Gav

I can see your reasoning, but will of course be more prone to detonation if the ignition map is left unchanged. I guess alot has to do with what ECU are you using, how well it's tuned and other factors such as consistent fuel quality and charge air temp.

Ahh.... sorry Antz, that's what happens when I don't read the thread correctly! Hope to have some reliable mid 550rwhp after the next rebuild and with a bit of work should be able to bring on the boost a bit sooner and eliminate the terb shuffle (although it does get other driver's attention when it sounds like a train is approaching them!)

Antz The power curve seems a bit "peakier" with full power a bit later in the rev range than I would have expected with 2530s. The link below is what I achieved with what should be laggier GT-RS terbs. Note that there had been minimal setup of cam timing and boost was a moderate 17 psi or so. http://www.skylinesaustralia.com/photopost...&cat=500&page=1

Looks very similar to an original HKS that I bought some while back. I'mm sure it will be a good performer. Free bump btw!

Before my engined failed, I was getting the same boost almost 1,000 revs higher with GT-RS terbs, so even with "tweaking" the cam timing, it just won't be possible to get the same response out of the larger terbs as SK says. I'm believe with the head work, cams and internals that I've had done to support high RPMs that I will be able to reap the benefits that these terbs should offer over the 2530s. Will need to wait until I get the motor rebuilt ( again ) to quantify the benefits (if any).

Thanks Ken - was wondering about that! My windscreen is totally sandblasted from "testing the calibration at full scale deflection" of the Tomei speedo that I installed some while back.

For the street DON'T get an unsprung centre! Well, not an HKS one anyway - mine is bloody 'orrible (on/off - i.e stall or whiplash) Luckily you can fit a sprung centre and I will be doing this.

I'd be interested to hear how you go with the embedded aerial - I assume that you're using this for your radio reception?

benm's right on the mark. I could never get a failed coil to register and different resistance to a known good one. After doing the substitution caper a few times, I just ended up going with the Splitfires. They are now coming down in price and they really do make a difference.

Hmmmm...interesting. Are these std turbos? At what boost? Wondering if it is possible that the terb shuffle that I get is not solely from fitting the GT-RS terbs?

Good timeslips in a GTR comes at the expense of wear and tear - literally! Decide if you have the spare cash for clutches, gearboxes, driveshafts or diffs before you try those rev limiter launches. That said, a hell hard launch even in a near std R is bloody good fun!!

Agree that wide band lambda will give more accurate information, but this is only for initial tuning right? I guess that I'm thinking about having something installed permanently. I don't think that this would extend to having 6 gauges nor does my ECU have 6 aux inputs, but perhaps a single gauge with a 6 position switch (or 3 gauges with 2 positions...you get my drift). Just some food for thought about modifying the manifolds when they're off for accepting probes.

Saw something at work today which got me thinking. On some underground mining equipment, there are exhaust temp senders that are only 15 mm and screw into a 4mm socket. These give individual exhaust "runner" temps. Each probe was around USD80 from a European Supplier. This doesn't include any fittings or gauges. The output is a 4 to 20 milliamp rating that is very easy to convert back to temps via the supplied table. OK - my point. Is it worthwhile fitting one of these probes to each runner of an aftermarket manifold? I would imagine that there may be some turbulence generated, however the probes are only 3 mm or so in diameter and only need to just go into the exhaust gas stream. Possible uses would be for trimming of individual cylinders during tuning as well as letting you know if an injector is blocking (for example). Any thoughts?

DB - PM sent

All up top - but the engine was/is set up for high revs anyway (high lift cams, extensive porting, big low mounts).

This shows the manifold that I'm talking about. It appears that the std pipe (with the "Twin Turbo" badge) won't fit and you require some aftermarket or custom pipes from the terbs to the IC. Anyone with experience of these?

Yer digger - that be the one. The HKS variety seem to use a "bellows" type of bridging pipe that presumable gives a little bit of play. I would imagine this would help ensure good fitting of the manifold against the head?

Sort of on the same topic, does anyone know of a cheaper version of the bridged low mount manifiolds? My GT-RS terbs shuffle like a bastard during boost build up and I have the option of either adding a bridge to my existing manifolds (prefer not to as they are nicely ceramic coated inside and out) or selling them to buy a bridged pair.

I would think that's not really the "spirit" of the forum. I'm sure anyone that want's to make money from copying the design would not rely on low res photos from this forum and would just buy one from Japan. Along your line of reasoning, I paid a lot more a couple of years ago for my '93 GTR than people paid up until recently for 15 yo imports. I also paid a lot more for my genuine HKS terb manifolds than people pay for local or Chinese copies. But that's my choice. Out of interest, I'm also using a single throttle conversion myself and am happy for anyone to look at the details of the plates and the custom throttle body. A hotly debated topic but personally I think it's an advantage for a high revving, standard 2.6L with high lift cams. I would imagine a single throttle body also helps with a map sensor type ECU setup. But again, my choice.

So you've signed some sort of secrecy agreement with Jun????

Good luck - nothing gets the adrenaline going like when a fast R starts to "torque steer" at mid track!!

True that on the "ingredients". Will get there 'tho! 11.68 @ 124 mph, with what was a "conservative" tune on 17 psi boost and supposedly conservative timing. Just worked out why the tacho was out - was running MT slicks on the back! Don't really want to go into what happened to the motor on public forum, water under the bridge with a Perth tuner