Kinks

Yes, if you have a correctly set up plumb-back on a MAF-based engine then it may help throttle response as opposed to BOVless. (remove plumb-back requirement for MAP-based). And if you are running REALLY high boost pressure then BOVless may accelerate turbo bearing wear. There is also some thought towards keeping pressure inside the intercooler + piping. The rotating assembly in a turbo is quite light, and rather than worrying about slowing it down you can rely on maintaining a bank of pressurised air so that when the throttle opens you have a volume of pressurised air available that can go straight into the engine, produce power, and produce a lot of exhaust gas to spin the turbo up again. With a BOV that is venting all pressurised air, you may have a faster turbine speed but when the throttle opens you have no pressure and the turbo has to build pressure in the intercooler + piping all over again. It would probably be fairly straightforward to measure the result by logging TPS and MAP, come to think of it.. I may play with it sometime in the future to see what works better

They are "ok". Enough people have had a problem with them (myself included as of last week) that I can't recommend them any more. My most recent set appeared to be causing an intermittent misfire (12 months old), I have put splitfires in there now. So there's 2 ways of handling it. You can either be nice or be a douche. Being nice is replying with "check the stickied FAQ in this section, it sounds like a coil pack issue" - it takes 5 seconds. Or just don't say anything. Being a douche is replying with sarcasm or derision, that doesn't help anyone. It is searchable via google but SAU's search engine is pretty bad. Also, intermittent issues are a pain to diag hence asking for expertise. If you have a car that always misfires at WOT near peak torque then it's an open and shut case of coil packs or spark plug gap. Intermittent issues are a PITA. If you want to shit on people visit Performance Forums. About 10-15 years ago it was a great place. Good call on consult cable + ECUtalk. Being able to read fault codes off the stock ECU is fantastic. Although I don't think R33s throw a code for ignition system, my R34 certainly did (until I ripped out the stock ECU anwyay)

sugestions as above are good. Also there is often a fitting with a warning label that says "do not open when hot" near the front of the inlet manifold (ie at the top of the inlet manifold, closest to the radiator). This is the highest point in the cooling system and can also be used for bleeding. To bleed it you need the top half of a 2L coke bottle jammed in the radiator neck with a bit of gaffa tape around it to provide a seal of sorts. you need an inch or two of water above the radiator cap level to effectively bleed the system.

Getting kinda sick of the newbie bashing here on SAU. If you want a forum full of cynical arseholes I know another place that used to be good. Go there and shit on people rather than ruining this place too.. There are a few common things that go wrong with ignition systems in general. Coil packs - if you bought a cheap brand replacement they are known to have random failures. You need to buy good quality coil packs. Plugs - need to be gapped to 0.8mm in most cases unless your coil packs are really healthy. Coil pack loom - sits in the valley in the top of the engine and gets really hot and really brittle. 100 bucks or so for a new one, there's a connector at the back of the engine and the coil pack loom is swapped over really easy. But it's good to narrow down the problem before just throwing money at it. Intermittent problems are a bitch to chase. At least if it's a consistent problem you can eliminate the cause. When it comes and goes, normally that sounds like something is making a poor connection. Check your coil packs and the coil pack loom plug at the back of the motor. Unplug each one and spray it with some electronic cleaning solvent (from Jaycar). Shake out the excess solvent and plug everything back together. If it does start misfiring, with the engine running pull out one coil pack plug at a time. When you find the plug that DOESN'T make the engine run worse then you've found the one that was already misfiring. Then it's just a process of elimination to see if it's a dodgy connector, a dodgy coil pack (swap coil packs between cylinders and see if the problem stays with the cylinder or follows the coil pack).

Going to Pedders and expecting quality suspension work is like going to Maccas and expecting a quality dinner. If you ball joints are worn and have play then the change in toe will definitely make the suspension feel wobbly no matter what else you try. It's pointless trying to align worn suspension. You have 4mm rear toe in at the moment (+ve toe is toe in). 4mm toe in is huge, and pointless. Fix the ball joints and then set zero toe front and rear. As a baseline that is a good setting.

How dare you bring logic and personal experience into an internet argument

cats do change the O2 reading... yes. They probably change it more at light load too, at full noise the air won't be in the cat long enough to react. Also, my muffler is a triflow so there's a limit to how far the tailpipe probe can go in. At light throttle it's easy to get a bit of reversion from the open air which makes the reading show lean (more residual O2). Not sure though. At any rate it's driving heaps nicer now.

