Afshin

Here are a few thoughts, if it’s running lean and missing, that it is less likely to be ignition related as poor ignition more often results in poor combustion and rich mixture. If it’s lean at low RPM and not high load, then it should not be fuel delivery, so fuel pump, injectors and pressure are likely OK. For low load lean mixture I think the likely players are faulty AFM or poor connector/wire. I know you checked the AFM per the manual, but that method may not be sensitive enough to pick up poor signal for part of the operating range. I would certainly go to the junkyard a get a cheap used AFM and see if it changes anything. Plugging and unplugging the connector and cleaning them can fix such gremlins quite often, but you probably have already tried that and it seems that you replaced the harness. Was this problem present before and after replacing the harness? I strongly recommend using a connector cleaner, if you have not used any since the problem started. If the problem persists, I would then pick up another distributor from the junkyard and see if it changes anything. This would not be my first guess, as you tested the distributor as well and it is running lean and not just misfiring, but you can never tell and you are somewhat stuck and you have gone thru all the basics. BTW is this truly RPM dependent or is it load dependent? Does the RPM at which it happens change when accelerating in first or second gear vs 5th on the highway? Does it do this when revving the car in neutral? Are you sure it is running lean and if so does it run lean first and then miss or is it simultaneous? Lastly at what point do the SDS additional injectors start kicking in?

I also thought he was overly harsh. Center Force clutches can do a nice job of providing extra clamping with stock pedal feel and work well for moderate increase in power (~13 psi), at least for people who don’t drag race. The front strut bar is a great addition! While the rear bar has less effect with the ZX rear set up, I imagine that by virtue of tying the two strut towers together, you probably get some benefit related to overall chassis stiffening. Definitely agree with the recommendation for adding rear toe/camber adjustability. You have gotten so much done with your car since. BTW, very nice choice/list of goodies. So where do you park car Are you driving it now or is it on stands? I’d love to hear about the power delivery and what made the most difference……..

Yeah , the whole accident was surreal. The details of it are so out there that I often don't tell people, as it sounds too much like a plot from a cheap B rated TV flick. I'm just glad that I have recovered from the injuries. As you figured out it Alex, had to be someone else at ZONC, too far for me to drive. BTW keeping my fingers crossed that you get the rotary conversion done and running this summer. It should be wild! And yes John, I certainly have the same 280ZXT. I got a new T3/T4 50e stage 3 from James Thaggard recently which certainly helped the top end (my last t3t4 had the stock turbine). Welded myself a full 3" downpipe (ugly as hell, but functional) Got an non-webbed intake manifold and slightly ported it, ceramic coated....(looks sooo much cleaner). I also switched to a SDS system a while back for on the fly programming. LSD, R compound tires (what a difference!) Got Sparco seats as my last cool but cheap seats were starting to bend and other little stuff here and there.... I also got a progressive water/alcohol injection unit, but have yet to install it. (Bernard is going to laugh seeing this as I have been shelfing it for a while after he successfully pushed me into buying it). It'll be in soon and should undoubtedly provide for some entertainment, hopefully the drivetrain will hold.

Hi guys, Unfortunately, before moving from CA in 2005 to go to the east coast, I was involved in a pretty bad accident. I was a passenger in a cab, whose driver seemingly had a heart attack, while driving. Long story short, we crashed hard, cab caught on fire and burnt to a crisp, driver died and I was in a shock trauma unit with a broken back (cast for two months) and tore every ligament in my left ankle resulting in a dangling foot. Fortunately, I was able to open the door and crawl out of the car avoiding getting burned. More good news is that I did not sustain any nerve damage and hence am back to normal (that is as much as I ever was). So, after the event I was away for a year and without my Z. Forgoing the details of my withdrawal symptoms, I also dropped out of the forum. Now, to bring this mini-saga to a more Hollywood like happy ending, I am indeed in Maryland and have further modified the Z which has been back on the road for a month now, stronger than ever and getting tuned for the Shenandoah and Summit point circuits. So, it was perfect timing and very nice to see this post!! As most of you know oh too well, once a junkie…

Well I have been away and off the board for the last year. I moved from San Francisco and will be settling in Maryland. I have been in NJ for the last few weeks and will try to make it on Sunday. Joe/rags, are you definitely coming?

