Custom Plenums (intake manifolds) for CA's

Post by **buffy** » Mon Oct 25, 2004 10:02 am

I'm keeping an eye on this and await your final results before placing an order. Looks good so far

Post by **float_6969** » Mon Oct 25, 2004 8:46 pm

iliketocrash wrote:why not just make a sticky with the title "Forum Issues" or something so all the new people can read it too or something?

Because I'm a crappy Moderator (Plus I don't think anybody reads those Sticky's anyway) But I'll give it a shot anyway...

Post by **iliketocrash** » Mon Oct 25, 2004 8:50 pm

i read the stickies... Besides, then if someone comes in complaining about something that is fully covered in a sticky then it gives reason for some good bashing. juuuussst kidding... or not. heh

Post by **float_6969** » Mon Oct 25, 2004 8:52 pm

THAT is all the reasoning I need! I'm always up for a good excuse to bash someone! Hehehe, well it's done, I hope that it fixes the problem...

Post by **ISL33P** » Wed Oct 27, 2004 2:33 am

results for individual runners are:from the front and all @ 25" (% variance on avg of all four cylinders which is 252.25cfm @ 25")cylinder #1 - 243cfm (103.81%)cylinder #2 - 276cfm (109.41%)cylinder #3 - 251cfm (99.50%)cylinder #4 - 239cfm (94.75%)

i questioned both the tester (which is also a well respected engine builder)and a dyno tuner about this and they can not see the slight variances causing drama on a turbocharged engine (dont forget the flow bench is using vacuum for measurement) where positive pressure is filling the plenum and therefore lessening the variances due to a constant supply of air available on each stroke. also remember that due to the firing order all cylinders do not draw air at the same time.

any questions let me know [email protected]

Post by **CA19DET** » Wed Oct 27, 2004 4:24 am

you need to angle the back on the plenum more, but it looks good,

Post by **f s t caz** » Wed Oct 27, 2004 6:41 am

so now that we have an idea of how much more air this plenum can flow, is the head going to be capable of handling the added air, or will it turn into the bottle neck of the system?

Post by **cortina-mk1** » Wed Oct 27, 2004 9:38 am

thats much better now we can see whats going on 1 and 4 need to be lifted to become a little closer to the 2 center ports

Post by **cortina-mk1** » Wed Oct 27, 2004 6:11 pm

isl33p have you tested/flowed at standard intake manifold?at this stage i will not be purchasing until i can see some eveness in the the runnersand a bit more flow

but thanx very much for all your efforts in developing parts for the CA

Post by **ISL33P** » Thu Oct 28, 2004 12:17 am

the head may not be able to keep up with the plenum but why not go as far as you can before doing any internal work, it is usually the cheapest way to go about getting power.

i will be getting the standard one tested some time during next week then we will have something to compare it to.

cortina-mk1 - you would be hard pressed to find a custom plenum that flows equally to each runner, no matter where the throttle body is mounted. how much does you head flow ? if you want more flow, all i can do is increase the volume and port the runners, it is up to you how far you want to go. if you go to a larger volume you may lose the current driveability and throttle response of your car.

and as i said before the flow bench is just an indicator working with vacuum where your engines will be developing positive pressure (boost) which throws out a lot of theories when compared to when working on naturally aspirated engines.

once the test car gets dynoed i will let you know of the results and we will be checking egt's of each cylinder to see what effect the difference in flow of each runner has on the exhaust side.

Post by **cortina-mk1** » Thu Oct 28, 2004 1:10 am

i know how much my head, manifold and intake manifold flows yes as well as what all standard one do as well

i would purchase and after market plenum if it is a noticable gain over what i have now

im not concerned with plenum volume at this stage

Post by **euroboy** » Thu Oct 28, 2004 3:23 pm

hey man,great effort on making this.I bet mk1 cortina just wants to see something amaizing and as a matter of fact so do i.

