Dale FZ1

I had the same issue with a freshly painted Greddy copy manifold, scraped back the paint at the grounding point, and fixed it. Click on tabs "Analogue Inputs" and "Analogue Status". Make sure it isn't displaying a voltage problem with the TPS. If an error exists, it should show up in the status tab as a red bar. Inputs should also show limited range rather than the typical 0.5 - 4.5 volt range between 0 - 100%. If you have a dicky system ground on the inlet manifold, TPS voltage won't run through the correct range and you will get all sorts of horrible lean running on accel. ie. Unless TPS output is correct, no amount of changing accel enrichment will alter what actually happens when you attempt to accelerate the engine speed. Otherwise you should setup a data plot and observe what the AFR actually does on accel. Then you might make an informed judgement about what to look at next.

Hence my comments above. The sensors are just a microphone that converts vibrations to an analogue signal. There will be variance between sensors as to what output signal is thrown to the ECU is associated with actual knock. However, common consensus seems to be that numbers at 20 and lower are distractors. If the OP was concerned, he should be having some action taken with a stethoscope.

Got to disagree with you there Paul. If it's knocking, it's bad. Full stop. Knock kills engines. The issue is if a sensor output of 30 is actually knock, or "general noise". Use of a proper stethoscope and comparing against observed readings is the way to really determine that. However I would look to keep those readings less than 30, and less than 20 under high load areas. Edit: reading the OP, you need to identify if it is high LOAD, or high RPM. They are different axes on the map. And if you are reading off the hand controller there is no way of readily identifying which cells are the offenders. Has anything else changed, including a fresh batch of fuel just after the plug change that might be of questionable quality? Sometimes the cause of things you observe isn't always evident immediately.

As an alternative, price up a set from Kelford and Tighe. Neither are likely to retain VCT, so factor in vernier cam gears (if you don't have them already). The Jap stuff is obviously very good, but remember there are alternatives - provided you're then prepared for an hour on the dyno to dial the cams in. Bummer about breaking a camshaft though. Hasten slowly, and use your eyes as you go.

Something like this? Bear in mind getting everything fastened to avoid fatiguing the water pipe takes a bit of work. Brass fittings and high quality hose does not cost the earth, and can still look - and do - the goods provided bling isn't the aim.

Remove the housing and inspect the gallery for blockage. Is it just some sort of sandwich plate that has ports for temp/pressue senders?

It comes down to balancing the cost vs power gain vs response improvement vs application, and/or whether you or your mate has the time and gear to do the job. Be mindful of what a set of fabricated manifolds cost too. Casting quality ex-factory isn't bad, but they are mass produced and not subjected to any significant finishing once they've left the foundry. There will always be a "weak link" when you start modifying from stock, but I think the important bit is to reduce restrictions where possible. There might only be percentage gains, but if you've got access to the gear and a bit of drive to learn and improve things, then go for it.

Is this the pressure you see at idle? If so, what do you see at middling rpm ie. 2500 - 4500rpm? Also out of curiosity what type/grade of oil are you running, and do you know what was done to the oiling system during the build eg. changes to top end restrictor/s?

It's going to be interesting to see how things go. Well done This would have to be one of the larger turbo sizes onto a road driven RB engine. My Vipec gave an instant first start, and an even idle within a couple of minutes. Similarly a bit fluffy off-idle when touching the throttle, but impressive out of the box.

Here's what ATP is charging in the US http://www.atpturbo.com/mm5/merchant.mvc?S...tegory_Code=GRT

Interesting to see what is floating around. http://forums.bimmerforums.com/forum/showt...d.php?t=1354371

Looking at the whole picture Kev, I’ll suggest that there is nothing inherently wrong with chasing 700hp. Use it how you see fit, too. If you’re accepting that the minimum engine rpm you’ll hit 20psi (is that what you calculate your RB25 will require to hit the power target?) is 5500rpm, then by rights you’d want to extend the upper rpm ceiling to avoid ending up with a fairly narrow and difficult to use torque range. You’d have to be prepared to buzz the engine harder than 8500, which would lead me to ask two questions 1. Have you looked at the gearing and final drive ratios for your road speed targets? If so, what do you reckon is likely to work with this powerhouse? 2. What reciprocating components would you use in the engine itself? I have no issue with whether you use a plain bearing spec turbo, more that the powertrain is configured as a whole. Given that the BMW boys have achieved some pretty good results Stateside, it’d be interesting to see what/how they do it. Typically the route seems to follow cubic inches via the M3 platform, but I think the 2.5 litre 6 cyl seems to run hard too.

Factory engineers place the valve farthest from the turbo, and closest to the throttle. Air mass travelling through the piping and i/c have a certain amount of inertia, and I'd think you want to relieve the pressure closest to the throttle. Packaging would be easiest over on the compressor side depending on your pipework layout. Suggest giving it a go, and if unsatisfactory then have another go with a location near the throttle then. Lots more time/effort if you want to mount it on the RHS and get the return plumbing right.