Using a 300ZX harness is probably better than using a 280ZX-T harness since the connectors to the ECU are so often faulty on the older harnesses (however, it does not fit in nearly as nicely because of the different ECU location and V6 configuration, so it is harder to put in). A few others have used the 300ZX harness with good success. Of note, several people have fixed unrelenting “gremlins†and intermittent problems in their EFI systems after soldering 300ZX ECU connector in place of the 280Z and ZX’s ones. The reason I converted the 280ZX-T harness is that it was already in my car, hence it was considerably easier to swap by changing a few wires around and convert it to run with the 300ZX ECU and MAF.

280ZX in competition (practice vs. theory): 1979 Newman wins summit point then another 6 out of 8 races and then won national championship at Road Atlanta and breaks track record, including that of the Sharp Z. Logan Blackburn was second in another ZX and Leitsinger got 3rd place, showing a clear dominance of the ZX. The Sharp prepared 280ZX breaks the Sharp prepared Z record, hehe (not that I have any biases . Newman takes overall win for C-production class that year. 1979 Devendorf wins 9 of 13 races and gets IMSA GTU championship 1979 Posey wins several IMSA races, including Lime rock 1982 Electramotive turbo competes in GTO class against the mighty BMW M1 and Porsche RSRs and won 6 of 10 races to take the overall title. 1982 Sanches takes overall showroom stock A class 1983 Hendricks takes overall showroom stock A class 1983 Sanches takes showroom stock GT class with 280zx turbo 1983 Kawahara wins RAC rally privateer’s prize 1983 Newmann wins several individual GT1 races 1983 Devendorf/Adamowicz win 4 consecutive GTO wins 1984 Hendricks takes overall showroom stock A class, again 1984 Clement wins SCCA GT2 class 1987 Clement wins SCCA GT2 class, again (There are many other individual wins and track records that I have not summarized) Some benefits of 280ZX platform: Significantly stiffer chassis (which in my opinion makes more of a difference than the benefits of rear strut vs. semi-trailing arm design. But then it does add weight), engine further back in bay resulting in perfect 50:50 weight distribution, wider track, and much better aerodynamics. Personally, along with Dr. Ferdinand Porsche, while not my favorite design, I have no serious problems with semi-trailing arms. On or off the track.

ROFL I just broke out in a laugh while I was pretending to work, you guys are killing me here.

You can also have them weld 2 pre-purchased 45 degree mandrel bends (will need several other pieces to be sectioned/welded for the final product). That way a good shop without a mandrel bender (which is rare in many areas) can make one for you.

The hardest thing for having one made for you at a local shop or by yourself pertains to making the turbo flange from which the 2.5" pipe can be welded to. I got a very nice pre-made flange from GrayZee on this site (very well priced). You can PM him and see if he can get you one (he might even be able to get you a complete downpipe as well, cheaper than MSA, but I'm not sure, just check with him). It will make it a lot easier (and much cheaper) to go to a good local muffler shop with the flange at hand than to have them make one, if they even will.

Most of your gain is going to be in the 45 angle replacing the stock 90 degree angle. I had read the 2.5" with 45 degree bend will flow better than 3" with 90 degree bend. So the 2.5" 45 degree should make a huge difference and be more than enough, as already stated. Perhaps the effort of 3" may prove useful on a ZX were the 90 degree bend is still present in the downpipe, as it will flow less than the 2.5" in the Z.

I'm using the same one as sleeperZ. Just replaced my flowmaster with it. It flows much better (gained 1 psi boost without touching anything else). And it is indeed quieter, which I initally found hard to believe when others said the same.

Sounds great! Can't wait to see the issue. I think the magazine has been expanding nicely over the years and that your coverage of all the Z models is commendable. I always look forward to technical articles and would enjoy seeing more of them. A nice comprehensive and detailed brake article will be enjoyed by any sports car enthusiast. BTW there is no way I would let my subscription lapse.

