DonE

I just spent 3 days on the JB Racing engine dyno with my new re-rebuild, using the Link ECU and timing the cams to 2.3mm. Here is what is different over the previous build:

> Link ECU
> twin Bosch 6 pole coils
> 2 Link 3 channel ignitors
> crank and cam sensors are hall effect
> mototron 60lb high impedence injectors
> knock sensor

First, since I am using wasted spark, I measured the resistance in the plug wires. Wow, was there a difference. I am using Clewett wires and found 9 of 12 wires within spec, and the remaining 3 over 17k ohms. The reason was corroded plug connectors. So, we replaced all the plug connectors with magnacore, stainless steel connectors which fixed the problem.

It took about 2 hours to dress out the engine once it was on the stand. We then went through everything (connectors, sensors, etc). I chose to use the electromotive cam position sensor and for the last kick in the crotch, it failed all the tests. I called Neil Harvey at Performance Developments at 4:30pm EDT and he had the vendor drop ship me a new sensor by 0930 the following morning. The sensor came from FL (remember, 4:30pm phone call), and Neil made it happen.

The next day, we installed the sensor and had trouble synching the cam and crank timing. We got it working OK, but Neil sent his scope to us via overnight delivery to make sure. He did this on his own and paid the freight (and took the risk of damaging his $5k scope). Unbelievable customer service. We were able to do our first full pull later in the day. We double and triple checked iginition timing against the software to ensure the obvious.

The third morning was spent measuring sensor output and precisely locking the sync and timing. From the engine dyno, we measured boost, EGT, torque, HP, oil temp, oil pressure, ambient temp, humidity and so on. We also measured EGT on cylinders 2 and 5, and found less than 30 degrees difference from side to side. The majority of the temp differences were less than 10 degrees from 3500 to 6500 rpm.

Here are the parameters:

> one bar boost spring
> inlet air temp - 45C
> max rpm - 6800 rpm

Max torque - 470 lbft
Max HP - 530

Torque at 3200 rpm - 304 lbft

Max EGT - 1533F at 6200 rpm
AFR from 3500 to 6200 rpm - 12.8

I'll put the engine in the car this weekend and see how it runs by the seat of the pants.

The service I got from Neil Harvey at Performance Developments was outstanding. I probably called him 30 times over the past 3 days and each time he took the time to answer my questions, and twice got the EFI software programmer on the phone with me to explain a function - the programmer is in New Zealand.

Rgds

m42racer

Now thats what I have been talking about!

Great numbers Don. You should be happy with those at 1 bar. Thats real good. Good torque too. I'm sure Neil gave you a map that got the engine started without to much trouble. He's usually very good at guessing a starting point.

How do you like the new Link. Its impressive isn't it. There is years of development in this new Link system. I saw it about 1 year ago in a development stage and was impressed then. I know its even better now. I watched a dyno pull from 3000 thro 8500 RPM vacuum to 22 PSI and the A/F numbers changed less than 1/4 of 1 A/F point. I bet the engine ran smooth and started really well. I think this system will set a new standard in EFI systems in the affordable range.

Glad to read everything worked out good for you. Now hopefully you can enjoy that car. Well done.

125shifter

Excellent news!!!

I can't wait to hear how it runs... again.

Geoffrey

Don, that is great. I see you were using a DTS dyno which I like very much and have used quite often. One thing I don't like is the lag between the electric throttle control so as you move the throttle in the control room, the engine lags behind. Not a big deal and everything else about the dyno I like very much. Did you connect the air turbine and fuel meter to be able to see the BSFC and BSAC as well as the engine CFM requirements? Being able to measure those things is what is nice about an engine dyno.

RE EGT. I have seen the most difference between EGTs when measuring within a bank, 1-2-3 and 4-5-6.

RE AFR, you are running 12.8 AFR under 1 bar of boost? In my experience that is too lean for the air cooled engine used in a racing environment. Perhaps it is fine for short bursts on the street, but I'm suspect of even that.

jimculp

Don,

Very interesting post. Do you mind going into what knock sensor you are using and how it is performing?

Thanks,
Jim

DonE

So far, I am happy with the Link. It has so much more control features than I am used to. Most of them came in handy, such as being able to adjust fuel cells in tenths of a percent. I was able to dial in AFR's exactly as I needed.

I can't say enough about Neil. The base map he sent was nearly perfect. The injector master was perfect, the cold and hot starts were perfect - we started the motor each morning and after each session (hot) with just the starter and nothing else (no throttle movement and no adjustment in the tables). The timing and fuel tables were close and required minimum time to adjust and test. Thanks again for the introduction to him.

DonE

You have a good point, but we also have conservative timing and good EGT numbers at 1 bar. The knock sensor showed nothing either. I even have a map under full boost with 13:1 with no knock and good EGT numbers. I was encouraged by Neil to try this number based on his turbo builds and tuning.

One other point. We tried very conservative timing numbers such as 28 degrees at 3500 and 10 degrees on boost. The power was far less and EGT's were in the mid 1700 range.

