Noz

Yeah.... Still in Leicester....

Haha, I might do for a laugh. It's still only running a T28-sized turbo, so won't be anything special power-wise. It's done over 50 full-bore launches on the gearbox down the strip, so who knows when it will let go...

I reckon £15k and not a penny less. "Low miles" being about 193 from new :)

Heh, just Googled "Tewksbury" to check the distance.... Might pop down in the Pulsar seeing as there's no drag racing this weekend.

I wasn't missing your point either, but fitting larger injectors isn't a solution to the OP's question. Plus, I didn't appreciate you insinuating I could be fudging numbers ;) I answered the OP, you addressed myself. Fitting larger injectors is not going to help produce the power he requires with stock turbos. He needs to build up a 2.5" intake kit, not have a bespoke one made, source some turbo elbows (they're easily cheap enough) and investigate the stock manifolds and whether or not he can afford/find a set of 2nd hand items. Everything he buys/fits/modifies HAS to increase efficiency for him to achieve his end goal first & foremost. A slight increase in fuel delivery if required can be sorted with an ADJUSTABLE FUEL PRESSURE REGULATOR (my Nismo adj FPR cost £20), NOT a set of larger injectors. P.S. Yes I would, having seen how much stockish VGs make power-wise and also how they behave on the road with a dual intake set up first hand ;) The intake piping, elbows & manifolds are restrictive at ALL power levels. How on earth do you think Nissan managed to keep a 3L V6 Twin Turbo engine down to 300bhp (apart from the terrible stock map). You need to look into how it all affects the way that power is produced.

I'm not missing the point, I know exactly what the OP is looking to achieve and also how it can be achieved. That IS the point of my posting on this thread from the viewpoint of someone that knows what is attainable, not what he's been told or read. Although I try to steer away from bhp figures being the be-all & end-all, the VG makes peak power at roughly 6000rpm. After this point with stock turbos boost pressure drop off drastically, hence the injectors aren't as troubled as you'd think. Bigger turbos, you need larger injectors due to the air flow at higher RPMs. I didn't get close to maxing the stock 370s at 21psi and standard fuel pressure with single intake, stock intercoolers and cats in place (less efficient = higher BSFC). The log file has been posted. If the OP is keeping stock turbos and has a strict budget, he needs to concentrate on increasing engine efficiency, therefore maximising the STOCK set up. There's no grey area if those are the stipulations: dual intakes, 2.5" charge piping, very efficient intercoolers, turbo elbows, manifolds if within budget. If required, he needs to increase the fuel pressure slightly. What use are larger injectors if the restrictions mean you've got to push 1.6 bar boost pressure on stock turbos? Getting the stock turbos to make 450bhp without their reliability nose-diving is the obstacle that needs to be overcome here. It is not simply a case of one solution fits all. As I said, he needs to think outside the box to overcome budget restraints.

Look forward to it :thumbup1:

But increasing the size of injectors gives NO GAINS WHATSOEVER. Sorry, but this statement is very, very wrong. Reducing intake restrictions is essential to lowering BSFC (more power for the fuel used). I've been mapping various OEM systems for nearly a decade now: Bosch Motronic, Weber-Marelli, Nissan Jecs. I have a good idea of what is achievable and what is not when it comes to mapping. This comes from actually doing it, not from being around it... I had a 5th injector on my old Fiat Uno Turbo 10 years ago. It's a terrible approach. But again, just by increasing the fuel delivery abilities, you don't achieve any more power whatsoever.

