1989 331is

[oakey]

More great results and thanks for posting the graph
She must shift

[reggid]

More great results and thanks for posting the graph
She must shift

there is very little info out there regarding real gains from different mods etc so i am more than happy to help out.

I suppose its no real suprise that when you start making big changes in displacement that the whole lot needs attention.

cruising in top gear at 80mph it probably pulls as hard as when stock in 3rd when you floor it and yet it isn't even fully on cam by that stage

[BigBavarian]

looks very very nice great pics

[bss325i]

What does it rev like in comparison to a B25?

Also do you have a stock flywheel?

[ricey46]

Very nice Sport reggid, in the right colour too!!lol.

Any more pics/ under bonnet pics??

[oakey]

We want sound clips, we want sound clips!!

[rebelcruiser]

very nice

[reggid]

This is the only underbonnet pic i have for now, and things look a little bit different now with black intake manifold, different plug wires, a little more dust, dirt and other crap.



the only small exhaust clip is quite old (still running AFM and motronic) goto 53sec on the video



its not as silky (refined) as a properly running B25 but revs much faster since reciprocating and rotating masses are smaller and much more torque.

I use a lighter flywheel which is around 12-13lbs iirc.

[poolnoodle]

Nice car mate, good to see some more oz cars on the zone (no rust, lots of cracked dashes!!!).
Where did you get the 15" BBS? I have been looking for some for ages without success.
Let me know if you ugrade to Alpinas and want to let the BBS go

[reggid]

Nice car mate, good to see some more oz cars on the zone (no rust, lots of cracked dashes!!!).
Where did you get the 15" BBS? I have been looking for some for ages without success.
Let me know if you ugrade to Alpinas and want to let the BBS go

Thanks,

new years resolution is not spend money on the car unless its absolutely neccesarily e.g petrol, oil, filters etc so don't hold your breath....lol

I got the 15" BBS from a guy on this board JonB iirc had them sent over for about $600AUD to my front door

[hassmaschine]

so this is where you've been hiding all the details on your M20 build! in hindsight I really wish i had done two things - the 89.6mm crank and 11:1cr pistons. oh well, my 2.8 is still fun and has untapped potential in it.

[xavier]

Do you do all your own engine work or is there a BMW workshop you can recomend in OZ?
Ta
Xavier

[Simon13]

the long and light 138mm rods will be helping aswell i expect

[Jhonno]

I think the effect of proper rods and pistons is severely underestimated at times..

[juniorGT]

[quote="hubble"]
quote]


awesome pic... nice car

[reggid]

Do you do all your own engine work or is there a BMW workshop you can recomend in OZ?
Ta
Xavier

It depends what it is...........i did a cam swap a couple of months ago and had to pull the head but wouldn't like to pull the entire engine with the facilities i have. I built up a spare engine on this occasion and had Motorworks swap it in.

I can thoroughly recommend Motorworks located at Roseberry in NSW

[reggid]

I think the effect of proper rods and pistons is severely underestimated at times..

I would say the most important part of the build was the exhaust and tuning (apart from extra CC of course) as per last RR plot. The light flywheel and internals make it rev quickly and responsive but i don't attribute any significant amount of power to these. I only went with the light rods because the pistons were made to use them (clever marketing ploy).

[nm1]

your car is lethal one of my favourites on here

[reggid]

so i fit some 16" Alpenis

[Rav335uk]

so i fit some 16" Alpenis

You mean "Alpinas"

[RobbieT]

so i fit some 16" Alpenis

Is that what we're calling 'Pina reps these days?

[reggid]

so i fit some 16" Alpenis

You mean "Alpinas"

no;) i blame my spelling i type how it sounds, lucky my name is not Al ...lol

[reggid]

Did some exhaust mods a few years back, everything I did went backwards and by a lot”¦.lol



The engine seems really sensitive to the exhaust. Perhaps the exhaust side of the head is not working well (MM hardly do anything to the exhaust side for their head, cam etc due to emission reasons) or perhaps that it is overcammed and the ”˜right’ exhaust helps counter some of the side effects/problems ”¦.

Run 1 to run 2 was a catalytic converter change out where the new cats were moved closer and side by side as opposed to staggered
Run1



Run 2



Further investigation into this never found out what happened. I even put back a similar set of cats and used photos to position them as close to where they were but it didn’t do squat. Perhaps it was something to do with the dyno setup on Run1 and as such it is not real or there was another issue at play”¦..

Run 2 to run 3 was a x-pipe relocated closer to the engine
Exhaust from run 2



Exhaust from run 3 notice the x-pipe is closer to the engine



Run 3 to run 4 was a cam timing change (advanced 8 degrees). i did a cam belt change at the same time and thought maybe the timing shifted a few degrees. while i found good gains the shape of the torque curves shows that this was not the problem. the real problem is the relocation of the x-pipe


I will redo the exhaust shortly in preparation for my new build to get more fasts from the engine

[reggid]

been wanting to ditch the intake manifold for a while it just doesnt work well for a bigger engine and more power

For those of you who have seen this thread

http://www.e30tech.com/forum/showthread.php?t=118357

this is new but it is a copy and paste from that thread

So in preparation for a new engine build later this year I thought it was time to get a few of the bottlenecks sorted. One of them was the intake manifold.