Geoffrey

"One other point. We tried very conservative timing numbers such as 28 degrees at 3500 and 10 degrees on boost. The power was far less and EGT's were in the mid 1700 range."

That would be expected since the timing is happening so late.

DonE

Over the past couple of weeks, I've read a lot of posts regarding timing. There is lots of advice where to start, but in reality you need to get on a dyno to be sure. You can either be leaving performance on the table or put a hole in a piston, so it makes no sense to plug in a value and go for a ride (unless its stock).

For example, I tried 20 degrees at 1 bar of boost to see what would happen. I lost 20 hp compared to the 15 degrees that was there. Down low, I started with 28 degrees but didn;t like the EGT or throttle response. I went to 34 and both issues improved significantly. I tried a couple more degrees with no affect on torque or EGT, so I left it at 34. I was very surprised at 22 degrees of initial timing - the engine really likes that instead of the 11 I had with the TEC3. I guess the engine will take what it wants.

Also, I tuned for overall performance (torque), longevity and drivability. If I left HP on the table, so be it. You will notice the max HP is at 6200 rpm. Thats fine with me given the torque its producing.

FYI - the CF for the dyno was 1.044 for baro, temp, humidity.

sand_man

Excellent news, Don!!!! And everything you said about Neil's knowledge, skill, and customer service is TRUE!!!!

m42racer

Don,

Your very welcome. I have been through many "shops" if that what you want to call them, and spent huge amounts of money and got very poor results. I found Neil through a racing buddy, and have never looked back. I now get the same service etc as did World Champion Formula One drivers. The experience and service is so different. In this business it costs money. Its nice to know that you are buying quality and experience.

Now the real test will happen, in the car and the feel on the throttle pedal. I will be interested in your opinions of the Link verses the Electromotive Tec 3 system, once in the car and running. I'm sure you are going to see a huge difference.

In my opinion, the Link is now in the brotherhood of the very top of the line ECU's, offered by EFI Tech, Motec etc, but at the cost of many of the lower systems.

As far as the A/F numbers are concerned, if the EGT's are good, I cannot understand why running any richer could help. They show whats going on in the Cylinder Head. I'm wondering if the old concern about running these engines rich is based upon never having EGT numbers available when making this decision. I think alot of tuning is done based upon A/F numbers only, instead of peak torque and then looking at the other factors. Makes for a lower overall torque curve. But you can never go wrong with been safe I suppose. Well, second I guess.

klein90

Don,
What is involved in changing over from a Electromotive to a link ecu. And how do you get of hold of neal.
Thanks
Mark

Rob S

Don,

Congrats on the progress. Sounds like you have a running machine again. It's incredible how every last bit of Electromotive stuff kept failing on you right up to the bitter end! I, too, have a very good impression of Neil Harvey; he was very helpful and provided a number of parts, services, and advice during my build and afterward.

Your numbers are very similar to mine, though the test conditions were slightly different for my run. The closest comparison I have handy is a run at 0.9 bar, with 103 octane fuel. I assume you ran 93 octane pump fuel, did you?. Your torque appears to come on a bit earlier (which wouldn't surprise me with your cams), but that may depend on where the sweep was started and how fast it was done. Mine started at 2750, and I don't recall the sweep rate without looking. For 0.9 bar and 103 octane fuel, I saw 268 ft-lb at 3250 RPM and a peak of 496 ft-lb at 5250 RPM. The torque hovered just under 500 from 4500-6000 RPM. The highest horsepower recorded for that particular run was 544 at 6000 RPM, but the slope was still climbing when the run was terminated, so I don't know how much higher it might have gone. My guess is not much -- maybe 550 or so at 6250. I also have a 91 octane pump gas run at 0.9 bar, but it's not handy right now. As you would expect, numbers are a bit lower for that map, and they're considerably higher for the 1.2 bar/103 octane map. The EGTs for all my runs were generally in the mid 1500s; that's where the engine seemed happiest. AFRs ended up in the low to mid 12s under full speed and load.

I'm using the same injectors you're using. What fuel pressure were you running? Mine was at about 3 bar statically. Did you have any concerns about duty cycle? Mine are running fairly high; on the next round, I may up the system pressure a bit to compensate for that.

We'll look forward to your driving impressions.

DonE

Here is their US site. The phone number is Neil's (Performance Developments).

You will need to replace everything Electromotive to ensure everything works correctly - sensors, ECU, harness, DFU's, etc. I am keeping the power harness as its pretty basic and should work fine.

DonE

Hi Rob

My fuel system pressure is 3.8 bar using the stock 3.2L system. Duty cycle shown in the software was about 72%.

When I used 12.5 AFR at WOT, the EGT's were in the low to mid 1400's, and torque fell off.

Something I did here much more than I did with the TEC3 was verify timing with a light. We verified timing from idle through WOT. I probably did it 2 dozen times each day.

And how nice is it to tune an engine on a stand rather than a chassis dyno? We pulled plugs, checked compression and leakdown, fixed a small oil leak and generally kept an eye on the motor. It will be tough going back to a chassis dyno, except for some misc work.