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Hybrid e30 m325i s50b32 - NZPC Article

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This car makes me want to keep my m325i ! Awesome work man.

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F*** yeah Josh, congratz

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cheers fellas .. Can add 1:18.3 around hampton under performance, hoping to better that in July.

@ brunch, was going to say before you left to remember to get use to listening to the TV and not be temped to look down in traffic, All common sense stuff really :D enjoy! :)

Also remember boys .. few s50b32's still for sale up at HellBM. Best performace upgrade ever.

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Haha yeah unfortunately multitasking isn't my strong point so I'll stick with listening only!

Thanks though, great to get working.

@ brunch, was going to say before you left to remember to get use to listening to the TV and not be temped to look down in traffic, All common sense stuff really :D enjoy! :)

Edited by brunch

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Looks like we will be doing a S50B32 conversion into a customers `87 M325 in the coming weeks. Very impressed with what you showed him on the weekend.

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Such a mean machine.

Tis a crap magazine though, surprised to see a car of that glass featured.

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ugggghhhhnnnnnnn

You deserve a gold star!! Your e30 is so damn perfect.

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Ha nice mate. Stretch, offset and lowness also look the part

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Pure Awesome, well done Josh you must be very proud!

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Please resize your pics.

jokes. Badass.

PS you going Jamez track day?

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Please resize your pics.

jokes. Badass.

PS you going Jamez track day?

hahaha ..

Yeah will be there testing out some new stuff. If I can dust off the 25 year old programming skills and make the program in time heh

Pure Awesome, well done Josh you must be very proud!

Yeah getting there .. ticked all the boxes so far. Im just worried about when do I call it finished? heh

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Full story and specs:

1986 E30 m325i with s50b32

The project started after I had finished my modified e46 330i. I need something outside of my daily driver that I could take on the track that was a bit more suited to the task.

Being inspired by some of the modified cars coming out of Sweden and Norway and the crazy event that is Gatebil, the scene was set.

One night about 4 years ago I invited some of my BMW pairs along for a beer or two to help plan the project, It goals were for a light weight, great handling rocket that you could throw around the track but could still out pace most vehicles on the road today.

The chassis was chosen, it would be a NZ New 1986 325i motorsport m-tech1, which I was very lucky to find for a good price before the prices of these vehicles started to go up. This example had been stored in garage and driven for many years on the open roads of the south island. So was in near perfect order for its age.

The engine was a different story. I had a phone call from a friend of mine who has his hand in every part of BMW racing in New Zealand. He had a s50b32 motor for me which would need some work. So I purchased this, a new gearbox from a z3m (m-coupe) as well as a single trailing suspension arm/half-shaft assembly. The thing to realise about doing this sort of thing in a country like NZ is that these parts just don’t exist second hand, unlike in Europe where m3’s and z3m’s are pretty common. I soon realised I would be buying and importing a lot of ‘M’ parts new from BMW.

After having the engine stripped down and checked .. I would need to replace the pistons, skim the crank and run over size bearings which got me thinking about weather I had made the right choice as the bore had some water / rust damage from when it has been left outside however luck would have it a couple of years later another friend of mine phoned me and told me he knew were a low K s50b32 was sitting and the guy just wanted to sell it. I had the budget for a second motor and it was an amazing price so I took the opportunity while it presented itself. In my hot little hands I had a 321hp 38,000k s50b32 from a BMW 98 M3 Evo sport. It included all the bits I didn’t have, DME (ECU), complete engine loom and special expansion chamber headers etc. These engines are already very highly strung with a small margin to guarantee reliability and road driveability. Features such as under piston oil squirter for cooling at high RPM, high compression ratio, Individual throttle bodies (ITB), forged crank and true hydraulic variable valve timing on both the exhaust and intake sides which has been lifted from the s70/2 from the BMW powered McLaren F1. If you look at a s70 it is in fact two s50b32’s essentially glued together to make a v12.

Ray from HellBM kindly supplied me with a workshop and any parts I didn’t buy new. My best friend Brendon and I had just finished working our bands (Antiform) album at the time and decided to get started on the engine conversion.

We poured over any information we could find on the net to find the best solutions to each problem, which of there were many to overcome, including translating Swedish and German languages!