There are no high hp M20 around that persist with the cast OEM manifold it just doesn't have the flow or tuned characteristics to make a lot of hp. i wanted to sort something and my current engine is being used as a test mule.

I had originally thought about jenvey throttles but since RHD already had sorted the linkage, runners etc with proven results I decided to go this path. Also being significantly cheaper and a locally designed product from a guy (Rama) who knows a thing or two about high performance m20’s certainly helped the decision. i also live within an hr of his workshop

The compact throttles give a lot of freedom with regard to runner shape, design etc.

I decided on 42mm throttles because they would suit my new engine which will have more compression, a much better cylinder head, better camshaft and a few other go fast bits.

I would have chosen 40mm for my current spec engine as a 40mm throttle will support 320bhp and I was only making 250-260bhp at best on the standard manifold. I felt 42's should still work well on my old girl though strictly speaking not perfect.

IMO It is nonsense that there are kits are available with 45mm there is probably only a few naturally aspirated m20 in existence that could benefit from throttles that large without sacrificing a good chunk of midrange, this size should not be the norm.

Having done literally hundreds of dyno power runs I understood the importance of a baseline to find out as accurate as possible the benefit from doing any mods.

My baseline is well down on what it made at its best back in 2009/2010, this is due to various reason i wont elaborate on here except to say mostly to do with exhaust changes and an old engine which doesn't have the compression it used to.

Nevertheless I had a baseline with which to do an APPLES to APPLES comparison and the baseline was done only a couple of weeks before i was to convert to ITB to minimise any other chances affecting results.

1) BASLEINE: my baseline is actually a long way from stock but the cast long runner manifold still features ;)
- MM pulse tuned intake, which has tuned extensions and the end of runners are cut up and port internally
- 63mm BBTB with Silicone Elbow
- Custom big filter air box cleaner with larger K&N panel filter see here http://www.e30tech.com/forum/showpost.p ... ostcount=1
- Custom tuned with MAP. Back in the old days i saw significant gains in midrange and top end by getting rid of my m30afm

Tuned extensions of MM pulse tuned manifold


Ported exit


2) Part DBILAS kit: I bought the plenum off ebay and the manifold from dbilas new
- Dbilas manifold adapter, ported to reshape injector area which has a rather large bump in it. The injector angle was modified to better match port angle and aimed at valve rather than port floor
- RHD 42mm throttles and linkage kit
- Dbilas plenum with silicone reducer couplers knife edged adapter and K&N cone filter.
- Custom tuned on Alpha N (TPS)



3) RHD FULL Length Runners ( 300mm length head face to trumpet)
- CNC manifold (preproduction version), port matched to TB not port matched to head
- RHD 42itb,
- RHD CNC spacer
- RHD trumpet
- Untuned









4) RHD MID Length Runners ( 250mm length head face to trumpet)
- CNC manifold (preproduction version), port matched to TB not port matched to head
- RHD 42itb,
- RHD CNC spacer
- RHD shortened trumpet
- Untuned

You will notice that engine was last tuned with the dbilas setup so (3) and (4) are using the tune developed for the dbilas which is not optimal by any means and there is certainly improvement to be made with the full RHD setup by a simple tune.

For example the 300mm runners leaned out about 0.6 to 0.8 across the board so it is moving more air and adding some fuel will help

Here you can see the difference between the manifold adpaters the RHD one is pretty much perfectly aligned with the port to clear the booster and you can see the spark plug through the runner with throttles open and inlet valve open. so it is a nice straight shot



Here is the dbailas manifold adapter before it was cleaned up with a die grinder to get rid of the hump.





It aims at the roof of the port and would introduce a lot of turbulence in this area which can affect fuel suspension and therefore combustion efficiency not just raw CFM (dry airflow).

The dbilas adapter is 45mm diameter at the start and is only 55mm long so the size is wrong to start and not a lot of room to transition the flow to the 885 port so basically it’s far from ideal. The RHD which is longer at approx. 110mm (IIRC). i port matched to the 42mm throttles (comes 40mm standard) so no step changes in area at all and the transition is gradual to the head.


RESULTS

GRAPH 1: baseline vs dbilas



DBILAS

Torque curve is nice gradual shape but midrange is down alot and this is evident while driving. There are still gains to be had past 5500rpm with peak 10whp topend gain and much bigger useable power band as power doesn’t fall over as fast. You could rev it to 7000-7500rpm and ride the power plateau and be a lot faster but there is room for improvement with no tradeoffs.

Throttle response is good and drivability not even comparable to common plenum single TB, it is miles better with ITB and alphaN. Will idle like a baby and tootle around easily, no grumpiness at all.

Still the smaller throttles can’t change the fact that dbilas hurts the midrange and is inferior to the stock manifold for midrange.

Reason is the rest of the runner volume is still too large and the runners are too short perhaps 200mm. The good thing about the dbilas is that it fits and clears the booster.

