BMW 635CSi Restomod

Author
Discussion

e28525e

466 posts

149 months

Saturday 30th December 2023
quotequote all
Fantastic work. It's great to see another 635csi on the readers cars forum!

With regards to steering, mine is totally standard and I have no issues with it. It is perfectly manageable, and mine has to deal with quite a lot of input as the tail wags a lot with 400lb ft. It's certainly much better than my E30 325i was with it's stock 21:1 ration rack and pinion. The e24 is 15.4:1, if I remember rightly. It has a little play just off centre - but that was engineered in for sneeze factor, I believe. As soon as it weights up, it's fine. No problems on track.

BlueBob

275 posts

253 months

Wednesday 3rd January
quotequote all
Great work, interesting project. Re steering, some e9 race cars used the e21 steering rack - mounts behind the front cross member. Another option is the e12 manual steering box used on the more basic models, although needs small work at mounting point on cross member.
BTW, e12 struts on an e9; something to be aware of, they have different inclination (camber) angles strut to spindle. Also, e12 m535 and e24 have the larger diameter hub bearing spindle over the base model e12's (and e9).
Huge choice of mods you could make depending how far you to take it. Stitch welding and boxing in chassis leg to bulkhead in engine bay area good start - latter in the e9 homologation.
Keep up the good work, great inspiration for others.
Vaguely remember your e9 build somewhere in the past.
(I have group 2 e9 and e12 race cars - some of the build is under Renn59 on Facebook)

BlueBob

275 posts

253 months

Wednesday 3rd January
quotequote all
Headers; RHD equal length can be done with steering box, and with dry sump pump and twin brake masters. Made some for my RHD e12 race car, tight, but can be done.

300bhp from an m30 is quite a challenge and costly. Alpina only achieved about 260 with higher compression and head work. Getting that extra needs much to be done. A dry dumped 3.5 m30 race engine producing somewhere around 310/320 will cost £20k+ now.

Start thinking re wheel width at bodywork stage. You will find you are limited without 2.25" coilover conversion on the front and possibly a recess in the trailing arms at rear.

Edited by BlueBob on Wednesday 3rd January 14:24

ingenieur

4,230 posts

189 months

Wednesday 3rd January
quotequote all
BlueBob said:
Great work, interesting project. Re steering, some e9 race cars used the e21 steering rack - mounts behind the front cross member. Another option is the e12 manual steering box used on the more basic models, although needs small work at mounting point on cross member.
BTW, e12 struts on an e9; something to be aware of, they have different inclination (camber) angles strut to spindle. Also, e12 m535 and e24 have the larger diameter hub bearing spindle over the base model e12's (and e9).
Huge choice of mods you could make depending how far you to take it. Stitch welding and boxing in chassis leg to bulkhead in engine bay area good start - latter in the e9 homologation.
Keep up the good work, great inspiration for others.
Vaguely remember your e9 build somewhere in the past.
(I have group 2 e9 and e12 race cars - some of the build is under Renn59 on Facebook)
He's not doing any steering mods as the steering is perfect as it is. Several other owners have chipped in to confirm this. It must have been only me who found the original steering to be a weak point, something wrong with my car specifically and not a general problem - lol.

E90_M3Ross

35,723 posts

220 months

Wednesday 3rd January
quotequote all
BlueBob said:
Headers; RHD equal length can be done with steering box, and with dry sump pump and twin brake masters. Made some for my RHD e12 race car, tight, but can be done.

300bhp from an m30 is quite a challenge and costly. Alpina only achieved about 260 with higher compression and head work. Getting that extra needs much to be done. A dry dumped 3.5 m30 race engine producing somewhere around 310/320 will cost £20k+ now.

Start thinking re wheel width at bodywork stage. You will find you are limited without 2.25" coilover conversion on the front and possibly a recess in the trailing arms at rear.

Edited by BlueBob on Wednesday 3rd January 14:24
You can turbocharge them and get that sort of power pretty easily, if that's your bag.

some bloke

1,206 posts

75 months

Wednesday 3rd January
quotequote all
I worked at a Hotel in Melbourne in the late 80s and a regular guest had one of these that I would park for him. It was gold with a similar colour interior (bit hazy now) but I remember being very impressed by the electric seat adjustment.

ingenieur

4,230 posts

189 months

Wednesday 3rd January
quotequote all
some bloke said:
I worked at a Hotel in Melbourne in the late 80s and a regular guest had one of these that I would park for him. It was gold with a similar colour interior (bit hazy now) but I remember being very impressed by the electric seat adjustment.
Mine was a 1989 highline. Compared to regular cars people were driving in 1989 this thing was like a spaceship. Your average everyday Ford for instance would usually have a wet interior from badly fitting door seals so would have condensation all over the insides of the windows and would start most days, but probably not every day.

some bloke

1,206 posts

75 months

Wednesday 3rd January
quotequote all
ingenieur said:
Mine was a 1989 highline. Compared to regular cars people were driving in 1989 this thing was like a spaceship. Your average everyday Ford for instance would usually have a wet interior from badly fitting door seals so would have condensation all over the insides of the windows and would start most days, but probably not every day.
I grew up in rural NZ prior to going to Melbourne; you had a luxury car if it had carpet back then.

