Found a nice surprise today....

[Mr Project]

I bought this turbo E23 735i a couple months ago. The previous owner had died and his son was selling the cars, so I didn't have tons of details on the setup. It appears to be an old Cartech kit along with some other things.... But no aftermarket gauges at all, so I didn't know anything about how much boost it was running, A/F, etc.

Ordered gauges this week and I was pulling some panels off to route some wires, when I found something tucked away up underneath the knee panel:


This led me to pull the glovebox cover to take a look at the DME, and I found the rest of the setup:


It was actually disabled, the harness had been pulled and jumpered. I plugged it back in, and the car still runs, it says that it's pulling timing pretty frequently, so the sensitivity might need adjusting.

Anybody have any experience running a safeguard setup on an M30? Good/bad/useless? Tips?

[itsbrokeagain]

I havent seen one of those in years!

I remember the days they were using that on Sport Compact Cars project Miata in like 2001.

If you could get it working right that would be pretty awesome.

Otherwise sell it to me

[Kyle in NO]

I have heard that since M30 engines are so "noisy" internally, it is hard for a knock sensor setup to work properly. They tend to pick up engine noise as knocking and retard the timing inappropriately.

[winfred]

i always kinda wondered if you got the sensor low enough in the block you may get away from enough of the solid lift valve train with aluminum head amplification to make it work, i may attempt a KS on my e30 as it seems to have a natural knock point between 4800 and 5100 give or take a little when heat soaked, adding fuel and dropping timing barely effect it, t'wood be nice to have that demon exorcised when i go onto the paxton, could effect engine life slightly i am not looking forward to tuning around it when i get the blower on, i can hook up a sensor and log it on my vantage and see what various positions on the block does to the normal signal of my b35 in da shark for a kick, may make for good info for when i cram that bigazz holset under the hood and make that thing less comfy

I have heard that since M30 engines are so "noisy" internally, it is hard for a knock sensor setup to work properly. They tend to pick up engine noise as knocking and retard the timing inappropriately.

[Brad D.]

I have heard that as well regarding the natural "noise" of the engine false triggering the knock sensor. Depending on the capability of that older J&S unit though there are some frequency filters that can do a decent job of hearing knock through the engine noise. Whatever the case, it's pretty cool that that was in the car. I don't think I would use that AF gauge though as it's not tied to an actual wideband and therefore will be basically useless for tuning.

[///ARINUTS...]

J&S also made a version of the "johnson box" for the 745i which incorporated the o2 sensor with the coolant temp sensor for the ECU. Most faithfuls rip it out and restore the harness back to the way it left the factory. The 745i factory ECU actually has it's own knock control box and its mounted right there behind the glove box. 0 261 201 003 is the number on the label. if you don't have that , then you might have this nifty item instead. i would follow the wires to see if its spliced into the harness.

[Mr Project]

I agree that the A/F is pretty useless off the narrowband. I have an LC-1, boost gooahj, and oil pressure gauge waiting to go in.

I haven't traced all the wires, but it's definitely wired to a knock sensor that's bolted underneath the intake manifold near the top of cylinder #1.

//ARINUTS, this isn't a 745i car and doesn't appear to have been converted using 745i parts, so it appears that I have the stock 735i ECU. I am wondering if it's been chipped, or if it's running stock timing maps, so I might pull it out and take a look.

[JohnP]

That model was made between '91 and '97.

Dinan included them with his turbo kits. I think he called it the Turbo Tronics IV.

google "knock controller demo" to see a coil on plug version work.