318is m42 project update

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tim_s
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Tue Feb 07, 2006 7:30 pm

thought i'd put up some newer pics, its been a while since i updated, but other commitments have meant i've lost a bit of momentum. end of this wk and this wkend should hopefully sort that out though!
the throttle bodies are happily mated up and are perfectly port-matched etc, looks factory, really is good. vacuum rail is also sorted, fuel rail is more or less sorted too. trying to shoehorn in an s14 plenum is proving a nightmare though. Problems are as follows:
-m42 sits too far back in the engine bay, so the plenum hits against the brake servo
-alternator bracket is bloody tight, as is the starter motor
- m/c tank and coolant hoses into cockpit v close too

with the throttle bodies at the angle they're at atm - which is the best position for them in terms of flow, injector angle etc, in order to mate up to the plenum, the trumpets require quite some kink... may fibreglass up the trumpets at the angle i can get them to fit, not very happy with this.
you'll see what i mean in the following pics. have to somehow attach the plenum to the engine too...
i may have to get someone to build me up a custom alloy plenum and get some tasty trumpets. this would probably be the best solution. as far as trumpet length and plenum design is concerned, my info so far seems to suggest that basically i want the longest trumpets and biggest plenum i can physically fit. if i go for a custom effort, it'll be an e46 m3 csl style slanted design.

fuelling is looking likely to be done by megasquirt, not sure whether to go alpha-n or speed density, and whether to leave the sparks handled by motronic... haven't heard back about the bottom end at the mo, will ring them tomorrow.
anyways, the pics.
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any advice much appreciated, if anyone fancies building me an ally plenum or some clever trumpets to make this work, please let me know!
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Tue Feb 07, 2006 7:36 pm

Cool! a good Q car on the road
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Tue Feb 07, 2006 7:58 pm

I don't know if the E28 M5 trumpets my be suitable or even fit but i'll put a couple of pictures up, if they look like they might be use full then i can take some more pictures and measurements ?

HTH

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tim_s
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Tue Feb 07, 2006 8:13 pm

andy, would be nice to know spec if possible. and photos are cool! the dia of mine are 50mm, and the bolts on the flange are 70mm apart iirc!
have a chap interested in making me some trumpets and a custom plenum for me, so i may be sorted. be nice to use the s14 one though. any input on trumpet length, plenum size etc? i know you have much more experience than me about this kinda thing!
cheers
tim
Last edited by tim_s on Tue Feb 07, 2006 8:20 pm, edited 1 time in total.
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Tue Feb 07, 2006 8:17 pm

Nice!

Though. all that effort and cash, might make it seem a bit incomplete if you don't get spark control too?
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tim_s
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Tue Feb 07, 2006 8:25 pm

yeah i know what you mean, but i'm very aware of my lack of ability as far as mapping etc is concerned. its not straightforward to get MS to control the m42 coilpack, the i'd have to map it too. i figure i can always have the motronic remapped if nec anyway, i think the fuelling will be the biggy. i want the car to be daily-driveable, so thats why i'm thinking of using a MAF, keeping motronic for sparks etc. i still haven't ruled out other options either.
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Tue Feb 07, 2006 8:31 pm

that's fair enough mate. Opens up that whole m42 chipping can of worms again :)

/me runs and hides

Gonna be sweet though when it's done!
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Tue Feb 07, 2006 8:41 pm

70mm

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54mm O/D

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45mm I/D

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145mm

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Custom trumpets/plenum might be the best way to go but expensive, i don't know a lot about the tuned length of a trumpet other than the basics like you were saying.
my info so far seems to suggest that basically i want the longest trumpets and biggest plenum i can physically fit.
This set up is supposed to favor more torque i think ?

If you find some one with an MS controled M42(with ingnition control) then you could see if they would share thier map with you ?
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Tue Feb 07, 2006 8:43 pm

Longer trumpets = more torque yes (dont they tim :twisted: )
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tim_s
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Tue Feb 07, 2006 8:53 pm

thats quite interesting, could probably use those flanges with s14 trumpets with a bit of modding, doesn't overcome the brake servo being in the way though, the plenum would need chopping. when i have the car in bits again later this week, will have a good think. cheers for that though!
as for trumpet/plenum stuff, have only really read this
http://www.grapeaperacing.com/GrapeApeR ... ystems.pdf
and stuff on e36coupe forums, but yeah, i want the tbs tuned for max torque.
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Wed Feb 08, 2006 1:40 pm

If you would like a nice alloy plenum made up. I would be more than happy do fabricate you one for cash. Internal trumpets will be know problem either. You would have to send me rubbing of the TBs you are using (or just the TBs) and tell me what diameter inlet you want and in what direction.

