Instead of tapping the S52 head for coolant temp sensor...

[KangamangusDriver]

Ian,
Thanks for your insightful knowledge!

Very good to know!!

[Jason89i]

i assume you are speaking of this adapter

http://www.turnermotorsport.com/html/detail.asp?PRODUCT_ID=TEN9989M50

[FONT=Arial]We have been using this adapter on our M52 / S52 conversion E30's and have had no issues with inaccurate readings. .........

Again, we have never had an inaccurate guage reading using our adapter when wired properly. We have done a number of conversions on E30's here and have sold dozens of these mail order, we have not had any problems with the readings to date.


Doug
TMS

doug -

what am i missing here? have you added a resistor to the wiring adapter? i assume the adapter is not just taking the gauge temp signal (2 of the 4 prongs) and sending it to the cluster (did not work for me.)

not trying to be argumentave, just trying to understand how you got it to work.

cheers, jason

[ian332isport]

have you added a resistor to the wiring adapter?

This is also not an option. You can put a resistor in parallel with the temp sender, but the value you choose would only be any good at a specific temperature. You could possibly use a thermistor in parallel with the existing sensor, but you are then back to the problem of where to mount it.

I have not made the necessary measurements yet, but you may be able to use another dual temp sender in place of the water fitting (throttle body heating), and use both sides of the dual temp sender in parallel (and possibly some extra resistors) to get it to read about right.

Ian.

[matt]

Here is some information that may clear up some issues regarding the temperature sensor when running a 2.8 or 3.2 M52/S52 in an E30.

First, the reason we developed this part. Yes, you can drill and tap your cylinder head and add a second sensor. The only problem with that is that it is risky. If you do go that route make sure whoever is drilling is good. If they aren't, or if they do not set up the head on the mill, you could drill at the wrong angle, creating the wrong plane. This will result in a bad seal between the head surfrace and the sensor. This can lead to leaks or damage to the head.

Second, our mehtod compared to the manifold adapter option... We like to have our sensor in a constant coolant flow. Adapters off the small coolant supply line to the throttle body can give you false readings. This is due to the fact that it is not in a constant coolant stream. The coolant in this line is controlled by the temp. controlled valve in the airbox, so since this valve can close and cut off flow when outside air temp reaches a certain level, that is obviously not an accurate reading. Plus air flows over the adapter, this can also change in the readings. This is not critical, but we like to have the best possible readings.

Doug
TMS

I don't know of anyone who keeps that valve in the line. Most people on here (not me...) don't even bother running the coolant hoses to the manifold, they just hook the spider hose to the cylinder head.

On the S52E30 I helped with, we plumbed the TB to the coolant hoses and put the adapter in the line. We've just now gotten around to ordering the proper sensor for it, so I can't tell you how it works yet.