I love the way it looks but i have a few pointers if you allow the advice.first the air rushes through and #1 runner is kinda hidden.There is 2 things you can do. Make the front of the plenum longs and the angle going to the first runner less harsh so it will see a lot more air. Second have the tb point even more to the left.(the second one though might disturb the air into the #4 runner.

about #4 runner you eaither can make it longer(so there is stored air) or make the back end round so there isn't a big flow turbolance.

This will improve the flow on #1 and 4 very much!

ps: just an advice don't take this the wrong way plz, as i am sure what you did so far i wouldn't have been able to do....

Bess

Post by **euroboy** » Thu Oct 28, 2004 3:32 pm

actually one more thingif you can make a "river bed" or a groove starting from close to #3 going to #4 you will increase the area of sucking for #4 and the flow will be much better that's if you trying to reach equal flowbut my best advice is check the stock one and i guess stick with those ratios or if equal flow is the best then i guess these tips might help!Bess

Post by **cortina-mk1** » Thu Oct 28, 2004 5:22 pm

i think its great ppl are making stuff fer a CAwell done but im not going to spend more money on something that will not give 'me any gains

Post by **ISL33P** » Fri Oct 29, 2004 1:52 am

thanks for the tips euroboy, points taken and good points they are. testing will continue and so will the development and design.

with regards to your tips, this is all fine but there are other factors that need to be taken into consideration when making custom parts. the ease of fitment, total amount of mods required to standard parts to make fit, engine bay space, coolant hose positioning, piping direction/positioning, fuse boxes, batteries etc etc etc. after all that, it has to also work and work properly.

flow test results for the standard (unmodified) plenum will be availble by mid next week. we can go from there.

thanks again for the tips.

Post by **euroboy** » Fri Oct 29, 2004 2:56 am

#4 is the worse flowing one....and i checked the pics more carefully...the air as it rushes in it's getting slammed at the end tank....the end should be more round OR if you stick with that design have the end be flush with #4 runner so the air is redirected into the runner

for #1 extending the plenum forward i see no space issues as it should be able to clearly miss everything big....the TB isn't it on FWD ca18dets going to be a ***** since the intake (is or should be anyhows) by the firewall?)personally i don't care since i drive s12 ca18det but just something to take into consideration

Bess

Post by **CA19DET** » Fri Oct 29, 2004 8:47 am

jsut make it on order, then you can flip it over before you weld the runners on the plenum, that way the TB will be on the correct side,.

Post by **ISL33P** » Sat Oct 30, 2004 12:39 am

if end the plenum flush with no 4 it will flow even less due to not having enough air around it to to draw and it will defeat the purpose of having such bellmouths due to their ability to draw air from below the bellmouth top.

cortina-mk1 - so a total 343cfm compared to 555cf, is no good ?

Post by **float_6969** » Sat Oct 30, 2004 9:02 am

ISL33P wrote:...you would be hard pressed to find a custom plenum that flows equally to each runner, no matter where the throttle body is mounted...

If you have the manifold extrude honed, it will even them all out and they should all flow equally w/in 1% (I think thats what they said) Extrude Honing

Post by **cortina-mk1** » Sat Oct 30, 2004 12:10 pm

ISL33P wrote:cortina-mk1 - so a total 343cfm compared to 555cf, is no good ?

these figures are generated from blowing through the throttle body and they are not a true indication of what is going on in each runner

that why i ask for indivdual runner flowas i have said before ....for other ppl there will be a gain...but for me there is going to be no benefit at this stage

theres no drama here

Post by **ISL33P** » Sat Oct 30, 2004 10:45 pm

..... and this is how the turbo works. it shows the ability of the plenum to take advantage of the greater amount of air available. it isn't all as bad as you may indicate.

do you have figures on what your head & plenum flow ? i would be interested to see what is needed to make a benefit on a setup like yours.

Post by **cortina-mk1** » Sun Oct 31, 2004 8:40 am

ils33pyes as i have said beforei do knowand float_6969 is right

and i have never said anything was bad....

