the Coupe

[Afterthought]

Yeah hopefully it’ll come out alright .
The other piece that’s missing that I don’t have yet is the little velocity stack piece but I’ll be making that soon maybe this week.
So I haven’t done any sort of calculations yet on what the volume of the intake manifold should be . I started reading into the volume and length of runners and just ended up find a lot of different ways to go. I’m just trying to make the best intake I can while I’m at it , but there is so much to take into account like displacement , cam duration, desired rpm. I mean for it to be legit I’m sure it would need to be flow tested and the rest of the setup to match .

I had a couple ideas for how to make a manifold that’s even more “professional” looking which would be
1- buy a pre made one and adapt it to the car like pictured below

2- make a set of runners like The RS3/TTRS port injection runners . But flip the bolt pattern on the manifold side, so I could run the TTRS intake upside down . I thought it would be cool but the problem I see is this would put the inlet in the top and I’m not going to buy an expensive used one to find out it doesn’t work. I could run it in the standard configuration though. I think it’s got provisions for flaps ,position sensors and other shit I don’t ever want to see again though .so that’s how I end up trying to make it .

These could be really cool but you’d have to modify it for 5

[audifreakjim]

Awesome! Also, you want the slot to have the same area as your TB so it isn’t a restriction if it’s too small. If it’s too large it will not distribute the air as evenly.

Technically it should flow the same, instead of just having the same area, but that would take some serious modeling.

[alxdgr8]

Companies will machine the Jenvey backplate to fit 5
https://foxinjection.com/collections/je ... -machining

They call out Audi I5's on the larger plenum
https://foxinjection.com/collections/je ... 70mm-inlet

[alxdgr8]

https://store.jenvey.co.uk/pub/media/do ... B_ISS3.pdf

Jenvey by Vex Art, on Flickr

[alxdgr8]

You know you want some ITB's...

https://rennsportfactory.co.uk/product/audi-20v-itbs/

[Afterthought]

You know you want some ITB's...

https://rennsportfactory.co.uk/product/audi-20v-itbs/

Holy Crap. I'm too committed to this design already though. .. Its taken me an insane amount of time. Like if I went to work for the amount of hours I've spent on this flange I could have bought those ITB's or really whatever intake.
This car will likely be like a 1983 that cost the same as an RS3 or 996 and has less functions but lighter and home made which is cool.

[Afterthought]

Awesome! Also, you want the slot to have the same area as your TB so it isn’t a restriction if it’s too small. If it’s too large it will not distribute the air as evenly.

Technically it should flow the same, instead of just having the same area, but that would take some serious modeling.

I guess I haven't looked into TB yet or what I should use. Most likely ill get most of the intake manifold tacked together then have to stop and figure out where the rest of the stuff goes. Like radiator etc,

[ChrisAudi80]

https://store.jenvey.co.uk/pub/media/documents/drawings/APSC-70_WEB_ISS3.pdf

Jenvey by Vex Art, on Flickr

Damn that's hot.

[Afterthought]

I'm sure you've read Bufkin's pages on the manifolds...you're better off designing a standard manifold for a street car.

Alex, you mean standard as in single chamber right? I did look at James' website.
I have been reading on it quite a bit and seen his collection of pictures.

Dual plenum, I think it is cool but I understand it needs to be optimized and ive read that many people get it wrong. In addition most likely the rest of the engine needs to be optimized with it as well. But my question I guess is how far off would it be. I mean are we talking 3% difference or 10 % in performance? Because the stock manifold even has holes going through it for factory allen wrench tool, it cant be that great , but I don't know.Im not trying to go to pikes peak necessarily or Max HP but It might not be ideal if I end up with a powerband from 5-8K and have to drive the ballsack off the car everywhere like its a KX125.

So Ive had many different ideas for making the manifold, and still can't figure out what.
I first was going to cut two pieces of wood into an oblong biscuit shape and hammer aluminum around it to make an S1 E2 design. I think this can be done really easily. But I would make a single forward entry instead of a dual.
Then I got to researching and from what I could find the Dahlback design which is a big chamber with a cone feeding into it is potentially a more proven design. Likely not hard to make to make either but surely harder than a single chamber.

So what Im going to do now is maybe see if I can model it in cad and if there is a way for me to do any sort of flow modeling there. This would help me decide on design and runner length, Etc. Its all just good practice I guess.

I'm guessing there is a reason why the newer audis have flaps in the intake , maybe they are taking advantage of the plenum space at a certain RPM or something, or having the best of both worlds like a single plenum at one rpm range and larger plenum when the flaps are open . Or mainly they're taking advantage of the Audi owners by having them replace flapper motors and sensors and other expensive parts and the dealer having their car for months.

