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Posts posted by JBSRace1

  1. Axle retention device is a positive lock to keep the axle from separating from the differential like a C-clip eliminator for a GM 10 or 12 bolt.

    This is the portion of the rule I was referring too.


    "" Cars running 10.99 (*6.99) or quicker that weigh more than 2,000 pounds (907 kg) with independent rear suspension must have swing axle differential replaced with conventional differential housing assembly. ""

  2. I personally feel that changing out the rear suspension, (especially ignoring the bigger issue regarding the Z car suspension, which is the front suspension, not the rear), because it is weak and/or can’t handle power, or is a poor performance design for a sports car is an assumed and/or misguided concept that we see come up from time to time. I understand wanting to install a different rear suspension and different differential for the sake of “because we canâ€, or for “WOW factor†to make our Z a little different from the rest, but I don't understand that swap from a performance stand point regarding drag racing, road racing or performance street use. The OE Z car rear suspension has proven itself in strength and design! From a performance perspective, the front suspension needs the attention WAY before the rear does. The hows, whys, and what fors, have been documented in our "Brakes, Wheels, Suspension and Chassis" section. Peruse through the stickies at the top of that section for some very good in-depth info.


    Not sure what sort of power you are planning to put to the ground, but below is a picture of one of our members with a Blown, Nitrous dual quad V-8 on drag slicks, (the differential and rear suspension wont see much more brutal, punishing power delivery than that without flipping the car over!) running 9.2 seconds in the ¼ at 153+ MPH! For perspective, that car is going 0-153 MPH in 9.2 seconds, with the stock Datsun Z differential and suspension! This car runs this fast, and every-time that stock Datsun differential and rear suspension is absorbing enough power/torque to "yank" the front wheels off the ground, time and again on the stock parts. I know of at least one other member running 8 seconds at 150+ on the stock Datsun differential and suspension.

    Geometry wise, the stock Datsun rear suspension isn’t too bad. It’s not perfect, but not too shabby, especially considering the age of its design. These car with the stock rear suspension design are still successfully campaigning on the race tracks against today’s offerings with much more modern suspension designs.


    I would agree that there probably is some to be gained handling wise with different suspension, but will take several years in sorting it out, (geometry adjustment, spring rates, balanced to the rest of the chassis, chassis stiffness etc), and only the most discerning road racers among us would be able to notice that difference, and with what is known about how to make the current Z car suspension design truly competitive on the track, would cost far less, time invested in setup and tuning would be shorted by not just months, but years, etc. Again, for the sake of making a Z car different than the rest, wanting to give it WOW factor, or just because we can, I say do it. From a performance standpoint, it will cost more money, require several more years invested in tuning tweaking, before it would be “acceptable†or hopefully, a better performing design than a nicely sorted out OE Z car suspension, and that is only if the person doing the tuning and tweaking is savvy enough regarding chassis design and tuning.


    That’s my $.02




    That is a bad azz Z no doubt. But how is he getting past NHRA tech? Or is he just doing test N tunes at none NHRA events?



    NHRA rule 2.3 REAREND


    After market axles and axle-retention device mandatory on any car running 10.99 (*6.99) or quicker and any car with locked differential. Cars running 10.99 (*6.99) or quicker that weigh more than 2,000 pounds (907 kg) with independent rear suspension must have swing axle differential replaced with conventional differential housing assembly.

  3. I have not had a turbo but My 383 chevy V8 works good for me.

    Although I am sure there are faster ones around I have yet to run into one at any of dragstrips that I go to.

    I do not do much 1/4 mile racing mostly all 1/8th mile but I do go somewhere almost every weekend threw out the summer months. The last 1/4 mile pass I made was a 9.53 with a 1/8th mile time of 6.07 But now that the weather has been getting a little cooler I have been putting together a string of 6.02's the last few weeks. I am bracket racing and trying more for consistency than just ET so I am leaving the line at 3800 rpm to help hook on a less than perfect track. I believe that if I was to turn the leave RPM up to 4500 5.90's in the 1/8th would be no problem.

    Add a little N20 and it would really be a wild ride.

  4. 1: Angle plug


    2: I Dont know what the ones that are in there now are for or who made them. But they have been hammerd almost closed in several places.


    3: I am fixing to change engine combo to match my camaro. After years of working with it I found the most power and consistancy with headers of that size.


    4: Yes Drag Only.


    5: The Mtr that is in there now. Leaving at 3400 and shifting at 7000 runs 6.30's in the 1/8 @ 108.

    With the new engine combo it should run 5.80's

  5. Who makes a good set of headers to fit in my 70 240 355 cid? Or would I be better off to just build my own? I have built sevearal sets in the past for my other cars but it takes alot of time and a pain in the A$$. I would like to find a set that would bolt on with out having to do alot of fabrication. Pref 1-3/4" pri with a 3-1/2" collector.

  6. As a genaral rule if you Failed on Co it is running rich not lean. Hc is efected mostly by ignition Cap,rotor,plugs,wires. Nox is from to high combustion temps, EGR, Cat are the number 1 problems. If you where lean your Co would be low and Nox would also go up slightly becouse of the extra combustion heat from being lean. A air flow sensor can cause a rich condition but it should also make it run ruff as well. As stated above the O2 sensor will drasticly effect Co and need to be changed every couple of years and most never get changed until there is a drastic problem. Also a Vacume leak on a Fuel injected car will make a lean condition and the computer will try to correct it by making a rich condition.

    If you have a good mechanic at a shop you trust they should be able to find your problem fairly easy.

  7. Katman

    The 18" I spoke of in the first post is total suspension travel from a rest to the point that the tires come off the ground. If you where to mesure from the front bumper to the ground on a leval surface. Then Start to jack up the car the bumper would raise up 18" before the tires would come off the ground. That is Alot. It is possible that someone has put the wrong struts in this car I have not had it that long. But with it limited to 4" it works like a dream.

    On a car with limited traction front end rise helps move more waight to the rear and helps traction but with enough traction it can be a pain. Limiting the front also helps get the tires out of the beams and improves reaction times & ET, the car is spending less time going up and more time going forward.

  8. Tech is not a problem. But they will not hook.

    You would be better off with your street Radials.

    The Side walls on a round track slick are extreamly stiff and the compound is way to hard for drag racing. If you cant get Drag Slicks lower your tire psi to around 20-25 on your street tires and drive around the water. Do a light burnout with out the water and you will be better off than with the roundy round stuff.

  9. Katman

    I understand about center of gravity and how a drag car works this is not my first trip down the strip. The problem is not with going to high. With the front end limited the front end will come back down sooner. With as much travel as this car has the front end stays up the entire length of the track with the help of the front springs pushing it up. I have been real successful with doing this in all my other cars over the years. They all have Upper control arms and are easy to limit on the upper control arm. This is the first time I have had a strut car to limit. I got it down to 4" tonight and we are going to Albany tomorrow and I will find out how it works. I would like to get it down to 2".

    Thanks for all your advise

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