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Ironhead

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Posts posted by Ironhead

  1. The seats look like old school Recaros (two different models).

     

    As to the upholstery, unfortunately there are thousands of places that can recover a seat.  I have no idea the significance of the "atom" symbol.  Assuming the seats were...newish...when they were upholstered, it well could have been done decades ago.

  2. Very clean fab work there!

     

    Good idea taking the "floor" of the dry sump mount down below the frame rail.  Mine is level with the frame rail, and simply will not take a 2 gallon tank, at least not unless I want to make a hole in the hood.  I imagine you know this and planned accordingly.

     

    Good to see ARE is still in business.  I tried to get ahold of them to make a purchase a couple of weeks ago.  Didn't answer my call (during business hours) and didn't return my message.  So I bought it from Peterson.

  3. I know nothing about the AIM PDM specifically, but I heartily endorse the PDM concept.  It adds immense functionality and flexibility while actually simplifying wiring and implementation in practice.

     

    Using multiple old school gauges, fuses, and relays to wire a car is positively stone age in comparison.  I am using a Motec PDM, and whenever AIM releases theirs I wager it will be every bit as good while also significantly less expensive.

     

    I'm curious...does the Terminator setup come with fully tuned maps for the various models of LS?  One of the reasons I wonder is my last build has standalone EMS that required complete tuning.  Here I am 15 years down the road, and the tune is still frustratingly imperfect.  It is easy to tune WOT and midrange, but all the little things, like light throttle drivability and AFR, idle under differing conditions, etc, are maddeningly impossible to get perfect.

     

    I wanted to use a crate engine this time, with the factory tuned EMS, and be done with it.

  4. I wanted to second the recommendation for the KIA Sportage door weatherstrip....

     

    I initially got the weatherstrip from Vintage Rubber.  It fits fine, but is quite stiff and it is a &^%$#*&^ to get the door shut.  

     

    The KIA part is much softer and more pliable.  It results in a quite tolerable door shut effort even when brand new, and I'm sure it will soften even more over time.

     

    On sort of a tangent, it is really an eye opener how cheesy and poorly engineered things like weather stripping, seals, and trim pieces were 50 years ago as compared to modern cars.

  5. On 1/28/2021 at 11:26 PM, 260DET said:

    Sometimes a reality check is needed and that can be provided here by looking at Z race cars and their results. The fastest Z's have always used the basic stock suspension, it's great that there are those who think outside the box and who are willing to put their $ where their mouth is, Once they do that however they need to turn a profit so they have to be commited to their product. What does not seem to be widely understood by potential users is the complexity involved in any suspension redesign. At the very least the actual dimensions and locations of all components needs to be established using proven methods. Until that is done we have what is basically promotional comment. Bye, getting real is often not popular.

      

    I don't think there is any question.  Most of the aftermarket suspensions for the Z completely mimic the stock design, and just add a bit of adjustability to suit wide tires, lowered cars, track focused use, etc.  They also include poly bushings and Heim joints to cater to drivers who want tighter handling and will tolerate more NVH than the designers at Nissan could have gotten away with designing into the factory car.  I am using the T3 setup and that is definitely the path that they followed.

     

    The reason Apex is getting more scrutiny here is because they went a bit further than that, not to mention have displayed some issues with meeting deadlines and getting parts out.

     

    You won't get any hate from me. 

  6. 9 hours ago, JMortensen said:

    Couple pieces of advice from personal experience. Moving the rack forwards or back makes very little difference in practice. I moved mine back as tight to the xmember as possible, then decided to do a Woodward rack and the ps servo is right in the way, so I had to move it forward to fit. Had moved the rack back purposely to add Ackerman, and then a year or so later found a link that showed how to sketch it out on graph paper. Did that and found that the difference was tiny, so then when I had to move the rack forward, did it again, graphed again and ended up with something close to parallel steer. Not ideal for autox, but hey, throw some static toe out at it and it's just not a big enough difference to sweat over.

    As to using a lot of bumpsteer shims to move the tie rod down, I was running my car like that for a while, it was good enough. Bolt is better than a tapered pin though, according to an engineer friend of mine. He said the tapered pins move around more and are more likely to break, and also that the thin circle track bumpsteer shims that I was using are not the best. He suggested running a really thick walled tube tapered down to fit on the rod end. I don't have a lathe, so I welded a rod end spacer to some thick wall tubing and then ground it to the right length with my belt/disc sander. Took a while, but it worked. Here's a pic of the old and new versions.

