1983 BMW E24 635csi Track Car Turbo Build
Discussion
e28525e said:
alex98uk said:
This looks great. Bet it's going to sound mean!
Cheers, hopefully not too mean that it can't pass noise regs.. If you get noise problems at tracks, then that's what i would suggest trying ;-)
helix402 said:
Excellent job. Reminds me of the time I had a rather rapid (as rapid as a 19 year old could make a 1.3 Corolla go) drive to a racing circuit. This was followed by a dash the club house to drink as many pints as possible before turning in to my tent.
The morning brought an early alarm call as the BMWs headed out to the circuit. The ground vibrated as many barely silenced straight sixes passed. Including a lovely selection of E24s.
Thanks, and that sounds like a great memory The morning brought an early alarm call as the BMWs headed out to the circuit. The ground vibrated as many barely silenced straight sixes passed. Including a lovely selection of E24s.
Max_Torque said:
One option that works really well in terms of passing noise tests is to send the "tailpipes" to opposite sides of the car! That way the total sound pressure level is split across a bigger area!
If you get noise problems at tracks, then that's what i would suggest trying ;-)
Thanks for that. She's not too loud, thankfully. I was under the impression the exhaust couldn't exit curbside in order to pass mot? If you get noise problems at tracks, then that's what i would suggest trying ;-)
e28525e said:
Max_Torque said:
One option that works really well in terms of passing noise tests is to send the "tailpipes" to opposite sides of the car! That way the total sound pressure level is split across a bigger area!
If you get noise problems at tracks, then that's what i would suggest trying ;-)
Thanks for that. She's not too loud, thankfully. I was under the impression the exhaust couldn't exit curbside in order to pass mot? If you get noise problems at tracks, then that's what i would suggest trying ;-)
(unless you car was homologated otherwise, eg Mclaren SLR )
Ahem. Long story short, we got it on the dyno and the were making good progress with the mapping when the turbo sh@t itself. Luckily, it was on the exhaust side so nothing went in the engine. I have now bought another turbo and will be fitting it this week.
This is 50% throttle, you can see (on the bottom graph) what initially we thought was the wastegate opening and shutting but is actually the turbo surging and about to implode:
This is 50% throttle, you can see (on the bottom graph) what initially we thought was the wastegate opening and shutting but is actually the turbo surging and about to implode:
Well, after locating another turbo (slightly larger this time, a Borg Warner s300sx3) we set about adapting the pipework to make it fit. Also after some research, we figured out that the orientation of the wastegate was wrong for the boost we were running (it can be fitted two different ways). However, it wasn't a straight forward adjustment and more time was spent modifying pipework before we took it to the dyno. I also fitted a 71 degree stat which dropped the cruising temp from 100 to around 80. Money well spent!
The dyno session was semi-successful! The car ran brilliantly and the turbo spooled smoothly but we had wheelspin after around 3700rpm or 370lbft torque. The dyno at Steve's work is set up for classic Porsches and is set in the ground so it wasn't possible to strap it directly down onto the rollers. We did try it with lead in the boot and in 5th gear but to no avail!
As fuel was already dialled in accurately we just turned the boost up until it made just under 1 bar. This is approximately 400bhp and high 400s torque (lbft). I will get a decent power run in the future but for now lets just say its plenty quick enough! I took a friend's for a spin in the car and he said it felt a good deal quicker than his bosses 420bhp Celica, probably due to the torque..
The turbo and injectors are able to handle a fair bit more (500+) but at this stage I am just going to run it at 0.9 bar and see how it performs in track. I'm sure it will be plenty!
Video of events here: https://youtu.be/fNBgn6ZMPdE
I also bought some road wheels and tyres to get it off the semi slicks. These were a bit tired so I gave them a sand back and a quick lick of paint. They look tidier but not perfect, but that was the goal! Pics of the car are with the old wheels, I'll upload some pics with the new ones when I get the tyres fitted!
You get a blue hat if you can guess the donor car the spoiler came off..?
The dyno session was semi-successful! The car ran brilliantly and the turbo spooled smoothly but we had wheelspin after around 3700rpm or 370lbft torque. The dyno at Steve's work is set up for classic Porsches and is set in the ground so it wasn't possible to strap it directly down onto the rollers. We did try it with lead in the boot and in 5th gear but to no avail!
As fuel was already dialled in accurately we just turned the boost up until it made just under 1 bar. This is approximately 400bhp and high 400s torque (lbft). I will get a decent power run in the future but for now lets just say its plenty quick enough! I took a friend's for a spin in the car and he said it felt a good deal quicker than his bosses 420bhp Celica, probably due to the torque..
The turbo and injectors are able to handle a fair bit more (500+) but at this stage I am just going to run it at 0.9 bar and see how it performs in track. I'm sure it will be plenty!
Video of events here: https://youtu.be/fNBgn6ZMPdE
I also bought some road wheels and tyres to get it off the semi slicks. These were a bit tired so I gave them a sand back and a quick lick of paint. They look tidier but not perfect, but that was the goal! Pics of the car are with the old wheels, I'll upload some pics with the new ones when I get the tyres fitted!
You get a blue hat if you can guess the donor car the spoiler came off..?
Edited by e28525e on Tuesday 7th January 07:40
Great work. Looking good. 
Mk3 Capri for the spoiler?
Are you content with the mapping so far then?
Eg You’ve got enough done to know it’s safe at max revs etc?
I’m a worry wart when it comes to fuelling in turbo cars, but I think I might have headed to a different RR before a full blown track session.
That’s just a passing observation mind. Not meant in a patronising P’heads way.
Mk3 Capri for the spoiler?
Are you content with the mapping so far then?
Eg You’ve got enough done to know it’s safe at max revs etc?
