ianz

Hello All, Thanks to everyone for the great posts! I am currently doing an LT1 T56 swap into a 78 280Z. I am using the JTR kit and have a question. Did you all use the offset engine mount spacers and if so, did you go by the manual and put the thick (2" spacer) on the driver side? Clarification would be appreciated as doing this seams to move the engine over to the passenger side so far that the exhaust header will not clear

Hey Mike Never thought Nasty car would come in handy, but this is AWSOME!! I've been away for a while but Tony D gave me the heads up about this and hear I am!! If you go for the second day, count me in for a donation cheers, Ian

Again, They don't call aero a black art for nothing...... There are two concepts that address under body aero..... 1. Block as much air as you can from going under the car to minimize lift caused by the air being slowed down by obstructions (suspension transmission, exhaust, etc.... 2. Guide airflow purposely under the car through smooth ducts which create downforce Option 1 is much more common, but option 2 is what is used on professional race cars..... For the Z car, well, probably option 1 since not everyone has computation fluid dynamics capability on his or her PC a splitter is nothing more than a horizontal surface below the stagnant high pressure air right in front of the car.. this increases front downforce, which could make the car tail happy at high speeds........ for street cars, the general rule of thumb for the minimum speed the aero is effective is 60mph and above, although I designed an aero package for a specialized race car that needed downforce at speeds as low 25mph (it's top speed was about 70mph, so it's a different animal as far as how low is too low, full bodied race cars have between .5 to 1 inch of ground clearance and computer generated aero packages specifically designed for the car. for a street car, I would not run less than 3 inches

ZROSSA, Aero improved Z for the street... There in lines the conflict!! if you said Z for the track, well that’s different, but for the street, you must have sufficient ground clearance for driveways and speed bumps, not to mention sufficient airflow through the radiator in stop and go traffic. I think for a streetcar, the G-nose setup Tony-D spoke of is the best compromise, just add a vented hood BUT make sure the vents are at least 18 inches or more away from the windshield, otherwise you force more air into the hood due to the hi pressure region in front of the windshield (otherwise known as cowl induction)

Hey Guys, man this was a BAAAAD thread to come across while your at work!!! A couple things you need to address here. Aerodynamics are NOT an intuitive science!! so what looks good won't necessarily work well!!! There a too many interdependent variables and NOTHING IS FREE!!!! We are merely trying to minimize the losses created by a body moving through the viscous fluid known as "air" and harness some of its energy to our benefit if possible So first of all, some clarifications: 1. The concept of two air molecules starting at the same point traveling around opposite sides of a smooth body and meeting again at the back of the body is known as the "Kuta Condition." This is used in inviscid flow theory along with Bernoulli's methods as a way of "characterizing" the function and flow of air that we cannot explain directly. The other concepts mentioned pertain to "downwash" which is a more Newtonian concept of redirecting the air that is used in conjunction with inviscid flow theory to estimate aerodynamic loads. Because we are not able to measure EXACTLY how air functions all the time, we deal in generalities that allow us to approximate what is going on...it is a very artistic science as a result..... 2. Given the concepts of #1, an automobile is inherently lifting off the ground due to it's shape being like a wing. The top of the car is longer and smoother causing the air to move faster over it than under the bottom of it. Add to this all of the obstructions and heat transfer from the engine to the air passing under the car which further increases its pressure, thus further contributing to lifting the car as well as increasing the drag resistance on the car. OK so if you can minimize the obstructions to the air passing under the car and better yet, speed up the air in the process, you reduce both the drag and the lift acting on the car...... So think of the underside of the car and the ground below it as a wind tunnel.....the air running under the car goes from a large area in front of the car to a small area under the car which (if it doesn't contact any obstructions) will speed the air up and lower its static pressure. This is the function of a smooth belly pan under the car, but nothing is free, so now the air under the car is moving much faster than the air around the car and specifically behind the car so if this fast air runs into the slower air, you "choke" the air flow which will greatly reduce the effectiveness of your belly pan. You must then find a way to slow the fast moving air down back towards the rear of the car increasing its pressure back to the rest of the air around the car without effecting the air behind it still moving through the "neck" of the tunnel under the car. Hence the need for the diffuser which allows the air to smoothly expand and slow down to the speed of the air behind the car, which if done correctly can even help to "suck" the air out the back of the car..... The Diffuser DOES NOT create downforce, it increases the effectiveness of belly pan.... This is the baseline to start with.....a continuous smooth surface that runs from a large space at the front of the car, necks down smoothly to a small space at the middle of the car, and expands smoothly to the back of the car. If you add skirts to the sides of the car, you box in the tunnel, further increasing it’s efficiency…. The arrangement that ZR8TED has is beautiful, and I dig it, but it is more of a rear wing than a diffuser, thus he will get rear down force benefits, but not see the drag reductions thus will need more power!!! This explanation is the benefit of an aerospace engineering degree... The detriment....action movies seem really stupid and borring to me!! Cheers, Ian