First up was which engine mounts to run, OEM m5 engine mounts gave the correct amount of support and stiffness for the torque of the engine. New e21 gearbox mounts were used with a special alloy cups to stop movement.

A Group-A drive shaft was used as it was the correct length from the ZF 5speed z3m gearbox to the new z3m ‘finned’ 3:15 diff.

Suspension:

The rear suspension was complete replaced with z3m and aftermarket. The trailing arms, up-rated ‘M’ half shafts, from a z3m (m-coupe) as they fit perfectly on the e30 Chassis as BMW just happened to use the e30 plans for the basis of the z3 chassis. Handy 

This setup also allowed me to use the m-coupe hub and paved way to change over from the annoying wheel PDC standard of 4x100 to 5x120 of which there are lot more wheels available.

The shocks installed were Koni yellow race adjustable shocks and sourced from the US BMW racing scene matched Eibach 700 pound rear springs.

Also sourced from the US a ground control adjustable perch kit to allow height adjustment and adjustable top mounts.

Also installed was a Ireland Engineering adjustable sway bar with re-in forced support plates bolted to the boot floor as the stock ones tend to bend under hard track driving.

The front suspension starts with a brand new set of e30 m3 struts and hub (also 5x120 PDC) a converted ground control spring perch cupping Eibach 525 pound front springs with a Koni yellow adjustable race shock inserts. The sway bars are again Ireland Engineering adjustables.

The top mounts are ground control camber adjustable. And I have increase front castor using a set of treehouse racing eyeball arms which allow the 18x8.5s just turn lock to lock. This also help remove the e30’s ‘twitchiness’ and increases cornering speeds as it essentially makes the wheel base longer. I have dialled in 3 degrees of negative camber and toe out to match.

Brakes:

The brakes where interesting, one of the most important things to me was the age old saying if you want power, you need to be able to stop. The standard 325i brakes were pretty pathetic so I employed a set of Wilwood 332mm slotted front discs using the US sourced Wilwood SL-6 slim line 6 pot callipers. The calliper mounts and floating disc hats where also sourced from Massivebrakes.com which make special kits for BMW brake conversions.

The Rear brakes worked out really well, The new ‘M’ z3m rear 315mm rotors and 2 pot provide perfect break and heat balance.

To drive all of this, some pretty big changes were needed under the hood. So a up-rated 25mm Audi v8 master cylinder was used and a booster from a MKII golf 1.3 uk model. The reason for the smaller booster was the intake plenum on the engine just wouldn’t fit. Cutting into the plenum was not an option as this effected flow into the engine, and this is one of the main areas the s50b32 gets it power from, highly efficient air flow.

To also fix this, Brendon and I had a friend draw up in CAD a new re-enforcement offset plate which was laser cut out of stainless to move the whole assembly over 40mm. We also had to modify the pedal drive rod for a e34 5 series one.

Steal braided lines tie the whole lot together.

On the track the pedal feel is amazing, you can really feel the points when your about to lock it up, which helps when diving it into the corners. There is no ABS which I think is an improvement on a track day car.

Steering:

The steering rack was quite difficult, It turned out to be one of the most difficult things in the project. I bought a 2.7 turn z3 steering rack and steering linkage which was near new however fitting it with the engine headers and the sump was a nightmare.

Lots of careful modification to the headers and shimming the rack mounts and legally modifying the steering linkage finally allowed 2mm clearance from the sump and 8mm clearance from the headers for the linkage. It was worth it however, any time the tail kicks out on the car you very easy to catch with a quick correction on the steering wheel.

The engine was left fairly ‘stock’ which is a kind of ironic thing when you talk about ‘M’ engines. A very experienced top running BMW Targa driver once told us when visiting the work shop that it’s the best of both worlds, a high performing NA ‘race’ engine with all the benefits of longevity as rebuilds are costly on these things.

We did however have to change the sump to a E34 5 series sump and oil pickup as the s50b32 sump doesn’t clear the e30 cross member as the well is at the rear of the engine.

With the E34 sump there is also the added bonus of good oil supply under heavy braking on the track as unfortunately one flaw the s50b32 sump design has is it will loose oil pressure after a corner as all the oil has flowed to the front of the sump in a race situation. A few BMW open class race cars have run bearings because of original s50b32 sump shortcoming.