Thanks for the info guys. Jon I really like the weight equivalency estimation/rule of thumb and the subjective part is just as helpful. John are you referring to this article: http://www.grmotorsports.com/archives/results.php?ie=UTF-8&oe=UTF-8&q=wheel+weight&btnG=Google+Search&domains=www.grmotorsports.com&sitesearch=www.grmotorsports.com I get GRM at home and have seen this one, the article describes wheels manufacturing nicely and says as i have seen over and over that lighter wheels are significantly "better", but again give me no feel about what they mean by "better". Significantly better mostly for competition and pro. drivers (e.g. you) or also significantly better for an amateur enthusiast/weekend warrior (e.g. me). Like I said, just trying to get some idea (in other words where on my priority/wish list to put "expensive lighter wheels"). John, do have any personal experience with this that you could share?

Nice to see the two runs with the AFRs, very informative. I'd love to see the second dyno run when you play with the timming. Also curious, what octane were you using for the high boost runs?

Regarding this topic, I have searched in various places and could not get any rough estimation in numbers or feel related to how much performance is gained by going with lighter wheels. For example, my wheels (without tires) are about 21lbs, how noticable would the performance gains be by going with 15-16lbs wheels? I know there is no direct answer and it depends on set up, use ...but I just have no idea if I could tell the difference on the track (smooth surface), street (non smooth surface) in terms of handling,braking... Any experience objective or subjective would be helpful. And no, I'm not willing to put on the 80lbs wheel set up on my Z and experience the difference first hand

The SRF is a silicone ester based fluid, which is different than the regular silicone fluid. It is much better and will not result in problem when mixed with regular glycol based fluid. I would however not mix the two fluids together such as topping the SRF on regular dot 4 (a regular flush should do). I think that the SRF while being arguably the best fluid, may not be worth the extra cost (your pads may fail from the heat before the ATE fluid does...). I would spend the extra money on better pads and upkeep of the brake system. Also, regular flushing of the brake system will do more for you than getting SRF fluid. Lastly, I don't think that the SRF should cause problems with non-absorbed water build up and corrosion.

mine idles best at about13:1. idles poorly at 14:1

Here is a very long summary about brake fluid from my files that I had posted a while back: DOT 3,4 and 5.1 fluid are all glycol based and generally compatible. However one may offset the benefit of the better fluid if mixing it with lower grade, so it’s always better to flush the whole system with the newer fluid. Also some are more different than others despite the same DOT rating, ie synthetic, different viscosities and different amount of hygroscopic (water absorbing) properties causing them to absorb brake system moisture, and over time the boiling point is gradually reduced. The Dry Boiling Point is the temperature at which a brake fluid will boil when new in its non-contaminated state and the wet boiling Point is the temperature a brake fluid will boil after it has been fully saturated with moisture. The requirement for wet boiling point minimum is 284F for DOT 3, 311F for DOT 4 and 356F for DOT 5.1. These numbers are the minimum and many of the better brands far exceed the minimum requirement (e.g. castrol SRF has wet boiling of 518F, dry boiling of 590F). Difference between Dot 4 and 5.1: DOT 5.1, albeit confusing in designation, is effectively a lighter viscosity synthetic poly glycol fluid with DOT 4 performance parameters. It was developed for use in mechanical ABS systems that require a higher cyclic rate to better deal with pulsations. It is not a “higher “performing fluid. DOT 5 is a silicone based synthetic fluid originally designed for use in military and government vehicles where regular maintenance could be problematic. It is non corrosive and is marketed as a “lifetime†fluid often used to preserve brake systems in antique vehicles and those that sit for long periods of time between use. It was never intended for high performance application. DOT 5 fluid is not hygroscopic, so it does not absorb water and may be useful where water absorption is a problem as one of the reason for its development (military equipment and tropical environment..). However and perhaps ironically this brings up another serious concern as moisture enters the system (can not be prevented), it is not absorbed by the fluid, and can result in moisture collecting in the calipers which can very easily boil causing vapor lock and system failure or can cause corrosion where the water collect (it has to collect somewhere since it is not absorbed). DOT 5 fluid is now most used/best suited for show car applications where its anti-corrosion and paint friendly characteristics (does nor ruin paint) are important. DOT 5 is not compatible and can not be mixed with other fluids since it can result in slugging. I think previously some race teams used to use DOT 5 it because of it’s higher boiling point, however the new poly-glycol synthetic fluid have the same or even better boiling point along with better pedal feel (dot 5 is more compressible and has spongier pedal feel) so DOT 5 has fallen out of favor. Personal recommendations: DOT 3 is outdated and not suited for aggressively driven cars, dot 5 is problematic and should be avoided. DOT 5.1 is good and best suited for ABS systems which leave us with dot 4. -Castrol SRF. amazing fluid, (wet/dry 518/590F) very low hygroscopic affinity (does not absorb much water) and the highest boiling points, and the most expensive by far (actually it is a silicon ester not a glycol based fluid, but it is not the same as the dot 5 plain silicon which can't be contaminated with glycol based fluid) -Castrol LMA. (LMA=low moisture affinity) cheap, available at most stores, not race fluid but very good as low maintenance and high performing fluid and is actually suitable for most aggressive street applications and can still handle occasional track days with vented rotors.. (wet/dry boiling 325/490) -Motul 600 one of the best race fluid(based on wet/dry boiling point of 421/585F) along with Neo (identical) but is also very well priced, can be used for daily street/track cars. Does absorb more water (more, but not extremely hygroscopic like most race fluids which need to be changed very very frequently).Great choice if car goes to track often, if you don't leave fluid in over 8-12 months and if live in a dryer climate. -Ate type 200 also known as super blue and super gold (wet/dry of 392/536F). Outstanding fluid good for race and street, can last for two years (not racing off course). This fluid is possibly the best for aggressive street as well as track use type of car/driver. It is also cheap, best found online, has a wet boiling point of 100F greater than the Ford HD or AP 550 fluids (AP 5.1 matches the Ate but is much more expensive) and works well on the track for me. Also with the different colors for this fluid (blue and gold), when flushing your system you can tell when the new fluid comes in by the color. One last point, while technically the different non DOT 5 fluids are all compatible, it is not advisable to mix them since people have reported poor performance, spongy pedal feels and so on when doing so. It is best to flush the system when upgrading to a better and new fluid.

Yup, I got one of those kits a few years ago (kragen now has some cheap ones I believe). Works great!

I personally think this was long overdue. While I greatly enjoy political debates, I also think that certain things have there own place. The site is called HybridZ, which for me is a place to unwind and discuss tech or fun issues related to our common hobby and escape from the more stressful aspects of life (virtual sanctuary). There are other sites for political debates and there are much better political news sources than HybridZ. I think we should stick to what we do best on this site. I vote to keep the “realities†of everyone’s political and religious perspectives/biases separate from this nice technically oriented and fun Z site.

I run about 20% quality antifreeze (e.g., toyota) with redline waterwetter and distilled water (to avoid build up of mineral deposits in the cooling system, which decreases thermal conductivity/heat loss). I feel that with this combination I get both good anticorrosive and cooling properties in my coolant. Another potentially important thing that is too often missed is to use an actual Nissan thermostat. The reason I say that is that MOST of the aftermarket thermostats have a smaller opening for the coolant path, and hence flow LESS coolant. IMO the Nissan or equivalent thermostat is a must (there might be a aftermarket one that has the same diameter opening, I have not seen one, regardless the nissan one is cheap). The difference in diameter in often quite striking!! Also, what size fan are you running?

Bernard, I think your torque converter not locking until 4000RPM has a lot to do with it. I imagine the peak torque to be around 4500 rpm . I would not be surprised if the current dyno graphs more so reflects boost build up with max boost coming on at about 4800-5000rpm. Also, it is not uncommon for a dyno to be off by huge margins, specially if it has not been calibrated.... Also, looking at the graphs, I don't think that the main culprit is restriction (However, you should get ride of the 2" piping, at least with 20psi of boost). You have too much power in the higher rpms and climbing hp as well, I would expect the hp t be falling off much sooner with any major air restriction. I would not trust that dyno run sheet for anything! Also sleeperZ, I was just thinking about the correction factor for the dyno run you had, if it was the standard correction factor for a non-turbo car, it could be significantly off, since NA cars lose much more power with altitude (they can't pressurize the air and make up for lack of barometric pressure and hence air density at altitude).

Sean, I sent you a map, let me know if you don't get it. I will be redoing the timming when I get to the East coast and can put real non-CA gas in it.

I would definitely get the tokicos over the KYB (I use KYB's for the family car).