The Individual runners got rid of the really annoying dip in the torque curve at 2700-3000rpm on the OEM manifold which is probably due to cross talking nature of the common plenum.

GRAPH 2: #1, #2, #3 & #4



FULL LENGTH RHD (300mm) #3 BLUE

Straightaway using the dbilas tune AFR leaned out 0.6 to 0.8 of a point so definitely moving more air. Despite not retuning it gained 20whp peak (untuned), 30whp at 6000rpm, probably 40-50whp at 7k the power doesn’t fallover anymore and reving it out it is a lot faster due to the bigger area under the curve. Pretty much all the midrange is back then some, the bottom end is as good. There is a small band about 600rpm where stock manifold (MM modified) is better but a custom tune would probably fix that.


MID LENGTH RHD (250mm) #4

Basically as for 300mm but the 300mm has better midrange 4000-6000rpm. Topend is essentially the same. A higher rpm engine will tend to want a shorter length and 250mm might suit some engines better. Give the engine what it wants

Time for a custom airbox to ensure only cool air gets to the engine since socks are not particularly great”¦”¦.then a tune.

i recommend anyone looking for performance to get one of these kits. BFYB is there without question

http://www.racehead.com.au/?wpsc_produc ... 30-m20-bmw

starting to get back to the power it had before and i havent even fixed the bastardized exhaust yet

[NoTurbo]

That is one tasty motor and I really admire your attention to the small details.

[S38B38]

Great looking car,, and lots of mods

i wanna ask you about this

1),, an OZ 325is = close ratio gearbox and 3.91,, that is an ULTRA low gearing....

[reggid]

Great looking car,, and lots of mods

i wanna ask you about this

1),, an OZ 325is = close ratio gearbox and 3.91,, that is an ULTRA low gearing....

it is not the close ratio box that is 1:1 5th.

1st, 2nd and 3rd are longer than the regular 5 sp. 4th and 5th are the same.

if i recall 1st gear is longer with CR sport box and 3.91 vs regular 5sp and 3.73 so 1st is not too short at all

[reggid]

gear ratios

sport /std

1) 3.35 3.83
2) 2.03 2.20
3) 1.36 1.40
4) 1.00 1.00
5) 0.81 0.81

FD)3.91 3.73

so 1st and 2nd overall ratios are longer

[reggid]

couldn't get the main section how i want with clear finish so reverted back to plan A which is flat black and a bit more OEM looking which i prefer anyway. kept the CF finish for the lid.

will get proper photos when i can take pics during daylight hours and also with it installed and trumpets inside etc.

[reggid]

curved adapters 3D printed in ABS plastic and clamps from 48mm trumpets (e21 JPS aka RHD) so that i can use a thicker wall without crushing them. they are to get everything inside the airbox and clear the hood without using a excessively short runner and provide additional clearance to the booster and not shroud the trumpet. you can rotate the whole trumpet to point them forwards slightly to but you need to rotate them all because the centre spacing is about 90-92mm and diameter is 80mm of the bell mouth



trial assembly, trumpet length is 30mm shortened to have same centreline runner length as previous. i chose 30mm so that i can shorten them a further 30mm if needed more fasts. the new engine will require about 25mm shorter length according to calculations and simulations. the dyno will decide so i favour the longer length in the interim



this is why they are needed. this is runner 2 (no curved adapter), runner 1 is worse and runners are angle downwards. runner 6 is angle upwards but less of an angle this is to clear the booster by additional amount



runner 1 & 2 are angle down to give about 30mm less height, runner 3 is about 20mm but is not 100% needed. this was done to centre the trumpet in the box height wise



a view inside from the inlet



did some conceptual CFD to deliberately look at shrouding (distance between the trumpet and wall opposite opening) and some basic distribution to convince my self it wont be a disaster. i modelled the trumpets longer so they get quite close to the opposite wall to exaggerated the issue



quite a bit of flow comes from around the sides rather than from straight above







alot of flow comes from bellow the bellmouth



open trumpet flowed 0.152kg/s by itself. when flowed with box it is 0.150kg/s runner 6 and 0.152kg/s runner 1 so not much difference to open trumpet provide the K&N isnt restrictive. i have room for larger filter so will search the K&N site for suitable one

[reggid]

did the install today and everything fits and runs well.

unfortunately it is a fair bit quieter than open trumpets but still better then stock and dbilas which are too quiet.

definitely alot more power than the socks which lose about 15-20whp but i never drove this setup without socks so i dont know whether it will match the dyno run of 152kw with open trumpets no socks.

still got to find a better sized K&N filter and make a heat shield.....

[jimmyspeed]

brilliant work !!!

are you just running spark from the distributor and standalone fuel?

[reggid]

brilliant work !!!

are you just running spark from the distributor and standalone fuel?

spark is also from the standalone but still single coil, dizzy and rotor (for the moment atleast)

[dimebag_from_hell]

I need a soundclip of this badboy peeling rubber!

[S38B38]

The transmission ratio is similar as G280 ((M5)) vs G260/6 (535))

that ITB ,,looks just fantastic......