Post by **mbmbmb23** » Sun Oct 31, 2004 11:39 am

ISL33P wrote:results for individual runners are:from the front and all @ 25" (% variance on avg of all four cylinders which is 252.25cfm @ 25")cylinder #1 - 243cfm (103.81%)cylinder #2 - 276cfm (109.41%)cylinder #3 - 251cfm (99.50%)cylinder #4 - 239cfm (94.75%)...........

Would you perform that same flow test on the OEM runners so we can find out how the OEM flow varies from runner to runner?

Your prototype looks really good. If you can get the flow rates slightly closer Im sure you'll have a bunch of takers, especially if you had these on ebay. I'm assuming theres a core charge if we dont send you our original runners for you to convert?

thanks,

-m

Post by **float_6969** » Sun Oct 31, 2004 8:16 pm

He's going to.....

Post by **cortina-mk1** » Sun Oct 31, 2004 9:27 pm

mbmbmb23 wrote:...I'm assuming theres a core charge if we dont send you our original runners for you to convert?....-m

yes that is a good question as the original head pate and start of the runners is being used

...isl33p... how are you going to deal with this to make the manifolds?

Post by **ISL33P** » Mon Nov 01, 2004 12:06 am

re: extrude honed, when you consider the small distance i have of the standard runners, this will have a lesser effect than on what it would on std runners. there are greater variances in std ones when compared to when they are machined (cut), they are pretty much exactly the same.

it may be considered, but i am trying to keep the overall cost down. it may be done as a one off for testing or for someone who wants to pay the extra, and we'll see how we go from there. if i was to get each one extrude honed, costs will be at least the $US650 mark compared to the $US500 and not what people want to pay. but if they do, i'll do it.

re: runners - it will be cheaper than expected if you send me a set of original runners as i will, soon enough , run out. i am getting the std one tested in the next day or so. even better if someone have at least two spare and we can strike up a deal.

cortina-mk1 - how much does your head flow ?

thanks for all the feedback.

Post by **ISL33P** » Tue Nov 09, 2004 2:10 am

damn the japanese and their unlimited funds to testing and development. i got the original plenum flow tested and the results are (all at 25"): my design#1 - 221 cfm 243 cfm#2 - 220 cfm 276 cfm#3 - 220.5 cfm 251 cfm#4 - 207.5 cfm 239 cfm

There is some good news for me out of this, the japanese had the same problem i did with one of their cylinders (#4) as i did with #2 and they didn't think too much of it.

I will let you guys make your own opinion of this info, as i have already made mine.

Damn development is time consuming....and not cheap !

Post by **euroboy** » Tue Nov 09, 2004 6:50 pm

are the #'s above you from YOUR design or the original design?if they are from your design then can you please include the STOCk design #'s?

Post by **NeedCAforS13** » Tue Nov 09, 2004 8:33 pm

euroboy wrote:are the #'s above you from YOUR design or the original design?if they are from your design then can you please include the STOCk design #'s?

um first number is stock manifold, second number is his design...

Sean

Post by **euroboy** » Tue Nov 09, 2004 10:34 pm

oh ok thanks for clearing that up man....

well the difference between them i dunno man

the #'s on the stock manifold seem more direct...there is a +-5% difference between the flow on each runner and there is a +-10% in your design....if you can try to squeeze this % of difference into a better # then a lot more ppl might be interested.

The thing i might suggest japs didn't worry too much is because 5% is toleratable in the automotive industry and in stock form this wouldn't hurt.In highly performance engines the flow INTO every cylinder is crucial as you are trying to squeeze the most out of it.I do hope you continue making it better because i know i want one when i see some better #'s

the gapping between each cylinder flow is a bit too much right now you have to narrow that a bit...stock the first 3 cyl are almost dead even just #4if you can work towards that goal would be superbBess

Custom Plenums (intake manifolds) for CA's

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