Afshin

No, pin 16 out of the Z31 ecu feeds a negative signal to the air regulator just as pin 108 on the Z ecu sent a negative signal. Also someone asked if you could feel an immediate gain in HP with this set up. Well you do feel some gain in HP (my guess is only about 15 peak HP), but most notable is the greatly improved throttle response and broader power band, so the car runs much better and the power comes on sooner and runs significantly faster than 15 peak HP would suggest. You also get much better metering of air under higher boost to about 12-13 psi where the Z31 MAF maxes out (it happens much sooner with the AFM). Lastly gas mileage improves by a good 3mpg (others had the same experience), that's until you turn up the boost again because the car is running better Good luck with the swaps (it's quite easy to do once you look at the original EFI diagrams and follow/highlight the few wires that need to be switched).

Ahhh! thanks for the great info zxtman. Great to know that the x-member needs only to be loosened and partially dropped. I'm sure this info will save others from going thru Yasin's experience (and many others).

The x-member on the 280zx sits closer to the engine, so you can't get enough clearance. So I guess either x member needs to be dropped or tranny taken out. This is such an unsatisfying and pain in the a$$ job(can almost hear Yasin cursing in the background). Well yasin I hope is start going a little smoother for the next part. Keep us posted

On my ZXT, even after unbolting the motor mounts and jacking the engine up until the tranny hit the top of the tranny tunnel, I was not able to slide the pan out, so I had to clear the old gasket and put a new one in with the pan only a few inches down from the block (it was somewhat of a pain in the a$$).

Yes, however, if you ever decide to go with a 88-89 ecu you will then need the dropping resistors (the 88-89 ecu is set up for high impedance injectors) yes, cruise uses a speed signal, look at your 81 wiring diagram and see if a speed signal is going to the 33 pin on the ecu, if so follow the write up and the burn cycle should be taken care of by the new ecu. No, it's identical to the 84 unit. However if you want to use larger injectors you need to reprogram it. My 84 set up was working quite nicely, but wanting more as usual I then got a 88 ecu which Bernard reprogramed for larger 370cc injectors and more aggressive timing at low boost. Needless to say, the car has gotten quite fast My experience with Bernard has been absolutely great, and much cheaper than JWT. He is also working on some other features which I will try in the near futur which should make an excellent set up even better.

Great idea Drax.

Wow! looks pretty nice, good price as well.

Actually compression of springs does not change weight transfer. A car with solid rods vs springs experiences the same amount of weight transfer in a turn, acceleration or deceleration. For example, a shopping cart with no springs still experiences weight transfer when you push it around (items in the cart move around and wheels will lift off in fast turn, rapid stop....). Stabilizer bars for example do not change weight transfer in turns, then only minimize role which minimizes camber change in the turn which might then improve handling but keeping an optimal contact patch. They also improve transition time helping rapid maneuvers.. So various springs will not affect weight transfer in the drag car or the front end getting light, however I imagine it might affect time since some of the initial torque will be used to compress the car down instead of launching forward (again improved transition time with stiffer set up)..

You only need to take of the SVO original pintle caps off and then they fit into the intake without any other modification. you can also put nissan/toyota style pintle caps back on (injector works without the pintle caps, but need to be careful not to damage the injector nozzle) which fit into the manifold (same as the pintle caps on the original Z injectors). The only other mod is to shave (dremel) the plastic section of the O ring base on the SVO injectors and then slide a fuel hose over it and clamp it. the whole thing took me half a day. Pretty easy to do.

That bracket looks amazing

It should make no difference if you have the force applied thru a set of four or two sets of four studs. the torque applied to each set of studs is constant, which means you are exactlyas likely to snap a stud with 1000hp with or without a spacer. In another words each set of studs (original and spacer) are independent of each other, do not change the torque applied to each other and do not weaken the system, regardless of power.

Please do a search first, this topic has been brough up many times and is currently being discussed in the turbo section.

How to kill a Z06 on the cheap ? Come on guys, it's a piece of cake, pick out of the following: 1) a little sugar in the gas tank 2) grease up the tires 3) banana in the tailpipe (wedge in a dozen or so) 4) shot gun 5) stick of dynamite....

the msd unit works quite well in that it truly offers miltiple sparks at low rpm and much stronger spark thru out. they seem to be very durable as well. The higher the boost, the more useful the unit. When I installed mine the idle did get a little smoother. but if car is idling rough there could be another problem. Either way, I think it's a good investment, specially if you turn the boost up. So Jeff, you are running a gap of 0.025 wow, that's quite small, last time I tried a small gap it did not do too well. Maybee I will try 0.030 again (perhaps it was not the smaller gap) since my car sometimes boggs down at high boost. Off course I'm running much less boost than you are (15psi vs you're 23 psi or so

