GTRNUR

A friends R34 GTR power fc has an intermittent fault which is causing it to drop 2 cylinders at idle at random and reading negative air temp values on a 25 degree day. Its not just air temp being affect as well, Ive logged irregularities with the TPS and MAF sensors too. So Ive told him to re-install his standard ecu until he can source a replacement. I've since been told that his "mechanic" tried to do this, but the car would not start when the standard ecu was re-installed. Is it likely that this is BS, or is there some sort of proceedure that I need to be aware of to re-install the standard ECU in the car. (Injectors and coils are all standard. The car only has an exhaust and a boost controller.) I would presume the ecu would not drop its pairing with the transponder key when the ecu is disconnected from the loom. Otherwise if a battery ever went flat in a car, the keys would need to be re-programmed all the time. Thoughts... Suggestions? Cheers, Ian

So what's considered responsive with -5's? 1 bar at 3600 rpm?

In other runs last year he was doing 12.3 to 12.4. The more recent youtube footage taken this year is slower due to problems with the car not running right. An intermittent ecu fault would make his tune go rich and drop ignition to cylinders occasionally.

Well its not. He was consistent and ran 12.3's repeatadly. I know his reaction times are always good too, and he is pretty brutal with the car. I left out that he has an 80mm titanium exhaust on it too. At the time I'm pretty sure thats it for mods I've read that 11's are possible on stock low mounts if your willing to lean on them to the point of breakage. Turns out that it was 111mph too:

A mate ran a 12.3 @ 110 with his R34 vspec. Mods at the time were a twin plate exedy clutch, power fc, AVCR and a street tune to 1kg/cm boost. Estimated to be about 230kw atw. It was in the middle of summer and his tyres were shagged as well I believe.

Is this still available, or long gone?

Is this still available, or long gone?

I agree... All I can remember is .... -5's -5's.... In the end it doesn't really matter... Just don't take too long in making it drive again. Have the car off the road for too long while changing too many things and you will lose the passion for it. Or worse, You'll do something really silly like spending an extra $30-40K on it, and then end up selling it!

In a drag car, not a problem in the intake runners. Its not as though you put 25,000km/year on a drag car... street cars on the other hand. Thread lock won't help it. Virtually all adhesives will cook off at 800 degrees given enough time. Even using a copper gasket in the end of a bung welded onto the header pipes won't last forever as copper has twice the expansion rate of most iron based metals. A compression gland might work depending on what the gland is made of. If its exhaust rated they might use an inconel olive around the sensor. Sensor depth will depend on the sensor. For example, the PLX devices EGT probes have a 1/2" nipple on the end of a 1/8th BSPT thread. Only the nipple goes into the stream. The R34 GTR EGT probe for the MFD is about 35-40mm long, and goes all the way to about the center of the gas stream in the dump pipe. The R34 sensor also uses an olive style flange on the sensor, which seals up against the surface of the sensor bung in the dump pipe. Basically the same as a compression gland.

Placement of the sensor and the temperatures you look for will be determined by what you are trying to achieve. Depth? Just don't expose thread to the gas stream. After running twin EGT sensors in the manifolds pre turbo, I will never do it again. The cast iron manifold has a higher thermal expanson rate than the inconel that the sensors are encased in. The sensors use a 1/8th BSPT thread. The combination of the differing exapnsion rates of the materials and tapered sensor thread means you have to perodically re-tighten the sensor, or risk exhaust leaks. To give you an idea of the effect of this. Sensors that were tight and leak free could be turned by fingers only after a few heat cycles up to 850 degrees. Cast iron, steel and stainless all have this issue. If you are just trying to balance each cylinder, its just as easy to use a set of well matched injectors, and fine tune the trims on the dyno at moderate cruise load and a laser temp probe on each port as its exiting the head. A cruise load in 4/5th at 100km/h roller speed should see around 700 degrees egt with a 14.7 afr if your ignition settings are correct. If you have your injectors individually flow tested, you can run the bigger flow injectors where you see the hotter egt's, and then trim by ecu injector corrections to get it perfect. EGT is useful for economy tuning too. You'll see hotter than 700-720ish at cruise speeds if your ignition is too retard, and it can also produce heat induced detonation. Advancing the timing further cools combustion chamber temps and EGT's, as well as it makes more torque, and then you can pull more fuel which further cools the combustion chamber in a lean burn situation (not under load). I'm now using an egt sensor in the dump pipe in the same place as you would run the narrow band sensor. 2-3" from the turbo. Based on data I have from the pre-turbo sensors, I lose 50 degrees across the turbo. Peak EGTs meaured here are around 800-810 @ 7500 rpm with a 12:1 AFR.