But definitely free floating type (ie. requires an EW)?

Don't be afraid to "clock" things. Loosen your housing retainers and rotate the centre section slightly so that it's not straight up and down. That slight angle may help. If it's not enough, take the drain in and have the straight tail either bent a bit, or removed and weld in one with a nice curve. to point it all in the right direction. If the hose is too long, it may cause a slight kink as JonnoHR31 said.

If the turbine housing you use is the Evo spec IW, then flange pattern is the issue. If you use the EW 0.78 split pulse, then mounting a wastegate to the stock manifold is the issue.

Sorry, but the only difference comes about from whether the S15 was fitted with manual or auto gearbox. Manual = 450cc = brown/terra cotta colour Auto = 370cc = purple colour (same as the RB25) The ADM / JDM story was kicked off in a HPI magazine article and has remained ever since. Head to a Nissan spare parts counter and you'll find the truth via parts numbers. I know because I did it. I do believe the problem as above is not in the PFC settings, but something more likely with the install (probably) or the injectors themselves (possible but not as likely).

When I had S15 injectors installed, it ran perfectly with 82.5% and 0.12 lag correction figures and using the stock FPR. There was some discussion on this forum in the day regarding lag, and considering that their design is very similar to stock there may be little if any practical purpose in entering a correction figure. Another member was using a difference lag correction and we each claimed to have good results in terms of power, starting, driveability, and fuel consumption. Even the arguments over whether they are 448 or 450 or 480cc injectors is a bit academic because it's just a number that will determine what numbers go into your fuel map. My homework at the time suggested S15s were 450cc @ stock rail pressure, and they can/will flow more with higher pressure. If you hadn't bench tested them prior to install, could be worth pulling the rail out and crank it over to check that the fuel sprays without dribbling, and/or that they don't appear to be sticking open. Make sure your ignitor is disabled at the time, and limit the number of times you do it - don't want excess fuel vapours floating around the engine bay with potential ignition sources.

I spotted a 0.70 A/R on that comp cover, so assume it's the physically bigger TO4S style. Looks like you'd get away without touching anything. Wolverine is on the mark - do a dummy fit and you'll soon see what's what on the bench. Moving into custom stuff it's not unusual to have to make "adjustments", although I'd sooner keep that heat shield on the engine mount. The pics kyle785 provided suggest you may stand a chance of running the stock airbox if you really wanted, but the HKS manifold screams modified.

How hard are you going to rev the thing? Leaving cams and ports stock won't stop you making the power target, but would put a ceiling on rpm where it starts to flatten out. Might be overkill and overspending on the rods and harmonic balancer if your target is going to be achieved under 7000rpm. Those S15 injectors actually flow 450cc at std rail pressure, so not likely to do the trick for 300rwkW unless you play with FPR.

So what was changed to alter the boost control and stop it falling away quite as much? Very interesting to watch the progress with this setup over time, and I did wonder how the external gate mod would work. Also how well it lasts, given the sorts of problems most people report when welding cast iron. Top marks.

Agreed. Takes a lot of complexity and weight out of what should be a simple system.

That was my setup. Yes, it did everything I asked of it. 300rwhp @ 12psi and extremely tractable/streetable/responsive at low-middling engine rpm. The spec might have sounded a bit small, but the car covered ground pretty quickly without needing heaps of gear changes. One issue I saw was boost falling at higher rpm, and power flattening at 6000rpm. I believe the RB25 turbine housing may have been the culprit, and considered swapping in a larger OP6 housing profiled for that cartridge. Eventually it was bought by a guy who fitted it to an RB20, with pretty punchy results by all accounts.

Probably worth doing a search and checking out the experiences BHDave had with boost creep on a 3071 with 0.63 IW Garrett housing. I agree with Wolverine's comments about the product Hypergear are putting out there. There are a few options that seem like they're close to a bolt-up, and at the price point well worth a go. Following the Hypergear thread there seems to be quite a few satisfied owners and reasonably serious efforts to provide after sales support. It'd be interesting to inspect the 0.63 housing they use for the 3071 spec, and to know exactly what cartridge is used ie. if it has the full size 60mm or cropped 56.5mm turbine rotor. GT-RS would also be a tidy option at the targeted power/performance level if you could source something for a reasonable price.

The issue with that other engine would have been coil bind ie. at that peak lift the compressed length of the springs was too long and they broke. Generally acceptable max lift on an untouched RB25 head is somewhere around 9.0mm because beyond that to achieve satisfactory control of the valve, the valve spring dimensions come into play. Go too far and you end up with problems as above. That all changes if/when you have machine work done to allow the fitment of longer springs. Sounds like you need to consult with a cylinder head specialist, and someone who knows RB heads. There are people on this forum who've achieved pretty strong running combinations without putting in big lift cams. I'd say if you pay attention to detail in the preparation of ports, matching and assembly there's no real need to go past the 9.25 260 combination. Check the posts today by Fineline in the RB30 forum