BHDave

R32's have enough room to get the piping through under the battery tray on the vertical bit. they even have a little semi circular impression there as the GTR runs it's pipe there.

That was the main reason i ditched the 20. I used to drive my car alot for work and once the bigger turbo went on it was just unbearable for me.

Yeah, i noticed that, except i get boost about 800rpm sooner on the street than the dyno. Not taking anything away from yours, as the change in exhaust housing seems to have made a huge difference. My response with the rb20 and highflow was only marginally worse than what your's has (and nowhere near the top end) and the bottom end / midrange was non existant compared to my current setup.

I'm lazy, i like my rb25 r32 for the simple fact that i don't need to change out of 4th all that often once i'm moving. I'll get an rb30 when i want to pull away in 4th

How did your's run before you took out your afm to clean it? It may not be the afm you know, you could have a significant vacuum/boost leak in your intake piping which will give similar symptoms. Seeing as 2 ecus's dont like it and you've tried 2 afms i'd say you've eliminated both ecu and afm problems.

I've found that perfect runs pricing is as good as nengun or greenline overall. They are cheaper on some things and more expensive on others as is typical with most retailers. Perfect Run gave me the best price on my splitfires a few months back, and i had them in under a week aswell.

It's unrelated. Dump pipe gasket, possible as you may need to remove the front pipe. Manifold gasket, no.

2.5 year old thread. Is that a record? You are talking about sequencial turbos, Ideally you want something smaller than an rb20 one to spool up and something bigger than an rb25 one for top end. And then you need stupid amounts of time and money to get the whole thing working properly as you will need custom everything on the exhaust side of the engine as well as the compressor outlets. Before you go any further, take a look at the setup an a 2jz and think about how you are going to make that work on an rb20. Once you've thought about it for a little while, you'll realise that you will get better results for less money by swapping in an rb25, or upgrading your existing turbo to something like a 2530.

There's an option under the etc menu to adjust display properties.

I'd just be buying an adjustable actuator and set the preload so you can run 13psi or so. Shouldn't cost more than 250. The r32 dosen't have the aggresive rich and retard strategy that the 33 has so you will make some decent gains from this. Then save and get the power fc if you want to go further in the future.

Damn! I like cubes' idea! Trying the machined rb housing is probably the cheapest way you are going to get out of this and end of the day it may work wonders. Messing around with the front end of the turbo is more likely going to cause further issue, particularly if you are going to need further machine work to fit alternate wheels into different front housings. By the time you do all that you may as well get another turbo. Ideally i'd be looking for a smaller off the shelf internal gate turbo that is smack in the middle of it's efficiency at about 1 bar mainly due to the lack of 98 octane fuel you have. Id be setting a goal of around 230rwkw with very good response so a gtrs should do it, or a second hand hks2535, or even one of the 2871 range with an adapter (though thats not ideal). But before i did any of that i'd spend the hundred on the rb exhaust housing trial. No point spending thousands without trying a cheap alternative.

The weird thing about the turbo response in my case is once it has more boost wound in the shape of the curve is near enough identical until it hits a wall (and valve float) and the top of the curve flattens out around the 22 psi mark. It has about 1psi gradual drop off through the range up to about 7200rpm. Here's a couple of pics. It's an ugly lump of a thing. I dont have a shot of the turbine wheel. It was sold to me as a t300s, plain bearing, not water cooled. The t04e that was originally part of the kit was junk (seized) so i grabbed this one instead and had to chop off the bend. It was a bit of a punt that seems to have paid off.

You've forgotten all about your 15 year old fuel pump becoming tired. It's the prime suspect in 99% of running lean cases. Get a new one. Genuine Walbros are under $200 delivered and are a drop in replacement. It's half an hours work. Which workshop? I'm surprised it wasn't the first thing they suggested. EDIT. Just re read your last post. O2 sensor has no control over high load mixtures as you are in open loop. Any improvement you got out of swapping the sensor was a bit of a fluke (quite possibly due to the car being fairly cool). As you've said, the car is coming out of closed loop mode so you have eliminated all 3 possibilities you started with. Get a fuel pump.

Whats so weird about it? You've said yourself that the 7 blade wheel is more efficient at lower speeds than the 6 blade wheel and we are seeing those turbos making similar boost not much further up the rev range. Combine it with a decent manifold and a .63 turbine housing and you have a turbo that is starting to spin pretty quickly at low revs and make some positive pressure. What it makes at 2000 in terms of boost or power? boost, a couple of psi if it's in a high gear, nothing in lower gears. Power, probably a bit below 60rwkw, my dyno sheet doesn't go that low Control of detonation? That would be a decent tune with decent fuel by a decent tuner. In this case Ultimate and tuned by unigroup. Peak knock on the hand controller around 33-36, a bit higher (with the occasional excursion above 60)when using optimax or Caltex shit. Typical bolt on's, fairly big oil cooler as the turbo isn't water cooled, and a relatively small 400x300x60 tube and fin frontmount intercooler. Full load ignition, see the attached section of my ignition map. Actually, the forums won't let me upload an excel sheet. Basically L13-L18 between 2800 and 4000 range between an average of 17 degrees at L13 down to an average of 8 at L18. Minimal tuning has been carried out below this point as the car doesn't get there, it drops to 6. Peak afm voltage of about 4.8V though thats a little further up the rev range. It's a z32 afm. And it's 21 psi by 3200. We seem to be getting a little off topic. Mafia, whats your time frame on getting the rb exhaust housing on? Despite disco's disapproval of my suggestion to run a machined rb housing i think it is worthwhile to spend $100 now as an experiment rather than throwing your hands in the air and spending another 1400 on a new cartridge that may or may not work properly with your existing VG exhaust housing.

I don't think you're full of it. I know from my experience with the t300s that it requires a heap more boost than an equivalent gt30 to make less power. But i'm quite happy to accept that as mine is a pretty old second hand turbo and was relatively cheap. I dont agree that the t04s wheel is the root of all evil as you do though. It's just got an efficiency window the size of a bee's dick. I don't think surge will be an issue with the smaller turbine housing in this case. The turbo is making boost very high in the rev range which is either a restriction or an overly large exhaust housing. If i can have the same compwheel making considerably more boost 1000rpm earlier on a near enough identical engine without surge, then a smaller exhaust housing is worth a shot in my opinion. (particularly if he has access to a heap of them).

Mine made a touch over 240 during tuning but we took a bit of boost out and a bit of timing too. Final figure was 238rwkw on 20psi. The dyno ramp rate wasn't bringing the boost on as early as it hits on the road either. There's a copy of my dyno sheet in the rb25 turbo comparison thread near the end. Basically the car pulls like a train between 3 and 6k and then feels a bit flat at the top end even though it's still making power right up to about 7k. It doesn't really roll off either. Cubes, pm me your email addy so i'm not clogging up mafias thread with a bunch of my photos.

You probably want to remove the kink in the return to the intake before you block the filter off though. When the pcv shuts under boost all the vapour will be pushed/sucked out by the one hose anyway, it's pointless running a hose from each rocker. I'd maintain the current setup and be blocking the filter for a few of reasons, 1 it's an obvious defect, 2 i don't particularly like the smell of oil vapour, 3 if you maintain the line to the inlet then the filter is redundant.

There is no stamp on my turbo stating it is a hks (which is a bit of a worry) Though it is a garret stamped t3 rear housing, which leads me to beleive that it is a common enough housing if you want to get a hold of one. I previously ran a stage 2 gcg highflow and the response was near enough to identical to the current setup. This had a machined rear housing that looked to be about the same size as my old r32gtst turbo. Maybe that housing, once machined, is pretty close to the .63 you are looking for? I know the vg30 rear housing highflows have much poorer response than the regular highflows. It may be worth having an r33 rear housing machined up to suit. It couldn't cost more than a few hundred dollars and should improve response significantly. I have an hks kit, which is the low mount cast manifold and ex wastegate. As i said previously, i think that a log style manifold (stocker) should offer better response at the cost of some top end power.