I believe that MSA is working on distributing the hoods for the manufacturer so keep an eye out for them.... cheers, Ian

There are several guys on the west coast that currently sell carbon hoods and deck lids for 70-78. I have seen a carbon hood on a 240 (my friends) it looks great, all be it a bit ricer, and cut almost 30lbs out of the car. All the race guys out here are scrambling for these things the hoods are going for 300 to 600 bucks just FYI cheers Ian

Just go find more valves for the N42 (I think the N47 uses the same valves but do yourself a favor and check out the Geocities site) Even if you have to buy new valves, they are still available and not too terribly expensive..... that is DEFINITELY or best bet!! good luck, Ian

yank the 240 motor and drop in the 280.... take the distributor, intake, exhaust and fuel pump off the 240 motor and bolt them on to the 280 motor.....they will bolt right up that is the easiest way to get going cheap and it should run real strong..... if you could get the FI setup installed you would get better gas milage, but I have a stock 280 with SU carbs, header and a 280ZX distributer on my car and it runs great!! just my 2cents good luck Ian

Hey Pipelayer, I'f your only using the SUs for now, Why do you need an early balace tube?? Just cap/plug off all the smog stuff and your good to go!! If your in So Cal there are those of us that can help you out..... Cheers, Ian

I knew there was a 1/2 in there somewhere....

As john mentioned, bigger bar in the front makes the car understeer or "push", bigger bar in the rear makes the car oversteer. Suspension setup is about the most subjective thing on a car, especially a street car with an inexperienced driver (speaking for myself) If you are happy with the car's handling without sway bars, no one says you have to use them, there a pain!! you are running really stiff springs for the street (stock rate is 140 lb/in front and rear I think) but if the car is not too twitchy, and you like the way it feels, leave it!! If the car still has more body lean than you want, try using the stock front and rear bars off the 280Z. The motorsport and Sus Tech sway bar kits are HUGE in my opinion and designed to work best with soft springs, so they may be excessive in your case given the spring rates your running..... just my 2 bits...... good luck!!

not to step on Zline's toes here, but I think the 280 springs are the same diameter as the 240, the rears are just longer. I have seen people use the 280 springs on the 240 to give it a nose down rake rather than the standard rear squat....... Also, I don't think the 280 suspension is interchangable with the 240 given that the 280 has taller rear strut towers, but I may be wrong... either way, if you plan to throw new stiff springs on, I HIGHLY recommend doing urethane bushings and tokico struts while your in there otherwise you just wind up with a stiffer riding unresponsive Z.... good luck with it either way....

Are you using the stock springs?? If so, most guys switch to an adjustable coilover setup with 3.5" springs instead of the stock 6" diameter (not shure about the exact coil diameters by the way) so you gain an 1 to 2 inches in tire width without adding fender flares Or am I understanding what your trying to acomplish??

By the way, if you are using CV half shafts, using this diff mount accentuates the tolerance issues between the rear swaybar, swing arms, body and half shafts by limiting the swaybar travel (hits the diff before droop)...so be aware!!!

Good thread guys, I too have incorporated this mount on my late 71 240....... I made mine simpler than the drawings with just 3 plates 1/4" thick mild steel with thick weld fillets.....but the plate lengths and angles in the drawings were dead on. The bolt holes for the strap threw me a little, but I was able to measure and drill to incorporate the stock hole pattern on the diff mount. Be aware of this on the 240s. I actually drilled the side plate holes, bolted the side plates in the tunnel with the top plate resting above them and tack welded it together. The fuel lines on the 240 also presented a slight problem, as did the eBrake cable, but both were minor I bought the urathane tranny mount from pep boys for $22 (it varifies that its interlocking right on the package) and had to modify the slots to work with an R180 (they were too wide) and ground the urathane nubs off the bottom of the mount so the plate would sit flush on the top of the diff. The tranny mount bolt is VERY stout (3/8" at least) so I am not worried about it comming apart on me...... my car has a stock 280 motor with an 180 LSD rear (Solo 2 BSP specs) and I have had this mount in the car for 3 months with no apparent problems (solid and quiet!!) I have a vibration that comes on at or above 70mph but do not think its dif mount related.... I REALLY like this tranny mount especially after just helping a friend replace his cracked cross member (caused by prolonged use of solid diff mount) Thanks to the designer!! Cheers Ian PS I have pics of mine installed in the 240 if anyone wants to see them, just email me.....

