Custom Plenums (intake manifolds) for CA's

[ISL33P]

sorry about the post, it didn't turn out like i wanted it two. yes the no's on the left are for the stk manifold and the ones on the right are for my manifold.

the new design i am currently doing will try to even everything out. i am aiming for a max 5% variance over all runners as this is the same variance as standard and some cars have pushed the envelope with the standard plenum and had no prob's. to be exact like the factory will be nearly impossible on any one persons budget, but testing and development will continue as this is the ultimate aim. i will keep everyone posted.

for now, i am finishing one for a sr20 plenum and with experience i will hopefully get better results, i already have a customer waiting for one and the same sort of tests will be carried out.

my ca18 one is already sold and installation and dyno testing is only a couple of weeks away.

[float_6969]

I plan on having my stock Manifold Extrude honed within the next month or so. I don't know if you would be intrested in the results or not, but I could probabally have it flow tested to find out how it does. Lemme know what you think...

[NeedCAforS13]

i'd be interested ryan...

Sean

[slideways]

if the price was right, id also be intrested

[cortina-mk1]

I plan on having my stock Manifold Extrude honed within the next month or so. I don't know if you would be intrested in the results or not, but I could probabally have it flow tested to find out how it does. Lemme know what you think...

i think that is a very good idea float...it will be very intersting to see results

[ISL33P]

i would be interested in the results, for sure.

its a pity you then wont be able to matchport it to the butterflies/head becasue of such a large increase in diameter. it may disturb the air flow a bit. just my thoughts ?

[float_6969]

I don't think extrude honing takes out so much material that I can't match it. I've already matched the sub-manifold (the ones with the butterflies in it) to the head and polished it in all the appropriate places. I then plan on having the stock mani extrude honed and then matching that to the sub-mani. I don't have any personal experience with doing this, but I wasn't under the impression that it took out THAT much material...

[float_6969]

OK, so I just called them and they said that the process will only remove .003-.005" of material. I should easily be able to match that to the sub-mani...

[Nunook]

I would definately be interested to see either flow rate increase or a dyno run(before and after).And Extrude honing doesn't remove much material, unlike porting. It's more like smoothing the passages.

[ISL33P]

that's not much at all. you'll be ok to matchport it then.

i have then the guys over here do it and they take about 3-5 mm of inlet manifolds.

[float_6969]

The nice thing about the extrude hone is that because of the way that it works, they gaurentee that the runners will all flow with in 1% of eachother. I don't think that it will flow as much as ISL33P's custom mani, but the flow #'s should all be exactly the same between the runners.

[ISL33P]

it would be nice to see how they resolve the prob of #4. let me know when you have flow results.

i have just about finished designing a slightly different plenum, after conversations with a few experts, that will hopefully solve a few of my issues. it might be ready for testing in the next two-three weeks. i will get it tested at the same time i do the sr20 one.

[float_6969]

The reason that it can do that is because of the way it works. The fluid that is used only takes off material where there is pressure (or a resriction). If they use a jig that ties all of the runners together when they flow the material through it, it equalizes the runners because whichever runner is flowing the least has the greates pressure and is going to have more material removed from it so that it will flow the same as the other runners. I hope that made sense. If not check their site out HERE. As I said before though, I still don't think it will have nearly the quantity of flow that yours will. I'm just looking for a smooth and even flow because the HP #'s I'm after don't dictate the neccesity for it. (275hp)

[ISL33P]

clearly understood. thanks for the explanation.

[Projex240]

Regardless of the Small differences in the cfms per runner, i think that the overall improvement is excellent. True, the stock manifold may be great in terms of cfm consistancy between the runners, but it lacks where it counts. In full flow potential. Theres no problem in my book going from low 300's to mid 500' in temrs of flow. If these ever make full pproduction swing, im in.

Id like to see these made with the dual ford TB setup.

-Josh

[float_6969]

I couldn't agree more! If I was looking for some big #'s, I'd ditch the stock manifold in a heartbeat!

[ISL33P]

they will be in full production be the new year...hopefully. what is the duel ford tb or what does it look like ?

[Projex240]

I forget what mustang they came factory on, or what other cars had them, but its like a dual 46MM TB in one housing or something like that. Even if you couldnt go with a dual TB, a 65MM TB from a mustang would be a nice little upgrade.

-Josh

[ISL33P]

thanks for that projex. i think the twin 46mm would be too wide. not enough space in many ca engine bay's but would be nice.

the most common throttle body downunder is a ford 68mm, but i can make them to 70-71mm.

