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Very cool! I love the Volvo 940- it stands out as one of the best quality, and best designed cars ever made. It's an incredibly mature design evolved slowly fro
by _yb2s 2y ago
Very cool! I love the Volvo 940- it stands out as one of the best quality, and best designed cars ever made. It's an incredibly mature design evolved slowly from the Volvo 140 in the 1960s through the 240 in the 70s and the 740 in the 80s, and by the 940 they worked out almost any possible issue. I only wish one could have gotten them with AWD and a fuel efficient diesel (they had the latter but it was not sold here in the USA).
The author seems to have a lot of electrical hacking knowledge, but didn't know some car stuff that could have made getting these controls installed much easier:
1) They could have just swapped in a newer BOSCH ABS pump, which can activate the brakes electrically without involving the brake booster. European cars started getting these when they got traction control in the late 90s, but I believe some would be virtually (or maybe even exactly) a direct swap into this vehicle. I was able to do this in a VW with about 10 minutes of work, which uses the same basic ABS systems as Volvo. This is assuming the car already had factory ABS which I think most (but possibly not all) 940s did.
2) They could fix the steering problem by swapping in an entire electric steering rack- they're fairly standard dimension wise, installing a fully manual rack from a Volvo 240, or adding an A/C compressor clutch to the hydraulic power steering pump to disable it above parking speeds (the only time torque would be high anyways). Moreover, these racks are strong enough to simply work with the hydraulic assist removed, because people in the Volvo racing/performance community do it all the time.
3) This car does not have a carburetor- it is electrically fuel injected. You can see the fuel injectors and rail above the throttle body. This could be just a mistranslation if the author is not a native english speaker. However, more importantly there was a factory system on this car to electrically control the throttle for the cruise control. They are missing those parts, but they are cheap and common, and would have just dropped in to a bracket and cam already on his engine. They consist of a vacuum servo on the throttle itself connected to a box that can actuate this with an electrical signal.
- DebboR 2y agoAuthor here! Super surprised this made hackernews It does indeed not have a carburator (I wrote this while half asleep on a plane, I meant to say that it has a mechanical throttle/air valve which is cable operated). It also doesn't have ABS (although I believe this was an option on the car starting this model year), so swapping out that pump wasn't an option. The iBooster is a great and easy retrofit, definitely recommend! Haven't done it yet, but I'm just going to lower the pressure of the hydraulic steering by shimming the regulator, should be enough. It already steers somewhat ok without this mod too
- _yb2s 2y agoGreat to hear from you, and awesome project. I had an early 90s 240 that did have ABS so assumed incorrectly that yours would. Dropping the hydraulic pressure sounds like a really good idea, hope that works!
- deleted 2y ago[deleted]
- Ccecil 2y agoI am not sure about that particular car but some cars have a electrically switched valve on the power steering pump which lowers the pressure for higher speed travel (less responsive). You may be able to get "some" control just by disconnecting this (assuming it is there, my 93 Mazda 626 had one).
- _yb2s 2y agoNo, the power steering system on these is entirely hydraulic/mechanical. I’m surprised Mazda had such a feature so early.
- mnsc 2y agoI have a Xc70 now, from the year they stopped making these brutalistic work horses, and having owned a 740, v50 and a V70 before I believe this is peak "herrgårdsvagn". Nowadays the large Volvos like the v90 are stupid Chinese luxury cars that I will never buy.
- dzhiurgis 2y agoThey are masterpieces for people doing actual miles. Workhorses are for neglect and occasional cargo load. Completely different things.
- _yb2s 2y agoI'm sure some of their later cars after the 2/7/9 series are quite good cars, but they just don't appeal to me.
- ethbr1 2y agoAs someone whose first car was a 740, I'd drive one again in a heartbeat. Did everything you needed a reasonable car to do, well, and just kept on going.