JimX

Sydneykid I agree to an extent, but the difference in my plug colour is very very small. So small that between any 2 adjacent plugs I couldn't tell the difference in colour. It's only when I got 3 or 4 towards the front that I could notice the colour difference. I never checked my plug colour from the old plenum, but I would say it's just as likely that plugs 3 and 4 would be the ones running "perfectly" rather than 5 and 6 as it is now. From my understanding of plug colours, they all seem fine to me. They range from a light brown to a slightly darker shade of light brown, with absolutely no fouling even on number 1. So yes plug 1 is running richer than 6, but I wouldn't say "rich". I agree wholeheartedly that the standard plenum is more than adequate for 450hp+. But as I've already said, I didn't put it on for extra power. My main concern was throttle response, which has been markedly improved. My secondary concerns were easier servicing of plugs and injectors, and thirdly just the neater "custom" appearance.

Higher viscosity does NOT equal better lubrication unless you're running extreme type engines (ie, 1000hp+ drag cars). For most of our cars, if the rings and valves are still good, a 30 or 40 weight oil is good enough. Any thicker and you lose power for no real gain. The benefits of thicker oil in normal cars appear when your rings start to get a little worn, and the thicker oil will help seal the gaps a little better so you don't burn as much.

Roy, good question. I'm not really sure. The boost gauge splices into the factory line, which I think is on the plenum (it seems to go somewhere on the driver's side in the engine bay anyway). The EBC gets its boost reading from wherever. I think it gets it from before the intercooler because it's all on the left side of the engine bay. If the above is correct then there's not much pressure drop through the cooler. I've set the EBC to 1 bar and the boost gauge reads 15psi (maybe half a hair over).

How do you buy something COD and get to touch/feel them before paying? The post office won't hand over the box until you've paid it

S-AFC only. Because of the dips I'm considering getting a PowerFC. First step is to increase the dump pipe size to make sure it's not a strangled exhaust.

Hard to say how much I gained up high because (a) the cooler was also upgraded, and (B) I ran more boost after the upgrade. Pre-mods was 166rwkw @.8bar, post-mods was 215rwkw @1 bar. 20% more pressure doesn't equal 20% more power though, so I think that there has been a definite noticable gain in there. Plus it dips and surges like a bastard, once I get that sorted out and whack the new injectors in I should be getting well over 220 with a more even curve.

Wow, how off topic did this thread get? Well since the discussion is currently about comparing front-facing to top-mounted, I'll summarise my experiences. I compared my dyno sheets from before and after the installation of a bigger intercooler and front facing plenum, and down low I have about 2-3 LESS rwkw on the post-mods version. So I actually lost a tiny bit of power down low. But once it gets into the mid range, the new setup absolutely hammers the old. I don't know how much of this is because of the new plenum, or the better intercooler, but whatever the case it's better than before. In the upper rev ranges I have more power as well, but it dips and surges for reasons not yet fully known. Part of it was fixed with a stronger wastegate actuator, but there's more fixing to be done. I pulled all my plugs out and checked them individually a few months after the install. They were all very similar in colour, but very slightly gradually lighter to darker from back to front. So I believe this plenum does favour the rear cylinders, but not to any great extent. Plug 6 was a perfect light brown colour, and they got slightly darker from there. So I don't think I have any leaning out problems. Benefits I've found that I'm sure are the cause of the front-facing plenum are: 1, Better throttle response due to shorter intake tract. 2. Easier to get at spark plugs. 3. Easier to run cheaper top-mount injectors with a custom fuel rail. Also easier to take them out for cleaning/replacement etc. 4. Neatens up the engine bay (subjective I guess). I suspect that it's also given me more mid-range power, but as the upgrade came with a cooler upgrade as well I'm not certain how much (if any) is the cause of the plenum. I don't know if it's worth it (to me) to pay $1100 for a Trust item for the above benefits, but my home-made one cost me less than half that and I'm more than happy with it.

Around $80 each is around average I guess. $100 isn't too bad. $50 is the "buy it now" price. Update on my situation: I found a Commodore wrecker that has some plugs (for $5 each) but I didn't have time to get around there today. Maybe next week.

