joshuaho96

Start with an idle power balance test. Consult cable will let you shut off fuel to one cylinder at a time without having to risk breaking an injector harness clip or have the metal clip go flying off into the abyss.

I have never had to think about this before but that makes sense. Too much boost bleeding off going to the wastegate actuator will overwhelm the atmospheric vent.

Wastegate stuck open will make the exhaust louder because the turbine is being bypassed but it will not make a sucking noise. It will affect idle but not enough to cause issues. Only way for that to be an issue is if the wastegate actuator rod is so loose that exhaust is leaking out from it. Exhaust leaks are usually not that complicated to spot otherwise. Any leak will be magnified by exhaust visibly leaving soot or heat damage to gaskets, external surfaces of cracks, etc. Make sure the BOV is not stuck open. If this is running stock ECU/your tune is not speed density get rid of the atmospheric vent and do 100% recirculation. A boost leak test would show if you had a problem there. You can also try capping the throttle body and only pressurizing the intake manifold to see where pressure is leaking out. With the engine off the only path for it to leak out should be the intake valves.

Too cheap? I think it's pretty expensive.

Yeah, that will definitely do that. Don't delete the BOV altogether either as the factory MAF cannot deal with reversion induced by compressor stall.

I was going to say generally speaking if it's like 80k+ miles since the valve cover has been replaced you don't even attempt to just replace the gasket. The valve cover itself will likely be warped and it will continue to leak after replacement, just not as severely. The valve cover PCV diaphragm can also tear and create a major vacuum leak. Welcome to BMW life. My friend's 2006 330i was t-boned and totaled out so he also just got a 335i so I can add to this thread now.

They replace springs for sure. The remade in USA throttle springs feel much stiffer than the originals.

The two people doing this stuff in the US are https://www.instagram.com/resto_daddy/ or https://www.instagram.com/remade_in_usa_/. I went with the latter option but as far as I know both do good work.

Interesting, I've never seen a failure like that before but with the age of these cars and the general questionable-ness of all kinds of parts these days you can't rule anything out I suppose. Boost leak testing the boost control system would've revealed this though.

Check for blown capacitors, burned traces, cold/cracked solder joints, corrosion, etc. You can try sending the cluster out to a shop that specializes in electronics repair.

If you're using resistance mode on the multimeter of course plugging it in with a live battery won't yield a useful reading. Either disconnect the 12V while you do resistance testing or look up what the voltage should be for your current level and chase it back to the gauge cluster to isolate where the failure happens.

https://www.instagram.com/highintakeperformance/p/C7shBy-R3zo/?img_index=2 Looks like it's official. The originals are some kind of weird foam that is pretty fragile.

I have heard that these are being reproduced in ABS plastic. Announcement to the public is some time in the near future.

I haven't been able to try a coppermix twin but I tried a 997.2 Turbo 6MT the other day with a single plate organic clutch that had all the springs removed so it's "for race use" and a stronger pressure plate. Absolutely miserable to drive. I couldn't feel the pressure plate weight because the pedal has hydraulic assist from the power steering pump but the slip point felt like I had to flex my big toe to control it because it was so sensitive. The clutch also shuddered horribly at the slip point. My best guess looking at the previous owner documentation is they tried to resurface the dual mass flywheel due to supply chain issues + used a stupid clutch with no marcel springs or any of the usual tricks that trade burst strength for driveability. I ordered the coppermix twin. Once it gets here I'll try to figure out whether to shop this job out to a local mechanic I can trust or try to DIY it.

I'd be careful of rubbing past the fender liner because one of the main EFI harnesses runs through there with not a lot of room to spare.

https://www.platinumracingproducts.com/en-us/products/nissan-rb26-cast-blocks This is the solution I was thinking of. I would stay away from Tomei USA, their quality is a question mark to me. If you want an engine machined in the US contact Club DSPORT: https://clubdsport.com/ Tomei JP is probably fine but I recall they stopped doing pre-assembled short or long blocks. In general it's pretty tough to get any kind of RB26 block at the moment with Nissan so severely backordered.

PAR specifically offers stock ratios in their gearset and you could do whatever ratios are physically possible supposedly for no extra cost. I agree 6 ratios is better than 5, the factory 2nd gear is equivalent to the Getrag 2nd gear if you account for the differing final drive ratio though. The Getrag 3rd gear with a 3.916 final drive is equivalent to a 1.6 2nd gear in the FS5R30A. I'm about to swap the transmission out on my car, I'm tempted to send the one I have now out for rebuild with the standard "cross ratio" gearsets out there to see if it really makes such a big difference the next time I pull the transmission.