I’m a worry wart when it comes to fuelling in turbo cars, but I think I might have headed to a different RR before a full blown track session.
That’s just a passing observation mind. Not meant in a patronising P’heads way.
marky911 said:
Great work. Looking good.
Mk3 Capri for the spoiler?
Are you content with the mapping so far then?
Eg You’ve got enough done to know it’s safe at max revs etc?
I’m a worry wart when it comes to fuelling in turbo cars, but I think I might have headed to a different RR before a full blown track session.
That’s just a passing observation mind. Not meant in a patronising P’heads way.
Thanks for your concern but fuelling is fine.Mk3 Capri for the spoiler?
Are you content with the mapping so far then?
Eg You’ve got enough done to know it’s safe at max revs etc?
I’m a worry wart when it comes to fuelling in turbo cars, but I think I might have headed to a different RR before a full blown track session.
That’s just a passing observation mind. Not meant in a patronising P’heads way.
We got fuel data from the ecu, it tells us what the fuel is at any rpm regardless of what the dyno reads. If you have, say, table number 135@6000rpm@100% throttle, at that rpm the following cell will want slightly less fuel as the power is falling off, so you just use the same number or a value within 5% - it’s going to be safe.
And yes, Mk3 Capri, £260 cheaper than an e24 one!
Short video of the track day. Great fun, only one small fire to contend with when the oil feed came loose on the turbo!
https://youtu.be/T3UIJmT5JUc
https://youtu.be/T3UIJmT5JUc
Update time! Sorry it's been so long but the resent acquisition of an NSX got in the way.
Anyhow, my time with the e24 has mainly been spent managing the sheer amount of bloody heat this snail creates. First it cooked the oil feed to the turbo so I had to re-do that (temporary lead fix in shot)
It also started to misfire which I initially thought was the coilpack as I had already replaced all the leads prior to this with Magnecor race leads:
This time, all these somehow tested ok. So, after replacing the suspected coilpack with an expensive Beru one (along with plugs), I still had the same issue. I then started swapping and inspecting leads, which revealed this..
That's some serious f
king heat. So, I rang Magnecor again and they came up with these. We only went for two with this special sock on as they sit right next to the turbo and were the only ones cooked.
I also got them to sit better in the aluminium casing so they were tucked up as far away from the turbo flange as possible. Bare in mind, ANY work (including plugs) requires the removal of the turbo and lots of blood and swearing. I have got it down to a pitstop time now but it's still the worst job.
Anyhoo, I drove it a little while with all misfires sorted and then tried to ignore a ticking/blowing sound that only I seemed to be able to hear (none of my mates thought anything was wrong). You know what it's like though, you know the sound of your engine better than anyone else. I ended up starting the car up from cold whilst it was on a jack so I could place my hand in different areas to feel any blowing. I only had about 30 secs before hand hock time to feel about but thought I had found the problem - a blow from the WG flange. So, I took the WG off and noticed we had only mated it to the manifold with high temp RTV (wishful thinking) and this had totally vanished. I managed to modify an old exhaust gasket with a dremel in order to make a suitable gasket and put it all back together, only to find it was still blowing..from the manifold to angled adapter flange-a-ma-jig.
This was a concoction that had to be created in order for the turbo to sit away from the cam cover, unfortunately it meant 3 mating faces and 8 studs and bolts.
I shut the bonnet and went inside.
Today, I had a day off - so I found some enthusiasm from somewhere and stripped the whole lot down again and reassembled with new gaskets. I have never done nuts up so tight in my life. I didn't get many pics, just a couple of the fked gaskets. I was going to test drive it but it started to hammer it down. Hopefully, I'll find a dry moment tomorrow..
Anyhow, my time with the e24 has mainly been spent managing the sheer amount of bloody heat this snail creates. First it cooked the oil feed to the turbo so I had to re-do that (temporary lead fix in shot)
It also started to misfire which I initially thought was the coilpack as I had already replaced all the leads prior to this with Magnecor race leads:
This time, all these somehow tested ok. So, after replacing the suspected coilpack with an expensive Beru one (along with plugs), I still had the same issue. I then started swapping and inspecting leads, which revealed this..
That's some serious f
king heat. So, I rang Magnecor again and they came up with these. We only went for two with this special sock on as they sit right next to the turbo and were the only ones cooked. I also got them to sit better in the aluminium casing so they were tucked up as far away from the turbo flange as possible. Bare in mind, ANY work (including plugs) requires the removal of the turbo and lots of blood and swearing. I have got it down to a pitstop time now but it's still the worst job.
Anyhoo, I drove it a little while with all misfires sorted and then tried to ignore a ticking/blowing sound that only I seemed to be able to hear (none of my mates thought anything was wrong). You know what it's like though, you know the sound of your engine better than anyone else. I ended up starting the car up from cold whilst it was on a jack so I could place my hand in different areas to feel any blowing. I only had about 30 secs before hand hock time to feel about but thought I had found the problem - a blow from the WG flange. So, I took the WG off and noticed we had only mated it to the manifold with high temp RTV (wishful thinking) and this had totally vanished. I managed to modify an old exhaust gasket with a dremel in order to make a suitable gasket and put it all back together, only to find it was still blowing..from the manifold to angled adapter flange-a-ma-jig.
This was a concoction that had to be created in order for the turbo to sit away from the cam cover, unfortunately it meant 3 mating faces and 8 studs and bolts.
I shut the bonnet and went inside.
Today, I had a day off - so I found some enthusiasm from somewhere and stripped the whole lot down again and reassembled with new gaskets. I have never done nuts up so tight in my life. I didn't get many pics, just a couple of the f
ked gaskets. I was going to test drive it but it started to hammer it down. Hopefully, I'll find a dry moment tomorrow..Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff