GTRNUR

Makes my head hurt doing that kind of maths! Someone should teach John how to use MS Excel. Im sure he could then create the mother of all engine calc spreadsheets. I noticed the mentioning of a water/meth injection system too. As your already running with 12 injectors, where will you be putting the injector nozzles? Just after the BOV's and before the plenum, or are you modifying the plenum further to support direct port injection as well?

Pics of the AFM deletes if you have them please. Are they they cast alloy HKS ones?

Im using a Tomei pump too and though I'd kicked the full catch can issue until I drove the car around Winton. Sure the engine does have some blow by, but show me an engine running above 1.8 bar that doesn't. In a straight line or on the dyno has proven itself to be fine. The return drive from Victoria of over 3000km put only moisture in the catch can. No oil. I believe that at Winton the long 3rd gear left hand corner(3) was my main problem. Its a 4500-5000 RPM corner so your oil pressure is up and head filling is at its worst. Then when you factor in that there are no oil drains on the right side of the engine the oil all collects in the right cam cover. This is where the 2JZ really has it over the RB's with drains along both sides of the block (logical)! The only hope to control oil flowing out the cam covers really is to drain it back to the sump. The return setups that seem to work all return from a forward mounted catch can, and return back to the sump on the right side of the engine. The disadvantage of this is that the forward placement allows moisture to condense easily and then return as sludge to your sump. Which is ok if you change the oil before and after each track day immediatly, but is not ok for a street car. I believe the best setup is to do what Nismo do. Put the catch can next to the ABS unit where it is hot above the turbo's, and where it can return via the turbo oil drains. The heat in that area will help seperate oil from water vapor in the blow by gas, and reduce oil contamination as a result. You could then optionally connect that can back to the intake, or to keep oil vapor out of your induction system you could vent it through a second forward mounted catch can. Thats my thoughts anyway.

I think its fairly safe to say that if you don't spend the money in the bottom end to achieve your power goal, you will instead have to spend it in the top end. I don't believe there is any money to be saved with creation of big power. You end up spending it somewhere in the end. By that I mean either .... RB28 + mild head work/cams, 8000 RPM and 25lb boost with your T51 class turbo. or RB26 + heavily worked over head with 272/step 2 valve train components. 9000 RPM and 25lb boost with your T51 class turbo. If it takes 2 months longer to afford the stroker, then wait for it. It really is worth it. I know which of the two above options i'd prefer. ID1000's would achieve the 500kw goal easily with a water/meth system... (still my new favourite modification).

Music!

It would be a shame if this happened because the driver was worried about getting caught up in that Operation kilowatts blitz...

Bugger... active exhausts are the only real option then. At least until they start testing cars under load.

You could argue that its not defective to drive a car that doesn't rev, just as its not illegal to drive a car thats running on 5 of its 6 cylinders. To my understanding, they can test the car as is but not alter its tune or anything mechanically to make it fail a test. You could also say that at 2500 rpm in 6th gear the car is doing 20km/h above the national speed limit. (Perhaps the car detects guys with blue shirts and high visibility jackets, and prevents the driver from doing anything illegal.) It seems only fair that if they test a car in a manner that would cause it to fail, that we should develop methods of cheating in that test. They claim they are measuring noise where peak engine torque is developed, but seriously who drives their car everywhere at 5100 rpm? The test itself isn't fair for cars with RB's. If I had to guess the average RPM that my car is driven at, it would be about 2000 rpm. Active exhausts that open up valves based on boost pressure are also definatly worth implementing. So long as it can't be altered while the car is stationary (and being tested), who's to say its illegal. All lamborghini's have them from factory, so why not put it on the car too. I have heard of brand new SS commodores failing emissions tests for noise straight out of the showroom.

I wonder what would happen if when the car was tested that it wouldnt rev over 2500. It wouldn't be too complicated to put a fuel cut relay on the injectors power rail that is triggered by an input of 0 road speed, and and RPM activated switch. Two of these, one monitoring engine RPM and the other wired into the road speed signal. Link in the clutch switch and the car will drive like a normal car still, but it won't let the engine free rev above the pre-set RPM. Unless the car is run up on a dyno or it was being free revved with the clutch in, it couldn't be tested above 2500 rpm. So it would pass. http://www.ebay.com/itm/DIGITAL-RPM-ACTIVATED-SWITCH-Adjustable-2-000-9-900-RPM-/140641680354?hash=item20bee5bbe2&item=140641680354&pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr It would work with factory management too.

Wakefield raceway looks like fun. 6-700m main straight before the kink would make for some interesting top speeds. Perhaps next year. One long drive a year is enough for me.

Thanks for your thoughts and I follow what you are saying. Regarding tuning, and appropriate AFR's there are two schools of thought I have come across. Your approach is one in that saying a 12.5:1 afr is safe. I would agree with that if I had individual nozzles in each intake runner, I could consider leaning it out further as I could be sure the combustion temps for each cylinder would be closer matched. But as I am injecting post intercooler in the intake pipe I cannot be 100% sure WMI is evenly distributed all the time. It will be close, but not perfect. I am also only able to monitor EGT's in each manifold before the turbine, and not at each cylinder port. The second approach to WMI tuning (which I use), is to tune the engine first for peak power with the normal fuel. Monitor EGT's at their peak. My engine was consistently 800 degrees at the dump and 840-850 at the collectors at 7500 with 1.6-1.7 bar boost. Total fuel delivery was around 3.9-4lt/minute. Then when adding WMI, the injector nozzle sizes need to be 20% of the total fuel delivered, and the distribution of the nozzles is 25% pre turbo and 75% pre throttle body. 800cc in my case. I am spraying 900cc though for a little more safety. With this done and a base fuel map re-scaled to achieve 11.5:1, ignition is added until knock levels are similar to before. Then fuel is further removed until EGT's at the end of the run match the result of the standard fuel tune. This approach optimises ignition by advance using the benefit of the octane boost WMI adds, yet keeps EGT's where they need to be to make the turbo's work at their best. While a better performance result might be able to be had by spraying pre-turbo at lower boost levels, my concerns for tuning are not entirely performance focused. I am driving the car daily as a work/company car, and below 15psi boost its still awesome to drive. Spraying later means I use less WM mix overall. The engine doesn't need an octane boost to control detonation at low boost levels as it is an 8.2:1 cr engine with stock cams. Also, spraying later when air velocities are higher at the turbo intakes means that for any given amount of WMI sprayed into the intake, evaporation/vaporisation is more efficent. This equals less turbine impeller erosion. So while what I have might not be the most efficent for overall perforamnce, my general needs are met.

Thats my understanding of it as well. Ideally you do aim the injector at the back of the intake valve, but in this case it is a second set of injectors and different rules apply. The normal concept of injector angle is more for the primary set of injectors and relates to stopping or reducing fuel pooling in the intake manifold. Being it is a second rail the additional 6 injectors are only active when the engine is under full load and the throttles are wide open, and when airflow is at its highest. Which eliminats any pooling issues immediatly. The second rail of injectors are probably also fireing sequentially as well, considering the motec thats driving them. I am surprised Bobby didn't just go with a set of ID2000's though. They are very stable to very low pulse widths and individually deliver enough fuel to drown someone in 60 seconds. Using ID2000's would have meant the spare injector bosses would be available for use with my latest favourite modification... Water/Meth injection!

Ive got a mate with a Kakimoto twin muffler titanium system on his R34 gtr and it does sound good and is definatly a lot more quiet than my Ti-R system. Like you said, its probably not legal, but its close. And miles quieter than the Ti-R system. Look at the Nismo systems if you are after something that could pass for legal.

The piston to head clearence is about 1mm in the quench area (less at higher rpm due to rod stretch). When the rod bearing went by by that clearence disappeared. Then the piston crown quench area collided with the head. Chain reaction effect.

Go away! Why stop at just 3lt?

I havent read much about the Precision Billet 6765 CEA turbo, but arent they basically similar in response to the small T51? Which on a 2.6 means the wastegates are't going to open till 6k or so? Response like 4500-9000 sounds more like someting Bobby's going to achieve with his fancy scavenging venturi manifold and lopsided turbo trim. Either way im keen to follow another build, subscribed!

I did initially as my fuel map combined with the WMI had the AFR's dipping into the 9's at around 5000 RPM. Once I came to terms with just how much more lean it could run safely, and pulled out a heap of fuel from the base map it all came good. Im using standard 6 heat range NGK iridiums gapped with 0.8mm gaps, and stock coil packs. Works perfectly.

The boot trim would still fit behind teh tank and pump, but I'd have to make some holes in it. Everything is mounted off factory holes or bolts at the moment, no holes drilled anywhere. The supply hose goes through the factory drain grommit. No sence in making it perminent until its 100% sorted out I figure.

That explains why I can't find it... I figure if WMI should be considered regardless of fuel. A small plain water system (post turbo) on an E85 tuned car would buy that safety margin that you lose due to E85 detonation sounding different, and it would also allow you to run leaner safely. Instead of using the methanol/alcohol approach to tuning where you just drown the detonation in fuel. My finalised rough tune has my EGT's peaking at 810 degrees at the dump pipe. This is with 19 degrees of ignition at peak torque advancing to 25 degrees at 7500 rpm, with 1.75-1.8 kg/cm boost and 12:1 AFR's. Knock values are still below 10 as well. Im nearly tempted to re-tune to lower octane fuel to see how it goes, and save a few $$$ on fill ups. The map has more than 2ms of fuel pulled out of it in top end compared to a straight BP89 tune, which means the 700cc injectors have the headroom to run 2kg/cm boost and max out everything again. This is something I might try after the version 3 engine is running, as this motor was never meant to make more that 700 crank hp.

Yeah im pretty happy with it too. The pump runs nearly silent. At least you can't hear it over the engine. It also flows 1500cc/min which is enough for an RB running 1250cc injectors and BP98. This tank holds about 5 litres and it appears to easily last more than a tank of fuel does. One other little curious thing I noticed is that the pre-turbo nozzles solved my boost drop off in top end issue. Its possible that the in hot air temps of north qld I was running close to the limit of the GTRS's as it would drop 4-5psi at 7500 from 5000. Not anymore. The increased compressor efficency due to cooler air intake temps have cured that. There is a thread on the aquamist forum about an R33 GTR with a pair of GT2835's that made more power than the GTRS's were supposed to be able to make as well. Where is this WMI discussion in the club section you mentioned? I had a look but couldn't find it.

My nozzle placement was simple as I already had the extension in the middle of the intercooler to plenum hose. I just had a couple of 1/8th BSP stainless fittings tigged on there. My spot welded hose clamps are continuing to work well too. 1.75 bar and no leaks or popped pipes. These are 280cc and 300cc nozzles. I've hidden one of the solenoids under the carbon air deflector in front of the radiator. The supply hose then runs over to the airbox side of the car where I've mounted the second solenoid, external to the box and to the right of the charcoal canister. (shiny... didn't photograph well). Sorry I don't have any pics of how I've arranged the nozzles inside the air box, but basically ive used a few fittings and a pair of 150cc injectors that aim at the air path. The boot setup is pretty rough, and temporary. Im going to put the pump under the car once I source a diffuser, which will serve to protect it a little. I'll also put a smaller tank upstream from the pump to prevent sloshing and air bubble issues. I finished the rough re-tune on the weekend and tried to book some dyno time, but the tune shop I use have their dyno in pieces at the moment. Its going to be a few more weeks till its working again.

Or until you have a car accident and the modification is noticed. Then your property, 3rd party property, and CTP insurance becomes invalid and you spend the rest of your life riding a bus because every cent you earn goes to paying off your debt. If is above board you minimise your chances of having issues later. A dodgy RWC could be obtained but that doesn't protect you down the road. All it allows you to do is bypass a step and allow you to get number plates on the car. Its still not legal. RB25/30's I've seen in QLD Skylines all had mod plates. Its a general engine substitution code LA1. Any QLD workshop that does engine conversions of any kind can at least point you in the right direction. If your lucky they can even do the code for you. Just curious, but can VIC transport defect a QLD registered and modification approved car?

There's plenty more to come. Including version 3 of the engine that currently under development.

The water temp differences between the front and rear of the block will affect fuel atomization and vaporization but not airflow. Over 100 degrees the variation in the size of the intake ports will be about 2.3 thou, which is barely measurable. Considering the cylinder head will at worst have only a few degrees of temperature variation from front to back, you couldn't possibly measure it. The improved vaporization effect in the hotter cylinder means that if you injectors are 100% perfectly matched, the rear cylinder will run a little lean for any given AFR. Something which is easily corrected for with an injector trim. Do you know how those flow results were measured? Was it a complete intake from plenum to head and measured at the combustion chamber? I still wonder about the merits of worrying about this sort of data. Given that once that plenum is pressused and provided the head porting is all matched, there shouldn't be a variation in pressures seen at the back of the intake valve, and hence any flow variation either. To me what this means is that in an off boost situation and when the throttle is snapped open, some cylinders will obtain slightly better airflow. Which means that there will be a slight variation in cylinder pressures and resulting torque produced in each cylinder. This on paper would also require slight variations in fuel and ignition to achieve the optimal result. But having said that considering the airflow in a vacuum or wide open throttle(yet off boost) situation, the variations in injector pulse and ignition advances required to correct for this would be extremely small and barely worth correcting for. After all, how long can you hold WOT till the engine starts making boost.... not long. If only someone could flow test an intake manifold with 25psi of pressure pumping into it, instead of just pulling 25"Hg of vacuum through it.

Update. The re-tune with the water/methanol injection system is nearly finished. I've had a few issues getting the nozzel sizes correct and setting the triggering pressures but now I am past that there is just fine tuning to complete. I have tried a few variations of the setup but the current implementation is as follows. I have a 5 lt boot mounted tank with 50/50% water methanol mix. I am using a cooling mist 250psi pump in the boot which is triggered by a relay, fired from pressure switch that switches at 15psi. There is 3 nozzles in the system. I have a 2 x 50cc/min nozzle concealed in the airbox that spray into the air intake stream before each MAF sensor. (maf sensors are not used with my setup, they are there for show only). I also have a 250cc and a 180cc injector in the return hose from the intercooler just before the plenum. The 250cc nozzle and the 2 x 50cc nozzles come on at 15psi. I am yet to enable it, but will probably enable the additional 180cc injector will come on at 22psi. The main reason I have gone with a water/meth system is to cool down the air intake temps. It is not uncommon in summer to see air temps in traffic well over 60 degrees. Even 65 degrees on the hottest of days. The water methanol system is instantly dropping the air temps by at least 20 degrees, possibly more. Its hard to say exactly what it has dropped to as the sensors aren't reacting fast enough. The temp drop alone has resulted in a huge improvement in performance. It is like driving the car at night in winter in 18 degree air temps, when the outside air temp is really 35-36 degrees. The exception is that I am not getting full boost (25psi) till 4500 RPM still. Where as in the cool climate of victoria at SAU nationals a few months ago full boost happened at around 4000 rpm. The in cylinder cooling effects I have noticed have also been interesting. I have added another 4 degrees of ignition while at 25psi (1.75kg/cm), and the advanced knock values are still below 10. EGT's on average have dropped about 40 degrees when on boost as well. Peaking at 740-760 degrees measured at the dump pipe. The other interesting effect is that the addition of methanol has allowed me to pull nearly 2ms out of the fuel map at peak load area's of the map, and it is still dipping into the mid 11 AFR's. I hope to make the time to finish the tune this weekend, and look at getting some dyno time to produce some new numbers next week. My gut feeling is that it is well into the 400kw's despite our tropical air temperatures. That is all.