does anyone know how to do this? i'm used to my old HEI or MSD setup, but i haven't noticed a way to do this on the bosch distributor.

Dunno about the fancy stuff, but. Check out the rubber vacuum tubes and connections and if they are oldish replace them. Mine is noticeably peppier since I have done it.

Geoge

The old wind bags on this board don't know a thing about that cause they don't rev past 6,000 rpms with their crappy stock ignition systems.

MEGASQUIRT it if you got da balls.

Actually I don't know a way to do it - but maybe someone dies.

Raising octane helps. Here's why:

The knock sensor retards the timing as soon as it detects knock, which of course happens sooner and more often with 87 octane. The result is that if you step hard on the gas, not that much happens if using 87 octane. Changing to 89 gives considerable improvement even on non-turbo engines, as the timing stays advanced pretty much as it was originally programmed.

I think that going up to 91 or 93 (whatever's available in your area) will probably help further, but you'll have to decide for yourself. Turbo users swear by 91/93 octane and report the beast is relatively useless otherwise.

--
[aka Sophie's Maintainer] Sven: '89 245, IPD sways, E-fan conversion, 28+ mpg - auto tranny. 850 mi/week commute.

re: "...Turbo users swear by 91/93 octane and report the beast is relatively useless otherwise...."

I thought that the knock sensor started with the B230's ('86 and on, I think), such as my '93 -- I certainly don't have one on my '84 B23. And wasn't the last 240 turbo in '85 (or maybe '84)? So it doesn't seem that the benefit of using 93 octane stems from having a knock sensor permit greater advance -- unless the turbo's had knock sensors.

Of course, the turbo's might still have benefited, simply by allowing the owner to set a more advanced timing. I've done this with one of my other cars (a custom-rebuilt, high compression engine in an M-B 𖒐GE] in which I've advanced the timing, but I'm constrained to using Sunoco 94 in the summer months as a result). And since it's (also) an '84, without a knock sensor, I'm dependent on using the "knock sensor attached to each side of my head" for a warning to lift up on the gas when I'm pulling my boat trailer up a steep grade. :-).

Knock sensors arrived in 1983 with the B23F engine with LH-2.0 in USA, Canada a year or two later. Apparently it was something Volvo really wanted to make sure their service techs took note of, as my '83 factory manuals point it out several times with a big "NEW!!" preceding mention of it.
--
Bob (son's 81-244GL B21F/M46, dtr's 83-244DL B23F/M46, 94-944 B230FD; grocery-getter Dodge minivan, hobbycar 77 MGB, and a few old motorcycles)

my model is an 84 245. i also believe the knock sensor came in with the b230...i can't find one on the side of my head. i think the main reason why turbos can get more power out of high octane is the fuel's increased resistance to detonation, i.e. higher boost levels can be obtained if desired. of course they can also add the terminal 11 trick and water injection for even more boost (>15 psi).

Ken,
Knock sensors started with the B-23 in '83 for NA cars, 240 turbos did not get them but all 700 series had them. If your '84 doen not have one there is something wrong, the same ignition system was used from '83-'88, there were 2 different distributors used, the infamous "white cap" and Bosch.

240Ts used preimum to take advantage of its ability to prevent knock so they could run higher boost safely. All turbos had was a pressure retard system on the distributor, they would have benefited greatly from a knock sensor system as they got retarded under boost whether they were kocking or not.

Additional advance makes a large difference for those of us that can do it (pre '89)
--
Dave Shannon
Spring Valley, California
'67 1800s
'73 1800ES
'88-240
my pages

Wow! I had no idea that I had a knock sensor ('84 240DL, B23 na, USA model) -- I really thought I remembered a discussion here that said that the knock sensors started with the B230's. I've always used premium simply because I've believed that they (Exxon, AMOCO) put a little more additive (e.g., detergents) in that grade of fuel -- nice to know that my car is also benefiting by extra power.

Where would the knock sensor in this model be located, and what would it look like (in contrast to the other sensors)?

I appreciate the info!

Yep it's under the intake on the block down around #2/3 cylenders. It can be hard to see what with all the hoses, I am fairly sure that it uses the same boss on the block that the later cars use.

If I remember right the connector may be a bit different on the early knock sensors so it may look like a temp sensor, don't have an early car anymore, but the green books show only one female spade terminal on it in the pic.
--
Dave Shannon
Spring Valley, California
'67 1800s
'73 1800ES
'88-240
my pages

hi there dave, im guessing you are running advanced timing on the b230f.
have you looked into the saab acp system when you had your turbos?
just wondering. regards

Yea, 18º initial advance and premium, worth every penny with the VX and 2.5" exhaust.

The SAAB APC is the way to go if you are running high boost on a turbo. I pulled one but never got around to installing it before I sold them. The nice thing about it is the wastegate never "sees" any boost 'till there is knock, then the APC kicks in and backs off the boost, kind of like a G-Valve with brains.

--
Dave Shannon
Spring Valley, California
'67 1800s
'73 1800ES
'88-240
my pages