Twin Cam GT Bellett

[65bellett]

Hi guys I have been lurking on here for a couple of months and annoying Antus with my endless e-mails so I thought it was time yo start a thread and share my endless questions.

My Delco story started about 6 months ago when I purchased an Isuzu Bellett Gt that I had been chasing for a few years. The car was fitted with a 2lt Twin Cam Isuzu G200w that was running the standard 30+ year old fuel injection. My initial thought was to get rid of all that complicated VooDoo and put a pair of good old Webers on it and be done with it, but I had been chatting with Antus and L20a and been hearing a lot of good stuff about this Delco hacking business. After a few beers and a lot of talking it was decided that I was going to put a Delco system on the car. Now to the reason why it took a couple of months to get to the car and get cracking with the Delcoing. I live in Melbourne and the car and the experts were in Adelaide. So finally after a lot of phone calls and a few weekend trips (a couple of sickies as well) my car was Delco equipped.

[65bellett]

Now unfortunately due to a lack of time and the fact I damaged the radiator in the car before trailering it home to Melbourne we were not able to do a great deal of testing before I left Adelaide. This has been good in a way as I have been able to learn a lot more about the system and TP5 in a hands on sort of way. The first major problem that I seemed to run into was the dreaded harmonic resonance from the ABS sensor picking up the timing marks in the harmonic balancer. This took a lot of fabrication and changed appearance quite a lot.


Since making these mods to the bracket the car now drives a lot better through the rev range but it is still far from finished.

Here are a few of the logs I have made in the last couple of weeks

gt first run.xdl

This was the first run

(21.39 KiB) Downloaded 602 times

3rd run gt.xdl

After a bit of bracket tweaking

(207.29 KiB) Downloaded 543 times

new bracket.xdl

(251.36 KiB) Downloaded 578 times

I would love to hear what you guys think

[Holden202T]

i haven't had much experience with abs sensors other than im trying to use one for a speedo pickup on my gemini race car, but from the pic of yours it looks like the pickup in the end is on an angle .... not sure if this has any effect on it or not but i reckon it should be straight up and down .... if thats the case all it probably means is you need to weld up the hole for the bolt and drill it down a bit closer to the base plate to get it straight.

it may not effect it (VL400 or someone might be able the verify) but i reckon if it does effect it, you might get dodgy crank trigger readings or it may pickup a pulse on a larger degree angle.

[VL400]

Excellent conversion

The sensor tip should line up with the trigger tooth - ideally the tooth size (or in your case the slot) should match the sensor tip exactly. Awhile back I did some testing and found that the slot/tooth width does make a difference to the output wave shape but couldnt see much change rotating the sensor. Will check your logs out later too.

[65bellett]

Cheers for the quick replies. You are right on that the sensor is not sitting straight in the bracket. I had a lot of trouble getting the sensor to line up with the wheel as the timing cover I was bolting it to was not flat so it was sending the bracket at a few funny angles. To fix this I ended up cutting slits into the bracket and then bolting it up to the engine and in the dodgiest of ways I bent the bracket to line the sensor up to the bottom wheel. Once it was all lined up I then cut gussets up out of 3mm plate steel and then took my time welding it all back together so as not to get any distortion.

Here are a couple of pics of the current alignment

75d1ac86.jpg (101.95 KiB) Viewed 8789 times

aac48292.jpg (85.16 KiB) Viewed 8789 times

the white out marks on the sensor show me where the centre of sensor is.

Here are some of the pictures of my notches

1eaa1a7f.jpg (74.72 KiB) Viewed 8789 times

Just to give you guys an idea of where the bracket is sitting

89fcbc7d.jpg (102.15 KiB) Viewed 8789 times

This photo is before I got down to get a better alignment between the wheel and the sensor

[antus]

Hi, good to see some pics of this project up on the forum I havnt had a chance to look at the logs yet, will check them out tonight. Did you manage to get rid of those DTCs (on the data list page)? Can you post up a pic of the car from the outside, just for interests sake? Cheers!

[65bellett]

Vl 400 are you saying that the notches in the bottom wheel should be the same size and the little shiny bit in the bottom of the sensor? Does the orientation of the sensor have any effect? Told you I had lots of questions

By the way I would love to hear what you can see from the logs.

[antus]

The shiny bit in the end of the sensor should cross the wheel straight, eg if you are looking downwards at wheel ======|===== where | is the notch, then the shiny bit in the sensor should also be aligned |

At the moment yours looks a bit /

[VL400]

Yeah from the info I had read about these sensors the tip of the sensor and the tip of the trigger wheel tooth were meant to be the same size. I used a trigger wheel with varying width slots to test it and instead of the blue trace here being a very fast rise and fall it ends up a bit slower and more drawn out..

The ECU still triggered off it fine though, and from what I could tell all it meant was the cranking dwell was a bit longer. Only thing is it might not be (might be perfectly ok too) good for the extra tooth sync setup like the DIS module your using has.

The polarity of the sensor wiring is important though, the blue trace will invert with the wiring swapped.

[65bellett]

I think you are right Antus. I am going to pull the bracket off again to give it a tidy up so I may see if I can swing it around a bit. I will also measure the sensor tip while I am at it.