IMO I would stop there but it's up to you. At the power numbers you're asking about the stock 05U block will start showing issues. Even an N1 block might not be enough. PRP is trying to do blocks and heads that will be ready for big power right out of the gate but it remains to be seen whether any of that is any good. It might be great. It might be awful. It's hard to say until enough people have gotten their hands on one and run it for extended periods.

I think you want an RB34 build at that point to go with a G30-770. Also if your dyno is reporting whp and not crank horsepower you should know your tuner is probably massaging the correction factors to make customers feel better. GTIII-SS and -7s are good for high 300 whp on pump gas, maybe just over 400 whp depending on the setup. E85 will push it into the mid 400 whp or so.

What’s wrong with 2.6 first gear? I’ve done lots of 2nd gear starts from almost a dead stop and it just requires more clutch slip. A 2.6 first gear would be easier than that. I feel like the stock first gear is only good for severe traffic congestion where you need to be able to do 5 kph idling in first gear. Out in the US 120 kph is a very normal speed to be doing on the highways. If anything it’s slow, I regularly get passed by CA highway patrol doing that kind of speed. Out in the desert and plains even 18 wheelers are doing 130-140 kph. I would be less down on the Getrag if not for the fact that they cost north of 10k USD used and you’ll spend probably another 5k on a rebuild at least. I got my FS5R30A from Nissan for 1.5k USD. The cost of building one is maybe an extra 3-4k if you keep it reasonable. The final drive change to account for the 0.793 6th gear is also a pain to deal with.

The GTIII-SS turbos are not made for 650 hp crank. They just aren't going to do it. The turbine housing is smaller than the Garrett -7s. The turbo in general is smaller than a GT2860R-7, if it makes the same power as -7s you should be happy. Honestly I would be really happy with your results as far as power delivery goes. Hitting peak torque by 3500 rpm if that's actually happening in 4th gear in the real world is not normal for an RB26 at all. I have heard of people doing 2.8 strokers with GTIII-SS engines but I don't think I've ever seen a dyno sheet of it. I would be worried that the torque falls off faster than RPMs can rise so instead of getting a wider power peak you just shift the whole curve down 500-1000 RPM and end up with an engine that's no fun to rev out.

For street use I wouldn't bother with a clutch type LSD on the front especially on a mostly RWD car like the R32 GTR. It will affect steering feel and you're really not going to get much benefit out of it. If you insist on putting in a front LSD I would go with a Quaife or similar Torsen/helical LSD as that will have less impact on steering feel. R34 6 speed swap is not really worth it IMO. If you don't swap the final drive on the front and rear differential the car will rev much higher on the highway. For 120 kph it will sit at 3700 RPM, perceptually higher because the factory tachometer reads a little high. Stock transmission it's closer to 3050 RPM for 120 kph. If you change the final drive ratios you will have to either change the gear on the vehicle speed sensor or use some kind of converter because the gauge cluster is taking RPM of the transmission output shaft, not the differential output shafts. Add in the cost and the fact that it's not actually that much stronger than an FS5R30A especially in hard use due to the specification of ATF and I've given up on the idea of using a Getrag 233 in these cars. It's just not worth it considering the huge cost. If you want a stronger transmission build the FS5R30A. PAR Engineering supposedly will do whatever gear ratios you want. You can move things around so 1st and 2nd are not so clearly optimized for 0-100 kph acceleration. The gap between 2nd and 3rd is gigantic for autocross. OS Giken and a few other shops do this, take your pick.

I agree it's subjective, I'm likely going to have to see if a local owner with a Nismo twin plate or some other twin plate is willing to let me try parking lot maneuvering with their car to really feel confident. But it sounds like for now that's probably the way I'm going. The Nismo clutch is full face organic + copper blend as far as I can tell with a sprung hub and a relatively low spec pressure plate. That's a combination of things that seems like it should stack the deck in its favor. Twin plate is the only hang-up honestly, I've never driven one so I don't know if it's too grabby for me and my poor driving skill. Kind of interesting, but I really don't feel like doing a conversion to push clutch.

Getting back to the actual subject though the Xtreme twin plate I'm a little skeptical of. Higher clamp force + requires a pull to push clutch conversion. I'm not super sensitive to cost but the ATS clutch is 700 USD more and another 35% extra clamp force over the Nismo. With how weak the yen is the Xtreme organic twin plate is actually substantially more expensive than either the Nismo or ATS clutches as well, although I haven't priced everything out after shipping.

Most likely if the speedo works fine it's the driver circuit in the cluster that takes the VSS signal and converts it into a neater format for the ECU/HICAS/etc. Pull your gauge cluster out and clean the board with contact cleaner, all that fun stuff. Look for corrosion, signs of burned contacts, failed solder joints, etc.