Unigroup

We should have just went down, however there was a lot of pressure to stay back and catch up on work. Next year we'll make a better effort. I'd like to get together some cars and go down. Yavuz Unigroup Engineering

Thank you. The engine is receiving a new head gasket and turbo. It will be ready to run again in approx 4 weeks. Waiting on parts to arrive. Yavuz Unigroup Engineering

Sorry about the low quality pics. To answer your question, we're revving to around 9000rpm, and trying to stay as far below that as possible for reliability. I feel that the cams are not the best choice and the engine wants to make peak power beyond 9K. The cam timing ended up rather unusual to bring peak power rpm lower. We're just about out of adjustment as the valve will hit the piston if we advance the inlet cam any more. Yavuz Unigroup Engineering

Update After a full day at Unigroup, we stayed back at work to see what we can do about the problem. There is no time left at all to finish the car unless we have tons of luck come our way in the last minute. We've checked the tension on the head studs. We're hoping to find some of them loose below spec. No such luck. They are already tight, there isn't even the room to put more tension. This is the final straw. Sadly there's nothing left to do in time. I spoke to Julian (owner). He's not 100% sure (it was a long time ago), but thinks the head was put on re-using the old head gasket. It was due to last minute repairs and the right part was not available. So it lasted surprisingly long considering the power levels. The engine also has done a lot of hard running since. So the engine doesn't owe us anything, we owe it. So what's next? New head gasket - We still have more boost to come. We also have a nitrous system, which has never been turned on. We need the head gasket 100%. There's going to be some serious cylinder pressures. New turbo - This one makes me excited. Engines, heads and cams changed little compared to turbos in the last 5-7 years. Easiest way to make more power is running modern, more efficient turbos. I'm guessing close to 600kW at similar boost levels. New cams? - We're thinking of going back to a smaller grind. The current 280s only made marginally more power if any extra power. It's hard to compare as the cams were not the only change. The smaller cams definitely drove better, had more midrange and bottom end power. When you only have 2.6ltrs on a car this weight, you can feel every kW lost in the lower rev range. The plan is to keep the car street friendly so it can be driven. This is not a race car build. Cheers, Yavuz.

Thanks! I had a look through the list of mods in your signature. Looks impressive.

Update - This one is not going to end good… Last dyno session was stopped due to radiator neck leaking. It's all fixed. Plus we were forced spend nearly a full day on the car going over other things. We had to sort out electrical gremlins with sensor supply voltages, re-wire low oil pressure cut off, plus other things…It hasn't been a fun day. We've fitted a set of recessed tip spark plugs. These plugs are quite cold (9 heat range on NGK scale). These plugs are worth a try if you have an engine that is prone to engine knock. I've looked at the engine logs from the dyno a little closer. The exhaust manifold pressure is still lower than intake manifold pressure (29psi vs 27psi & 22psi vs 14psi). It can be beneficial to to try more overlap in cases like this. Higher pressure intake clears the chamber and forces the exhaust out. In turn you get better cylinder filling, and more power. Hence I've got extra overlap dialled in and hopeful for better results than last time. Here we go, on the dyno again, fingers crossed I just want it finished this time. Low boost runs to warm everything up is good. I can't wait to turn the boost up to see what it will do. Here comes the big run. Engine does not sound happy and the run is stopped early. We have water out of the radiator again. We're back to the original theory. The head seems like it's lifting. Good result, better power at same boost as before. 540kW at just under 30psi. We spend some time checking everything, and decide give it less boost to test the problem. Power is up everywhere on lower boost. 530kW now on 27psi (2psi less than before). On 22 psi engine is up 20kW. But we still have the problem with keeping water where it should be. In theory this engine is built to handle boost pressure similar to what most of us put in our tyres. So we have a problem somewhere… I'll see what we can do about the head lifting. The biggest problem is time available. To make matters worse, we already have a full day tomorrow. Yavuz.

I don't have any before runs but there are more dyno graphs on the next post. It would be great to get a video, but first need to get hold of a camera with a decent mic so it doesn't clip. The sound turns to mush which is half the attraction. Yavuz.

If people are enjoying reading it, then we'll do our best to keep it going. Thanks for the kind words. Yavuz.