So where can you get Amsoil from here and how much does it cost?

Sorry, I missed that I will try some Commodore wreckers too.

Jimbo yep Have you seen it at Hills?

I'm getting similar problems with my T04, and similar unknown causes. Part of the problem *was* the wastegate, but not all of it. I upgraded it to a stronger unit but I'm still having slight surge/hesitance problems in upper rev ranges. The next step for me is a bigger dump pipe and machining out the exhaust housing a bit, but I don't think that's all of it either. I think most of the reason is just that this turbo doesn't like high boost.

Sorry to dig up an old thread but it's all relevant I'm after the same set of plugs, but I can't seem to find any. I tried Coventry's on someone else's advice but they don't have any. I also tried ringing a couple of Mazda wreckers but they had none either. Does anyone know where I can get them from in Sydney and roughly how much I should be paying? I'll try a few more wreckers in the meantime. Edit: I'm going to try Findapart.com.au and see what happens.

Just to go against the trend, mine is perfectly fine It reads around 6 when cold and drops to around 3 when warm. At idle that is. When driving it goes up.

Out of interest, how much would a factory ECU be worth, for both pre and post 95 models?

I think the old "crap at the bottom of the tank" is a myth. The fuel doesn't pick up from any lower just because the fuel level is lower. So in theory it should be sucking in whatever is at the bottom of the tank whether it's full or almost empty. Whenever you fill up it would mix it all up anyway. I've had a look in the bottom of my tank when I was changing the fuel pump and it all seems pretty clean down there. On top of that, your fuel pump has a sock, and there is a finer fuel filter in the engine bay. I've run my Commodore out of fuel once, and my Torana 2 or 3 times and I never suffered anything adverse because of it. What I *have* heard of happening is some cheap fuel pumps require fuel flowing through them to keep them cool or they overheat and shit themselves (eg, most or all Kia cars). So running out of fuel on these cars could kill your fuel pump very quickly.

MM2death I don't think that's your O2 sensor, but your cat temperature sensor. On the factory exhaust a warning light on your dash comes on if the cat starts to overheat.

I didn't think you were serious, but I did think it was in poor taste under the circumstances. I think the best thing to do would be to forward this thread to Mark and let him respond directly if possible, if he can't speak to Steve because he's in Japan. Does anyone have his email address?

Possibly But I'm not disagreeing with the sentiment of your original post. I'm disagreeing with others vilifying Hills and jumping to conclusions thing before any sort of remediation has been allowed to happen. I'm not going to bother praising Hills for the good stuff they've done for me because I believe that in this case it's not relevant. I don't care how GOOD they have been to me in the past, because if it comes to the crunch and they rip me off big time in the future, all that good stuff they've done before will be meaningless. Therefore, I like many other people have a vested interest in seeing how they treat you regarding this plenum. I'm not actively defending them here (because your situation has nothing to do with me personally), I just want them to get a fair chance of putting things right. If they don't put things right, then let the cannonballs fly

Hmm well you should change the diff oil then. Since there's not much oil in the diff you may as well put Royal Purple in if you can afford it.

One thing I've learned about car stuff is if it does the job, there's no sense in upgrading. Royal Purple may be the best, but if your box and diff are fine with Redline, what are you actually paying for?

You could ring up one of the many compliance shops around, they should have plenty in stock. The restrictor is put in by them, they don't have them in Japan so it's probably no good to ask Nissan for one (although they might have them for other cars that might fit the same, like 200SX). Should be a couple of bucks.

FFS, what is all this bitching and threatening about what you're going to do to Mark/Hills Motorsports if you haven't even SPOKEN TO MARK YET?! If you speak to him and he tells you to **** off THEN come back and bitch and I will agree it is justifiable and I daresay Hills will lose my business as well. But until that happens a lot of you are just talking bollocks for no reason. Do you think maybe that's why the other thread was removed?

Lepperfish, but if you never floor it you shouldn't use much more fuel than a stocker.

Pics for me too please. xoose@bigfoot.com