Tom's Track Car - BMW E46 -Lots of updates


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Update - 25th November 2018

So It's been a while since I've been on the forum, only popped on here and there to reply to PM's I've received keeping in touch with people. Lots of new build threads and projects on here now. This thread had ended up nearly onto the 3rd page in this section.

Since the last time I updated the progress on here I've been very busy with motorsport but haven't touched the BMW hardly since it was on the dyno @ EFI.

This year I have been helping a couple of friends with what we can now call as a small racing team that have been racing Enduro at club level. Ranging from 45 minute Road Sports races to 3 hour races in Club Enduro, both with 750MC club. It's been a great year to be part of the racing and travelling to venues all over the UK and experiencing the Racing.

The Final Race

Race of Remembrance was the last race of the year for us. It consists of a 12 hours endurance race through the day and night, split into two 6 hours sessions combined together to make 12 hours of track time. This was pushing what we had learnt this year as a time to unprecedented levels. Over this 12 hour period we were expecting to refuel the car between every 45-60 minutes, swapping drivers and tyres when required. Little did we know how challenging the race would actually be on the car and the team


During the race we had to take on a range of major fixes to the car which included removing the gearbox to replace a broken clutch 3 laps into the race, replacing sections of the wiring loom to fix broken wires due to fatigue, chasing fueling faults which ended up being caused by a slowly occurring blockage to the fuel pressure regulator and then finally limping the car across the line at the end after snapping a drive shaft clean off in the diff 20 minutes from the end of the race. We were able to remove the damage shaft and limp it across the line only running one shaft. There will be more updates to come on this on Facebook.


Amazing experience to be part of for the full weekends with a large marquee set up at the Anglesey Circuit for the weekend. Racing in both the day and night was an amazing experience.

Back to the BMW

Back in September I booked the Yearly winter track day at Oulton Park, I hadn't touched the car since Anglesey except to take it to EFI Tuning down the road from me to check the fueling and the power it was making.
I pulled the car out and took it for a test drive, checking basics over on the car, I still have the luxury of having the car on the road, taxed, MOT'd and insured to am able to test it.
First thing I noticed was the grumbling front wheel bearings so ordered them the weekend before the track day and swapped them over, fresh front hubs fitted to the front and the studs transferred over.
Other than that the car felt perfect. It was loaded up onto the trailer ready to take it down the Oulton Park.


As usual we're/I'm the first person to turn up at the Circuit on a track day, normally also the last to leave after running the car right to the end of the last session of the day. Turning up to the circuit in the middle of November and the track being dry first thing in the morning was an unusual feeling. Fitting the dry tyres onto the car for sighting laps felt a little odd too but the conditions for the day were prime with warm weather and patchy skies.

The car was faultless again all day at Oulton. I'm still getting used to driving the BMW as this is only the second day out on track that I've driven it, also the first time at Oulton.
During the first few sessions I took it really easy just driving around in some clear track getting used to the car again and the lines, weird to see a few Clios over taking me in the first few sessions as the car is a totally different machine to drive.


As the day progressed the lap times started to fall, by dinner time I had managed to get the lap times down lower than my fastest ever lap I managed at Oulton in the 2.5 years of owning the car. The BMW has so much more grip in the corners and the the way it's able to push it's self out of corners with the drive from the rear is incredible, combine that with 245ftlb of torque across most of the rev range it's a much quicker car with the potential to go a lot faster if I'm willing to push it!


The problem
With the track day only expected to run till about 4pm I had an amazing 30 minute session that ended at around 3:30, just before the fuel light came on I dove into the pits to call the day a success. Jumping out the car I pulled the laptop out and the SD card from the front facing camera which had been running connected to my phone call day via bluetooth. Only to find 30GB of photos from the sessions throughout the day!

Knowing I only had 30 minutes left and zero video footage from the track day. I quickly grabbed another SD card from the van, friends of mine grabbed 20L of fuel and threw that in the car, picking up a good friend as a passenger we set off to make the most of the final 30 minutes of day light left before the chequered flag. This turned out to be one of the best sessions of the day with hardly any cars on track and went on to be the fastest laps of the day. I'd managed to at least get 30 minutes of video footage from the BMW's first time out at Oulton.