I'm no cam expert (and no idea how to diag by the sound of it), but how did you decide on the clearances and are those hot or cold readings? http://www.sau.com.au/forums/topic/397382-rb25det-neo-r34-gt-t-valve-clearances-solid-lifters/ Workshop manual in the above thread says 0.31mm intake and 0.51mm exhaust when cold. 0.31mm = 0.012" which is close to your figure. 0.51mm = 0.020" so your exhaust side has about half the clearance it should have

If you put the effort and expense in, and you match everything up properly, it is worth it. If you buy some ling long piece of crap for $200 and expect it to work just because it's split then you only have yourself to blame. It's easy to f**k up a split dump, but it's hard to f**k up a bellmouth. Keep the law of averages on your side unless you have the time and expertise to make sure a split dump fits properly. I'm a huge bellmouth fan because I hear stories of obstructed wastegate travel ALL THE TIME.

there's a real figure. nice broad power curve there it would certainly pull well and feel nice to drive.

"flywheel kilowatts". Why not print it out in HP, then it will seem even bigger. Estimating "flywheel kilowatts" is like measuring your dick at 4" and estimating it up to 6" based on losing a bit between your nuts and your arsehole. If it was actually on an engine dyno and MEASURED, then that's different. Having taken the time to bag you though, XR6T is a decent package and easy to make power from given they're only running 4psi standard. I'm glad you're happy with it. But it's a red flag to a bull posting that sort of thing around here

I've got a set of splitfires on the way. So that should fix the coilpack issue. Was hoping to put off doing the FMIC for a bit, but I knew someone would tell me I was wasting my time with the SMIC sooner or later. Thanks Trent John, our primary reference for knock was listening for it on the dyno. I have also set background knock by doing a run a while back with retarded timing and then using those values to zero the log. I think in the midrange my background values are around 80-100 and only from 3000 to 4500RPM, otherwise background levels are zero. I have CEL/MIL set to come on when a knock of 75 is detected (above the background) and it is fairly reliable at showing when actual knock is present. Sometimes Mark's golden ears picked up low levels of knock that I couldn't hear. But yeah, it's funny how much mechanical noise (such as coming off throttle) produces false readings.

Base timing was checked while locked, it needed the trigger offset adjusted in the Adaptronic to produce 15 deg with the CAS midway. Was off by about 7 degrees otherwise. Cam timing also checked against the engine cover marks as the tuner initially suspected it was a tooth off with a midrange hole like that.

Log attached. I have a temp sensor installed on the crossover pipe. What's "high" as far as intake temps goes? I saw 40C on this short run, but it was still heading north. I'm hoping to do a track day in a couple of weeks time. Have seen a bit of RPM jitter before, definitely not more than 500RPM but I can't remember if it was 300, 400 or 500... this run was pretty clean for RPM signal. Also, the wideband calibration is off. It's reading up to 1 AFR richer than is actually the case - ie my wideband was showing 13.8 on the dyno while the tailpipe sensor was showing 14.7. Richer mixtures seemed to be a bit closer most of the time.. I need to do another open-air calibration on it to see if that fixes it, I did one when it was new but you're supposed to do another after 3 months as John (zoomzoom) said.. I only just realised they need a recal after 3 months. log.txt

Yeah I saw last night that they recommend doing another calibration 3 months after install. I have not done that, only the cal at install time.

Yeah. Depending on the exact cell, it was 11-14 degrees at about 4500rpm. Have you checked your timing by locking it (Adaptronic) and verifying with the crank marks + timing light? We had to fiddle with the trigger offsets to get it to line up properly with the CAS set in its normal spot. Otherwise we would have been about 7-8 degrees out. What wideband are you using (and where is it installed)? Your symptoms sound similar to mine - I'm using the Innovate LC2 with the sensor about 10" in front of the cat and the calibration seems to be off compared with the dyno wideband. The LC2 appears to be reading a richer number than it actually is, so we retargeted my light load AFRs to be 13.8:1 to compensate. The engine was a lot happier with that.