The most frustrating thing I find with MAP sensor ecu's is the lack of capability to accurately tune for altering altitudes or atmospheric pressures. I initially used an atmospheric compensated GM 3 bar sensor, and it would over compensate and run lean at higher altitudes. I've now switched to the Apxei 3.5 bar sensor and it goes the other way. The Apexi sensor is a far better quality item for accuracy and reaction speed. I've picked up massively noticable throttle response and eliminated a flat spot that would occur during the transition onto boost. This is balanced out by the need to have a completely different map made up when I drive up a hill. The PIM value is changing near on 400-450, which is nearly 1/2 a load band cell group in the vacuum range. This means a cruise AFR of 14.7 turns into a fat 13.x. Add to this that the air temp sensor is adding more fuel due to the air temps on the tablelands being at least 10 degrees cooler than the coast. This charactoristic is more noticable off boost than on, but I can't really say for sure as I've only driven the range once with the new sensor in the car and it was pretty much all at a slow pace. The on boost load bands change at a PIM rate of 2000 per band. MAF sensor tunes are SO much easier to get correct, and they compensate way better at altitude as it is measuring air density/temp/volume all at once and all the time. Less drift in tune. Map on the other hand, just compensating with air air temp sensor to predict altered air density just isn't enough. The only correct way to do it would be to use a propper atmospheric pressure compensation sensor, and use the sensor data to alter the MAP sensor value by a % over RPM.

I purchased an aluminum muffler recently and I've got to say its pretty impressive. The quality was flawless, and its surprisingly quiet considering its a straight through. 1.1kg as well, which was a factor for me as I was trying to keep the weight of the exhaust down to a minimum, and full titanium mufflers aren't generally available for this kind of money. http://www.ebay.com.au/itm/Aluminum-Race-muffler-3-3-out-al-/270590975652?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f007a9ea4 I used a magnaflow in the same car with a different engine setup once before. Stainless steel quality is good, but they are very heavy by comparison.

How much did you inject Rob? Being a 1000hp engine I can see how you would have lost power if you were using a large volume (800cc or so), because as you said ... not knock limited. But a small nozzle pre-supercharger would have given you the air temp drop without slowing down the burn as much.

Have you tested the actuator with an air compressor to see if it begins to open at 5psi? 1. Dial back the regulator on the air compressor to fully closed. 2. Connect the air hose with an accurate pressure gauge, to a hose running only to the actuator. 3. Dial up the regulator slowly and observe the pressure that opens the gate. It should be very low. If it hasn't started to move by 5psi then its stuffed. 4. LISTEN for leaks in that actuator. It might have some pinholes in the diaphram. I can't see how an internally gated 3040 from an xr6 with the standard actuator and 5psi boost setup would overboost on an engine that has 1lt less capacity. It just won't happen. So either the actuator is seized or has an internal leak (pin hole), or the wastegate mechanism has seized in the closed position

DId I watch the wrong video, or did none of you actually watch it and instead decided to have a rant instead? This guy is talking about making it easier for ICV and other vehicle modifications to be certified.

I've used Techline ceramic coatings on my manifolds and turbine housings on 2 of my cars. Coatings are inside and out of the manifolds and turbine housings. I've proven the coatings hold up to sustained heat around 850 degrees no problems. Looks good too. I don't know who of the companies you mentioned use the techline products, but the key is in the application. I have an aluminium oxide/ceramic base under the black TurboX coating. Competition Coatings did a set of CP pistons for me in one of my other engines. The finish looked great. Never produced any performance data with that engine though. Changed the recipe before getting that far.