I've used a little bit of that video footage to make a Clio 200 vs BMW E46 comparison video. This is the most common question I get at the moment is how do they compare? You can see for yourself.

Both of these are good clear laps around Oulton. Bearing mind I had 2.5 years of seat time in the Clio compared with 2 days on track so far in the BMW.

Also here's a little video of the car from the pit lane taken by a friend of mine.

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Fantastic Tom, what a write up!

Very good story with the comparison and thanks for doing the effort to do the video, very interesting to see. Blimey I can't believe you've got 2 years already in the BMW project, where does time go?


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Fantastic Tom, what a write up!

Very good story with the comparison and thanks for doing the effort to do the video, very interesting to see. Blimey I can't believe you've got 2 years already in the BMW project, where does time go?

Only started building the BMW May this year Yiannis, glad you're enjoying reading the progress...

1st December

So will the car being so flawless over the last two track days I had a chance to go back to Oulton Park the following weekend. A friend of mine was taking his freshly built 182 down there for testing so it was a no brainer. Once I know the car had survived the track day. The following week the car was booked in. I left everything packed in the car and the van ready to go again the following weekend...


The night before the track day I gave the car a once over, quick bleed of the brakes just to make sure, swapped to wet tyres ready for the wet weather that was forecast. The conditions were completely the opposite to the previous weekend. Very wet track, lots of spray and as everyone knows Oulton is a very greasy place in the winter months. Turned the coil overs back 4 clicks on the front and 6 on the rear.


The car ran a dream throughout the day, with only one little off through Hislops on next to no throttle at all. Video doesn't show a reason for it either.
The track dried out as the day went on, there were a few forum members booked on to so it was good to have a good chat with friends between sessions.


Managed to get the dry tyres on for 2 hours at the end of the day just as about 50% of the circuit was showing a dry line except from the last couple of corners. Learnt so much over the past 3 track days in this car. Brings it a lot more attention and really proved it's self in the wet conditions at Oulton. Only passed by a total of 3 cars on circuit all day.

After 3 track days I'm at the point now where I'm going to take some time over winter to check the car over, make some improvements and iron out a couple of flaws. Only managing to put in 3/4 laps before the oil temps are reading 120 degrees, so must get around to finishing the oil cooler install, got a strange vibration through the whole car too which I just drove through over the afternoon sessions, found some play in the front left wheel bearing which was replaced 2 track days ago, something to investigate.

Finally, I learnt my lesson from the previous weekend and double checked the camera was in the right settings.
Put together a couple of Youtube videos....

Few laps from the last sessions before the chequered flag.

Interesting moments and Highlights

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Awesome Tom, what kind of lap times were you getting on the Nov day? I've not had a chance to watch all vids yet.

Sent from my SM-G950F using Tapatalk


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Awesome Tom, what kind of lap times were you getting on the Nov day? I've not had a chance to watch all vids yet.

Sent from my SM-G950F using Tapatalk
2.05/2.06 in the dry with a passenger, The car has much more time in it, just confidence in the corners, still adjusting to how the car drives and don’t want to push my luck with it too soon. Will be back to Oulton in it next year to see what it can do with more seat time.
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Well after a wet and windy Saturday working on the car between rain showers, I have spent many hours writing up a thread on Piston Heads.
Going to take the build thread for the BMW over to Piston Heads from now on. I know I have most of the people that have posted in this build thread over recent months on Facebook. It appears that this isn't as interesting to the Clio world as originally thought and that will be a better target audience for the build thread including the Racing from 2018 into 2019
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Popped on here to reply to a number of message and tags I've missed this year. Had a good read through some of the build threads, great to see how some of the cars have progressed and that members are still posting. Things have been very busy with the car, constantly improving and pushing the car further and further.
Also popped back on here after the years I spent building the clio I had some great conversions and met some great people too through this place.