If all the stock wiring is still there, be sure to find the illumination lead for the sterio display....I made the mistake of thinking this was a ground and would up blowing fuses every time I had the lights and the radio on at the same time..... I have a 240 so it may be different on the 280, but your new sterio should have an Illumination (or Dimmer lead), so if you find the correct wire lead from the car, connect them and your sterio display brightness will be controlled by the dial on your dash for the gauge brightness (dimmer) 8) Also, if you have access to a pick a part yard, find the mating sterio plugs on a junk car (nissan uses similar plugs in a lot of places) and make your own harnes so if you wanted to go back to stock you haven't butchered your wiring harness in summary, you should use 4 wires from the stock harness..... constant power switched power gound illumination then run your own speaker wires amp remote turn on ect.... good luck Ian

Hey fellow aftermarket ECU folks...... Has anyone used the stock 81zxt crank trigger signal to drive an aftermarket system???? Does anyone know the output specs of the stock trigger wheel?? # of pulses ect.... I would like to use it to drive a megasquirt/megajolt system.... Thanks in advance, Ian

Yup, the emissions laws will always be an illogical, knee jerk, convoluted mess. That’s what happens when politicians try to control a complex technical issue. So as a result, it is better to ask forgiveness than permission. The Idea that a stock 1972 impala belching hydrocarbons is legal while an LT1 converted Z running fuel injection with much lower emissions is not is absolutely REDICULOUS but happens to be fact.... I think the guy from Texas is on to something...do some research into the local custom/hotrod clubs to see how they address this mess. I believe many of them register as historical vehicles. This holds you to a limited # of miles per year, but it's an option. My question is how do you register or transfer title on a non stock pre 74 car (aka a Z) in Ca. I think a smog check is still required for that, so what do you do??

JMO, but I've heard it's better to keep the existing NA trans in your ZX and just swap the turbo motor, ECU, exhuast and intake, and don't forget the oil cooler.... if you use the T-5, you need to swap out the rear end as well, and the N/A tranny is smoother and plenty strong from what I understand.... good luck.... Cheers, Ian

It's all about fuel atomization guys....... for a carbureted engine, a slightly rough surface on the intake ports promotes turbulent flow which tends to keep the fuel mixed with the air in the intake. if you are running big carbs and cam with a lot of fuel delivery, a polished intake can cause puddling of the fuel.....(thats bad...) polishing the intake can be a benefit, but for very specific conditions/applications. I’m with mudge, remove any big casting goobers and your good to go... also, match porting the intake to the head can help a lot too. If your really serious about it, find a race shop that can flow bench, extrude hone, etc. your intake manifold, but if your running SUs that’s overkill. Just get triple carbs...... unless your running hi compression and a big cam, mods to the intake manifold are not going to give you a lot.... good luck, Ian

I believe there is a stop tab on some of the SU carbs with the detent dial mixture adjustment that wont let you turn it more than about a turn, but I am not as familiar with that type so I may have mispoken...... No affense lockjaw!! 8) So I repeat....buy the video

The 72 carbs have a different needle valve mixture screw than the earlier SUs do, so disregard the 2.5 turns thing There are MANY writeups on tuning SUs, all similar, but still different. do a couple of checks before you go any further. Remove your air filter(s) 1. check the oil in the tops of both carbs, and makes sure the lift can (the sliding assembly that the Needle is attached too) in both carbs has resistance when raised by hand and fall easily with a pronounced "clunk" 2. also make shure that your nozzles are seated up against the bottom of the carbs (Actuate your choke and you'll see the nozzles moving in and out of the bottom of the carbs. 3. Buy the Z therapy Video......

navstokes@yahoo.com

Hey everyone, The bill has not come up for review yet, but I wrote a letter and submitted it to all the legislators....they sent back a bunch of info and long story short, if passed, the bill will a. Exempt all vehicles 1960 and older b. Exempt vehicles 1960 to 74 that are driven 12K or less a year c. Require all 1975 and newer to be tested as they are now. The bill will go into affect Jan 2005 if passed. The real down side is the current laws allow for a rolling 20 year exemption starting next year so all the 260/280 guys could benefit..... I personally don't put more than 12k a year on my 240Z, but I wrote a letter apposing the bill anyway. I would like to know more about the roadside emissions testing (mainly in LA), and how they address older cars?? If you are truly interested in speaking out about this, go to zcar.com and do a search for "emissions" or "smog" for the past 2 months, there were a few postings on how and who to contact. Ian