thehelix112

I wouldn't be putting the wheels out much more than stock. The ZG flares are only ~3" high remember. You are almost certainly going to have more travel than this and if you have the tyre flush with the very edge of the flare it will slam into the guard. Either that or get the wide wheels so you can say you have them, then stretch the crap out of your tyres to clear the guards, and go slower than someone with no flares and correctly sized wheels/tyres. Dave

Cool. I think a cam'd throttle (if thats the correct term ) and throttle-dependent boost limit would help improve the drivability of a lot of turbo cars. Both on the list of future mods for mine. Dave

Justin, Surely that assumes linear throttle application. In modern systems, such as drive-by-wire T/Bs, and even cable throttles, its definitely possible to have non-ilnear actuation and the best of both worlds? E.g, if the circular track that the cable pulls on to open the T/B is an outward spiral then I think(!) you end up with an appropriate actuation. The amount the T/B is open O (in degrees) is given by: Let x be the movement of the cable. Let r be the instantaneous radius of the arm acting on the butterfly rod. O = 180 * x / pi * r Just made that up. Probably incorrect. Dave

Hey, Thanks for the compliments. Everything is bolted to the floor (via rubber isolaters of course). I also have the power to the battery feeding in from above through the floor. The 044's terminals are on the top, whilst you can see the lift pump's in the pic I posted (not hooked up yet). I relocated the battery to the boot (as it sat where my turbo now sits), and each pump has its own relay taking its feed directly from the battery. I seem to remember hearing/reading something about a pump's flow ability dropping of markedly with reduction in voltage and didn't wanna toast my engine because of a crappy wire. Good luck, Dave

Just to reiterate(elaborate?) on point number 2 there Paul, the ways to maximise velocity is to keep the inlet tract as follows: 1. As short as possible. 2. As straight as possible. 3. As close to a gradually decreasing (slight X? degree taper) ID as possible. 4. Just as with inlet ports, keep the inside of any pipes the air flows through relatively rough. This is to prevent boundary layer build-up leading to separation. This will allow you to make best use of whatever pressure differential you have. Be it the vacuum generated by the piston's descent below atmosphere, or the vacuum below the boost pressure generated by a turbo. Either way it spells more air in the chamber, with better mixing, which means more power for you. Dave

Oh I missed that point, I am not sure why you need the EFI pump to be under the surge tank. Its the lift pumps job to keep the surge tank full and hence the EFI pump supplied with fuel, not gravity. On my setup I have never seen any fluctuation in fuel pressure (which is set at 60psi base). Dave

I put mine just in front of the fuel tank. I fit a fuel filter, Bosch 044, a Carter lift pump and a ~1/2 gal surge tank under there. Snizen tight and a total bastard to do up that last nut.. Dave

Wow. Now I wanna see it go around their test track and do better than the swedes. Dave

When you say a 78, is that an S30 or an S130? If its an S30, I am interested in the bare struts (all four). By that I mean just the strut/stub axle assembly. No brakes, discs, hubs, springs, shocks. Thanks, Dave

Could be that when you rebuilt it you tested it before the rings had seated properly. Could be the last time you tested it you didn't have the throttle open and this time you did. Could be the head gasket that was replaced has a smaller crush thickness, though I kinda doubt that. Dave

Interesting question BRAAP. I must admit, I am running a 65mm throttle body, and won't be going bigger anytime soon as I get 95% power at 50% throttle. I think there are other considerations to be made though. For instance, if the inlet to your plenum is 90mm, a 90mm T/B would allow you to provide minimal disruption to the flow as it enters the plenum, whilst keeping the T/B as close to the plenum as possible (hence improving throttle response). I agree throttle response will suffer with a larger t/b, all other things being equal, assuming you still have linear throttle actuation. I am sure there is an art to tuning t/b actuation, but I'm also sure its possible. If one is prepared to do this, I think the ideal T/B size is one that already exists in your inlet tract, preferably as close to the plenum (in single T/B) or head (ITB) as possible. For example, if you have 3" intercooler piping, and a 4" ID cylindrical plenum, a T/B anywhere between those two, placed as close to the plenum as possible, but not requiring a sharp change in diameter, would provide minimal flow restriction. However, having 2.5" intercooler piping, and a stock L28ET inlet manifold, with a 90mm throttle body, well, yes that falls into the milo-tin exhaust category. I know some fool with 2.5" piping, and a T/B the flares from 3" at its opening down to 2.5" at the exit, feeding into a stock L28E manifold. (Yes, that I DO plan on upgrading). Dave

Although from Australia, I will put my nationalism aside to say that I would be wary of any manifold that has more attention paid to the outside, than the inside. Hope it holds up for you ok. Dave

If you're young as you say, my advice would be to spend the money on suspension, brakes and wheels/tyres. Will be great fun to drive, and you'll learn a lot in the process. Dave

