Yes it has been ages, honestly I did forget about this blog but truth be told I have had a lot of questions come through about steps taken in my projects so figured it was about time I got back into it. Also worth noting if anyone reading this is after some killer Velocity stacks / trumpets to suit their 4age 20v setup then head to … holla.

Quick update today though, just a picture of the AW taken today after its weekly scrum up… The old girl is still looking good…



So one of the things I have been doing alot of lately is designing up my own parts to suit the projects I’ve been working on.

Ive been on the lookout for the ultimate set of billet Alloy trumpets to suit the 20V 4AGE ITB’s that not only suited the size I was after, looked cool and also didn’t rape my pocket…I decided to design and make my own plus a few extra. Keep an eye on the blog over the coming 3 weeks as I will be selling off a couple sets from the over run.



Ok so hopefully this post will help anyone looking at sussing out the tacho (in my case a 1993 Hiace RZH113) issue using a 5V square wave RPM signal from an ECU. Ive been driving it around for 9 months now with no working tacho and thought I’d do some homework and get it sorted.

Background to all this shizz: The original 2RZ that came in the hice would have had a feed from the coil to the tachometer supplying it with a 12v voltage spike causing the tacho to correctly display the RPM.

Thats all changed though, Ive got another 4 cylinders (4+4=V8) and a Spitronics aftermarket ECU outputting a different type of signal better suited to newer tachometers / aftermarket units.

Problem solved : A Tach adapter is needed here! You have options too… You can Google the Megasquirt tacho adapter schematic and follow that through to make your own or you can look around and see what is for sale. I spent ages looking at different brands that do tach adapters but be aware that different tach adapers convert slightly DIFFERENT signals and this may not be clear when browsing the product on the web…. I came across 2 options I would and have willingly spent $ on… MSD tach adapter 8920 and the Procomp Electronics adapter, both retails for around US$70. I went with the Procomp, piss easy wo wire up taking about 15min to do a clean job… Ground , IGN , 5v feed and Tach out… easy!

Tach works BUT next problem was the tacho reading 2X what the engine was doing… Why? because the ECU is sending out 1 pulse per spark, now the engine has 2 coil packs instead of 1 and so the tach reads double the pulses.. Well thats what I believe anyway..

Problem solved: Now this worked for me , your Hiace / Hilux or whatever may be totally different but there is info out there regarding calibration using a potentiometer if your factory tach doesn’t already have one on board, if thats a negative for you go check this out…..For me though, I went to Jaycar and bought a standard 5K POT just incase but to my delight after removing the cluster and undoing the 3 small screws from behind and removing the tach unit i saw a small white POT used for calibration. See below…


Cool now that was done all I had to do was plug it back in, start the engine with the PC and tuning software going, look at the PC to see my RPM and twist the POT until I got the correct RPM on the dash, checked it through the rev range and bang , done!

Hope this has helped 😀



Way too long

It’s been ages since my last post, shits been happening but I just aint been posting….. nor has Leppa. Ive bought another m90 charger off a Thunderbird, manifolds getting made aswell so will have to suss out an update on the van to cover all the bits people may want to know…… until then…

More stop

When I brought the black AW11 as a rolling shell the dude I got it from gave me a box of random bits , in this box I discovered a set of twin pot ST185 calipers in pretty good condition.  I hadn’t thought about a brake upgrade until coming across a set of 275mm / 4 x 100  TRW slotted rotors that , with a little modification would fit the calipers.

So bought them , and started sizing them up on the car and this is what I found and modified….

  • Diameter of these were too large, now from what I have read these would have fitted the larger single pot Celica calipers with no issues. So I machined them down to 256mm..
  • Skimmed 0.3mm off the back of the rotors as they were slightly scuffing the calipers.. You can also just modify the calipers to suit if you wanted.
  • Thats it!


Really if you have all that you need and a spare 3 hours or so you can pull this off. Everything bolts straight up with few issues at all. As for braking well I need better pads as Im using the ones that were on the calipers and although the response is slightly better Im still not that impressed by it all and think I can get it better.

Ages between posts

You know it… Leppa now has ANOTHER vehicle. This one runs … ah and is sweet. Datto 1200 ute! More pics to come…..

1UZ Goodness

And its up for sale!