Pm me for more details and prices.

Thanks,

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Wed Feb 08, 2006 1:51 pm

318-is wrote:Longer trumpets = more torque yes (dont they tim :twisted: )
That's not necessarily true. Go too long and you might end up with lumps and bumps in the power curve where you don't want them.

If you're experimenting with trumpet lengths, I'd make sure there's some method of adjustment.

45mm throttles is pretty bloomin large for a 1.8 too! :D

Sure I'll have probs with my inlet runners, but I'm a bit stuck for space unfortunately:

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Dan318-is
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Wed Feb 08, 2006 2:07 pm

dude that is one hell of an engine bay

obviously i meant that within reason; what are the effects off to shorter TBs then?

o/t but turbo brown were abouts in aldershot r ya?
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tim_s
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Wed Feb 08, 2006 2:30 pm

lol turbo-brown, my tbs are 50mm 8O
but the car will soon be a 2.1. but yeah the tbs are still huge.
i'm going to go for about 6" trumpets i think, based on s50/s14 trumpet lengths (the bmw ones if anything are a little longer, but they are also curved which is confusing with regards to air speed etc), trying to keep things pretty close to what bmw have done, especially with the s50 as i'm essentially building a 4 pot s50 (same tb dia, similar head etc).
if you have any input or info on trumpet length or plenum design, i'd be grateful.

doug, that sounds great. i got talking to a chap on an e36 forum last night, but i'll pm you and explain the kind of thing i'm after aswell. i'm going to measure up properly this wkend, but looks like the trumpets may need to have a slight bend in them towards the front of the engine just to clear the brake servo. i will make a cardboard template of the plenum and do all the measuring properly this wkend and sort out some pics. getting a trumpet and even a spare pair of tbs to you would be no probs. whereabouts are you?
Cheers!
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tim_s
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Wed Feb 08, 2006 2:32 pm

btw turbo-brown, that engine bay is insane. i take it thats two turbos and throttle bodies!!!! :cool: :eek:
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Wed Feb 08, 2006 2:58 pm

I do like Alex's efforts, top notch oold chap !

Tim, you have you tried offsetting the engine height on the nearside, , perhaps tilting the engine further towards the offside would give you a tad more clearance, can always skem the engine mounts a little Too M8

who know, might all fit then

As for MS on an M42, you'll be blazing a new trail Tim, numero uno, but thats no real issue, MS can run a MAF if you like and output a load signal to moronic to keep the 3D mapped ignition

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tim_s
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Wed Feb 08, 2006 3:36 pm

yeah, is a good point ant, had been thinking about this a bit. i reckon if i did this it would certainly help a bit, but would still have clearance issues with the brake servo. the best way to do it really would be to move the brake servo/mc to the driver's side i reckon.
i can get the trumpets to fit by cutting them near the flange to add an angle as you can see in the pics. i could fibreglass them up like this, but i don't like the kink, the trumpets are quite short and curved too, and are crappy plastic so im beginning to think its not worth the bother - the s14 plenum would also need an angle grinder taken to it too to clearance it a bit from the brake servo and alternator (will prob do this later in the week).
i've been beginning to think about custom stuff because i think its better to design something spot on from scratch. bit of a shame as i think the s14 plenum is a nice looking and obviously well designed component, and i've got to the stage where i don't want to spend extra money unless i really have to.
ant, i'll reply to the MS thread later once i have some more thoughts etc, i wouldn't be quite numero uno, it looks like there's a chap in the states who has half got MS working on an e30 m42, i've pm'd him for lots of info and maps! he appears to have mentioned some trouble with the crank signal. I'm still keen on MAF, but its not set in stone. i have lots of things in my head which are pretty unfounded. i just don't know enough yet. things such as a MAF is better for my daily driver - but i don't have any experience or theory to back this up!

i'm not too concerned one way or another about doing unique stuff - there's enough on this engine that's unique - the 2.1 conversion is the only one like this i know of, and is done using some pretty rare components, and i've never seen a throttle body conversion like mine, only ever seen pics of the dbilas kits.
I'm really not sure about using MS to do sparks etc. i'd like to keep my coilpack ideally, how difficult/costly would it be to use my cam signal and an an extra coil driver on MS?