No it wont. I have a t300s, which is the same t04s comp wheel as you and a .63 T3 rear turbine that looks to be identical(ex gate though). However it is a hks low mount setup. I can have 7, 12, 17 or 20 psi all in by 3200rpm (that's in third, it's too quick for me to tell accurately in second as i have to look at the hand controller, my stock tacho is a waste of space). And it isn't ball bearing either. Disco seems to be having fun bagging the t04s comp wheel, but as far as i can tell, it isn't alot worse than the current generation 6 blade wheel. It is less efficient, particularly at low boost levels, and wont make the same outright power as the current generation wheel. The power you are making is pretty much on the money considering the fuel used and the boost you are running. Your issue is response, the power will sort itself out if and when you run more boost, just don't expect 270 plus like bigcarl, i made 240 at the same boost, which i was happy with considering the response i have. I dont have cams either and the exhaust gear is set to zero atm. I'd be looking for thing's like intake restrictions, exhaust restrictions, possible cam timing (particularly if the timing belt has been changed). The stock exhaust manifold should be able to flow enough that you can make 7-14psi early in the rev range, even if it drops off at the top end. In all honesty with the log style manifold and bb core you should have better response than me. Also considering the highflows have a near enough identical rear wheel and work well, i wonder how the rear housing can be an issue.

For internal? I've had them set at 10, 12 and 14psi depending on the amount of preload run.

The stock nissan ecu and the power fc seem to sweep through the af ratio on cruise as you have stated when looking at an a/f gauge. The funny thing is, when running a data logger i never saw a wave pattern when i logged cruise. My rb25 has a slight surge, similar to what you are describing but at really low load, light throttle, and no where near as prononced as yours. I had put mine down to using 550cc single pintle injectors. What you can do before splashing out on a new ecu is get a tune done in the mid and low range part of the map with the closed loop control switched off and get your mixtures as close to stoich as possible. That way the ecu isn't having to swing as far trying to correct the cruise mixtures. Edit: Hook up your speed sensor. It has all sorts off effects on power steering weight and hicas and could well be part of the problem. I assume you have the hicas locked (if you have it).

Good choice. The ex gate isn't too obvious if you are still running a cross over pipe. You can alway plate it and run an internal gate turbo, theres a heap of room around the exhaust side once installed. And because you are running a 30 block you probably wont have the same issues fitting the big ass comp cover in that i did (stupid engine mount)

For twins on an engine of that size with that sort of response you are really looking for something pretty small. A pair of turbos of a Z32 300zx maybe could do it though you may find the response will be significanly worse on your engine than the VG30 due to lower efficiency. Due to your low rev limit they may be a bit big to be honest. You could even go a pair of T2's off an old ET pulsar. It was 1.5 with 2 valves/cylinder. They are pretty old though so would require rebuilding. There may be a new version of it for sale by garrett.

So you gained 10 from the exhaust and another 10 from the revised dump. Sounds more reasonable, though there is still some conjecture about the performance of the short split dump at higher power (as in the bolt on replacement dump) vs the one piece as shown by mafia. Thats the main thing i'm asking as the drop off as shown on the graph could well be a sign of the top end choke commonly associated with these type of dumps and may well be more pronounced when you start making more power.

You are saying that you gained 20rwkw with a dump pipe, a front pipe and an otherwise stock exhaust? Because you'd be aware that a 20rwkw gain by installing a full exhaust is considered to be pretty good. Also the way that the power is really starting to dive at the top end isn't a good sign (i'm assuming that the throttle wasn't eased off). I'd be interested to see what happens once a higher flowing exhaust is fitted as it is the biggest restriction in the system at the moment and may explain the drop off. It should also net some significant power gains. Is your split dump a bolt on piece between the turbo and front pipe or have you created a new dump/front with the collector merging smoothly in the same way that mafia's does as shown above?