Sounds like a pretty solid fault. You need to confirm fuel or water on that plug. You can eliminate fuel by disconnecting the injector for that cylinder and starting the motor for a moment with no plug to dry the cylinder. The install a clean and dry plug, re-start and idle for 30 seconds or so. The stop again, remove and inspect the plug. How did you check the ignition for the cylinder was working ok?

Its possible that variation in clearences or impropper shimming of the bucket could hold valves in one cylinder open, but that would also be evident in a compression test. It would test lower than the others, not higher, so I would be inclined to think not.

Your on track with your troubleshooting, but have moved down the wrong path a little. A vacuum leak around number 2 would cause it to burp and pop at idle a little, but not flame out completely. A faulty cas also would not drop the same cylinder consistently. It would be doing it on all the cylinders or not run at all. Does it rev cleanly and crisply, or does cylinder number 2 never appear to fire.... Or is it only drop ignition on Cylinder 2 at idle? What is the idle speed? Is there a noticable drop in RPM when cylinder 1 is unplugged, and did you PROPERLY balance your throttles when connecting your throttle linkages. Does it do this cold as well as when hot? Last of all... is it losing coolant, and is the number 2 spark plug clean or wet when its removed? If its wet see if it will evaporate instantly to dry if you blow on it (indicating fuel), or not (indicating coolant/water).

I know a guy in the ukrane that is rebuilding his RD28 based RB30. He is using a Nitto RB30 90mm crank this time. The last engine made upwards of 1200-1300hp, and ran 8's in an R33 GTR shell. In the end a piston cracked and let go, resulting in a rod leaving sideways through the block. Only the cams survived, everything else was a total loss. This is generally the result of any failure in a high power engine. Small issues become big issues very quickly, and then its all over. He used an RD28 because RB30's aren't available over there. The extra water jacketing around the outside of the block makes the more rigid for sure, but the cylinders aren't any thicker than an RB26/RB30 block once bored from 83 to 86mm. They are about 92-94mm OD at most. That being said the rigidity the water jacketing adds around the block would do wonders to greatly reduce twist induced block cracking. I believe his RD was also 1/2-3/4 grout filled. Cooling wasnt an issue as he ran methanol. No thermostat and an electric water pump with a resivour was the extent of the cooling system. No radiator. Running no more than about 60 seconds from burnout to finish line helped too. I see one other advantage to using the RD28 block as well. The Rb30's are getting more and more scarce. Using an RD28 allows blocks to be scavenged from a whole lot more patrols as well as the ford mavericks. If I can find some more pictures of his engine I'll post them up.

Seriously thick walled wrist pins you've got there! They look to be at least 1-1.5 mm thicker than a standard pin. I would have thought you would be using titanium rods too for the deck height you are running as well with this engine. Is that a GT500 2.8lt crank? Also, whats with the banjo fittings on the back of the head? External oil supply, rather than through a block restrictor?

If your lucky. 99% of people upgrade to a twin plate for their gtr once they fry the standard single plate. In the end you'll be lucky to give it away.

Further investigation has revealed that I had probably exceeded the maximum torque rating of the gmax. My last dyno torque figures was 574mn and I am pretty sure I am exceeding that now with the most recent engine changes. It had probably been slipping a little all the time, and its now only getting bad now that Ive given it a hard time too often. I have decided to go with the exeedy twin carbon D clutch. Hopefully it will be here in a few weeks.... I get withdrawls from not driving the car after a week so its going to be a hard wait!

Impressive effort with the detail of the lettering there Paul. Nothing stealthy about that!

I have a theory about my clutch failure... If a disc is in backwards I'd have to pull the pressure plate further to get it to dis-engage. Over time this has probably damaged the spring. I don't think welding the clutch would be too much of an issue really for most. The car in question was around 800hp at the crank, and I think it was a 1300kg ATS carbon twin plate. Thanks for the heads up Marko. Clutch purchase now put on hold till next week I think.