Just called the engine shop, they're still playing with the same scooby-do which they were playing with a wk and a half ago when i took the engine in, and haven't started my engine yet. don't want to rush them or piss them off, but the engine's spent the last month having engine shops do f all to it.... :x
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Wed Feb 08, 2006 6:21 pm

Holy crap!

50mm! 40mm is big enough for 50bhp/cylinder running N/A!
Different kettle of fish I know, but Pug people reckon that 90mm trumpets are just about right for the Mi16 engine (which incidentally has 40mm inlet ports)

Mine is a twin turbo and 6TB setup, nothing like making things overly complicated is there :lol:

I'm actually just down the road in Ash Vale 318-is :)
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tim_s
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Wed Feb 08, 2006 7:11 pm

yup, they're huuuge! iirc s14 ones are 46mm or 48mm and s38b36/8/s50 50mm. bmw obviously like to use big throttle bodies! the trumpets on most bmws appear to be longer than 90mm... guess its to keep the velocity up with such large tbs. using 50mm throttle bodies wasn't really out of choice but because they're such a good fit.
yeah your car's only slightly complicated!!! must sound incredible.
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tim_s
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Wed Feb 08, 2006 7:14 pm

one q though, why did you keep the m20 if going to all that trouble? (that is an m20 under all that isn't it?!)
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Wed Feb 08, 2006 7:24 pm

:lol: Sounds pretty fruity, but it's never really been above 1500rpm under load, and only round to about 3000rpm with just a blip of the throttle.

TBs are wicked though, just blip the loud pedal and the revs instantly shoot round the dial with the whole engine angrily trying to climb off it's mounts :twisted:
one q though, why did you keep the m20 if going to all that trouble? (that is an m20 under all that isn't it?!)
It is still an M20 under there. If I'm honest, I didn't know there were so many relatively easy conversions (M30 etc.) when I started :(

Whilst I'm being honest, I wouldn't recommend that anyone copies what I've done, it's more trouble than it's worth, and "twin turbo" is really worth no more than bragging rights as I'm sure than Ant or Fozzymonster's cars would whip my ass!
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tim_s
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Wed Feb 08, 2006 7:35 pm

pretty good bragging rights though! how much boost you running? what CR etc?
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Wed Feb 08, 2006 7:52 pm

Should be running about 9psi on a 9.7:1 CR

Might well need to lower that boost a bit more though! Also, I've not yet driven it with any boost yet, but with any luck Ant will be free to help with his magical tuning device on Friday :)

Certainly adds to the effect when you get to say "two and a half twin turbo" I guess, but the only people who've asked haven't really had a clue what I'm on about so I've started just saying I drive a brown beemer now. :roll:
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Sun Feb 12, 2006 8:37 pm

bit more of an update. getting the plenum right is proving to be a right sod. there is simply f-all room around cyl 4 cos of the brake servo. plan is so far to use the plastic flanges i have onto the throttle bodies with really short bits of silicone hose to a double-sided flange on the plenum which goes to a bendy trumpet. trumpet length 5", to the butterfly about 6". also permits an interchange for 3" straight trumpets, which is the longest you'll get in without seriously restricting airflow to cyl 4.
plenum needs to be an inch smaller between brake servo and t/b (width), a bit longer towards the dipstick (will bend the dipstick a little and let the plenum come further forward else cyl 1 will be firing into the plenum), and the height needs to be a few inches smaller. will have to make up a more accurate plenum sometime.
any comments and suggestions appreciated. am not over the moon about crappy plastic trumpets and bent trumpets, esp as they seem to slightly restrict one another's airflow, but that's the only way i can see to get some decent trumpet length. otherwise its 3" straight ones, but i'll try both and see which is best.

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Mon Feb 13, 2006 6:50 pm

Have you thought about using foam to shape a plenum mould?

I know you wouldn't be able to 'see inside' it to position trumpets but you could fill the space well and radius all the edges. If you used your existing cardboard template to rough the shape and refine with sandpaper/rasp. Then layer fibreglass and resin on it to make a mould. You could then layer whatever material you like into yuor shiny mould, making various runs etc. Carbon fibre sound good? You don't have to use an autoclave I beleive.

The foam they make surfboards or arrange flowers in would work...

Just my thoughts..

