Aim data system for FV - Questions

[Gary Slahor]

Pardon if some of these questions have been asked before, but I'm in the process of purchasing an EVO4S plus G Dash system for my Vee and need some help before I place the order.

1. What thread for the sensors that screw into the block. 1/8 NPT or 10mm ?

2. Is the AIM RPM filter a definite requirement for the distributor/coil ignition system, to give steady RPM readings ?

TIA........... Gary

[Steve Davis]

Gary,
'Sensors' that screw into the block. There should be (at least) 3 sensors.

1). CHT - should be a 14mm ring terminal to go under a spark plug. Generally #3 plug is used, but it's not imperative. #3 is used because it USED to be the hottest plug in early standard (fan housing) configuration. The oil cooler was inside the fan housing and partially blocked the air to the #3 cylinder. Not an issue in today's "current vee" configuration where the fan housing is not used.

2). Oil pressure - the OP outlet is in the side of the block below the distributor and in front of the stock oil cooler location. I believe the thread is 'something metric', but a 1/8 NPT will screw into it just fine. It might not accommodate whatever the stock fitting was again, but that's not generally an issue either. If you have one of the myriad of optional 'full flow cooler/filter' configurations, you can also come up with your own answer for that somewhere in those lines.

3). Oil temperature - the OT sensor can also be located in different places.. the most common being the port at the bottom of the case in the front under the #2 cylinder. It takes a 'block off' plate held on by two 8mm nuts. That block off plate will be tapped with (probably) as large as 3/4 NPT and as small as 1/8 NPT. If you get the 1/8 NPT sensor, you can use brass adapters to drop down from whatever is there to that size. If you have a remotely located filter and/or cooler, you could also mount your OT sensor (or OP as well) in those lines. SO.. again, get the smallest NPT sensor that's available so you can adapt down to it from wherever you decide is the most appropriate for your car. Wherever you mount it, you need to make sure the sensor end is actually IN the oil and not just in a 'dead end' passage that might not be in the 'flow' of oil.

BTW.. since you are buying NEW, be sure to get the GPS option. Although nothing is PERFECT, using GPS eliminates the issues associated with a trackside located tx/rx that can easily get forgotten during pack up to leave the track.

As for the RPM pickup.. the most stable method is to put a magnet on the front pulley and trigger a mag sensor mounted by 'some configuration' that you can devise. Other than that, using the RPM 'filter' that is available from multiple vendors is pretty much REQUIRED to get a half way decent signal that will give you reliable RPM indication. My old XGLog unit still has issues even with the filter, but it does work acceptably. I just didn't realize how bad it was till I started using the mag sensor on my CDS system. THAT method provides a perfect signal, but it's a bit more complex to get it working than just attaching a wire to the coil .

Hope this helps,
Steve, FV80

[DannyPip]

The oil pressure idiot light port on the case is indeed 10x 1.0mm. 1/8" NPT is close, very close, I believe it is 27 threads per inch. This is similar to the 25.4 threads per inch of the metric one, but not exactly the same.

Make sure if you use the factory port to only tighten it snug(or until it doesn't leak), it is very easy to crack the case there. Either way, something has to go in that hole.

The later type4 case had a flat there and the oil pressure idiot light switch used a copper sealing washer. Better way in my opinion.

As far as an rpm pickup, the magnet on the pulley is a good idea. It isn't hard to buy or fabricate a mount that goes to a case bolt behind the pulley. Mario Vellata of The Dub Shop sells a Hall Effect sensor and mount for behind the pulley, however that uses a 36 tooth 1 missing pattern on a wheel for crank position on EFI. Use his photos to help you fabricate something. Here is just the Hall sensor:

https://thedubshop.com/crank-sensor-hall-effect/

I use his VR sensor and wheel on a type1 in a 550 Spyder. The 3 pin Deutsch connector works very well for easy disconnect.

[romoman]

AiM makes M10x1 temp and pressure sensors if you want those instead of the 1/8npt.

All current AiM systems are GPS based, so no worries about that. Make sure you don't get an old system with a GPS08 - you want a GPS09.

RPM should not be a problem on any new system. I run a current AiM system off a coil without any trouble.

[Gary Slahor]

Thanks for the replies.
I think that gives me what I need
Much appreciated

Gary