1983 BMW E24 635csi Track Car Turbo Build
Discussion
She's down off the ramps and seems to be running well! MOT on Friday and then some tweaks to the map to accommodate the extra boost. There seems to be a slight issue with traction in any gear at the moment, hopefully the longer diff will fix that but it'll have to wait until the autumn!
Hoping to make Helmingham Hall on Sunday. I'm coming from Ely way if anyone fancies a convoy.
Hoping to make Helmingham Hall on Sunday. I'm coming from Ely way if anyone fancies a convoy.
Helmingham was great, as always. Got stuck on the grass though!
After that it was a few tweaks to the fuelling by Steve and off to the dyno!
Not before a weight in:
Pleased with that! Weight from factory is anywhere from 1420-1480kg for the 5 speed.
I chose Emerald for the power run and I'm glad I did. They were most helpful and did a fair bit of mapping while she was on the rollers.
Injectors were at 95% duty with 0.8 bar of boost. 385bhp at 5400rpm and 403lb ft of torque at 4500rpm. Full boost at 2750rpm, turbo prob wants another 0.5 bar before its running at full efficiency. Super driveable at present with great response. Pleased with that! Bigger injectors, some more chuff and another tune and I think I'll leave it there. Somewhere between 1.2 and 1.5 bar so as not to over spin the turbo. Current power to weight is 300bhp/tonne.
After that it was a few tweaks to the fuelling by Steve and off to the dyno!
Not before a weight in:
Pleased with that! Weight from factory is anywhere from 1420-1480kg for the 5 speed.
I chose Emerald for the power run and I'm glad I did. They were most helpful and did a fair bit of mapping while she was on the rollers.
Injectors were at 95% duty with 0.8 bar of boost. 385bhp at 5400rpm and 403lb ft of torque at 4500rpm. Full boost at 2750rpm, turbo prob wants another 0.5 bar before its running at full efficiency. Super driveable at present with great response. Pleased with that! Bigger injectors, some more chuff and another tune and I think I'll leave it there. Somewhere between 1.2 and 1.5 bar so as not to over spin the turbo. Current power to weight is 300bhp/tonne.
Hello, all
Another little update. I've found some Siemens 875cc injectors for a decent price so these will be getting ordered in time for the next tuning session on November 1st. Boost will be turned up to approximately 1.2 bar (currently 0.8).
I have also ordered a new AFR sensor as the one fitted had done it's time and the oil temp gauge has also given up so I have another one of those to fit as well. I am currently using the oil pressure to figure out when everything is up to temp!
Installing an aftermarket M30 "turbo" cam or hotter Schrick was also considered but these tend to alter the torque delivery and you lose the early shove you get from the stock B35 cam. This stock camshaft was used in the e23 745i and the Alpina B10 Bi-Turbo, so you'd think it would be a decent compromise!
Vernier pulley was also considered but as the cam operates both the inlet and exhaust valves, playing with this would simply move the power band up or down the rev range and, as you set it and then button it all up and see what happens, it's a bit of a risk when you're paying for a full tuning session without the ability to alter timing..
A new exhaust will be made up for the run, the single side exit box has had a kicking and it's now too loud to pass track limits and also is very uncomfortable in my right ear! Going back to a 4" with rear exit and two silencer boxes is the order of the day.
Here is some footage of the power run:
https://www.youtube.com/watch?v=vy2nWTfQTPA&li...
Cheers!
Another little update. I've found some Siemens 875cc injectors for a decent price so these will be getting ordered in time for the next tuning session on November 1st. Boost will be turned up to approximately 1.2 bar (currently 0.8).
I have also ordered a new AFR sensor as the one fitted had done it's time and the oil temp gauge has also given up so I have another one of those to fit as well. I am currently using the oil pressure to figure out when everything is up to temp!
Installing an aftermarket M30 "turbo" cam or hotter Schrick was also considered but these tend to alter the torque delivery and you lose the early shove you get from the stock B35 cam. This stock camshaft was used in the e23 745i and the Alpina B10 Bi-Turbo, so you'd think it would be a decent compromise!
