thehelix112

Ben, Can you provide weights of any of these components? Seems like that'd be rather important information for anyone actually thinking of shelling out that sort of dough. Dave

My L28E computer at the moment is running ridiculously rich, so much so that when the car is warmed up it won't run. Current theory I have (from RTz over at hybridz) is that the water temp sensor is bogus so the car isn't backing off from its warmup enrichment mode. Other possibilities are that whatever it is that switches the ECU from cranking to post-start to warmup to running modes is broken. Stands to reason that if you can control or modify both of those things, you can replicate the same behaviour but have a good effect. Dave

Wow. Lots of good information here, lots of not so good information too. Modifying the front roll centre for a race-car is not necessarily bad, its just another tuning tool. NZeder is right in as much as changing only the front one alters the relationship between front and rear, again, another tuning tool. The downside of course is that its far more difficult to alter the rear roll centre so you become limited in what you should do with the front by the rear. Other thing that perhaps bears mentioning is that you may be limited in how much you can space the outer tie-rod end attachment to the steering arm by your wheels. I have 14" wheels on my zed in the states, and its awfully close: Also, I fail to see a reason why you can't use both the strut-spacers and adjust the inner LCA pivot. The spacers adjust where in the bump-steer curve the suspension travels, the inner LCA pivot alters the bump-steer curve. NZeder is on the money. Make something to test the bump-steer and test it. I need to, just haven't gotten around to it. Excited to see what I might find. Dave

Whats the point in arguing about something so subjective? Four wheel drifting to someone might be tight clean lines to someone else. Suffice to say the slip angle is likely to be > 0? Dave

BP7ES here. I've fouled a couple of sets with a less-than-ideal tune, but once tuned properly, go just fine. Dave

Just in case anyone was suspicious, I can vouch for 240hoke and his ZG flares (which I have seen first hand and fit nicely). Well known chap over at hybridz.org, and he does good work. Sah, Dave

Why would it be a pain in the arse? Its not absolutely nothing to do with how the car feels over bumps, thats handled by the springs/shocks. What it does have to do with is how the loads transmitted to the chassis affect it. Soggy chassis = soggy response. A stiff chassis is a good thing. OEMs go to massive lengths to get their chassis stiff, it improves everything about the car. Fewer squeaks from the body bending/flexing for example. Leave it. Whoever did it looks like they knew what they were doing. Or atleast knew that its a good idea to reinforce the sway bar mounts in the chassis rails. Dave

Fix it yourself? Its not that hard. Dave

Hey guys, Just missing home a lot right about now, so figured I'd post a little hello. Been in California since March last year, so its been since then that I've seen/worked on/driven my zed. Makes me very sad. I miss my car. Poor baby is sitting there awaiting new bearings. Note to all: if you're running a turbo, oil cooler, don't trust that the previous owner knew the difference between a L18 oil pump and a L28 turbo oil pump. Oh and check your oil before you go around a track Hehe. Anyway, I'm looking forward to coming home sometime in October, and first order of business is a quick rebuild, and a practise day. Hope to catch up with a few people there. The car isn't road registered anymore, so no cruises unforunately. Anyway, take it easy all. Dave

Haha.. if by `well set up' you mean `full blown race motor thats completely and utterly undrivable on the street'. Or do you have proof of such an engine with usable torque from street rpm? If so, I'd love to see it. Deus Ex, I say go for it. The L28ET is a stout little engine as long as you take care of it. That means a good fuel system, and good fuel/spark control: don't skimp on these things or you can be sure its a question of when, not if, they screw up and take your engine with them. Dave

When compression testing there is no point cranking the engine will all the plugs in. You're just making the starter work harder. Additionally, if you have a blown gasket between two cylinders it won't show up as well with the plugs in. 1. Take all the plugs out. 2. Disconnect dizzy cap. 3. Sit someone in the car and tell them to hold the throttle WOT and crank. 4. Count the number of compression strokes (you can hear them) and make sure you crank it for the same number across cylinders. While the plugs are out its a great time to inspect them and see how your engine is running in general. Guide here: http://www.nightrider.com/biketech/spkplghnbook.htm#We Ideally you want the insulator to be a light golden brown I believe. As for Z's having `grunt', I can't say that has been my experience. They are a small displacement inline 6 based on a 50yo design, you can't expect too much out of them. Dave

And that function (flat-shift) can easily be added to most aftermarket ECUs. Then you are only loosing the time it takes to add that small sideways component to the 2-3 and 4-5 changes. Is that time, measured in milliseconds, worth AUD1250 to you? Not me. Dave

Interesting. But thats a lot of money for not much gain. Does have high blink/wank factor though. Dave

http://www.amazon.com/How-Restore-Your-Datsun-Z-Car/dp/1931128022 For the lazy. Dave

OK, first let me apologise for coming across agro, my bad, no excuse for it. What I would like to convey is that a street, even a good, quick street setup, will never be particularly good on a track. Everything is just too different. The conditions on the street are much more varied and incomparable with a race track. The street has holes, race tracks don't (or shouldn't!); street tyres are designed to last, racing tyres are not; street tyres cannot produce anywhere NEAR the loads on the suspension that racing tyres can; race cars do not putter around slowly, thus their dampers are valved differently than street cars. On a race track you get rewarded the more lateral grip you have (little/no point going around a track with proper street tyres IMHO), you will never get anywhere near using this grip on the street (and if you do, you're being damn dangerous and will wind up flat). Its just not possible to have a race car that drives well on the street, nor is it possible to have a street car that is as fast as possible on a race track. You have to pick one or the other. Dave

Tim, The bellhousing I used was what was already on the car, a 280ZX 5-speed.

I am running a S14 SR20 box. Not sure what makes you think its a difficult conversion blue_leaf. As lurch says, all very simple stuff. The advantage to the later `C' boxes is the gear width, selector `beefiness', and shift feel. I am by no means a gearbox expert, but I don't really see the downside to using a newer, stronger, nicer gearbox? Dave

Does't exist. If its a legal street car, its slow and will get its arse handed to it by any well-setup dedicated track car. Remember the video of two old OLD AE86s handing a BNR34 its anus on a track inside 3 laps? Case in point. You say you don't care about ride quality, but `want the car to be able to be driven over the bumps'. You can't have both. Also, it confuses the issue immensely if people just say `Tokico' and `Koni'.. What Tokicos? What Konis? I do believe both companies make more than one damper. And if you give me a friggin colour it confuses me even more. Koni have specific numbers indicating the series of shocks they produce, I don't see the need to revert to the colour they paint the insert. </rant> Take Matt's advice. Get reasonable street rate shocks, as good a shocks (with as must adjustability as you can tune/afford (8610 double simul adj, 8611 double indep adj), and learn to drive. The car maketh not the fast lap times. Dave Dave

Sulio, To be honest, IMHO there is no point doing something half-assed. Either completely strip it and build it up from scratch and know what you've got, or throw some bearings at it and be done. Oh and as far as checking the bores for roundness/taper, you probably want a machine shop to do this, unless you're willing to invest in the guages required. Note, buy a cheap piece of crap gauge, and guess what sort of engine build you will end up with? Dave

Tis an excellent point Sulio, and highlights the fact that the engine (and the car) is a system. You can't change one thing without it having an impact on something else. And as such, everything should (needs!) to be designed to work together. Dave

Seems to me that the main goal for any race car is to get it as light as is possible. If you're particularly attached to a Z31, then thats that. But if you're not, there are plenty of other cars (coughS30cough) that are lighter to start with, and better equipped to run an inline 6. Dave

Ah.. now this is where things start to get complimacated. You have to match the port size with the cam in this respect. The larger the port the more revs will be required to produce intake flow at an ideal velocity. By ideal I mean within the range that will make appropriate use of the air's inertia. I am still learning as much as I can about cams and cylinder head flow, so the rest of this will be conjecture. Obviously, assuming that a port is so big that it isn't being made best use of until a certain RPM range, it is also necessary to have valve timing that facilitates maximum flow in the same range. Atleast, this is how I understand it at the moment. I'm sure its a simplistic view, and disregards a lot of important factors. Hence the signature. Dave

Lets clarify, when you talk about triples, you are really talking about three dual-barrel carbs/throttle-bodies/inlet tracts. Thus you have an individual throttle body for each intake port. This HAS to flow better than a standard SU-based manifold where one port feeds three cylinders and the manifold splits off. Imagine the air on its way in. With an ITB setup (triple webbers for example), the air goes into the trumpet, past the butterfly, then it sees the valve, and voila in the chamber. With a factory setup, air goes in the trumpet, past the butterfly, then sees a triple fork in the road. So the air slams into this fork, and spills off to the sides, now all disrupted and slowed down. The path through an ITB system is much cleaner, and will provide much less of a restriction to flow. This is of the utmost importance to N/A engines as the amount of air you get in the chamber is determined by the pressure difference between atmosphere, and the vacuum generated by the piston's descent during the intake stroke (and valve timing/lift of course). For forced induction cars, we have control over this pressure differential, and can literally force more air in almost at will. The downside is that the more boost, the hotter the air, so we get to a point where the pressure differential is outweighed by the reducution in charge density from increased temperature. I don't want to proof read that because it'll be dribble, but I hope that makes atleast <some> sense. Dave

I don't have time to respond to all of this, or to write an essay on head flow (which would be entirely theoretical and supposition anyway), but I believe the reason why you have rough walls, is to prevent boundary layer separation. If the wall is completely smooth the boundary layer just gets bigger and bigger and bigger and bigger until it separates, and you end up with slow turbulent boundary layer flow near the walls. So you make it rough so you continually break up the boundary flow, creating indents of dead-flow as zedevan says, and it never gets the chance to become separated and turbulent. Dave