Jai

PS Moving the MS/servo to the other side sounds like a very good plan. The whole lot is over there on the Z roadster I have, gotta have a look and see how they've done it. Maybe the car can be cut/welded or get one to fit somehow. Another option I'm interested in is a pedal box with bias bar built into it. It could even be verticle or in-cabin type (with remote reservoirs) if there's room under the dash.. My only concern is the everyday feel of them..If I can live with no servo (they have a larger mechanical advantage though don't they??) I need to research!

Bit long for a PS!
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Mon Feb 13, 2006 7:08 pm

Jai that sounds like a top plan, but could you elaborate a little (actually, a lot!). This would be a learning experience for me to say the least. This is not something I have any experience with at all, my fibreglassing skills are pretty non-existant. I reckon with some web tutorials and stuff (if anyone knows any good ones would be good to hear) I could make a fibreglass mould, but I know nothing about CF.
could you expand a lot for me, or do you know anyone who might be interested if I were to create a mould.
but great suggestion, i hadn't even thought about that. i made a much better shaped plenum today so feeling a bit happier.
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Mon Feb 13, 2006 8:27 pm

Tim, that is looking FANTASTIC!!!!!!!!!!

I wish i could say the same for my iS. I am still having trouble getting money together.

I went to the same breakers that Gareth got his M3 bits from for his M30 conversion. I asked about some S50 TB's and the bloke wanted Ԛ£300 for them!!!!!!! :eek: :eek: I'm seriously re-thinking my whole project ideas at the moment (i don't think i'll ever get anything bought/made/built etc at this rate :? :roll: :cry: ).

I'm looking at other ways scratching my petrolhead/speedfreak itch and they're sounding a cheaper, much cheaper!!! No tax, insurance, MOT's to worry about :D just going very fast!!!!!!

But, as my friends say about me "he used to be indecisive, but now he's not sure!"

So if i've done my sums wrong then i might just have an iS on TB's running MS in the future..........who knows........

(oh for the want of a lottery win)
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Mon Feb 13, 2006 8:47 pm

IS there anyway you can rotate the engine? (using different engine mounts on one side)

Looks good 8)

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tim_s
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Mon Feb 13, 2006 8:55 pm

cheers andrew/tommy. i'm not too sure about rotating the engine, have given up on the idea though really. what i've got now (i've done some more work on the plenum today and got a much better flowing design) is quite good. the prob with rotating the engine is the steering joint runs pretty close to the exh manifold, and i just don't fancy messing with it. its the same story with the brakes - i can do things to them and would if there's no other way, but would rather exhaust all other options first.
a fibreglass or carbon plenum has really got me thinking. having an alloy one built would cost a lot of money, and look only OK at best, so may look into this a little more. any help as always is appreciated!
tommy, once i have mine sorted, a lot of the hurdles will have been crossed, so you might be able to knock something up quite cheaply. i've also accumulated some quite good contacts through the engine building and throttle bodies, so if you do consider going down a similar route, i may be able to help! and more than all that, the finished item is going to be great. the throttle bodies now they've been tinkered with look like they were made for the m42.
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tim_s
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Mon Feb 13, 2006 8:56 pm

and tommy, whats your going v fast without tax/mot/insurance idea?!!!
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Mon Feb 13, 2006 9:23 pm

600cc's, a 14,000rpm redline and two wheels!!!!

Did a track day this weekend with a mate at Cadwell Park on my Kawasaki ninja 600 road bike!! Cost Ԛ£60 for 6 20min sessions!

Was fantastic!!!!!!! Front wheel 2ft off the ground (at god knows what speed) over the top of the "mountain" was the scariest thing i've ever experienced on two wheels.....yet soooooooo addictive!!!!

Braking at 140mph at the end of pit straight, dropping down a gear, heaving the bike left into "coppice" knee down, nailing it up hill, braking, dropping down another gear heaving the bike right........ (I could go on)

So basically i'm toying with the idea of selling the iS and the E21 and getting a track bike with the money.

My mate is in an amateur racing series called Derby Phoenix. I was thinking of getting the same track bike as him so i can learn my way around it with his help. He also has plenty of spares (he's just bought an engine off ebay for Ԛ£5, with a buggered alternator)

I just plan to do track days on mine at the mo, but i'm sure he'll come along for the practice.........

