maybe I'm missing something but only research those guys had to do was with runners length and plenum size which could be calculated and then just fine tuned.

I have access to school's fab lab so it's not a problem for me to sit there and make 1 or 2 manifolds. Now that school is also getting AWD dyno to work with Big 3 and their trucks I'll be able to see some numbers too

I disagree about average DSMer, they do care about cost, why you think there's so many people swapping out parts from different cars (supra fuel pump, IC, etc.)? Because it's cheap. Only those who are serious racers are willing to spend lots of money for somebody to engineer parts for them. Just my $0.02

 

[JET]

AWD- I don't think you did read the whole thread. The first couple of pages were devoted to the problems we saw with existing manifolds. You have stated that you have seen nothing new, but yet you haven't told us any specifics on who has tried any of the designs that we were talking about.

I seriously doubt that all of those designs have been tried. Like Autronic said, the average DSM'r is a cheap ass and price is a major concern. To fabricate the manifolds we are talking about is going to take alot more labor and ever more labor to fit them because we are going to move the TB. The others that are mentioned put the TB in the stock location to make it easier to mount. We don't care about easy, we want what works best.

So far you have just stated vague responses with nothing to back it up. If you are going to give something constructive to this thread, please do. I would just like some data or theory behind your replies. This is not a flame or anything, I would just like to see this thread get back up to the caliber that it was.

 

[awd4bangr]

Originally posted by JET
AWD- I don't think you did read the whole thread. The first couple of pages were devoted to the problems we saw with existing manifolds. You have stated that you have seen nothing new, but yet you haven't told us any specifics on who has tried any of the designs that we were talking about.

I seriously doubt that all of those designs have been tried. Like Autronic said, the average DSM'r is a cheap ass and price is a major concern. To fabricate the manifolds we are talking about is going to take alot more labor and ever more labor to fit them because we are going to move the TB. The others that are mentioned put the TB in the stock location to make it easier to mount. We don't care about easy, we want what works best.

So far you have just stated vague responses with nothing to back it up. If you are going to give something constructive to this thread, please do. I would just like some data or theory behind your replies. This is not a flame or anything, I would just like to see this thread get back up to the caliber that it was.

Jet -

In the first three pages of this thread the only existing design you or anyone else says is bad is the Magnus design. Call Magnus and Extreme and ask them how many different manifolds they have built and tested on cars. You live in a area where you had lot's of access to see different stuff on one of the top cars in the country. Rau has never been secretive about letting people look at his car. Remember Speedwerks? They had many of the Extreme / Rau trial components hanging around after they didn't work as expected.

Nobody has done more design and testing of intake and exhaust manifolds for drag applications than Extreme. They built so many different variants trying to find the best combo. Extreme was the first DSM to go with 4 individual throttle bodies. RPW is the Austrialian company that does most of the one off intakes for the Mitsu cars, they are the ones that did the design you like so much. They are also the ones that helped Extreme do some of thier designs.

Call Archer and talk with Russ and ask him how many intakes they built looking for power in non drag applications. It was around 30 different intake / intercooler designs they built and tested. Stuff many people consider high tech and the way to go now are things they did 10 years ago.

All of these parts were designed for that shops race car first and retail sales second. So cost to build was never factored into any of them. People who are at the level where the really need an other than stock intake shouldn't be worrying about the price, speed costs how fast do you want to go? Unfortunately this applies even to DSM's.

My original constructive addition to this thread was a source for parts and a simple statement that I've seen these designs done already and for one reason or another they didnt stand the test of time.

It's your time and effort to do as you please so don't let me get in the way.

Good luck!

 

[autronicDSM]

So how did 4 individual TB worked out on Extreme's car since you know about this? That's a first time I've heard about anybody trying that on DSM. Thing is if you don't know all these shop owners and you don't have connections then you have no clue who tried what and if it worked. So either give us more info if you know what works and why, or drop the whole thing of telling us that everything was already tried.

 

[awd4bangr]

Originally posted by autronicDSM
So how did 4 individual TB worked out on Extreme's car since you know about this? That's a first time I've heard about anybody trying that on DSM.

I'm not sure if they still use it or not, give them a call.