The fuel is supplied by a 500hpWalbro external tied into a 2 litre surge tank with external low pressure high flow accumulator pump, which is a bit overkill but it allows me to avoid fuel starvation/leaning out for at least a few laps of Hampton downs!

Cooling is taken care with a US sourced e36 m3 all alloy Fluidyne radiator which holds 33% more coolant than stock We use a e36 m3 remote expansion tank to regulate pressure.

Oil cooling is was piped using AN lines to a stock e30 325i cooler which works effortlessly.

The exhaust system was designed and TIG welded up in 2inch with mandril ‘thin walled’ stainless by Brendan Dunker at Niteparts/Convert ltd.

As this is another major area the s50b32 engine makes its power advice was sought around the best configuration from Gavin @ Hi Velocity. The final design was a 2 inch pipe from the headers all the way as far back as possible to retain mid range torque, threw a high flow stainless removable centre muffler into a 3 inch single pipe onto a e60 550i v8 Remus stainless rear muffler.

We also had fabricated up a laser cut flanged straight pipe centre section for extra flow and noise on track days.

The sound allows the engine to really scream however sounding fairly sedate at idle.

The interior of the car is fairly stock ‘houndstooth’ motorsport livery, with the addition of a sports steering wheel and a DTM direct linkage short shifter. This gives the car a very firm mechanical feel shifting up or down, its great for feeling if you have hit the mark when heel/toeing a down shift.

I am working on a Racechrono GPS lap timer touch screen system at the moment which will be added soon. This will be a removable system to bring the interior back to stock.

I use a Sparco 330mm 39mm offset suede racing steering wheel for grip. It’s a great feeling wheel which in my view has the perfect amount of diameter to match the steering rack ratio. It’s great for catching those slides too!

Electronics

Where to start! This was the other hard thing on the build. For two main reasons, ODBII just didn’t exist in 1986 and there was quite a bit of literature around for the 1988 onward e30 face lift cars but not 1986 pre-facelift cars.

In a lot of cases there were differences in wiring, sensors, senders and instrument clusters.

The only way was for us to trace the old scanned in 1980s factory circuit diagrams and work out the circuits ourselves.

I wont bore you with too many details as you would need the rest of the magazine to cover it but issues such as start motor ignition from the DME (ECU) was different and fuel tank senders to gauges.

Some really cool outcomes were we got to retain the BMW transponder chip drive away protection system called EWS.

The car also was fully functioning ODBII which allows us to run logging systems along side the GPS lap timer while racing.

The programming of all modules was done the hard way using HellBM’s GT1 coding tools. Another thing we had to research and learn ourselves.

The DME (ECU) is the high powered MSS50 Siemens unit which obviously drives the engine but also keeps the variable value timing (VANOS) at its optimum which allows for the best of both worlds. Low end torque at lower RPM and high peak horse power and torque all the way up to the 8000rpm rev limit.

The stock s50b32 loom was mated to the stock pre-facelift e30 body loom to and all power and relays were modified in the fuse and relay box to retain a factory look and finish.

Driveline

There were no reasonable priced light weight flywheel and clutch setups around. So I thought I’d have a crack at building my own one up.

The flywheel was knocked up in CAD and machined from a single billet and the original ring gear was removed from the old dual mass flywheel and used. This gave a flywheel that could handle the strains of 8000rpm however only weighed 6.23kg.

This was balanced perfectly with a modified SACHs pressure plate pulling a solid 450hp capable 3030ft pound. A carbon ceramic clutch was used to allow the car to be driven with no problems in rush hour traffic.

Performance:

There is nothing quite like a screaming straight 6. If you have ever heard the induction sounds of a DTM race car, you’ll get an idea of what this thing sounds like. You can hear it before you see it when the throttle bodies are opened up at full noise.

I was at a recent track day testing it on a very wet track, once I got traction I was pulling away strongly from a b5 Audi RS with no issues. It recently kept up with an e60 m5 around hampton downs and have posted a 1:18.3 lap at last count.

The thing that’s surprising with this thing is the instant throttle response. The rush of power comes right down from 1500rpm all the way up evenly to 8000rpm. Its like having a high powered turbo car power on tap at any RPM.