[Jeffers_S13]

Hello all !

After weeks of searching I have finally discovered this thread and registered on this forum, Cortina Mk1 is a familiar name, Im in the UK and spend a lot of time on the SXOC.COM forum.

This thread and the project it covers is of great interet to me, the design you have come up with is very similar to one that I have had in mind for some time. I have found only one site covering a custom made inlet although it was for an SR20 on which I was basing my design. I can send pics if you like, I forgot the link but saved the pics, it may be useful for your next project ? It has a longer neck before #1 inlet and also a curved rear and a subtle inflexion at the side to create a kind of scooped vacuum effect to 'save' air for number 4, pics would help more than words...it also uses ram pipes, but from the pics I have it looks like the guy made #4 much shorter, not sure if the guy did any flowbenching to prove the design.

Anyhow, the reason I need to make a custom inlet is for a kit car project Im working on, where the OEM inlet will stick up through the bonnet, Id rather keep the bonnet as standard to avoid ugly bumps and bulges so am planning on going down the custom inlet route. After looking at what I can ditch from the inlet, it is easy to tidy the whole look of it, as I wont need brake vacuum and the water heating for the TB and the rear will be ditched. The only thing that I was planning on keeping was the AAC valve set-up, but on this thread it has been said it can be ditched aswell ? how so ? I assumed you'd be using a TB and an aftermarket ECU to control it but it seems no ? can you or anyone elaborate on how to move it to the firewall ? I guess two pipes could be run from it, has this been done before is this how the GReddy one works or is it mounted to the manifold like the OEM one ?

Also, would you mind letting me know what thickness aluminium you used, I was planning on using 3mm as I have an abudance of the stuff and any thicker tends to crack when bent.

And, is there a newer thread than this that I have yet to find ?

Thanks

James

[ISL33P]

hi james,

photos of those plenums you mentioned would be nice. i am dropping off adifferent design at the welders tomorrow and new flow results will be available by the start of next week.

as for the aac, i will leave it to the ca experts on here to give you an idea of how to set it up. as for the computer, it is preferable to run aftermarket as this negates the need to keep the standard sensors/controls on the standard plenum.

material wise, yes i use 3mm, easy to work with and very strong.

[Projex240]

anything new on the plenum?

-Josh

[ISL33P]

yeh, it was welded up today and it is getting dropped off for flow testing tomrrow. will have results by mon/tues, fingers crossed.

[buffy]

Good news

[drftnassmofo]

hey is33...i dont even care.....ill take one as is...its friggin hott!!

[ISL33P]

if you are seroius send me an email [email protected] and i am sure we can sort something out. also send me some more details about your car.

btw i picked it up from the wleders (better welds than the last one) and have dropped it off for flow testing, will have results friday night (ozzie time) or monday night.

[ISL33P]

results for individual runners are: all figures quoted are at 25". % figure is the variance between the avg of all four cylinders.

just to refresh your memory i have added std and Ver. 1 flow ratesSTANDARD cylinder #1 - 221cfm (102%)cylinder #2 - 220cfm (101%)cylinder #3 - 220.5cfm (102%)cylinder #4 - 207.5cfm (96%)

Ver. 1 - just to refresh your memory. overall flow was 555cfm.cylinder #1 - 243cfm (104%)cylinder #2 - 276cfm (109%)cylinder #3 - 251cfm (100%)cylinder #4 - 239cfm (95%)

Ver. 2 - new results. new overall flow is up more than 20% and flow to each cylinder is also up by more than 15%. variance of avg results only shown.cylinder #1 - 95%cylinder #2 - 105%cylinder #3 - 100%cylinder #4 - 95%

due to someone trying to copy my design, flow figures will only be given to those who purchase a plenum if requested and rounded to the nearest 5% which i quiet close to what the actual result is. 1% or 2% difference will not effect engine performance at all.

as you can see flow is well up and i have also reduced the variances between each cylinder. i have another trick left up my sleeve for Ver. 3 which will definitely increase flow for #1 and #4. i only make one change at a time to make sure i am getting the (positive) results from each change.

hopefully results will be available sooner than this update.

what do you know think ?

[fanta]

Progression is awesome, can't wait for the third installment

[djmace]

how much would one of these run us again?? ALSO will this clear the strut tower bar section so I can isntall a normal strut bar?

[RMiller]

Wow, that sounds great. Keep it coming.