 

[GalantVR41062]

AWD you dont get it do you? WE ARE NOT DESIGNING NEW MANIFOLDS THAT HAVE NOT BEEN TESTED. I just wanted to talk about designs that work and what to change a little to make it better, I was going to make a large plenium 5" dia and 16" long with the TB in the stock location, then have the runners start as the size of the port in the head then have it enlarge to a velocity stack in the plenium to get a nice radius edge to the runner then have the plenium overhang 1" on each end. then the exaust manifold out of 1 3/4" runners that has #1 and #2 go the the back side of the turbin inlet and the #3 and #4 over to the front of the inlet, then have the waist gate port off the collector instead of the #1 runner. And I knew that Sean ran indavidul TB, it was in Turbo mag a while back with Off the Leash Diamond stars.

 

[autronicDSM]

John,
Do you know if there would be a benefit of injecting fuel into runners instead of ports on the head? I would think that with velocity stack injecting fuel earlier would give better mix?

 

[GalantVR41062]

well its a good idea, but the problem is fuel control. The closer the injector is to the combustion chamber, the better the fuel control. Direct injection...

~John

 

[JET]

Pooling also becomes a bigger problem when it is farther from the head. That is why direct injection rocks! You know exactly how much made it in the head.

 

[JET]

Alright, I just got a reply back from RPW. They are the ones that had supposedly tried the design of my manifold. They said the design was very interesting and showed promise, but they had never tried anything like that. They do however offer 4 seperate throttle bodies.

 

[autronicDSM]

Sounds good. Who is RPW? Do they have a website?

What did they say about 4 individual TB, do they offer extra benefit compared to single TB or anything like that? I really want to try velocity stack with individual TBs but that will cost too much to "just try it".

 

[122andy]

http://www.usionline.net/122/Sheet Metal Intake/pages/sheetmetal1.htm
http://www.usionline.net/122/Sheet Metal Intake/pages/sheetmetal2.htm
http://www.usionline.net/122/Sheet Metal Intake/pages/sm_incar1.htm


Heres an intake I made, it has a 3.5" round plenum by 15" long. The runners are 2.25", tapered, and 6" long. Velocity stacks were incorporated just like the picture and drawings shown. They dont stick way into the plenum, either. I personally think the velocity stacks are a waste of time considering effort involved. Even if they do flow 15-25% more than w/o them, you have to figure that the number might not necessarily equate to HP. Dont let it fool you. Its kind of like how everyone quotes the 62-1 flowing 10% more than a 60-1. While this is true, it WILL NOT make a 500whp 60-1 car make 550whp just by bolting on a 62-1(many places advertise this). I guess what I am saying is flow increase percentages are directly proportinate to HP increases. You cant just take the percentage of increase and assume the HP increases by that same percentage.

Anyway, I made the intake because I was out of stuff to do on the car. The power peak even with the stock mani and 272s was 6700-6800, and I have to shift at 8000 to keep it spooled. The problem was the car would lose 60hp from 6700 to 8000rpm. So I figured I would take advantage of this area where power was just nosediving. I looked at all the intakes available, made my decisions, and went from there. Thats what alot of you guys need to be doing instead of typing out theories on the keyboard. Mild steel might be ugly, but it sure is easy to work with when making a prototype.

I took the car and dynoed it one day, and went back a few days later with the SM and re-dynoed it. Both days were on pump gas. Here are the dyno sheets before and after: http://www.usionline.net/122/Dyno Sheets/index.htm I kind of wish I would have revved higher on the stocker to whow how badly it drops, but you can see the general direction its going in. 8 pulls on the stock intake netted and average of 361hp(368hp max) and 320ft/lbs(332 ft/lbs max). 8 pulls on the sheetmetal netted an average of 368hp(389hp max) and 317ft/lbs(342 ft/lbs max). The averages dont seem very different, as these are peak numbers, but looking at the graph past 6500rpm shows some REALLY nice gains. At 7500 rpm it looks like 40-50hp and 30 ft/lbs over a stocker. The car peaks at 6500rpm and is pretty much straight across until 8krpm.

How does it work at the track? The car runs faster and quicker than it did w/o it, so I am happy. I will say this; the only cars I would recommend running a short runner intake on are ones that are having to shift at 8krpm anyway. Otherwise I think you are wasting your time. Besides, the benefits of having one arent totally spectactular, and street cars have run 10s on stock intakes.

Anyway, I just thought I would post this for you guys that might be interested.