Cornering is awesome, because the car is fairly light weight it really does feel like a go cart. steering response from the 2.7 turn z3 steering rack and high front camber is sharp and direct and rapid.

You really have to watch the rear end on this thing

Wheels

Road:

One of the added bonuses with switching to 5 lug (5x120PDC) was the choice of wheels. I scowed trade me and found a mint condition set of BBS LM 2 piece forged light weight wheels. The specs are 18x8.5 et30 on Falken FK-452 225/35r18. These where squeezed in to the arches with a minor guard roll needed in the rear. The front run 15mm spacers and longer hi tensile lug bolts. To bring the front offset to 15mm.

Race:

A set of BBS RC mono block 17x8.5 light weight wheels on Dunlop 240/625r17 D11 slicks are used for track day rubber.

The first run at Hampton downs showed that normal road rubber just isn’t up to the task after a few laps they overheat and kill the late braking buzz pretty quickly.

Body

The body is original BMW M-Technik1.

DRIVER PROFILE

Josh Purcell

Age: 33

Occupation: IT Consultant, Band (Antiform)

Length of ownership: Approx 4 years

Cars previously/currently owned: BMW e36 320i Schnitzer, modified BMW e46 330i, BMW e39 540i Motorsport (current daily).

Sponsors:

Ray @ HellBM, Brendon Dunker @ Niteparts/Convert ltd, Bimmersport.co.nz

Josh thanks: Brendon Spain for building this thing with me, Ray @ HellBM, Gary and Keith @ JC BMW, Paul & Brent @ Precision Autowerks, Conrad Timms, Westie, Ollie M, Ollie G, Bimmersport crew and of course my wife Ange.

Specs

Car:

1986 BMW e30 m325i

M-Technik 1 body

BMW Polaris Silver colour

Engine:

NA BMW s50b32 3.2ltr (321hp) from a 1998 e36 M3 EVO sport

e34 m5 engine mounts

Stainless m3 EVO headers and custom stainless tuned exhaust with e60 550i Remus back box (with straight pipe option for track days)

All alloy Fluidyne radiator (USA)

Motorsport oil cooler / AN lines

Gearbox/driveline:

z3m M-Coupe ZF 5speed

AKG Motorsport DTM short shifter

e21 gearbox mounts with aluminum caps

z3m M-coupe half shafts

z3m M-coupe hubs/bearings

z3m M-coupe finned LSD

Wheels:

Road:

18x8.5 BBS LM 2 piece forged wheels

Falken FK-452 225/35zR18

Race:

17x8.5 BBS RC monoblock light weight wheels

Dunlop 240/625r17 D11

Suspension:

Full 5 lug (stud) conversion.

z3m M-coupe rear trailing arms

E30 M3 front struts

Adjustable rear shock top mounts

Ground control fully adjustable coil over conversion kit.

Ground control camber/caster full adjustable top plates.

Treehouse racing modified eye control arm bushes / linkage

Ireland Engineering front and rear adjustable sway bars and links

Koni yellow race shocks (two way adjustable)

Eibach 525f/700r pound springs

Brakes:

Wilwood 6pot SL-6 Front calipers with 332mm slotted front rotors

z3m M-coupe full floating rear calipers with 315mm rear rotors

Braided brake lines lines

Audi v8/88 25mm master cylinder / mkII 1.3 golf booster.

3inch cooling system with hub backing plates.

Wilwood rear brake bias adjust valve

Electronics:

Siemens MSS50 DME (ECU) running full ODBII

BMW EWS transponder chip/drive away protection system

Misc:

E30 M3 Group-A driveshaft

z3 2.7 turn steering rack

5bar Walbro main pump and secondary accumulator with 2ltr surge tank.

Ultra Racing front strut brace

Ultra Racing rear tower brace

Ultra Racing under body brace

Interior:

Road: Stock motorsport interior

Race: Recaro SPG

Sparco 300mm steering wheel

RaceChrono lap timing system.

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Josh want to come do the fiat tarmac series?

probably should .. Think ill look at some of thise stuff next year.

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Absolutely stunning, I look forward to seeing it in action

Edited by sweetm3

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