LOL!! Air filters, back boxes, lots of boost on Auto turbos & stock injectors: 394bhp, 410lb·ft & 13.1s @ 110mph (at 382bhp, Had a BDC car on the dyno yesterday, S13 with 2L SR20DET. Won the Semi-Pro class last season with a remote-mapped CHIP & dautherboard that I supplied. He ran a shade over 300bhp on a dyno near him (Essex way) Yesterday, the same chip/map ran 295bhp & 329lb·ft on the dyno I use. As I have said a long time ago, anyone doubting figures I give are more than welcome to come & see me or any of my cars in action, either up the strip or on the dyno :) ***EDIT: I have actually given out a slightly lower figure & plot in the past before, as I wasn't absolutely 100% sure the dyno wasn't reading slightly high when the car in question appeared to be making too much power (it was accurate though, of course). It matters not a jot to me what the cars actually make. Air goes in, fuel goes in, timing is dialled in, torque is produced. Power output is simply a numerical result of this. What kind of sense would it make to inflate numbers to then have them take the car elsewhere only to be disappointed and question my abilities/ethics. Just because you yourself were not able to get the most out of a Zed in 13 years, please don't allude to number fudging in response to a post I make addressing a specific scenario for an individual (the OP). And that is YOUR prerogative. Not everybody's. If someone picks up a cheap TT Zed for £800 and wants 400+bhp, the option is there without having to spend an absolute fortune on parts that are not required. The Zed is a perfect candidate for both methods of approach, as it can be both a cheap banger or a 5-figure tour-de-force.

Ideally, everyone would have an endless budget for modifying their cars. But they don't. The OP doesn't, and has specifically asked about 450bhp as cheaply as possible. My post was specifically in response to his situation alone. Fitting forged pistons when the engine is out is cost effective and always recommended. Fitting new injectors is preferable. Fitting new everything makes my job a lot easier, as well. Poor mapping will kill an engine that is 100 miles old. Mapping a 300zx is no different to mapping anything else, the technology has been around for donkey's years. Since the late 80's in fact. It's insane to think that people will spend thousands fitting all their shiny new engine parts and then rely on a decade-old generic chip off the net to keep everything in one piece.

Sorry I can't be of help, but I can't think of one reason to fit a Unichip into any Nissan, let alone one as easily mappable as a 300zx :)

1. 450bhp is a walk in the park for any Japanese 2.5-3L turbocharged engine (VG/6G72/RB/1JZ/2JZ). Even my stock 1.8L CA18DET made 400+ for well over a year before being sold on. 2. 405bhp on 6 x 370cc injectors is perfectly fine with appropriate mapping. Increase engine efficiency to decrease fuel consumption, although at the point where a VG is producing 450bhp, fuel consumption is a moot point... Low load scenarios: Fuel consumption will be no different until you start with high-lift cams that require a richer AFR at idle & cruise. What does "on boost alone" mean? If you're genuinely looking to hit 450bhp as cheaply as possible, you'd be surprised what can be accomplished. You don't NEED larger injectors, for a start. You definitely don't need forged pistons. I'd be surprised if there's one VG30DETT in this country right now that actually requires aftermarket con rods.... Most importantly, 450bhp is not at the expense of sufficient reliability with a road car. Obviously if you're spending 99% of the time at WOT on track, then it's big rad, big injectors, big turbos, forged pistons, aftermarket EMS with decent knock control & individual cylinder mapping. For the average road car, however: Fully uprated exhaust system (elbows, downpipe decats, cat back, manifolds if cheap enough & engine is out). Dual intakes. 2.5" intercooler pipework from turbo outlet to throttle bodies, smooth bends & as short as possible. Think outside the box as far as IC placement is concerned. Most efficient intercooler(s) you can find. To help reduce the strain on the turbos, you want minimal pressure loss. To make the power, you need the coldest charge possible. Grade 8 spark plugs. If BSFC isn't reduced sufficiently with the above mods (all engines are different), then an adjustable fuel pressure regulator will give a bit of leeway with fuel delivery (3.5bar base fuel pressure = 400cc equivalent injectors, plus the fuel pump can cope at 1.5bar over atmosphere). You don't need to spend crazy money buying lots of parts to make power with the VG. What you do need to do is remove all the restrictions & compromises brought about by the factory installation/shoe-horning of Nissan's finest powerplant into the engine bay of a luxurious Grand Tourer. You don't hear RB26 owners talking about pistons & rods at a woeful 400bhp and RB #6 cyl ringlands are probably more susceptible to damage than VG #5 & 6 cyl ringlands. If an engine throws a rod, it's due to either a mechanical defect, component failure, poor build or bad mapping (piston melts, little end enjoys new-found freedom and shoots for the stars). Any idea what caused the 30k miler to go? Having said ALL this though, if you're actually going to the trouble of building/rebuilding an engine as opposed to just buying a second-hand one, you may as well build it with forged items to handle 600+ in the future, because all you need for 450bhp is a half-decent stock VG & bolt-ons.