 

[RED_AWD_BLUR]

Wow I am getting turned on buy this. Ahhhh we have turbo cars. thus we have way more velocity than a n/a car but dumping that into a big box just KILLS the velocity. Earlier in this thread it was discussed how dividing the flow would help. OF COURSE it would this is the technology behind divided turbine housings. This is even implemented on the new EVO 8! and in most large diesel trucks. This is because in a undivided turbine housing the velocity is dissipated and turned into more pressure. I left my IC engines book @ home so I won’t guess and explain but it has something to do w/ harnessing the velocity of the air instead of dissipating it. Look up the technology behind divided turbine housings. I have been wondering why they don’t use this technology for intake manifolds. I believe part of the reason is most cars are N/A not turbo. So there velocity is fairly low like the wind outside or in effect ram air. But we have turbos lets see the average 16G is 550 cfm right? So if we have this flowing through a 2.5” pipe it.
So (Pi/4)*(2.5)^2= 4.9”^2 (cross sectional area)
550cfm*(12in/ft)=950400in^3/min
(950400in^3/min)/ 4.9in^2=193614 in/min
193614 in/min*(1ft/12in)*(1mile/5280ft)*(60min/hour)=183.346miles/hr

yeah that’s right 183MPH I doubt the guy in his ram air comaro is getting that kind of speed. My theory I believe it is beautiful!!! Get something that is lightweight and already designed for this kind of flow. How a bout a large Intercooler Endtank!!!! And then you can weld in dividers but it should have a fairly even spread of airflow. Use this extra kinetic energy!!! That is the whole idea behind a velocity stack!!! So why throw all that speed at a flat panel!! It is ridiculous!! But in a N/A car the intake velocity is way lower so instead of doing a bunch of math for getting a tiny amount of energy on a N/A car they just COP OUT and throw it into a big box so they can get even cylinder filling! Divisions I don’t think you could do or they would be really difficult because you would have to divide cylinders 2&4 from 1&3, I think our firing order is 1-3-4-2 ( I think that is right but it would be the same as the divided turbine housing divisions.) this design may not work well @ vacuum but I don’t know. Any way sorry for taking up so much space.

Chris James
Jr. in mechanical engineering

 

[RED_AWD_BLUR]

now some one try it and get some #'s!!!!

 

[RED_AWD_BLUR]

Any Ideas?

 

[JET]

Alright, your air is coming throught the TB at 180 mph. Why do you think it is going to want to make the corner to go into #1 and #4? #2 and #3 are going to receive more pressure. That is why I did like a motorcycle exhaust and went 1-2-4. The main problem is relocating the TB. The cables will be all off and I don't know if they will pull right or not. I still want to try it sometime this summer.

 

[RED_AWD_BLUR]

Hmmm... You would be VERY surprised how even the flow really is. That IC tank uses a very special shape. Even so, If your theory was right then the manifold side of runners #1 and #4 could be slightly larger a flow bench could put an end to this mystery. There is a reason the end tanks ( the good ones like in post 95) are shaped the way they are and it isn't because it looks cool. These Intercooler guys spend hour upon hour trying to design the correct shape to evenly distribute flow through the IC. other wise it would be useless to have such a big IC. look at this web site:
http://www.are.com.au/techtalk/intecoolersMR.htm#Shape or Profile

IC design was discussed:
http://www.dsmtuners.com/forums/showthread.php?postid=336096#post336096

this end tank design is what makes ICs more efficent.

 

[RED_AWD_BLUR]

Originally posted by RED_AWD_BLUR
550cfm*(12in/ft)=950400in^3/min

it should be (12in/ft)^3 but the #'s are all right

One thing I neglected to mention was that the big box intake manifolds have a nice feature. If I recall correctly, the reason your intake runners are a specific length has to do with "tuning". the length of the runner is how fast the shock wave can bounce back and that is why the car gets a little higher power at that specific speed. The little shock wave comes from air piling up on the intake valve because it just closed. So this wave bounces off and hits the back of the intake manifold so that bounces back towards the intake valve and the wave reaches the valve when it opens.

Some old dodge's had this kind of exhaust manifold shaped intake mani.

 

[RED_GST]

HOW WOULD SOMETHING LIKE JETS-POST 45 THAT WAS A 2-4 DESIGN WORK ANY BETTER. HAVING PORTS 1-3 AND 2-4 HOOKED UP TO ONE TUBE. THEN YOU COULD POSSIBLE RUN UNEQUAL LENGHT TUBES, BUT THE UNEVEN VOLUME OF BOTH TUBES WOULD ENEN IT OUT.

 

[JET]

Quit yelling!! Read everything in the post. You will see there is nothing mentioned about unequal lenght tubes. The 2 tubes still flow into a plenum so the air is evened out. Running 1-2-4 is just the best way to even the pressure out. After talking to a lot of people though, I don't know if it would make a big enough difference to be worth while.