[ChrisAudi80]

I'm sure you've read Bufkin's pages on the manifolds...you're better off designing a standard manifold for a street car.

Alex, you mean standard as in single chamber right? I did look at James' website.
I have been reading on it quite a bit and seen his collection of pictures.

Dual plenum, I think it is cool but I understand it needs to be optimized and ive read that many people get it wrong. In addition most likely the rest of the engine needs to be optimized with it as well. But my question I guess is how far off would it be. I mean are we talking 3% difference or 10 % in performance? Because the stock manifold even has holes going through it for factory allen wrench tool, it cant be that great , but I don't know.Im not trying to go to pikes peak necessarily or Max HP but It might not be ideal if I end up with a powerband from 5-8K and have to drive the ballsack off the car everywhere like its a KX125.

So Ive had many different ideas for making the manifold, and still can't figure out what.
I first was going to cut two pieces of wood into an oblong biscuit shape and hammer aluminum around it to make an S1 E2 design. I think this can be done really easily. But I would make a single forward entry instead of a dual.
Then I got to researching and from what I could find the Dahlback design which is a big chamber with a cone feeding into it is potentially a more proven design. Likely not hard to make to make either but surely harder than a single chamber.

So what Im going to do now is maybe see if I can model it in cad and if there is a way for me to do any sort of flow modeling there. This would help me decide on design and runner length, Etc. Its all just good practice I guess.

I'm guessing there is a reason why the newer audis have flaps in the intake , maybe they are taking advantage of the plenum space at a certain RPM or something, or having the best of both worlds like a single plenum at one rpm range and larger plenum when the flaps are open . Or mainly they're taking advantage of the Audi owners by having them replace flapper motors and sensors and other expensive parts and the dealer having their car for months.

The flappers are to change runner length. As you know, long runners for low/mid rpm torque, short runners for high rpm.

[Afterthought]

The flappers are to change runner length. As you know, long runners for low/mid rpm torque, short runners for high rpm.

I was looking through some pics . Look at the runners on that Talladega manifold !

[Afterthought]

Velocity stack piece is done . This thing is already sucking air through it just sitting still!

[ChrisAudi80]

The flappers are to change runner length. As you know, long runners for low/mid rpm torque, short runners for high rpm.

I was looking through some pics . Look at the runners on that Talladega manifold !

Is this the legendary 25v head?

And that machine work of yours, sir! Damn

[Afterthought]

Here is a picture of it with a quick polish on the runners with a surface conditioning belt.
This piece looks amazing. Only problem is I actually have to weld it together and anything could happen at that time, especially with aluminum.


Here is another integral piece of the build.
Notice the check valve. I believe its the same one as in an audi 20V block, that eliminates the oil from draining down from the head.
Ill have to take a closer look at the factory piece but it appears to have a spring loaded check valve in it.






I need to study this plastic piece a little closer and figure out what exactly I’m removing from the system . Inside it appears to have an oil cooler bypass that says it opens at 1.35 Bar. Im slightly concerned about not having that because I don't know why its there or when it would operate. (ex, cold viscous oil, pressure is higher, its probably open)

[audifreakjim]

I REALLY wish mine had the check valve in it, that's a nice add.

[Afterthought]

I REALLY wish mine had the check valve in it, that's a nice add.

I wonder if you could tap/thread it and add one ? That’s a lot of work though to get that piece out I guess

[FFF]

Pat this is looking very good!!


Sent from my iPhone using Tapatalk Pro

[Afterthought]

Its looking good for sure I just need some time to work on it! The billet parts are the coolest parts I've made for sure- if nothing else its an excuse to expand my abilities. I quit on the intake manifold for now so I can figure out where everything else is going to reside, so i don't get ahead of myself, realistically that should get welded up for good last.

It seems pretty easy to leave the power steering on the bottom right where the AC compressor is (was), and leave the alternator and everything else as is. Only reason i could see to change that is, if leave all that shit on the driver's side of the engine I will have a huge unused space on the bottom passenger side (where stock URQ intercooler goes) , where , say, the alternator could be. I want to maximize the space I have because the engine bay fills up quick with catch cans, overflows, reservoirs, etc.
The lines to the oil cooler are already coming from drivers side. So I guess ill just have to look at layout and figure out what works, I see multiple ways it can be done.

I messed around with the starter a little bit. Getting the rough shape of what I need and then I'll have to test it and figure out exact thickness. Trimmed a timing cover and figure out what needs to go from the starter.


This isn’t perfect but it’s good enough for me to bolt the starter in place

[varia]

Man, this looks awesome!

[Marc]

great work. keep it up! intake is next for me as well after oil pan.

[the german]

So good. I love this. You’re making some very nice intake jewelery.