    I have an extra length of this tube so if you want to do this give me $8.30 for flat rate shipping and I'll mail you a chunk.

     

    My Woodward rack is one of the manual ones, so I had a bit more freedom about where to mount it fore/aft.  But, at Woodward's suggestion I just mounted it slightly behind the imaginary line between the tie rod pivots on the steering knuckles and have no plans to mess further with that.

     

    I think I'm OK on the bolt/bump steer spacer thing....I am using an AN10 (5/8") bolt spaced down with 1" OD  stainless steel spacers.  I guess my main concerns were:  How much total height of bump steer spacers is too much?  Also, are there any workarounds that I am missing.  Having the tie rod end cantilevered so far downward in a single shear joint just seems like bad practice, but so far I don't see any way around it. 

     

    9 hours ago, jhm said:

    Maybe I'm missing something here, but can't you move the inner mounting points for the LCA to match the angle of the outer tie rods?  Or are you not wanting to do that because of roll center concerns?

     

    @JMortensen, Jon, what adjustable front sway bar is that?  Have been going through mental gymnastics to design an adjustable bar for the front (with little success).   Did you move the frame mounting points forward of the stock mounting points?  That's the only way I would think you could use a straight center-section bar, true?  (Or minting bracket drop-downs, which does bad things to the end-link geometry).

     

    I can do that.  I would still need some bump steer spacing but the total amount would be much less.  My concern would not only be roll center, but the angle of the LCAs.  The LCAs would then be canted upward toward the outer ends when the vehicle is sitting at ride height.  For ideal suspension geometry, don't we want the LCAs pivoting as close to horizontal as possible?

     

    I know trade-offs are part of the deal when we go modifying our cars....I guess I am trying to figure out which trade offs have the least/smallest downside.

     

    Thanks for the help gents.

  7. Ok, I am near finishing final assembly on my car...here is the dilemna.

     

    The steering rack (Woodward) cannot go any higher because it will hit the oil pan.  Everything has been clearanced as much as possible.  I "could" raise the engine, which of course would introduce negative fallout in terms of CG and other issues.

     

    I have an Apex crossmember with multiple front suspension pivot points.  I am using the pickups in the stock location height wise, and matching the width of the inner tie rod pivots on the rack side to side.

     

    My understanding is that the tie rods have to have basically the same angle as the control arms or I will have bump steer problems.  This is doable, but it requires using a long bolt on the steering knuckle and spacing the outer tie rod Heim joint approximately two inches below the steering knuckle.  This is the part that bothers me.  It is a single shear joint, I cannot conjure a practical way to convert it to double shear, and that seems like a lot of stick-out and lever-stress on the bolt.

     

    Am I missing something?  Is there an easy solution here or is this just something that people modifying a Z front suspension have to live with?

  8. 9 hours ago, 280Z-LS3 said:

    Feel you on the re-engineering of parts.  Thought I had the engine placed right where "it should be" and now not so sure.  A few specialty fittings for the oil pan return line will and a few more thoughts on allowing space for headers should get the issue sorted. 

     

     

     

    Clearance between the header tubes and the oil fittings is a problem.  I used the lowest profile fittings on the market and it's still very close to the header.  I just put reflective heat shield on both the header and the fittings.  Sure hope that is sufficient.

  9. 1 minute ago, AydinZ71 said:

    a race car and a production car have so little in common... I now have a much better appreciation for that restoring the race car. We start with a production car as a platform for many reasons, most importantly we can “add” to or modify something vs. starting from scratch. There are literally hundreds of dimensional decisions that Nissan has already made for us, for better or worse. Much more manageable then doing something from scratch and having to learn dozens of lessons the hard way. 
     

     

     

    As a kid, I used to attend the IMSA GT races during the glory days of the racing Zs.  They primarily raced in GTU.  During the first few years I attended, all the GTU cars were production bodies with extensive cages and other mods to stiffen them.  Then suddenly, in the early '80s IIRC, everything changed.  I don't know if it was a change in the rules or just that the racing became more sophisticated, but overnight all of the competitive GTU cars were tube framed with fiberglass bodies....you know....nothing whatsoever in common with the production car except perhaps the engine block.  It might have been later than I recall...but pretty sure it was the 1980s.

     

    That was the same time the prototype cars took over for GTX (Porsche 935 etc) and I began to lose interest in racing.  True production based racing is much more interesting.