Yes Adaptronic can control the VCT. We actually did a run with it inverted - ie the opposite state to which you would normally use. The upper midrange showed no difference for about 1500RPM which was weird. below 4000RPM it was horrible without VCT. Plugs were replaced with new iridiums gapped to 0.8mm. AFRs are by choice, running richer makes you lose power.

pictures tell 1000 words.. dyno sheets attached. first one has torque, second one has AFR. can't speak highly enough of Mark from MRC. He showed me everything he was doing and the intermittent miss was a real time soak. He did well to improve what I had (blue line morning, red line afternoon) despite the temperamental behaviour. R34 GTT Adaptronic baseline pwr,torque,boost.pdf R34 GTT Adaptronic baseline pwr,afr,boost.pdf

RB25DET Neo Standard side-mount intercooler, turbo, injectors 3" JJR dump, metal cat, poxy custom catback with triflow muffler Adaptronic Yellow jackets 10psi What sort of timing would this usually take in the midrange (4500RPM)? I would have expected early 20's, but it won't take more than 10-14 degrees. Also, VCT helps lower in the rev range but makes no difference from 4500 to 6000RPM. I would have expected it to help until ~5800. Power nosed over at about 6500, making 178rwkw. Is this a reasonable figure or a bit low? Also a torque hole in the lower midrange ~3500-4500. Checked cam timing (it's fine). Issues with coil packs on the day but I wouldn't think they would count for a big difference? Seemed like an intermittent bad connection (would miss at idle then do a full power run no problem), maybe it was dropping out power to the coil primary halfway through dwell and causing some of the detonation issues? I think I solved the issue this morning by bending the pins #1 ignition coil slightly, then plugging back in. the coil pack harness is new (18months) from nissan.

I thought the octane rating requirement was dominated by compression ratio.. ie if you want to use lower quality fuel you should lower the CR eg fit a thicker head gasket or use a spacer. Otherwise you will have to pull a large amount of timing out to compensate (and you will end up with a worse result than lower CR / more timing). In saying that, the stock ECU usually has some headroom for bad fuel batches and the anti-knock algorithm is usually quite good. I always fill up on 98RON but once I could only get 95RON. Only tried flooring it once, didn't hear any ping but the engine was really gutless. The ECU would have detected low levels of knock starting and pulled a bunch of timing out. By contrast, if I can find 100RON it goes even better than 98.

this is quite possible.. or the CAS has dirty contacts (although this should cause poor running always I would think). original mechanic needs to fix it. or if you have lost faith, find a better workshop. one that specialises in skylines. if you take a skyline to someone who is used to working on carby motors you are in for a bad time. they have to be familiar with the type of car (turbo injected) and ideally the brand (nissan) too.

1. 100 is much too hot. It should sit arounc 85C operating temp. 2. if you run an airflow meter then you must have the AACV taking air after the airflow meter (so the air usage gets measured... otherwise the car won't idle). if you run a MAP based ECU (ie aftermarket) then you could atmosphere + filter it.. but then you need an extra filter etc.. I don't see the point personally. 3. pretty unlikely it'll get better on its own. you may be able to tack it up with some sealant. I once sealed the turbo water line behind the block by dripping some superglue on it. that held until I had time to get in there and replace the hose properly. 4. nobody has ever had a turbo die from not running a BOV. I ran a bovless skyline for several years pushing 14psi no problems.

Refuelling and free tyre choice.. that is good. Let's bring back more common sense..... Currently F1 has too many rules, and is so restrictive. Then they try and manufacture a show that is fake and boring. Prime example: DRS just makes passing a done deal. It's boring. Movable aero should get thrown out, or let everyone do it all of the time (ie to defend as well as pass). You can fiddle with the levels all you like but at the end of the day it's a band-aid that gives the guy behind an advantage that is decided by a committee. It's not 2 guys on a track with the same equipment dueling it out. I recently watched the 2006 Hungarian race and it was epic. The cars with their beautiful V10s howled, the wings were low and wide, tyres gripped. Yeah, they had traction control (not a fan).. and some time around then grooved tyres came in which was a bit silly.. but the show wasn't as farcical as it is now. I don't even bother watching highlights. Who cares. Drivers aren't racing each other flat out, they are just playing a car management game. I feel really genuinely sorry for those who have taken their whole lives and worked their way through the ranks to be fed this horse shit formula.

Hm google reckons that app is malware, interesting. think i'll give it a miss just in case

Those are great samples, thanks Trent. Sounds like very heavy det too, nasty. Would be interesting to hear varying levels of knock starting with very mild.. eg start from knock-free baseline and then adding 2 degrees in timing every 5 seconds and then train yourself to listen for light knocking as well.