Hello & welcome :) Pics!

How is the fueling & timing controlled?

Not on the 200sx, it's a (relatively) well-known cure for weeping seals on idle (Google "One Way Valve Trick"). Without having the car in front of me, it's difficult to say. The valves are between the front rocker outlet & the turbo intake piping, with the valves positioned to allow the engine to breath into the piping as stock, but not allow any air to flow the opposite direction? I can't see how it's resulted in what you're describing. I have mine vented to atmosphere, and if I put my fingers over the end of the pipes, it doesn't create a vacuum in the valve covers.

How come the dyno run was cut short at 4500 RPM?

Any half decent 10w40 semi will do the job unless you're tracking it. Don't use a 30 grade oil, it's too thin when up to temp for an old 90s Japanese turbocharged engine. The lower the first number the less viscous it is when cold.

1. Diagnostic check 2. Assuming code 55, determine which cylinder is the problem: 2a. Long screwdriver to listen to each injector firing. 2b. Remove coilpack connector one-by-one. A healthy cylinder with all components working will mean the engine drops on to 4. You'll find the problem cylinder when the engine note doesn't change. 3. Fix :)

Awesome looking Zed, but the eBay ad and forum thread (if seen in time) should have made anyone approach with extreme caution. Funnily enough, another recent thread made me think about this very Zed and I was actually watching it on eBay... Which "Apexi ECU" is it? SAFC II? If it's running one of those piggybacking the stock chip, the huge amount of smoke could be due to a cracked ringland on 5th or 6th as already mentioned in this thread. Compression test it first of all. The Mikalor-style hose clamps won't be helping keep the boost inside those pipes, either. If it was indeed "running over 400bhp at 13psi" (or 14psi in the later ad), then the turbos aren't stock. There is no mention of larger injectors. Stop booting it. It's not going to get any better ;) There's so much wrong with that paragraph I don't know where to begin. Sufice to say, the usual reason to abort a run at 4500 RPM is due to detonation or leaning out. A car that spins up on a dyno either has no tyres fitted, isn't strapped down properly or is running Herculean power levels. Find someone close by and get the fueling & timing/knock checked ASAP. Keep it off boost until you know what's going on. Good luck :thumbup1:

I love that pic!! Z32, GTiR & S13 all in the same pic. 3 of my favourite cars all in one sitting!

That's a shame. Fluke is one of my favourite books, along with Weaveworld by Clive Barker.

All the best :)

On mine, the best place to put a single sensor was the driver's side downpipe/decat, as this is the side that typically runs a bit leaner. You're still blind as to what the other side is doing though, so it does pay to check both sides now & again. With a sensor in the cross-over section, you're averaging two O2 readings, one slightly leaner than the other. It's the leaner one that is of interest. I think over in Australia they generally place a single sensor in the passenger-side as that is reported as being slightly leaner. Ideal solution is twin sensors, so you can monitor both banks independently. Same with everything Zed-related, two lots of everything. That's how my set up is going to be with the new exhaust system (finally getting rid of the stock cats :eek: ) The O2 reading doesn't change no matter how far the sensor is from the engine. It's only when using a tailpipe sniffer with large backboxes or if the probe doesn't reach far enough into the exhaust that you get very lean readings (on the gauge, not in reality) at idle.

HELL YEAH!! ....and the memories come flooding back! Me and a lot of friends had some amazing nights both here and at The Empire back in the late 90's / early noughties. We used to pile over from Whitby and stop over in Loftus/Boro/Guisborough/Redcar or wherever the party ended! Big Weekends back in the day, we'd have the tunes blasting in the car park and dance like goons afterwards! Best party nights of my life at Trees!

What, did you only drive it for half a day? :laugh: