Using a M30 cruise control set on an M88/3

Post here for mechanical and engine topics such as fuel issues, transmission problems, rough idle, exhaust, electrical issues, etc

Moderators: GRNSHRK, ron, bfons

Post Reply
User avatar
Stoffie
Posts: 362
Joined: Wed Dec 16, 2009 7:24 pm
Location: Belgium

Using a M30 cruise control set on an M88/3

Post by Stoffie »

Hi there,

I have a chance to buy a complete NOS M30 cruise control set and was wondering whether there were many differences compared to what's in an M635CSi or M6.

I imagine the connection to the throttle linkage would definitely be different, probably some mounting brackets as well.

Does anyone have some experience with retro fitting such a set on an M88/3?

Would the M88/3 specific bits still to be found anywhere still?

Any pointers would be much appreciated!
The M88/3 was all about power, no cats. At idle the raw fuel from the exhaust will make your eyes water like an old V-8 powered muscle car's exhaust did.
User avatar
Stoffie
Posts: 362
Joined: Wed Dec 16, 2009 7:24 pm
Location: Belgium

Re: Using a M30 cruise control set on an M88/3

Post by Stoffie »

I guess nobody has any experience with what I'm asking #-o

Could anyone help with some detailed pictures of the cruise control components in the engine bay of an M6/M635CSi ?

I'm sure there are some members with such a setup [-o<

I think I'll take my chance and get the set anyway and see what's usable or not.
The M88/3 was all about power, no cats. At idle the raw fuel from the exhaust will make your eyes water like an old V-8 powered muscle car's exhaust did.
GazM3
Posts: 1791
Joined: Wed Oct 26, 2011 12:55 pm
Location: Melbourne, Australia

Re: Using a M30 cruise control set on an M88/3

Post by GazM3 »

I’m pretty sure they came with it as an option. I guess the big question is weather the 055 ecu can handle it or whether it has its own ecu. All the m30 basted hardware technically should work. Mines under a car cover at the moment so I’ll confirm whether there are 2 postions on the throttle body mechanisms or 1. Also check perhaps Realoem site with your age and see if any cruise control specific parts come up.
BMW’s
84 E24 M635csi
90 E34 M5 3.6
94 E34 540i/6 SC E85
97 E36 M3 euro SC U/C
97 Z3 2.8 widebody

OTHERS
11 Audi S5 3.0 SC
19 VW Amarok V6
Drew
Posts: 44
Joined: Mon Mar 11, 2013 7:37 am
Location: Hiding in the garage, South Bucks, England

Re: Using a M30 cruise control set on an M88/3

Post by Drew »

slightly different, but I retro'd cruise from an E32 (M30) into an early E24 (M90). My issue was generating a speed signal waveform from an old-skool gearbox speedo drive, a totally electronic problem. The rest was plug and play. The E34 had a separate brain to control the cruise servo, so no integration with ECU was needed for me

your issue will be connecting the cruise servo cable to the throttle linkage. I would assume this is possible, but I have nothing useful to add!
brickwhite
Posts: 797
Joined: Wed Sep 01, 2010 3:29 pm
Location: Broomfield, CO

Re: Using a M30 cruise control set on an M88/3

Post by brickwhite »

My m88 has it, biggest problem is the throttle cable holder from the s38 doesn't seem to work exactly the same.

Image
- 12 535i
- 92 325ic
User avatar
Brucey
6 Series Guru
6 Series Guru
Posts: 10077
Joined: Fri Apr 09, 2004 7:17 am
Location: Cambridge, UK

Re: Using a M30 cruise control set on an M88/3

Post by Brucey »

being entirely separate from the engine ECU, you can retrofit cruise control to almost any '80s BMW. The system uses an electrically driven servo (which has its own ECU) to mechanically open the throttle, and then the fuelling is sorted out in the usual way. Inputs into the cruise ECU include

-speedo signal (so early E24s pre 5/82 ,with mechanical speedomoters, need a gadget to generate pulses eg mounted in the speedo cable)
- power +12V
- ground
- brake pedal/clutch pedal switch (which cuts the cruise control as soon as either pedal is depressed even slightly)
- wires from control stalk including set, resume, accelerate etc.

There are several different versions of the system though, and if you want to use the correct E24 stalk not every system will interface with it; from memory some stalks have five wires and some have four.


There are one or two other issues to address;
- the original steering column binnacle is a cruise-specific part, but the non-cruise part can be trimmed to have the correct cutouts in it for the stalk
- the wiring loom (and cruise ecu location) varies with the car (but this can be extended as necessary)
- the wire colours used vary with the version
- the bracket used to mount the servo is an E24 specific part

M30 versions usually have the correct brackets attached to the throttle linkage already, so the system is plug and play at that end, However M88 engines don't, and (I think) there are two versions of the throttle linkage so the mechanical parts vary more than you might expect. I have seen some DIY adaptations, most of which work OK since the requirement is simple, i.e. that the servo pulls the throttle linkage, without itself causing trouble should the throttle be opened using the throttle pedal in the normal way (which can cause the cruise control cable from the servo to run slack).

fitting cruise control is well worthwhile; the system weighs very little and give you more freedom to wiggle your legs and bum around on long runs.

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Post Reply