Definitely not the case, the AFM flap opens in response to more air being sucked in the engine. so if anything there is lag between the throttle plate opening first (you pressing on the accelerator), then the AFM flap opening in response to greater air flow. Check the AFM flap and make sure that it opens and closes smoothly, if it binds, it could cause erratic fuel mixture. Also if not already done in the last few weeks, unplug and spray ALL connectors to the ecu and afm. no harm in checking fuel pressure and all vacuum lines (you probably already have)... You can just unplug the knock sensor and see if it changes anything. the car runs perfect without it (it does nothing until it senses knock). I would also try the car with 2-3 degree of increase and then decrease timing, sometimes it makes a huge difference. Lastly 0.030) may be too little gap for that car, I would try it at .035-.038 range (factory is .039-.043). My car did poorly at .032 (with msd).

Hi, can you make a definitive choice about the Hp range 300-350 vs 450 is a world apart for a l28. you can get to 350 hp with even more torque relatively easily and remain reliable if the system is balanced and nicely done. 450 hp can certainly be done, but requires a lot more work to keep it reliable over the long term. I don't mean getting a one time dyno sheet of 400hp ( I don't count that), but running over 400 hp and being stable enough to run an open track event with that output. From what you describe it seems like the 300-350 hp range should keep you very happy (keeps me grinning all day), IMO after about 350 hp the car's chassis has difficulty coping with the power so you don't get much more performance, unless your game is quarter miles runs were you can never get enough power or contact patch. Also do think you might take the car to the track more often when done or will it be used solely as a street warrior ? Lastly, do you prefer well balanced performance (less lag, great handling, brakes, needing less money to stay reliable...) or is power the number one and two and three factor for you (e.g. sure good handling brakes...are nice, but not until it goes as fast as I can get it, I can never get enough power....)? I'll be glad to give you more specific (and biased) opinions about set choices after. One more thing, do you have an idea of your budget (off course I already exceeded mine by a factor of 2, so I don't know if budgets do much good)

As long as the aftermarket MAF is truly calibrated to the cobra and works well in a cobra, then I can't foresee any reason why it would behave differently with your set up. As you know, all it does is measure the voltage needed to keep the filament at the proper temperature and give out a referenced calibrated voltage, it should be irrelevant if the 3 volt for the appropriate air flow is going to a ford v8, nissan ECU.... As long as the MAF is calibrated the same and works reliably in the cobra, I would certainly buy the cheaper unit. If you already have not, I would double check all the wiring/connectors to the MAF real real carefully. Also if the cover pries off make sure no wires in the MAF have come loose causing the erratic voltage. I don't know al the details for the JWT set up, but is there a provision for the MAF filament clean cycle ?

Oil in the J pipe can be from either the turbo or high backpressure as caused by a faulty PCV valve or clogged line, so check those. While it could always be the turbo, as I said earlier, it is usually does not smoke with start up and if your turbo bearing was leaking oil from a year ago, I would expect it to have failed by now. (I have seen some oil in the J pipes in cars with working turbo's and without smoking or any noticeable problems) Why don't you try cleaning the J pipe, check to see if any oil is present in the manifold right after the throttle plate. Put it back together start her up and see if she smokes at start up. At that point there is no oil build up in the manifold to cause smoking. If it still smokes, likely the valve seals and then check and see if oil is accumulating in the J pipe. If not smoking and/or oil acumulates quickly in the J pipe, it may be the turbo. Don't forget the test your PCV hose/valve. No harm in rechecking the compression as well, a lot can happen in a year. I assume the spark plugs look well ?

The stock rear brakes on the ZX are more than adequate, all it needs are good pads to match. I thought that the big front kit would overpower the rear stock, but it did not, nor did they fade on the track. Go to JSK's website, you can email him thru there. Regarding rim width, unfortunately they are only 7" wich is good for the 225's. 8" or more would be preferable for 245's, but I'm not about to get new rims, so will do with what I have (there is more room in the ZX than the Z wich allows for 245's with stock fenders and strut housing).