Another quick update Problems seems to be behind us. Looking forward to the next dyno session. We'd like to have the tuning side finished off this time on the dyno. In preparation, we start going over the cam timing. This engine runs 280deg cams (more on the cams later). Lift is quite high, approx 12mm from memory. We check for piston to valve clearance. There's not much room, we don't have a lot of adjustment on the intake side. We'd like to make the peak power earlier and at the same time not give away too much from the peak figure. I'd prefer if the engine did not go much past 9,000rpm. There's 10,000 on the tacho. Ideally we'd like a custom tacho so that the 10K on the tacho reads $ and the next marker $$ and so on!!! Some experimentation with intake cam timing and we end up with again 420kW at 18-20 psi, but almost 1000rpm less for the same level of power. Looking better. Time for more boost…30psi, the engine is making approx 515kW, with the best run of 530kW. Not bad. One more run and we have water spraying in the engine bay and abort the run. Worst possibilities come to mind first; is it the head lifting?. Lucky for us, it just a cracked water neck on the radiator. We are pleased with the results but the car needs to come off the dyno again. We'd like to come back to experiment with the exhaust cam. If we run out of time, I'd be pleased to run with this power. There might be more in it and there's only one way for us to find out. Cheers, Yavuz.

Hi. Plenty of rubber under the guards. Cheers, Yavuz.

UPDATE #1 Back on the case of the misfire…We took quick look at the logs for further clues. Nothing there unfortunately. Fuel mixtures are ok, we have no reason to doubt the engine mechanicals. So quite possibly fault is with the ignition system. Also the sound and feel of this misfire tells us that it's most likely spark (ignition) related. We had new plugs, correct gaps, Mercury CDI coils and R500 CDI. Technically, with this ignition system we should have enough spark energy. So we're either looking at an installation fault or a faulty component. We are starting to run out of time and decide against further investigation. Even if we find the fault, we still need to fix/replace it and do not have any spares. Fastest way out of this problem for us is to replace the ignition system from another GTR. We need to make progress fast. We borrowed a set of spitfire coil packs from a broken RB26/30. We've wired in the Blackbox 6 channel ignitor. Everyone has their favourite ignition system. This one is my favourite. It's low cost and compact. The biggest advantage of this unit over the standard Nissan module for this application is the higher current clamp. (We have run over 50psi boost using this unit and ordinary Bosch coils). Opinions will differ here, but I prefer conventional ignition over CDI. Light load and idle is just livelier. Engines also tolerate leaner mixtures under light load with this type of ignition. CDIs also have their place. I run one after I exhaust other avenues. Engine is almost ready for another run on the dyno. Whilst we were looking for the ignition system problem we've discovered another potential problem. Have a look at the funky trace on the power supply to the ECU!!! It should be a fairly flat line. I would love the find out the source of the problem. However, time is once again the enemy. We decide to concentrate on the fix. We found a cleaner power supply else were and connected to the ecru. We checked to make sure that the problem was not present on the injector and coil power supplies. Lucky for us, no sign of the problem there. We fired the engine up with the new ignition system and electrical gremlins sorted. It sounded much better straight away and the fuel maps required fairly major changes to dial it back in. Back on the dyno, round 2…It's looking promising. First attempt, we ended up with 405kW and boost is approx 18-20 psi. Some changes to the tune, and we are now 420kW. I had a power graph to post up but can't locate it at the moment. To sum up: For peak power, we are not looking bad. However, boost arrives too late and the engine wants to rev past 9,500rpm. We decide that we should look at the cam timing before more boost to save time on tuning things twice. It's also getting late, we need to head home soon. Time to call it another day. Tommorrow: Cam timing and more tuning. Cheers, Yavuz Unigroup Engineering

Thanks!! We'll keep posting the updates.

Hi David, yes finally on the forums. Actually, I should say I'm back on the forums. Over 10 years ago I was into car forums that hard that I needed rehab to give it all up. This time it's not going to become a problem as I simply don't get the time. Cheers.

Yeah, we found that funny too. 540 reading was at Summernats. It was all in the correction factors. The reading was corrected for hot under bonnet temps plus the low barometric pressure at Canberra, as its higher than Sydney. I personally don't agree with the correction applied. It's a boosted car, so the effects of baro pressure is less the more boost you run...But I wasn't going to complain, bigger the number the better!!

Thanks! The ute is mine. I'll ask to see if Jules would swap the widebody R32 for it.

