how easy/hard will it be to fabricate a swedish plenum?my mates a fabricator and said he will have a go if i can get the measurements and a few pics to see how it goes together, do they need anything special to control the airflow or are they pretty much just a metal box?

and if anyones got one could they give me the measurements and dimensions PLEASE

 

don't think you can just knock one up.

just buy one, a proper one.

 

Agreed...

There is a lot more that goes into the trial and test than just fabbing a box matey, plus a lot of money goes into it too.

Best option is to measure up for yourself and design your own with trial and error included.



However its a lot easier to buy one for the 300 pounds or so that they are.

 

the orginal svedish plenums are very good(only sold throu mike rainbird)

other ones are copies that might not work that well

cheers

 

Pretty sure Danny B's inlets are tried and tested....


Might be worth a phone call

 

arent danny b´s the orginal design ??

 

I am sure danny B did have the original design and I know a couple of his went abroad and have been copied from what he has told me.

 

Not to sure tbh.. best of asking

 

so whats what then.

 

As i understand them, aren't they slightly tapered to allow for flow differences etc.?

Wouldn't fancy getting that wrong personally..

 

I am sure Danny will come on tomorrow and give us the rundown on Plenums and his prototypes he tested on his own car.....And were very successfull.

 

would be costly if it went wrong.

 

think thomas(supplier of mike) has modified dannys design a little bit AND had it flowtested.

iirc the difference between the worst and bet flowing cylinder is 4-6% but dont quote me on that (little bit of the mag manifold that ranj had fore sale that is 4% diff best to worst)

but mike or danny can probably confirm this

cheers

 

So was Danny the first then.

 

dicko have ya seen wennys new inlet manifold yet you might be able to get the sizes off his.

 

think so but not sure

could always discuss this with mike or danny.either way the danny/swedish plenum are tested and tried.could always get a friend/welder to copy it but is it as good as the real thing?

PS why would you do that?use the small turbo plenum up to 450bhp or so then open the elbow up..

cheapest there is

 

As for who done it first i'm not sure, the first one I made was in sep 99 along with an external wastegate set up using an ex cosworth F1 turbo,this was state of the art in the cossie world back then as I should have been running a T4
anyway while mapping with the first inlet and monitoring EGT it was clear that the inlet wasn't perfect so I went from box design on to the rounded tapered design which was made in early 2000, this proved to work good and I have sinced reproduce my manifolds to this design, I have not had them flow tested but in the past 6yrs there never been a fault from a result in using my inlets. I've alway ran one, Brom and SEAN B had them, Steve Scott Has one on his Fiesta after blowing a copy one apart then the same 'Coff' back resulting in blowing the ISCV apart and not effecting my inlet that is still fine to this day, The actual one made in 2000(first good design) is on Comedy Dans saph cossie that runs around 430RWHP andf that inlet is 6 yrs old.

Back to who was first with the idea I'm not even sure there the same but there BOTH good weather its mine or from Mike, just dont risk your engine to save a few hundred quid cus ya mate can work a welder, theres more to it than that!!

Look out for Performance Ford mag soon with my latest one off ST170 turbo fabricate inlet

Oh and also the adrenaline cossie Frame connectors

 

They're piss easy to fabricate providing you can accurately machine / cut the metal and are able to TiG weld. As already mentioned to make one to give equal / near equal air flow is a different matter all together.

About 3 months ago I made one of these to fit a 4x4 Saff that belongs to a good friend, IIRC it took about a day of messing about to get good airflow between all cylinders and to ensure it was rigid enough to take 50PSI without any expansion of the walls. Now that I have all the dimensions I reckon the actual fabrication time is probably only 30 to 60 minutes (un-polished and with the un-smoothed welds).

TBH I'm not sure how people manage to make alloy plenums which are apparently so easy to split (I'm referring to some of the recent posts on here stating something to that effect), the quality of the materials used and/or the welding must be absolutely shocking if they split that easily

In regard to dimensions; that’s something you'll have to find out for yourself, I don't think anyone who has spent time getting decent flow is going to give away that information for nothing.

Also tapered plenums have been around for ages, hardly something unique; most "original" ideas aren’t, they're just variations of themes or copies of copies.

 

just like to add seans old plenum was sold to a julain godfrey customer which now is running 700 bhp plus on race rule

 

need we say more.

brom get on msn, need a quick chat.

 

ring me 2moz matey i fortunetly got 2 bromettes here wanting to go to sleep
late nite working and no sleep gona kill me i know but i diie happy

 

For those that are interested, the design of the plenum IS NOT something you can just knock together and here's why.....

With the swedish style plenum the inlet (throttle) is at one end ahead of cylinder No.1 at right angles to it.

This put the point of inlet air closest to No.1 cylinder, no.2 is slightly further away, then no.3 with No.4 being the furthest away.

The problem this causes is that the runner lengths (throttle to inlet valve) are then all different. If left as is, no.1 would be supplying more air than No.4.

So to compensate, the plenum is tapered towards the rear.
By making this convergent this serves to increase the velocity of the air (thermodynamics), such that the airflow going to cylinder no.4 is speeded up in an attempt to get it to arrive at the inlet valve at the same time as No.1 (which has a shorter path).

You can see how the standard plenum supplies the inlet towards the middle of the plenum (actually closest to No.3) this therefore means No.3 get the best airflow over the others.

I started working out the maths and it got so in depth its far easier to make a test version and experiment with the maount of taper and fully bench test it until you can get the closest equal airflow across all 4. notice I say closest as that is what you'll get at best.

Considering the amount of money spent by the likes of Ferrari here's a picture showing the eventual (best comprimise) of the inlet plenum on the F430. You can see even they are not equal


So to be fair, you could try and make one yourself, but you need to give careful thought to the airflow and do various testing to ensure it is right. you could of course get lucky. Either way, I can see why people charge what they do for these since there is alot of work to produce the right end result.

 

 

At 30psi the Swedish items have been flow tested to 2% disparity between cylinders and on ALL of Harvey's 600+bhp conversions is his plenum of CHOICE .

These are the ONLY ones that I know of that have been engine dyno developed. Make of that what you will, but I personally think you'd have to be stupid to put a Ł200 "copy" on a Ł10k engine . Get it wrong and it's hasta la vista engine .