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Soarer (SC400) Programmable Engine Computer

October 2003

by Peter Scott

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The Harry Lemmens V8 auto ECU - $1200

180 km/hr speed limit removed
Redline lifted to 7500 rpm or 8000 rpm
User switchable Code!
1. stock
2. 7500 redline, advanced timing
3. 8000 redline, advanced timing

I posted my ECU to Harry, he modified and sent it back.

I bought one of these from Harry and I love it. I guess people want different things from an ECU. For me the biggest thing was the removing of the speed cut - properly. At the track the car would halt at 180 km/hr. So I tried one of those interceptor units that trick the ECU into thinking the car was only doing 179 (Apexi revspeed). But interceptors aren't perfect - since the transmission also thinks the car is doing 179 it won't change to top gear unless you lift your foot of the throttle slightly. Harry has removed the speed limit from the ECU - not intercepted it - the code has been changed. So the ECU and the transmission know you're going faster than 180 and gear changes are perfect and everything is great - that's the big carrot for me.

The increase in redline? - Not many V8's still make power up there - I have modified exhaust cams and my car  makes power a little bit higher than normal, but not that much. The redline is not changed during auto shifting - you have to manual shift to get the 7500 rpm. I like it this way. I can floor it and the car changes just like normal. When I'm at the track and stuck between gears, the higher redline is a godsend - gives greater flexibility. Corners at 140 km/hr (87 mph) I now have the option of leaving it in second rather than change to third or bounce it off the old lower rev limit - stuff like that. More fun stuff with the higher redline is chirping the wheels during  gear changes when manual shifting (I have a shift kit too).

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Harry has made the ECU selectable. You put a small screwdriver in that little blue box and dial up 1, 2 or 3. Position 1 is stock code, 2 is 7500 and advanced timing and 3 is 8000 rpm and advanced timing. It also comes with that computer plug - Harry can plug it into his computer and upload and change the code in seconds. One day the software to DIY may be available. Harry also has realtime programmable software on the way. But for now I like it just the way it is.  I wouldn't mind revisiting the Code when the Eaton blower goes on. I just leave it on position 2 and don't worry about it. Position three is just so that I have a higher redline than Rob Hayden with his MiNes Japanese ECU set at 7500 rpm! The Dirt Oval race guys use 8000 rpm when racing their buggies with modified 1UZ-FE V8's. Harry has enough room on the chip to upload several programs.

Just like Rob's MiNes ECU, the timing is advanced and is designed for Australian premium fuel - not Japanese rocket fuel of 102+ RON.  I use 98 RON fuel like BP Ultimate. The USA use a different RON measuring system, I don't know the details but our 98 RON stuff is equivalent to 92 in the USA or something like that - Numbers can't be directly compared. After driving Rob's Soarer with his MiNes ECU all those years ago I wanted one real bad - but the cost is up over $3500 !! - and you have to send the ECU to Japan etc.

I haven't done a before or after dyno yet - but I do have a personal yard stick. No far from my place a bridge goes over a freeway. The bridge has an expansion joint running across the road. I start the car at the bottom of the hill near a road sign and accelerate over the bridge. When the front tyres hit the expansion joint I note the terminal speed of the car. I used to struggle to break 110 kph when the car was "stockish". My previous best was 114 kph with BFI III, exhaust, cams and shift kit, the night I fitted Harry's ECU I cracked 117 kph!! Now this test means nothing to anyone but me - but the expansion joint test never lies - and terminal speed is the most accurate measure of power - not time over a set distance. I can use the Apexi to give me 200m times and 0-100  - but my times still vary run to run. I can repeat the terminal speed test and it is always pretty much repeatable time after time.

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This is the only before and after dyno graph I could find. It's Andy's supercharged UZZ32 Soarer with 5 psi boost and stock headers. Blue line is stock ECU, Brown line is MiNes ECU. Here's what Andy said running the same code as Harry's position 2 Code:

Many thanks to Rob for the loan (actually I'm not giving it back!!). Note the run was performed at FULL throttle. Peak Power is up to 178.9rwkW @ 5psi. The Graph is MiNes (Brown) & Stock UZZ32 ECU (Blue). MiNes appears to have a few degrees of spark advance at full load, possibly 2-4 degrees. A more rich mixture was recorded, up to one (1) A/F lower, (11.3-11.9). ...., peak power and great torque are prolonged with the MiNes. As you guys will understand, the results are at full load and don't serve justice to anyone else who hasn't experienced the MiNes ECU. Throttle response is faster, and part throttle driving is very exciting and I'd safely say that it would be difficult to achieve a more optimised progression to full throttle. By this, I mean that MBT (Mean Best Torque) conditions would almost certainly have been calibrated into this ECU, without detriment to fuel economy, only tyre wear.

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This dyno of my naturally aspirated V8 (can't wait to get the Eaton blower on) was also achieved running the same code as Harry's ECU. It's hard to separate the contribution of the ECU to the total power curve. Subjectively the car is more alive to drive with Harry's ECU - it makes more power up top for sure, gives me higher rpm options and doesn't have the speed limit.

I don't believe the ECU modifies the fuel curve directly. I remember when Aaron Elliot bought an Apexi SAFC or some such thing to modify the fuel curves. We spent hours on the dyno, well an hour anyway, adjusting the fuel curve and seeing no change in the power curve - that was weird. Aaron saw no advantage in it and sold it a few months later.

If there was a Power FC for the V8 auto I would have grabbed that - but there's not and never will be. There is nothing around at all for the V8 auto - the MiNes from Japan is the only thing I've ever heard off and costs a fortune. I nearly went the full custom install with an aftermarket ECU - but after some expert advice regarding cost, fuel economy and driveability I decided not to. So as far as I'm aware Harry's ECU is the only option for me, car still runs perfect in everyway - it's just had the annoying factory limits removed and more timing added.

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Here is a plot Harry did of something in the Toyota ECU - don't ask me what!

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It was over a year ago now when Harry first brought his mod board to the Nov dyno day at Lilydale way back in 2002 - also know as the happiest day of my life... (hahaha). Even before then I still remember going to Harry's house with all the coffee and the smokes and the him sitting at the computer designing the board with fancy programs, then getting the boards made in Singapore or somewhere, picking out chips - it took forever. I got mine now so I'm happy!

Driving a stock ECU Soarer seems flat and lifeless after trying this ECU. We are limited with the V8 with what we can do for performance mods.

I would recommend;
1. intake (say BFI III)
2. headers (email Neil Griffiths - he'll get them to you no matter where you are)
3. exhaust
4. Harry's ECU
5. Andy's Eaton blower (ready DEC 2003).

And change your oil and filter every 5000 km. And change your top radiator tank at 120 000 km before it cracks and leaks - because it sure as anything will. And check your leads when changing the plugs. And get your air cond serviced and oiled - and if the compressor gets noisy turn it off before it burns out the clutch when it seizes - and if it does seize get a new one - don't spend $1500 fitting a 10 year old 2nd hand one and having that one seize after 2 weeks. And bleed your brakes properly - the pedal should never be soft. And lube those door hinges with a spray lithium grease, let it penetrate for a week and wipe off. And get that trans serviced with type IV Toyota fluid. And don't reverse into anything in the driveway. And don't let the spare set of rims fall onto the car from a great height. And don't go too hard the first lap. And get more than one quote for exhaust work. And wash the inside of the windscreen now and again.



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