Tis indeed. Dave

Tony, I did indeed read all the articles from the link you posted, but alas, didn't see anything pertaining to siamesed bores, nor posting, which are the two things I have questions on. I thank you for answering my questions about liners, and for the link. I have learnt a lot. The transferrence you are talking about is my point about how the siamese joins would be affected by the installation of wet liners. I realise the joins are in the non-thrust direction, which is exactly my point. As I am picturing it, the only place the joins are connected to are the bores. Ie, they are horizontal tabs if you like that just connect one bore to another. Now lets say you grind all the original bore out to install a wet liner, what do you have at the join? You just have a little tab hanging in space. Then you fit the liner, and go to grind the original bore out from the other side, at this point our little tab is only connected to the material you are grinding out, and as soon as that material has gone, it is no longer connected and drops to the floor? Thats how I am picturing it, am I wrong? If that is the case, I don't want to fit wet liners, as I can see the benefit of having siameses bores (in terms of block rigidity), however small. That then leaves me with F54 bores, with dry liners if I choose to. Ideally I would like to be able to run around 88mm bore, for its benefit in terms of valve deshrouding. Which leads me to posting. 88mm, including liners, is getting the F54 walls a tad thin. So how can I improve it? Posts. I don't know much about them but they seem logical? Dave

Tony, Just to clarify, I am not interested in maximising displacement, I am interested in maximising block strength. From some other readings I have done (on the net, and often 3rd/4th/5th etc hand information), it would appear that the siamesed bores in the F54 where specifically placed to improve block rigidity. In the case that you install wet liners, what are these bore braces then attaching to? Wouldn't they just fall out? If so, in terms of block rigidity, it would seem optimial to leave as much of the F54 block intact (people talk about keeping the overbore no higher than 1mm). I assume that the siamese bores provide some longitudinal force transfer, which can also be added using posting? Does anyone have any information on posting the L bores? Linered or not. Dave

That and the flow was measured at .600 lift, and at 3" water above the `standard' 25. What was the valve lift your 225 was recorded at 1fastz? Dave

Tony, Ok. So your `one reason or another' in this case is `support expected load'? If the liners are purely there to reduce wear, the exactly what are they supporting? I can't see how linering a block makes the block any more capable of supporting more lateral piston thrust. I can see how, if linering with harder materials, it could make it more wear resistant. In fact, I can only see how linering makes the block LESS capable of resisting thrust forces, as the liner itself is not tied into the block at all, so you are simply removing material that distributes the thrust forces. Also, how does posting come into play on the L28 (F54 specifically). Obviously, if the thrust forces are greater on the power stroke, then posting becomes more important on the manifold side of the engine (the side the power-stroke thrust forces are applied to correct?). I recall the bloke who welded the crank and bored out a touch to make the L34 said he posted the block. Is this a common procedure in racing engines? I am mostly concerned about block rigidity on my engine above all else. If posting is going to improve that, and it would seem to(?), then that sounds like a good idea to me. But then why isn't it common practise amongst severly overbored L-engine builders? Or is it? Dave

Tony, Interesting. I am talking specifically about 280ZForce's old block (he has sourced a replacement and donated his existing F54 to me). Check this pics in his thread http://forums.hybridz.org/showthread.php?t=119614 such as this one: showing the liners from the top And this one, kinda showing the liners from the bottom I have another F54 block in Australia, that doesn't appear to have liners. I just recently found out the F54 block came to Australia in the Nissan Patrol, so assumed that the patrol version was different to the US/JDM F54. Do you have pics of US L28ET F54 blocks that are not linered? Or are you saying over the course of the life of Justin's block each individual cylinder failed independently? Dave

Hmmm.. i don't think so. Turbocharged engines don't see that much more cylinder pressure. They see slightly more pressure, but for longer (more charge to burn). And forgive me if I'm wrong, some basic engine knowledge lacking, but a piston skirt should never rub on the bore. It should be held in place by the rings? Dave

Forgive me, but I'm not seeing the connection? Is this because the pressure goes down those holes that exist in some pistons which apply pressure to the rings (and hence bore) to improve seal? Dave

Good info, but it begs the question: Why would a turbocharged engine have more wear on its bores? Dave

Hey guys, I freely admit I know very little about cylinder liners. I think I understand what they are, and where they are well enough. But what I don't understand is WHY they are there? Ie, why did Nissan see fit to equip the L28ET F54 block with cylinder liners, but apparently few other blocks? What advantage do cylinder liners give? It appears to me that they simply reduce the amount of metal that is actually holding the bores straight as opposed to a non-linered block? Phred/katman/johnc/et. al? Dave

I have a 3.54:1 locked R180 in my car. Its not that bad to drive, though mine has a habit of loosening the nuts that hold the diff cover to the moustache bar. When they're loose its a total dog as you'd expect, when they're tight.. well carparks are no fun, but everything else is. Dave

You WANT a rising rate of 1:1. That means that as you increase boost, the regulator increases fuel pressure so the injector sees a constant pressure differential between in and out, and its spray pattern is consistent. It seems that higher than 1:1 is for dodgey people who are too lazy/cheap to invest in the ability to tune their engine. Or I could be wrong...? Dave