GTRNUR

Thats at least a realistic goal. The last car build I started took 3 years to finish! Way too long, as I got so frustrated with how long things were taking I had time to buy an R34 and design an engine upgrade for it!

A reputable engine shop shouldnt be using plastigauge as the only means of checking clearences. I won't elaborate on that anymore, I think the reasons why have been covered enough already. It really sounds like the engine was just slapped together with a quick plastigauge check, rather than they assemble and check all the clearances precicely, so that it meets your requirements and will be able to support the power you are after with any degree of longevity. Check your ring clearences when it is torn down and re-checked. If they arent the same, and correct for every cylinder it will give you a better idea as to what the "build quality" really was. A lot of builders are slack as it takes time to file 24 piston rings precicely. 7 thou end float is the maximum recommended in the service manual. I wouldnt go any more than 8 thou with a thicker oil, otherwise keep it factory spec. The whole point of running the bigger clearances in the big end of the engine is to allow you to run a heavier grade oil (20w50) to have a thicker oil film, providing better protection for your bottom end bearings. Your bad ass external pump will meet the flow and pressure requirements but you really need to have the right clearances and run the thicker oil to make the most of it. You won't have any issues with oil pressure and the thicker oil provided you limit the use of your right foot until your oil temps are above 75 degrees.

+1 Your crank could be out of round, or the cradle might not be from that block (or just be a bad match for it). Every main on the crank and block should be measured at 3 angles using a micromoter and telescopic gauge. Only then can you actually be sure your mains are round and that your bearing clearences are consistent. If you tell a good machine shop that this is what you want done, they should be able to do it for you. Just torquing the cradle down and the associated twisting of the cradle that can happen is enough to give you an inaccurate reading.

2mm would be plenty, but check an RB26 block with a vernier depth gauge if you can get your hands on it. RB26 and RB30's use the same dimesion bearings, the only difference is that the 26 has the oil groove to provide better oil flow to the mains. Regarding your mains being too tight, have you worked out where the clearances are too big? What are the crank dimensions? Make sure your micromoters have been certified as well, its easy for them to become 0.5 to 1 thou out if someone has dropped them. You need to install your main stud kit, torque it to spec and have a machine shop tunnel bore/skim the main bearing saddles a little. Then the main bearings are re-installed and measured until you achieve the 3-3.5 thou bearing clearance. Remember your bearings crush a little when the cradle is torqued to spec. Align/tunnel boring the mains reduces bearing crush a little and increase oil clearances. Don't use an N1 pump if you are going to run main clearances this big. Im thinking Tomei or external oiling only, otherwise crank movement will smash the pump.

Long overdue update.... Tuning continues to go well, although I am still having some boost control issues. So far its now mapped up to 1.4 bar, but boost is taking at 6000 RPM down to 1 bar at 7000. Ive tried everything but cant get the eboost street to compensate. It has an rpm based correction option, and sensitivity settings that are supposed to compensate for this issue, but alas its not working. I am switching to another boost controller on the weekend, which will later be replaced with a new AVCR. I dont think i'll say the "dyno" word again till I actually have some results to post. I think Im jinxing myself. Every time I think im getting close, some other issue prevents the tune from being completed.

+1 on that. Just paid for my SAUQLD membership and am working on getting my L1 cams license so I can have a few laps as well. I'd hate to miss out!

As much as we would like our flywheels to remain flat all the time, in reality they never are. The moment you start to drive the car, friction generates heat hot spots that in turn cause iregular expansion of the material. This warps the surface of the flywheel and causes driveline shuddering in its wost cases. It is especialy noticable if you try and drive like a grandma with a 3 or 4 puck ceramic clutch disc and a bad ass heavy clutch plate. Conventional clutch setups have a flywheel directly bolt to the crankshaft. The clutch pressure plate is also hard bolted to the flywheel. And the clutch friction disc is in between the two, with its drive spline slipped over the input shaft on the gearbox. This allows for no movement anywhere in the driveline to dampen the opertation and engagement of the clutch. A dual mass flywheel is like a mix of a flywheel and a flex plate from an auto setup. The friction surface of the flywheel is rivetted to a mounting plate that is bolted to the crankshaft. This allows the flywheel to move a little and soften the engagement of the clutch as it engages. The goal being to make the car more drivable. This is a dual mass. See the 12 rivets in the pic: This is conventional Every R34 Gtr ive seen all have the getrag rattle at idle and in neutral. No its not age/wear related, having seen a standard vspec with < 30,000 genuine km and it still rattled.

The getrag's all rattle in neutral. Twin plate clutchs rattle only happens when your foot has the clutch pedal to the floor. When the clutch is engaged your listening to the gearbox. The dual mass is supposed to quieten it a little, but it doesnt. Get a louder exhaust or a bigger stereo. Putting your foot on and off the clutch a few times and you can get the sound to change and quieten sometimes...

More important than your boost is how hard you push the engine with the ignition advance, and how lean you run it on boost. A forged engine will in some cases tolerate a more agressive ignition curve, and a few more random pinging events, but in the end it will die as well. I think that the random combination of a bad tank of fuel and a particularly cold day kills more tuned engines that run on the ragged edge than anything else.

That explains the fitment and why it looks so good. The Nismo 400R bar I had for my R33 was also extremely well made. Yes the RB315DETT is still running well, but I just havent had the hours in the day to give it the time it needs. My home renovations and repairs have taken priority for the moment. Im going to have to promise myself to spend a day a week on the car so I can finish the tune. I feel you pain re: parking miles from everyone else and still having someone goose park next to you. Even parking diagonally across 2 spots doesnt work. Ive tried that and some idiot in a corolla decides to park next to you diagonally as well!

Those are Rays hubcentric 20mm spacers. Used to have a set before changing from stock wheels to te37's.

Beautiful! You have pretty much created the appearance that I am going for with my car. Did you use all Nismo genuine parts, or did you go aftermarket?

Conventional manifolds will try and split the gas flow after the collector at a 45 degree angle, so that gas flow is able to be equally distributed between the turbine and wastegate. Few jap manifolds come close to this though. Mainly due to physical space limitations (my opinion). The conventional approach is to use the wastegate gas tube angle and exhaust gas pressure to balance the flow of gas evenly through the wastegate and turbine in order to maintain a stable manifold boost pressure. The conventional approach is also meant to work with a typical turbo design where X size compressor wheel is matched to Y sized turbine wheel. This is not the case here with John and Bobby’s system. John's deign is to allow a turbo with a smaller than typical turbine housing to be used on a large compressor equipped turbo without the issues of massively high exhaust gas pressures, boost control issues, and surging. The goal being to have greatly improved boost response, yet still have the capability to sufficiently control exhaust gas flow to keep boost stable. For the sake of imagery, picture a GT40 size compressor wheel with a GT28 turbine size. (This isn’t what is being used but you get the idea). So the goal is to have the boost response of a 400hp turbo, yet have the turbo able to flow 700+hp on the compressor side. The venturi is not about minimizing disruption of exhaust gas flow. While it does do that anyway by evenly distributing wastegate gas back into the main exhaust stream, the venture effect is to create a low pressure area in the wastegate gas piping in order to accelerate gas flow through the wastegates and to increase the scavenging effect from the wastegate ports in the merged collector. As RPM and gas flow increase, so does the efficiency of the gas wastegate control system. Simply dumping the wastegate to atmosphere, or plumbing back in further down the front pipe will not be enough to sufficiently control exhaust gas flow with a radically trimmed turbo. Doing so would produce a very poor result due to bad boost control and higher than normal parasitic losses at the top end of the RPM range.

Not sure if this will be helpful, but this is a high octane sump on an R34 engine on an R34 crossmember with Nismo mounts. Plenty of room as you can see. But dropping the engine further by lowering the mount positions on the subframe, or re-drilling the alloy mounts so they mount higher on the block would definatly have at least 10-15mm of sump extending below the flat section under the crossmember. So there would be no protection for it should you hit something on the road, speed bump... or whatever. Your 10lt CRD sump might afford you some options though, as you could remove that 10-15mm from the bottom of the sump and sacrifice a little oil capacity to allow the engine to be dropped further. 7lt is plenty with a trap-door sump and the propper sized oil restricters in the head.

Stock R34's really only have about 30mm of clearance from the timing belt cover to the bonnet. Add some height to the engine and factor in how it moves around on a launch and its not hard to imagine contact happening. Your considerations are the height increase of the block plus the height of the spacer plate, minus how much you want to compromise suspension front suspension geometry by spacing down the cross member. Sadly I dont think there is many people on here that have done the 26/30's in R34 GTR's. BoostedR would be one to ask though as fitment is very similar with the R33 GTR's.

Ive tried the bolt on clamps with other pipe setups on other cars in the past. While the hose clamp pressure is higher, it also distorts the rubber and often creates a leak where it pinches the rubber. A lipped pipe and a conventional clamp always works best. I saw another approach on one of the High Octane video's from when they went to Japan. They used normal clamps, but the pipework had 2 bolts welded through each of the 2 pipes at each join. They would then use a metal strap with bolt holes to prevent the hoses from blowing apart. So that way the clamps only had to create a seal, and now deal with forces trying to seperate and stretch the hose as well. Seems we all us 3lt plus guys share the same brain. I'd been thinking of doing that and switching back to l-jetro to get an easier and smoother tune. Having just suggested the same thing to BoostdR, as he is having the same mad turbo shuffle from a free rev, and subsequent over fueling. Which also makes throttle response suffer as the map readings are basically all over the place from 1500rpm to when both turbo's are finally done shuffling and are at wastegate boost. A MAF after the cooler solves that issue.

I think its Steve-o's engine that was needing the tear down. My engine is still going strong. Ive been seriously sidetracked with other projects and work lately, and havent had a chance to do anything more to the car. I drive it whenevery I can though. The latest was that I've installed a catch can and have completed the drivability and final tune at to 0.8 bar @ 7000 RPM. Ive attached a screen shot of the lastest map, which is a 4th gear pull. Full boost happens at 3500 rpm. I am resetting the actuators to 1.1 bar tonight but wont be tuning tonight since having minor eye surgery earlier today. One other thing is my new fancy hose clamps. This should hopefully solve the issue I was having with blowing hoses off at 1.6 bar boost. Pics attached. They are basically 2 fully stainless marine grade clamps and are spot welded together with 3 straps and a 20mm seperation to accomidate the height increase of the engine. The hope is that the straps will prevent the hoses blowing apart. Ive decided to do the 1.1 bar tune myself as well, and then book some dyno time once I have that perfected. Im trying to maintain the near stock feel of the car and think its pretty close. Have a look at the RPM that full boost is achieved at. This is without a boost controller being used to ram boost on quicker too. Im honestly now sure when I will be ready for the dyno now as the engine project has taken a back seat to work and also some major home renovations. Realistically it could be another month.

I'll add, that venturi reminds me of the back of a jet engine too! You can just picture the swirling gases from the exhaust wheel sucking wastegate gas from the venturi and wastegate pipes. Awesome!

For a moment there I thought the ribbed piece of billet stainless was an expansion joint, but after watching the vid a few times I heard him say slip joint. Since its a slip fit it will take up any movement without cracking. Clever design! I especially like how he has gotten the wastegate pipe to seal to the slip joint. The pipe is a tight fit at room temp, but as it heats up the pipe will expand more than the billet piece, and it will create a seal. Reminds me of how the SR71 was built. All the panel gaps didnt close up until above mach 2 when air friction caused the skin to expand and seal up. Astonishing work Bobby and John!

Looks like fun at Mallala. I was going to say you seemed to have some difficulty easing it onto power out of the corners till I saw that you had 4wd issues. Also saw from your walk around video that you have the same massive shuffling issue that I had before switching to a d-jetro. Give it a decent free rev and one turbo will spool up more than the other, which directly affects your Maf sensor voltages. If you enable some watches on your MAF sensors with a datalogit, you will see a 1.5-2v variation between the MAF sensor voltages. So the ecu over fuels the hell out of it because it thinks its under load when its actually idling. Given the opportunity to try something else to tune around it and retain MAF sensor smooth tuning capability, I'd want to try a single MAF sensor and put it in the cold side of the intercooler before the plenum.

Yes, that pretty much sums it up. Street cars should not have N1 pumps.

It would be interesting to overlay the torque curves for the GTRS's vs -5's. Like you said, similar feel so the numbers must be very close. But down low obviously better, and up high possible less. With your hill climbs it will be fun though, not having it drop off boost in the corners, the evo's will have to watch out. Sorry to hear about the knock too. I'd hate to hear something like that... and experience that sinking feeling that quickly is mirrored to your bank account balance. On another note, my catch can finally arrived friday so with any luck dyno time for me will be later this week.

Yes all is still going well with the engine. A little over 5500k's on the engine now. I have been driving the car every day to and from work, and also to get my groceries! The only drama ive had was the rubber hose that joins the turbo coolant hard return line to the radiator top hose developed a split next to the hose clamp while I was on a long drive. Fortunatly it happened on a range, and there was a water fall near by that I was able to re-fill the cooling system with. I was able to push the hose on a little further and get home no problems. I've switched to synthetic oil now and have begun to lean on the tune a bit harder, but have noticed a little oil in the intake. Most likely due to all the factory polution hoses still being in place, and that I am reving past 7000rpm now. Ive had a catch can on order for 3 weeks now and its yet to arrive so I am now arranging a temporary measure in the meantime. I had hoped it would have arrived earlier this week as I was hoping to book dyno time for today, but no luck. Response wise the best Ive been able to achieve is full boost by 4000 rpm (in 2nd or higher gears), but it will also hold full boost at 3400 rpm when shifting from 2nd to 3rd. I think that -5's would definatly be a hoot on this engine though. It makes a lot of sense too as the response and torque would come on much earlier in the rev range. For the most part I shift below 4500 rpm anyway and its still plenty quick enough as a street car. Interesting what you have said about your surge issue and the autronic vs the D-jetro. Was there any differences with the intake? Ive read that deleting the maf sensors alone is supposed to help. Good luck with the re-tune. It will be great to finally see some -5 + RB30 results!

Finding leaks can be dam tricky sometimes. A leak thats up higher can convince you its actually leaking somewhere else in a difficult to repair spot. I was convinced I had a hard line leak a few weeks ago too, till eventially the rubber hose that links the turbo coolant hard return lines back to the radiator top hose split and it became obvious where the leak was. I couldnt see it initially as the hose I am referring to is located under the air intake snorkel to the factory airbox. The coolant leak was running from that hose, back along the pipe because the pipe is angled down towards the turbo. I hope its an easy fix for you.

I know a way it can be done! But, expensive beyond your worst nightmare would be the first reason you wouldnt do it. The second is what zebra said. Very smart move! Third... save your money and survive your P's with the small amount of points they give you. The if you want something faster, just go and buy it once your off your P's.