I'm using eibach pro kit/tokico. dropped the car about 1.5" The car is early in a turn in that picture so the suspension is slightly compressed. All control arm bushings are adjustable and poly. I find it very suitable for a street/track car. tires are 225/45/17 (same diameter as stock), Khumo 712 supra. Nice predictable tire, good for agressive street driving, could be stickier for the track (specially autocross). I plan on getting the Khumo ecsta MX next in 245/40/17's. Yes, I'm using my old stainless lines, along with a $2.00 adapter to screw it into the caliper (wilwood is not metric) I got the JSK kit which is listed at $309 which includes the hats for the rotors to mount on and the bracket to mount the caliper. So my complete set up costs me about $700 which I found to be a steal (excluding brake pads) the kit can fit in some 15" wheels, wilwood also sells a smaller bodied (narrow mount) 4 piston caliper for tight fittings. I believe Juan at JSK can tell you what the inner diameter of the wheel need to be to clear the set up (I believe he is using the same size caliper as mine on his car which has 15" rims). Drop him an email, he is very nice to deal with.

Burning oil at start up and after idling for a few minutes is classic fo faulty valve seals/stems. For turbo's, more often, it smokes more under load and boost, not at start up and idle. Oil pressure is less at idle, so if it's smoking after idling (and warm engine) for a while and not with high RPMs I would figure that it's less likely to be from high oil pressure. Have you had the chance to check compression in all cylinders?

I'm using JSK's kit and it has worked out great. Not only the car stops in a beautiful way, fast, solid, great feedback, confidence inspiring, smile on my face.... The car has been driven double time (one driver then another driver immediately after) for some very long and hard track days (open track for five straight 40 minute sessions in one day and 30 autocrooss runs on another day, many runs in the twisties, all with absolutely no hint of fade whatsoever). I kept the rear stock set up and put portefield R4 S pads all around. Interestingly, the front/back balance is quite good and I did not need a proportioning valve which I was sure I would have needed (my car used to lock up the rear prematurely before, so I guess this evened it out). stock brembo vented rotor next to new wilwood 12.19 by 1.25" curved vane rotors ($45 each) and JSK hat wilwood forged superlite caliper (they were black, I painted them), 4 1.75" pistons ($140 each)

The majority of members here have experience with V8 swaps, L24-28 mods and turbo stuff on the 240-280 model lines. Off course there are some Z31 people, but you should consider checking the http://www.Z31.com website since there is a lot more experience and knowledge related to the 84-89 300zx. In general the 88-89 turbo models are the best (have LSD, better fuel injection, nicer body and various fine tunnings of other components, the 87 also has LSD, but the fuel injection system is not as nice). In this class of cars I have owned a 280Z with a L28et turbo swap, two 280ZXT (modified), an 88 300ZX and an 1990 supra turbo. The earlier Z models are the most fun. the 300ZX was comfortable and very boring(compar to the other sport cars), even with the turbo. The 87-91 supra turbo is also very comfortable but with just a little bit of modification becomes a serious perfomer and blows away the 300ZX turbo in every aspect, fun, stability, comfort, engineering, power, handling...and with a straight 6 is easier to work on (the best years for the early supra's are 89-91). The supra while heavy,is also very very stable and tracked beautifully, the 300zx was heavy without being that stable. The only major weakness on the supra was related to blown head gaskets, which can be easilly fixed, many of the used ones have had the gaskets and studs already replaced. That's my 2 cents.

Sweeeet ! Time to test them on the track

A few more thing to consider: -G-machine TC rod kit, works great and is cheap (the MSA one works on the 280zx, but list it only for the Z, Victoria racer sell the same exact kit and lists it appropriately for the Z and ZX) -MSA rear camber/toe adjustment kit. It was a reasonable amount of extra labor to install (the kit is cheap), but what an incredible difference. Most of the ZXs get some toe out (check any old alignment sheet that you may have from before) which makes the rear of the car unstable/squirrely and give it wicked oversteer. I ended up taking out my rear crossmember (put new bushings there as well) and then used 2 as opposed to 1 rear kit which allowed me to adjust rear toe and camber seperately(each kit allows for one of two control arm mounts to become adjustable, when used that way you can't adjust toe and camber seperately). It made an amazing improvement, it felt like the suspension was reborn, one of single best mods on the car (my toe was slighlty out). If your toe is slightly out, the kit is a must and the car will never handle the way it should without it (much much more important than having coil overs). If your toe is in spec, then you don't have to have it, but if you are big on handling, it will be well worth it IMO. If you plan on taking it to the track on a regular basis (open track or autocross) then it's a must again and will allow you to tune your suspension. -Front camber adjustable bushing. These kits only allow for a little bit a camber adjustment and may wear out after some years, so not as nice as camber plate, but is is very easy to install and cheap. It allowed me to get my camber right were I wanted. I haven't done coil overs, so can't tell you about those inthe ZX (maybe some day). Yasin has them in his ZX, said the rear was a pain in the a$$, but like most, is very happy with them.