Vernier pulley was also considered but as the cam operates both the inlet and exhaust valves, playing with this would simply move the power band up or down the rev range and, as you set it and then button it all up and see what happens, it's a bit of a risk when you're paying for a full tuning session without the ability to alter timing..
A new exhaust will be made up for the run, the single side exit box has had a kicking and it's now too loud to pass track limits and also is very uncomfortable in my right ear! Going back to a 4" with rear exit and two silencer boxes is the order of the day.
Here is some footage of the power run:
https://www.youtube.com/watch?v=vy2nWTfQTPA&li...
Cheers!
Another update.
Two more days spent on the Turboshark. Firstly, we dropped the diff and fuel tank. Steve set about swapping the 3.73 crown and pinion for a 3.23, this will make the most of the torque and allow a 160mph+ top speed. Meanwhile I cut a hole in the tank in order to install a universal VDO level sender. The old one fell to bits and the space is now occupied by the Walbro 255 lift pump.
Diff back together with new oil:
Fuel tank dropped and new sender installed. This tank is date stamped 2001 and is in great shape. However, there isn't any protection from road poo and there was already a sizeable amount of mud stuck to the top which you'd never be able to clean off when on the car. I cleaned it up and coated it with stonechip.
While both of these were off the car, it made sense to reinforce the boot floor/diff mount as it'll be handling well over double the torque it was ever supposed to. The swirl pot and filter had to be removed in order to do this and these will have to be slightly modified in the way they mount in order to accommodate the reinforcement.
Lastly, it made sense to also reinforce the rear ARB mounts. The steel used for these is thinner than that used for the brackets that hold the old fuel filter and pump assembly!
Weather is turning inclement so a gazebo has been ordered. I've spaffed a lot of money on some 4" piping and a couple of silencers for the new exhaust. This will be be the main focus next week, along with installing an accusump system.
Cheers!
Two more days spent on the Turboshark. Firstly, we dropped the diff and fuel tank. Steve set about swapping the 3.73 crown and pinion for a 3.23, this will make the most of the torque and allow a 160mph+ top speed. Meanwhile I cut a hole in the tank in order to install a universal VDO level sender. The old one fell to bits and the space is now occupied by the Walbro 255 lift pump.
Diff back together with new oil:
Fuel tank dropped and new sender installed. This tank is date stamped 2001 and is in great shape. However, there isn't any protection from road poo and there was already a sizeable amount of mud stuck to the top which you'd never be able to clean off when on the car. I cleaned it up and coated it with stonechip.
While both of these were off the car, it made sense to reinforce the boot floor/diff mount as it'll be handling well over double the torque it was ever supposed to. The swirl pot and filter had to be removed in order to do this and these will have to be slightly modified in the way they mount in order to accommodate the reinforcement.
Lastly, it made sense to also reinforce the rear ARB mounts. The steel used for these is thinner than that used for the brackets that hold the old fuel filter and pump assembly!
Weather is turning inclement so a gazebo has been ordered. I've spaffed a lot of money on some 4" piping and a couple of silencers for the new exhaust. This will be be the main focus next week, along with installing an accusump system.
Cheers!
Edited by e28525e on Wednesday 18th October 22:28
Edited by e28525e on Wednesday 18th October 22:44
Anorak post. Gear speed changes for the 3.73 vs the 3.23 which has just been installed. Full boost is at 2750rpm.
3.73
............1...........2.............3.............4..............5
6500 33.48.....58.16.....91.53.....127.95.....157.39
6000 30.90.....53.69.....84.49.....118.11.....145.28
5500 28.33.....49.21.....77.45.....108.27.....133.17
5000 25.75.....44.74.....70.41.....98.43.....121.07
4500 23.18.....40.27.....63.36.....88.58.....108.96
4000 20.60.....35.79.....56.32.....78.74..... 96.85
3500 18.03.....31.32.....49.28.....68.90..... 84.75
3000 15.45.....26.84.....42.24.....59.06..... 72.64
2500 12.88.....22.37.....35.20.....49.21..... 60.53
2000 10.30.....17.90.....28.16.....39.37..... 48.43
1500 7.73 .....13.42.....21.12.....29.53..... 36.32
1000 5.15 ..... 8.95 .....14.08.....19.69..... 24.21
3.23
............1...........2..............3..............4..............5
6500 38.66.....67.16.....105.70.....147.76.....181.75
6000 35.69.....62.00.....97.56 .....136.40.....167.77
5500 32.71.....56.83.....89.43 .....125.03.....153.79
5000 29.74.....51.66.....81.30.....113.66 .....39.81
4500 26.77.....46.50.....73.17.....102.30.....125.83
4000 23.79.....41.33.....65.04..... 90.93 .....111.85
3500 20.82.....36.17.....56.91..... 79.56 ..... 97.86
3000 17.84.....31.00 .....48.78..... 68.20..... 83.88
2500 14.87.....25.83 .....40.65..... 56.83 ..... 69.90
2000 11.90.....20.67......32.52..... 45.47 ..... 55.92
1500 8.92.....15.50 .....24.39..... 34.10 ..... 41.94
1000 5.95.....10.33......16.26 ..... 22.73..... 27.96
3.73
............1...........2.............3.............4..............5
6500 33.48.....58.16.....91.53.....127.95.....157.39
6000 30.90.....53.69.....84.49.....118.11.....145.28
5500 28.33.....49.21.....77.45.....108.27.....133.17
5000 25.75.....44.74.....70.41.....98.43.....121.07
4500 23.18.....40.27.....63.36.....88.58.....108.96
4000 20.60.....35.79.....56.32.....78.74..... 96.85
3500 18.03.....31.32.....49.28.....68.90..... 84.75
3000 15.45.....26.84.....42.24.....59.06..... 72.64
2500 12.88.....22.37.....35.20.....49.21..... 60.53
2000 10.30.....17.90.....28.16.....39.37..... 48.43
1500 7.73 .....13.42.....21.12.....29.53..... 36.32
1000 5.15 ..... 8.95 .....14.08.....19.69..... 24.21
3.23
............1...........2..............3..............4..............5
6500 38.66.....67.16.....105.70.....147.76.....181.75
6000 35.69.....62.00.....97.56 .....136.40.....167.77
5500 32.71.....56.83.....89.43 .....125.03.....153.79
5000 29.74.....51.66.....81.30.....113.66 .....39.81
4500 26.77.....46.50.....73.17.....102.30.....125.83
4000 23.79.....41.33.....65.04..... 90.93 .....111.85
3500 20.82.....36.17.....56.91..... 79.56 ..... 97.86
3000 17.84.....31.00 .....48.78..... 68.20..... 83.88
2500 14.87.....25.83 .....40.65..... 56.83 ..... 69.90
2000 11.90.....20.67......32.52..... 45.47 ..... 55.92
1500 8.92.....15.50 .....24.39..... 34.10 ..... 41.94
1000 5.95.....10.33......16.26 ..... 22.73..... 27.96
Mark-insert old BMW said:
Wasn't there a 3.07 ?
There was, yes. It's what the car originally had from factory. It is just too long to be useful though -top speed would be 190.8mph! It would mean having to grab 2nd gear on some tracks and that would be pointless as it would be peak torque at that point. Trying to deploy 500lb ft at 40mph with lock on would mean many additions to my black flag tally
Edited by e28525e on Friday 20th October 09:01
Unfortunately, the most recent tuning session revealed a fuel pressure issue. This means I'm using it as an excuse to update the fuel system. The single 023 (044) pump and swirl pot is being removed and in it's place will be a twin Syvecs pump and surge tank setup. A new rail is being made up from extruded aluminium as the Nuke one never fitted properly (it hit the stat housing) and twin top hat extenders had to be used. Lastly a new FPR is going in with new pipework.
I am hoping to get this all in and tuned before the trackday I have booked on the 9th of December. It's looking unlikely that the old girl will make it so I may be taking the E30 again, which is no bad thing! Anyway, fingers crossed...
I am hoping to get this all in and tuned before the trackday I have booked on the 9th of December. It's looking unlikely that the old girl will make it so I may be taking the E30 again, which is no bad thing! Anyway, fingers crossed...
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