BlueBob

275 posts

253 months

Wednesday 3rd January
quotequote all
ingenieur said:
He's not doing any steering mods as the steering is perfect as it is. Several other owners have chipped in to confirm this. It must have been only me who found the original steering to be a weak point, something wrong with my car specifically and not a general problem - lol.
Made me smile. Even in the e39 there is quite a difference, I would take my (both former) 530 over my 540 because of the steering, quite souless in 540.

The power steering system is very heavy, a manual box or rack would help with lightness. Wear also creeps in on the boxes, some worse than others.

Court_S

13,851 posts

185 months

Wednesday 3rd January
quotequote all
Some great work to date OP; that’s quite a bit of rot to sort.

I’ve really enjoyed Yorkshire Car Restoration’s videos on Auto Alex’s rotten E30. The fabrication skills certainly seem quite impressive to a novice like me.

gazzol

Original Poster:

67 posts

211 months

Thursday 4th January
quotequote all
BlueBob said:
Headers; RHD equal length can be done with steering box, and with dry sump pump and twin brake masters. Made some for my RHD e12 race car, tight, but can be done.

300bhp from an m30 is quite a challenge and costly. Alpina only achieved about 260 with higher compression and head work. Getting that extra needs much to be done. A dry dumped 3.5 m30 race engine producing somewhere around 310/320 will cost £20k+ now.

Start thinking re wheel width at bodywork stage. You will find you are limited without 2.25" coilover conversion on the front and possibly a recess in the trailing arms at rear.

Edited by BlueBob on Wednesday 3rd January 14:24
Thanks for your positive comments re my work. Yes I know it is possible to get equal length headers whilst keeping the steering box but they're custom/hand made and therefore very expensive as opposed to off the shelf ones like the ones that Schmeidmann sell for £250 plus taxes which sadly don't fit RHD vehicles. With regards to wheel width I'm more or less committed to going with an e9 group 2 style wide arch kit like the Luigi race car so I'll be able to have very low or even negative et on the wheels so suspension clearance won't be an issue.
With regards to 300bhp.....yes I know that is a lot to achieve from an N/A M30 but the people who did Scott Osbourne's M10 head which was just shy of 90bhp per litre did mine, plus mine has more compression more cam and REC race valves. If I can make 85 bhp per litre I'll be very happy but I'm not interested in huge numbers anyway if I were I would have turbo'd iit. Incidentally the same people get 380 from their M30 race engines.
If anyone feels the need to go on a crusade to tell me about scrub radius and other associated problems with high offset on the front please don't.

gazzol

Original Poster:

67 posts

211 months

Thursday 4th January
quotequote all
Gooly said:
That video of the E9 is one of the best things I've ever watched. Good luck with the project, doesnt look like you'll need it though! A straight six manual BMW with an LSD is such a brilliant thing to have in the UK. Hope to see this on a set of BBS RC090s and nice chunky tyres ripping up Hartside sometime!
Thanks I'm glad you enjoyed it, there are a few other videos on my YouTube channel if you'd like to see more.

BlueBob

275 posts

253 months

Thursday 4th January
quotequote all
gazzol said:
Thanks for your positive comments re my work. Yes I know it is possible to get equal length headers whilst keeping the steering box but they're custom/hand made and therefore very expensive as opposed to off the shelf ones like the ones that Schmeidmann sell for £250 plus taxes which sadly don't fit RHD vehicles. With regards to wheel width I'm more or less committed to going with an e9 group 2 style wide arch kit like the Luigi race car so I'll be able to have very low or even negative et on the wheels so suspension clearance won't be an issue.
With regards to 300bhp.....yes I know that is a lot to achieve from an N/A M30 but the people who did Scott Osbourne's M10 head which was just shy of 90bhp per litre did mine, plus mine has more compression more cam and REC race valves. If I can make 85 bhp per litre I'll be very happy but I'm not interested in huge numbers anyway if I were I would have turbo'd iit. Incidentally the same people get 380 from their M30 race engines.
If anyone feels the need to go on a crusade to tell me about scrub radius and other associated problems with high offset on the front please don't.
Was wary of saying too much, having come across your good self previously I was confidently knew your beans wink

If you are stuck for inspiration on anything or a few tips etc mail me direct.

Think I have 11 and 12" wheels on the e12, and 13 on the e9 rear, similar arches on the e12....so plenty of scope. Thought about making your own headers? Got mine within about 2% by volume.


Edited by BlueBob on Thursday 4th January 12:08

BlueBob

275 posts

253 months

Thursday 4th January
quotequote all

BlueBob

275 posts

253 months

Thursday 4th January
quotequote all
Inspiration


ingenieur

4,230 posts

189 months

Thursday 4th January
quotequote all
BlueBob said:
Going to have trouble with your EGTs there!

BlueBob

275 posts

253 months

Thursday 4th January
quotequote all
ingenieur said:
Going to have trouble with your EGTs there!
Dont worry, had them ceramic coated smile

JJJ.

1,506 posts

23 months

Thursday 4th January
quotequote all
BlueBob said:
Thought about making your own headers? Got mine within about 2% by volume.


Edited by BlueBob on Thursday 4th January 12:08
Very impressive, hat's off.

braddo

11,299 posts

196 months

Friday 5th January
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I'm in awe of the bodywork repairs being done here. Hats off!

ferret50

1,622 posts

17 months

Friday 5th January
quotequote all
ingenieur said:
BlueBob said:
Going to have trouble with your EGTs there!
Plastic pistons as well?

biglaugh