Cadwell Park



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Sooo... After being asked by a few people if i was going to keep this updated, I've popped back to throw some updated in the thread from the end of summer and update it to this weekends track days...
So September 2019... Following on from Cadwell Park...

First job was to do some double checking regarding the few fuel woes I had out on track at Cadwell.
I found it is possible to get the information from both fuel senders in the tank up on the dash so I can monitor it while out on circuit and get a good idea of what is going on and whether I need to look at the option of the second pump or the tank baffle from the M3's that a few people have pointed me towards.

The 227329 in the photo below represents 22.7L in the left side of the tank


The plan is to keep this on the dash when out at Oulton next and see how the values on both sides of the tank go down when I get down to that 1/3 of a tank were I rang out of fuel at Cadwell. Better to find the problem with some data before I start throwing modifications at it.

While I was doing some messing I did some checks regarding fuel pressure in a few set ups

1 - Standard in tank pump into the old return less filter and regulator

2 - Standard in tank pump into a new filter and reg

3 - 225l swirl pot pump into the old filter and reg

4 - 255 swirl pot pump into the new filter and reg.

In every set up there was 55psi at the rail, slightly high but it's a very cheap fuel pressure gauge but every reading across all set ups was exactly the same which is good, just wanted to check everything was functioning as it should.


At Cadwell the highest temps reached on track was 106 degree oil temp and 100 degree coolant temp.
So I've cracked on with a job I've been meaning to do for a while but I've been watching and logging the temps and they've been pretty good at the last few track days. Cadwell being so warm on the day highlighted a little extra heat in the car plus everytime I go out i'm driving harder and harder as I get used to the car and my driving keeps improving.

When I did all the cooling modifications to the car earlier in the year I took a solid 20 degrees out of the coolant and the oil temps by fitting the splitter, drilling some holes and removing the AC condenser. There was always a 70mm gap under the radiator between it's self and the splitter that I was going to come back to filling if it was needed in the future.


First job was to come up with some neat angle brackets on CAD, 60 degree angle from the splitter to push the air upwards with a hex on on the back for a captive nut.



Printed off 3 of them from plastic


Mounted to the splitter just in front of the bottom edge of the radiator, will see what happens with the data logs with the hole filled in forcing more air through the radiator and coolers.


While I was under there messing with the car on axle stands I routed a duct through from the fog light up to the bottom of the air box. More cold air directly into the air box can't be a bad thing, one reason for doing this is the standard intake comes from the top of the kidney grills directly over the top of the radiators and coolers so lots of warm air in that area.


Obviously if I make a change I want to be able to test or log what is going on.
Using the Arduino data logger in the car for all the parameters that are available on the Canbus network. One of the values which is there which I'm not using at the moment is the exterior temperature from a temp sensor being the left fog light so I've relocated the sensor into the bottom of the airbox and now I can log that value as the Intake air temps and see what they are out of interest more than anything, can take the duct out on the next track day and see if it makes any difference with the cold air feed into the box.


Those are just a few of the little jobs I'm always messing with in between track days. Had the car on axle stands since it came back from Cadwell so it's nice and easy to have an hour or so working on it easily


So... one modification I wasn't planning on doing anything with was the engine but one thing led to another from a random thought process and well i'll let the photos do the talking..

12 months ago I took the car to EFI tuning for Chris to run the car on the dyno to get an idea of the power the car made, the AFR and how it makes power across the rev range. Car makes good figures for 140,000 miles engine but with a massive lump or torque from 2500-3500 but then dies off as it goes through the mid range.


I have friends that have or had experience with M52 engines and stroker 3.0's M52 with M54 rotating assembly and inlet cam using an M50 inlet making better mid to top end power at the sacrifice of some of the bottom end torque. I have found very little useful information regarding the M50 inlet on the M54 so going to document it all here as I work through it as this is a working progress rather than an update after it's all worked.

So I've sourced a M50 manfiold for use in this experiment. This is a much simpler manifold without the DISA valve in the M54 which will sacrifice some low down torque but the M50 has much bigger runners and a longer runner length

To go with it I've also sourced some pink top injectors which are the same 250cc but have a straight spay pattern to suit the location in the manifold were the m54 injectors have an angle spray pattern to suit the manifold.

I'm also going to use the fuel rail that fits the M50 manifold which has the regulator built into it and slightly adjust the fuel line routing which should actually make things a little simpler.


Started off by removing the M54 inlet from the engine


It fills a massive hole in the engine bay


Both manifolds sat side by side, the M50 is so much more simpler and lighter! Few more kg's saved here!


Eagle eyed viewers will have noticed the ports in the head vs the manifold are a different shape. Most people I've seen going down this route tend to pull the head off and start porting the head. At the moment in time I don't want to go down that route so I've decided to do something similar to what I've done on the exhaust side.

I've designed a 10mm adaptor that will go from the inlet to the head and used a computer to loft the difference between the two profiles.
(There is a lot of port offset in the drawing - read on later for the reason why)


I based the first version of the adaptor off a drawing I took from someone else's build thread on a BMW forum and 3d printed it in sections to offer it up to the head as a test.


Perfect fit against the manifold side and the holes for the studs to mount it to the head.


However using the drawing someone else had produced for the M54 head there was obvious mistakes when I put the prototypes against the head. I've measured and make some adjustments to the port alignments and written the changes onto the flange ready for redrawing


I then spent the evening adjusting the drawing from the measured modifications required as well as adding tabs to the bottom of the manifold adaptor to blank off some ports in the head which are used by the m54 manifold


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While i was at it I've also designed the plate that will adapt the standard electric throttle body onto the m50 manifold.
Both of these can be 3D printed as a final test before being sent for CNC machining.


Last job I was on with this afternoon between showers was the test fitting of everything I've got ready to work out how the throttle body is going to be attached to the standard intake box and MAF


Final job which is on going development at the moment is using Tuner Pro to adjust my current version of the ECU map to suit all the changes with the DISA and Idle Control valve not being used now as I plan to use the original throttle body to control the idle rather than having and idle control valve too.

Laser cut some card templates to test the profile of the head.

Testing the laser cut template on the head.

3D printed the adaptor between the throttle body and the manifold, made it to hold some bolts captive to act as studs to bolt the throttle body to the manifold easily.

Test fitting it all together, longer bolts required.

Finished building up the manifold using the original fuel lines with new rubber hoses, fitted another BMW PCV into the location of where the idle control valve normally would be, I am planning on removing the idle control valve and using the throttle body to control the idle.

While I've got all the CAD drawings done myself it seems a bit daft to have someone else make the gaskets for between the aluminium spacer and the head. I bought some high temp and fuel resistant gasket material and laser cut the gasket to perfectly match the profile of the adaptor plate sealing the air pathways in the head too which are no longer used.

Gasket material cut.

With the drawing all tested and checked against the head and the same done for the manifold side, I've combined the drawings to create a path for the laser cutting to remove the maximum amount of material without compromising on either port shape. Laser cut adaptor from 10mm aluminium.

Templates laser cut for the head side as well as the intake manifold to start the porting of the adaptor

Marked out the material removed for the porting.

Removed most of the material to match both profiles using the die grinder.

Roughed out and checked against the template ready for final cleaning up and polishing to take some of the roughness off the surface

Time to start to built it all back up in order.

First job was making new studs to be able to bolt down the now thicker intake assembly and put the gasket on the head.


Followed by the aluminium adaptor


Checking the port matching before bolting the manifold on


All bolted together, yet to finish the wrapping of the wiring loom but wanted to make sure everything is right and running before doing that. Also waiting for some new silicone hoses to arrive so just roughly mounted the maf in place for the time being.


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I have also replaced the fuel set up and the plumbing for the swirl pot under the car but didn't take any photos of this now. I'm now running an E36 fuel filter with the M50 rail with built in regulator which then returns directly to the swirl pot in the engine bay.
Finally was the last job to try and get it all running was changing the ECU map to try and get it to idle using only the throttle body having removed the idle control valve.

At this point yesterday the initial map I had prepared with all the changes I wanted to make wouldn't run the car at all. But having made so many changes to the map I started with the basics, checking for fuel, checked the plugs in the engine bay that had been off, multi metering the crank and cam sensors back to the ECU pins to make sure they're correctly connected as a lot of the BMW plugs are not keyed and can be mixed up!
Started with a basic map from when the car ran previously on the M54 inlet and got the car to turn over, run for a second and the cut out. Knowing it was purely just a mapping issue from there I've been building the Idle Control delete map up progressively in stages until I could get it idling well.
Long story short, at least 10 map revisions later I've got it idling and driving without hesitation, throttle feels nice and responsive now and I've removed all the fault codes surrounding the Idle control valve and the DISA Valve which has been removed in the process along with many other ECU changes to get to this point.

No engine lights at the moment, I'm sure there will probably be some at some point when it's driven properly,
ABS Yaw sensor unplugged at the moment as I don't run ESP/ABS but if it's plugged in I've still got the ability to have a clear dash without warning lights.


Next steps on the list is to prepare some base maps to take with me with a space ECU when I get it on the rolling road and experiment with some cam timing combinations to see whats needed to smooth out the power curve using the M50 inlet. The standard timing has some humps and strange moments in it around the DISA change over points to smooth out the power so will remove those as a baseline and take it from there when I get it booked in on the rolling rode and start to develop it from there.

One thing I did have to sort out was the intake to the throttle body. I got it running with the MAF just hanging in place, but that was never going to be a good long term solution but I didn't want to just put a cone filter in the engine bay.

The problem to overcome was the offset between the MAF outline and the in of the 90 degree hose when it was cut as long to the bend as possible.


Not only was the off set by 30mm a bit annoying I had to go down from 90mm to 76mm. I was going to try and make it with a step down hose and the elbow but the offset wasn't going in my favour so turned to what I know best. CAD, you've probably noticed this is common theme for me throughout.

Ten minutes messing came up with this.


I smoothed out the transitions a little bit from the CAD drawings above and sent it to the 3D Printer.


Fitted it up in place, perfect solution to the problem


While I was refitting the airbox into position with the IAT for the Data logger. The cold air duct feeding in direction from the fog log I relocated the M54 intake air temp into the airbox. I had messed around with scaling the calibration in the ECU file to suit the sensor from the M50 manifold but wasn't 100% happy with the accuracy of the readings to decided just to use the sensor which the ECU was calibrated for.
Make up a female - male extension to locate it in the bottom of the air box pre-filter.


I wasn't a fan with how the fuel rail was on view along with the injector wiring so decided to make some modifications to the M54 injector cover to make it fit over the M50 fuel rail. Two cuts and it fits perfectly bolting into position, Looks so much better and making the M50 conversion looking a lot more factory with the standard airbox too.

I wonder how many people that don't know will notice?

Another job on the to do list was the fit the second camera I picked up on ebay. Wiring it in the same way to back to the voltage regulator which is powered by a switch on the dash so both cameras start recording at the same time. Updated the firmware on both cameras and configured them to same to record on power on and continue to record for ten seconds after power off.
Can add rear view camera to the video overlays now. With Oulton park coming up I will also throw in the go pro as a passenger reaction camera for good measure too if I have any passengers come out with me


Spent a couple of hours this evening putting together some maps together for experimenting with some Vanos adjustments to go with the M50 manifold now the DISA is removed. Just waiting on an available date to get the car on the dyno to see if it even makes any difference. it's all a bit of an unknown.

First job was to create a way of adding sensor inputs to the Arduino Logger by adding a terminal board in the layers to be able to connect any analogue sensors. The one I was particularly interested in was fuel pressure with the changes to the system with the new rail and running the swirl pot now and running out of fuel completely at Cadwell. Will be able to view any fuel starvation now on the logs as well as viewing the fuel levels on both sides of the tank.


Second job of the week was getting the trailer out, little bit of maintenance required with some new side markers, jockey wheel and a replacement tyre, all ready for the track day but more importantly ready to take to EFI tuning on the Thursday.


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Arrived at EFI tuning around 12:00

The plan for the day was to first of all run the car on the Dyno and just see what it ran like with all the changes and get a feel for the new manifold. I have spent a lot of time adjusting the maps on the MS43 ECU to run the car without the idle control valve only using the electric throttle body for the idle, also removed the DISA valve from the ECU so no warning lights on.
I had already adjusted and smoothed out the Vanos timing because of the manifold design change, with the M54 the cam timing does a lot of backwards and forward movement around the DISA change over to try and prevent a dip in power.


First thing was some lower load and some partial throttle driving checking the AFR's, When i had the exhaust made we put a bung in the exhaust collector so nice and easy to put the wide band sensor for the dyno directly into the exhaust. With the partial throttle looking ok we moved onto some power runs.
First 3 runs we did together the car was making 230ftlb and 235bhp. I was always expecting it to loose some bottom end torque with the manifold change but was expecting it to make more mid range torque than it did at this point.

I took a bit of time to adjust some of the cam timing first of all starting with the inlet cam. Starting with advancing the inlet cam everywhere across the full rev range and doing a dyno run at that. This found a massive chunk of toque in the 3000-5000RPM range but lost a little bit of power at the top, from that I could then take the best bits of both cam timing maps.

Onto the exhaust cam. We didn't think the exhaust timing would make much difference but I went and retarded the exhaust cam across the full RPM range and ran it on the dyno again. It actually found a bit more torque in the middle between 3500 - 5000RPM so was able to factor that into the best combinations of cam timing so far.

At this moment in time the car was now making 243ftlbs @ 4500rpm and 243bhp @5700rpm. But the power after 6k was falling off a little quicker than it had on the previous manifold and it was also leaning out a little bit. We spent a little bit of time adjusting the fueling at the top end, didn't improve on the peak figures but were able to keep the power on a little longer after it makes peak power.

The final run of the day finished off looking like this:


This over layered over the top of the M54 manifold:

You can see where the power have moved around. No longer having a bit chunk of torque that falls off mid range there's a much better spread across the RPM range
I have since noticed that the two dyno graphs are offset by about 100RPM when you look at the rev limiter set at 6816RPM which is set when the car is running on the dyno which makes the graph looks like the power falls off earlier compared with the other trace.


Overall. I'm happy with it and I've found a lot out about along the way, I would be slightly happier if the power stayed up longer to 6500 but I wont know till I drive it on track, I do generally shift about 5800-6200rpm on circuit anyway. I was quietly hoping that with the manifold change that it would make a little bit more power towards to 250's but it appears the gains aren't there to be had without changing other elements of the engine now. Was it worth it? We'll see about that.
At the moment I'm sure the injectors are maxed out above 5500RPM so more work to come with this in the future...

The dyno runs compared are 12 months apart on an engine that's done 140,000 miles too.

Pretty much ready to go now for Oulton Park in two weeks time on the 16th November, looking forward to getting out in it again and seeing how it drives with the changes, I've not been to Oulton since we lost some weight too and rebuilt it over the summer.


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Slightly late update after Oulton Pack at the beginning of November. I've been waiting for a little bit more content to post in an update. I've been productive this weekend so thought I should write an update about Oulton and what I've been doing since.

So as usual I set off about 6am to Oulton, the forecast and conditions were looking perfect. I was one of the first people there and set bout unloading the car from the trailer. Did a little lap of the car park and parked it in the garage. Left the car set up exactly how it was at Cadwell. The track was a little damp during sighting laps but was dry by the first session, I was happy to have made it through sighting laps without any issues, no fueling issues, no limp mode, car felt good, pulled well I was happy! Parked the car in the garage letting the first wave of people go out on track, the car was looking perfect.


The first few sessions were going well, the car felt good and I was getting back into the swing of things having not driven the car since the summer.
Could feel how well it wanted to pull through the mid range but there was a distinct lack off pull at the top end, I was shifting at 6k for the day with a view to sorting it after the track day.

However the day wasn't going to continue going so well on the session just before lunch, I over corrected a little slide at Knickerbrook, as a result I ended up putting my back left wheel on the kerb and the car carried on sliding, when it gripped it just went straight on in the direction it was facing which happened to be off the track on the right hand side. The ground there was soaking wet and not the flattest of ground either.
The result was the car did 2 hops on the grass, before going sideways on the access road, luckily this pushed the car forwards away from the tyres, I managed to keep the car moving in the mud and get back onto the track without causing a red flag.

The video doesn't really show how hard the underside of the car hit the floor multiple times, everywhere you can imagine was full of mud and strips of turf.
Damage..... Ripped off the splitter, broke the V Band clamp off the exhaust, lost the fog light, coolant leak from the bottom of the expansion tank, radiator had come unsteated, broken off half of the PAS pulley
Took me 2.5 hours to get everything sorted and in a fit state to get back out on track, an hour of that time was driving part way home to get two replacement o rings for the bottom of the expansion tank to stop the leak that had formed.

Cracking on with getting it back out on track in the afternoon.

About 2 o'clock I managed to get back out on track. A passenger jumped in with me and we set off to test the car and try and get some more track time, I had the intention of only doing a few laps but the car felt exactly the same as normal so we carried on for a good 20 minutes.

Photograph of it actually out track

In the afternoon the car felt great, besides the hesitation coming out of a few corners and above 6k, but I found my stride again and got back into it. Actually managed to get the lap times down to 2:03 which is a couple of seconds faster than I've gone around Oulton.

Here's a couple of laps from the afternoon sessions:

Post track day....
After the track day while sorting out the videos and the data overlays for the speed, RPM and throttle, I added the fuel pressure to the video overlay and the pressure was all over the show, I initially discounted the readings as I knew the pressure sensor I was using wasn't really the correct range for fuel pressure as the sensor range was up to 3000PSI and I was only measuring 0-60PSI of that, as a result it provided me with a very small resolution, However I did a little bit of analysis of the fuel pressure and plotted it against RPM over a full lap and you could see a trend.

Every time the car went above 5000RPM there was a distinct loss of fuel pressure sometimes as low as 15PSI, this obviously ties in with the loss of power at the top end causing me to short shift. Here's part of the log below showing the drop of fuel pressure. Clear to see there was an issue.

On stripping down the swirl pot and fuel system last weekend I found a restriction in the pipe that was feeding the pump from the swirl pot. no wonder the fuel pump was running so loud when I fitted it and under high loads the fuel pressure couldn't keep the rail pressurised.

While it was all off, I've made a few changes to the fuel set up now which I was already planning on doing. The feed from the swirl pot has been plumbed with a bigger line now going up to 3/8". Changed the fuel pressure sensor for one with a 0-100PSI range to give better resolution for the future.


I've fitted a 328 fuel rail which has enabled me to go back to the M54 injectors which the ECU was originally scaled for. I couldn't run the M54 injectors with the M50 rail I had due to the injector height so ended up running the red tops.


When checking the car over I also spotted that the PAS pulley had taken a hit when I went off the track so that has been replaced with a new part



Other jobs on the list have been to give the car a good service, it's done 5 track days on the current oil and filter.


Fresh set of rear pads. These being cheap I only get two days out of a set but they're good at keeping the braking bias where I want it to be.

The car has also had a complete clean on the underside of the car, removing all the traces of mud and grass,

Got the engine bay put back together, now with the aluminium laser cut throttle body adaptor plate


Still needs a final wash but it's been too cold here today to be spraying water around

Pretty much ready to take to EFI tuning again on the 12th to run it on the dyno to check everything is in order now after removing the restriction in the fuel line!
Got a few things to finish off over winter, one being the new splitter for the front end, track down a set of fog lights and i'm going to replace the high pressure power steering hose from the pump to the rack just for peace of mind.


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Little additions to the car continue.
If you've followed the build thread this far you probably know i'm a sucker for 3D Printing.

Due to the change of fuel rail to be more flexible with injectors and have a valve on the end of the rail for checking FP I needed a way to bolt down the rail... I've quickly drawn some brackets to hold it down in place.

These a nice and simple but much nicer than them being made from a piece of metal

One large job I had done back before Oulton but forgot to post about was having a new windscreen fitted. This time it was a heated screen as I no longer have a heater in the car and only cold air blowing at the driver and the windscreen. Hooked up half of the screen to the loom I had already fitted in the car when I rewired it to see it in action

I've given the car a really good clean. Looking a bit strange at the moment without the splitter and fog lights, but they'll be refitted and replaced before the next day out. Hoping to be out mid February in it.

Popped the car down to EFI tuning to run the car again on Thursday evening just for a quick check after noticing the fuel pressure problems at Oulton.

With a little bit of help from a friend with a lot of technical know how I had a slightly different exhaust vano timing to change in the mid range. Running the exhaust much more retarded in the mid range to increase the overlap. This smoothed out the mid range a little more and made a bit more torque.
I've also spotted an area between 5900-6400RPM where the inlet would benefit from being a tad more advanced than where it currently is. I I've got data from a previous dyno run with that which picked it up a few bhp in that area but missed that area when combining all the best vanos maps.

Here's the graph as it stands at the moment. Not bad considering the standard figures at 220ftlb and 230bhp. M50 Manifold giving a much better spread of torque across the mid range too.

Video of the car on the dyno with data overlay 245ftlb 243bhp

Obviously there is more in the pipeline over winter. Started buying and collecting more parts for a few jobs I want to tackle over the new few months. Got a few ideas to make it a little more lively on track.


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5 Year since my first post on here when I started this build thread.

It's been very quiet over christmas with slow progress. Motivation to work on the car hasn't been very high so I've only been chipping away at jobs slowly. Also trying to decide what to do with the car from here. Probably finish off these few jobs and just use it though 2020.

One of the jobs that I've been wanting to tackle since I put the car towards was a knock coming from the rear sub frame which I have briefly looked at a few times but not enough to find where it was coming from. I however noticed a witness mark on the top and bottom of the rear sub frame bushes where the bush was obviously moving up and down at the rear depending on the load. Started with stripping down the rear end


On closer inspection I could see the bolt was bottoming out on the inner sleeve and not allowing the two parts of the polybush to clamp up fully against the subframe to prevent it from moving. Easy solution was the cut 3mm of the sleeve and then face it off on a lathe at work to give it a smooth flat surface.


With it cut down slightly you can see the yellow shoulders on the bush are tight up against the sub frame now.

Another reason the rear end of the car was stripped was to remove the diff because I had bought a 3.73 Final drive to see what it would be like to go even shorter. It might be too short considering I'm currently running a 3.38 over the standard 2.93. But only time will tell. Should give me a top speed of 130 MPH @ 6500RPM. My limiter is set at 6800RPM but I rarely rev it that high.


Started off stripping down the current diff with the Quaife and 3.38 FD.


Ordered all fresh seals from BMW, input seals, output seals and crush sleeve for setting the bearing drag on the input shaft


Input shaft assembly read to go back into the diff casing with the new crush sleeve

3.38 Crown wheel pressed off the Quaife diff and the 3.73 ready to be heated and refitted

Setting the drag on the input shaft to factory specification

Checked the gear pattern and everything was looking good so far. But upon checking the backlash with the DTI there was double the amount of backlash. I had to take it apart and adjust the side casing shims to reduce the amount of backlash and double check everything.
Finally happy with the gear pattern and the clearances.

Rear cover sealed on, ready to be cleaned up and repainted before refitting. Turns out it's exactly 12 months since I did this job and fitting the Quaife diff.

Other jobs which I've been working on in the new year is the replacement splitter after trashing the last one at Oulton. This time making it larger and running under the car back to the subframe to give better boxing in of the air coming through the front of the car into the coolers and radiator.

Making it out of 18mm plywood bolted straight to the chassis legs and the subframe easily takes my weight bouncing on the front edge of it.

Starting off with a few coats of varnish to seal it, a coat of black paint to cover the whole area before I start covering the front portion in filler primer and flatting it back to get it to a smooth finish the same as version 1. Then i will paint the front portion gloss black so it looks nice a presentable. As everything with this car it has to look as perfect as possible. A satin black spoiler isn't going to cut it.