(Sorry for stealing the thread :oops: )
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Mon Feb 13, 2006 9:36 pm

tim_s wrote: the throttle bodies now they've been tinkered with look like they were made for the m42.
Thought they would :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen:


Damn i still wanna do this!!!! (think i'll change my forum name to Mr Indecision........)
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Mon Feb 13, 2006 9:47 pm

lol, now there's an idea! i love motorbikes, my brother has one and i've always wanted to. is a sociable hobby too. I've refrained thus far due to money and the fact i need a car, and to be honest am a bit worried about killing myself! but what a buzz that must be on the track, can't imagine there's anything quite like it.... lol you've got me thinking about bikes again! one day...

have decided i'm going to try to build a fibreglass plenum, on the grounds that the most that would be at stake would be a couple of quid, and its all learning. the most fibreglassing i've done in the past is p40 for my front speaker build in the bmw and p40 in the bbs bodykit and rear arches of my ex mk1 golf!!! now any advice anyone can give is much appreciated!
if i get any good at it, then i will try a final layer of CF. wonder where i can get some foam stuff online...
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Mon Feb 13, 2006 10:01 pm

your work is amazing tim, you truly are a legend!! i wish my iS was like that...

anyway, a few points.

have you thought about using the brake servo from a mk2 golf. apparently, this is what the s50 boys do when the transplant s50 engines into e30's (or so i've heard anyway).

failing that, if you took the servo off, all you would have to do is create more leaverage on the brake pedal to compensate for the vacuum assistance. its basic physics. my explanation may not be so clear on here, but maybe a drawing or slightly more in-depth explanation would help???

as far as the throttle bodies go, you've made excellent headway already. your comments about trumpet length, plenum shape, tb diameter, etc are making us all think!

i seem to remember someone telling me that during the design process of tb's, trumpets and plenums, you must take into account air flow (which you have mentioned) vacuum and vortex. in order for the engine to run as best as possible, each cylinder must take as much as air as it needs and when it needs, and without any clylinders having an advantage over others (different lengths of trumpets). plenum chamber design must incorporate vacuum (capacity) and air flow (shape), as these are exceptionally important

thinking about how the air will enter the plenum chamber will also aid in trumpet design/length. as mentioned above, all cylinders must be equal. having too long trumpets may effectively starve the cylinders of air, as its difficult for the piston to draw it through the trumpet. (this also has alot to do with vacuum), however, if your trumpets are too short, there may not be enough vacuum to draw enough air and the vortex inside the trumpet will be insufficient when entering the cylinder to create an effective mixture?

i hope this hasnt confused oyu too much and has helped you as much as possible. my knowledge on this is limited (just things i read about and learn off other technicians, etc) and im not trying to preach to you, just lend advice!

im looking forward to seeing the end result. keep up the good work.
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tim_s
E30 Zone Squatter
E30 Zone Squatter
Posts: 1661
Joined: Thu Feb 03, 2005 11:00 pm
Location: Bristol/London

Mon Feb 13, 2006 11:59 pm

Cheers for the compliments!
and tis no probs stuart, i'm after as much advice as possible! Its all appreciated!
The plenum and trumpet design is a bit more involved than that though, take a look at the pdf on the pvs page for some insight into it. the plenum's function is to allow the air to slow down and gain density, the intake ports are tuned for both flow and velocity. tbh though with all the calculations in the world, some real world tuning and experience is what will matter most. for my purposes a lot of its quite irrelevant really as i dont have a lot of choice in trumpets due to space. as for the plenum, for my application, as big a plenum as possible is the ticket. again this is limited a lot by the space available. the tricky bit for me now, is that now I have decided roughly what the plenum will look like, how to ensure the csl style plenum (i'm not sure of the technical term for this type of plenum is) will supply each cylinder equally. At the moment cyl 1 is a bit problematic as the curved trumpet is pointing more or less straight into the path of the incoming air from the airbox at close range. bugger. this is why in some respects, straight trumpets serve me better than the curved ones on there at the mo. the other prob i have to work out is what angle of the sloping side of the plenum will supply each trumpet equally.
bloody tricky!

a smaller servo (mk2 golf or otherwise) will do little for me, as its not the diameter of the servo thats really the problem, but more than it sticks out into the engine bay. think its discussed earlier in this thread.

hope this clears up some stuff, fella! am sure it'll all come together soon anyway, and i may have to redesign some bits but thats all part of it i guess!
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2.1 318is, MS, LPG. 200bhp, 175ft/lbs GONE!
Boxster, e46 m3, e36 sport touring and alpina B3 3.0
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