Next up was E85. We were really looking forward to this upgrade. There's potential for more power. At the same time, we're not expecting a big gains, unless we are prepared to run higher boost. The reason is the engine ran quite good was not fussy with octane. The boost was around 25psi. We think the reliability should still be good at 30psi with E85. Reliability is no one priority, as people tend to get over car builds once they start breaking one engine after next. There’s no E85 at the drag battle. So we were either going to have two maps (Pump98/E85) or go fully flexible using an ethanol sensor for the drive down. We’re a big fan of the flex fuel setup, hence carry the Zeitronix kits in stock. With the parts waiting to go, it was an easy decision. The flex tune not only works well, it also takes care of the variation in E85. This batch came in at E82, and we’ve seen it as high as E90 (from United where it’s sold as E85). The variation is concerning and we think it's a good idea to have the display even if the sensor is not used for flex fuel maps. The ethanol sensor is mounted in the rear as per picture below. The fuel system runs a returnless setup with multiple pumps. The GTR runs an Autronic SM4. It was fitted when it first came out more than 5 years ago. It can run flex fuel setup with some clever setting up. Extremely flexible. I’ve always been impressed with Autronics. Despite it’s age, SM4 had the flex fuel tune running (This is a new feature on a lot of newer ECUs). We set the ECU up to keep tuning itself using a wide band O2 sensor. This setup works together with the ethanol sensor to make sure fuel mixtures are correct, no matter what fuel combination. I’m going to have to get myself a flex fuel setup soon. It’s just too good. No problems with having to find E85!. Once the flex fuel setup was up and running, we've drained the tank fully and started with E85 (82 in our case, see above). The car prepped for the dyno and strapped down ready for tuning. After some mapping it was time for the first power run with the boost controller off. It didn't go too well. Engine sounded good upto 7000rpm, then started to miss and got worse as the boost and revs climbed. The run was aborted. 398kW, not too bad considering the miss fire and first pull. We quickly checked the basics but did not find the cause of the misfire. Also the boost is coming on too late, and it looks like the engine is eager to go to 10,000rpm. Hmmm some more work needed there. It was getting late and decided pulled the car off the dyno. Tomorrow, we'll have a fresh look at the problems at hand and report back... Cheers, Yavuz Unigroup Engineering

We’ve had this widebody R32 GTR in the workshop. It’s been in the shop for a long time, waiting for custom parts and when ready, a tune on E85. A customer who has seen the car (can’t remember who) suggested that it would be a great idea to take it down to the drag battle (11-12th May). We gave the owner a call. He said that he had a few things on that weekend but could possibly make it on Saturday. He then suggested that we should take it down and he’ll meet us there. Ideally we would like more time to finish the car to a standard that we’d be happy with. However it would be fun just to take on the challange and see what happens. There’s now only 9 days to go. This is when I got talked into posting up daily progress on SAU. So here we are, first post! Here’s a little about the car. The car was built in the mid 2000s by the current owner, Julian. It hasn’t changed much since. In summary it runs: 2.6lt (Built by the owner - a cracking engine builder, he runs Jay’s Race Engines) Dry sump (We’re still working on this kit with Ross Balancers) Billet Turbo (I would love to try a more modern turbo on this car) 5 Speed Nissan gearbox (We’re concerned that it’s going to expire on the weekend) It has made up to 470kW on our dyno. It won a few dyno competitions and the best recorded power was 540kW at the wheels. These figures will not get any one excited these days. But 6 years ago it was respectable. We think turning up to this event with a car like this is like going to a gunfight with a knife. But it should still be fun... For GTR challenge, the cars have to be registered and run street legal tyres. We thought it would be in the spirit of the event to drive the car and leave the trailer behind. Towing a trailer would ruin the drive for me (it’s 4 hours from Sydney). It would be much more enjoyable with around 500kW on the highway. We have the finished Ross dry sump drive kit fitted, pictured below. It's ready for testing. So far it works really well with the new tensioner and power steer pump pulley. Belt looks stable even at near 10,000rpm. Keen eyes will also spot the Ross crank mounted trigger kit behind the harmonic balancer. This was one of the first cars that we've run this kit on. We had trouble with engine rpm signal stability (hard to avoid on high powered RBs). After fitting the kit there was a major improvement. Next up is E85. (I will continue this on the next post, I'm having problems uploading more pictures to this post.) Cheers, Yavuz Unigroup Engineering