  10. Just a bit more progress...

     

    My initial air intake was just a 4" tube with a K&N filter on the end.  I knew it would benefit from an air horn on the end, but I couldn't find a part with the attributes I wanted, IE would fit on a 4" tube, accept a large (but not TOO large) cone filter.  Well, if you look long enough on the 'net, you can find pretty much anything.  This was from Vibrant.  The constant re-engineering of things I am unhappy with after mock-up is one of the reasons this car is not yet running...

     

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    The engine bay is pretty much done.  The plug wires are off because I have to remove the plugs and spin the engine to build oil pressure....soon anyway.

     

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    Rear brakes are done and seemed to bleed easily, at least based on the solid feel of the handbrake.  Even though it wasn't "time"...I just had to bolt on one of the rear fenders to see how things looked.  Now I'll probably scratch it and hate myself....

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  11. 3 hours ago, AydinZ71 said:


    my old engineering professor used to call us “sophisticated Taylor’s”. Meaning, our job is to CUT material, not add unnecessarily. His point was, anyone can “guess” conservatively enough to make something work. Engineering is the process of adding just enough material, complexity, etc. to get the job done, and no more. He also taught us to not “fall in love” with a design, and be open to continuous improvement and criticism. 
     

    That always Resonated with me. 

     

    I love hearing stories/advice like that....

     

    Another thing....if one wants to pursue the "ultimate" no-holds barred suspension design for a "Z", the logical first step would be to ditch the unibody and completely tube frame the car.  The basic Z body is notoriously flexy, and while a well designed cage helps, the production nature and era of the vehicle would certainly limit any gains that could be had from the ultimate suspension.

  12. I certainly want to support places developing parts for our cars, but after perusing the "track attack" setup I have to side with those thinking it is just....a bit much.  I don't mean just money, I mean the overall complexity to benefit ratio.  I think it is more of an engineering exercise than something that would make sense to buy and use, even on a cost-no-object track car.

     

    A theoretically more advanced suspension design does not necessarily translate into a car that is faster or more fun to drive, and complexity can be a fault all it's own.

     

    I am reminded of the story I mentioned earlier...of a racing team in a pro-level GT racing class doing advanced "ground breaking" design work on their suspension system that they thought would win the series, and while they dicked around with that another team running a live axle won the championship.

     

     

  13. Agree about the large hardened washers, as I mentioned.  I often wonder why places like to include Allen bolts in locations like this where there is really no need or advantage to them.  These are good, grade 12.9 bolts (T3 likes to send weak and gall prone stainless hardware too, sadly), but one main issue here will be vertical clearance and in that regard Allen bolts are no better (maybe worse) than standard head six point bolts.  Like I said, I think button heads will be the best approach, although the threads in the blocks are M10/1.25 and button heads in that threading are hard to find (Belmetric has them).

     

    IMHO the plates (as opposed to large washers) would be a bit overkill, and having seen the parts I am not as concerned by the connected "T" slot as you are.  Keep in mind, that part is 1" thick.  It is very rigid. 

     

    I'm sure after running the car a bit, it will be quite apparent on inspection how the parts are holding up (if I ever get it running).

     

     

  14. I am using the "new and improved" front diff mount from T3.  Their original one was a flimsy joke, so I had fabbed up a .25" steel plate monstrosity to try to keep my diff from moving around.  Well, I am quite happy with these T3 parts and the one I constructed is getting scrapped.  I am probably saving at least 15 pounds in the process.

     

    Basically this uses billet aluminum pieces to bridge together the front and rear control arm pivot points, and then a third piece of 1" thick billet bolts to these to support the front of the diff.  I have read opinions from some that they believed even these new T3 parts are not adequately substantial and rigid to keep the diff from moving around.  I am no engineer, but I am quite confident that these new pieces will either rigidly hold the diff in place, or they will break.  The fact is 1" thick billet aluminum is not going to flex much.  And I seriously doubt they are going to break.  The design also eliminates the cantilever effect when using a short nose diff that puts so much stress on many front mount designs.

     

    Another plus is that this design is claimed to be compatible with the Ford 8.8" diff, which I probably should have used from the beginning and will be switching to should my R200 prove not up to the task.

     

    The only downside to these parts I can see:  It significantly encroaches into available space to run exhaust beneath the control arms.  I am about 75% certain it is going to interfere with my already constructed exhaust, but I like the design well enough that I am willing to modify the center section of my exhaust to make it fit.  I do think I am going to replace the four visible Allen bolts with lower profile button head bolts, and use larger hardened washers under them.  This will allow a bit more exhaust clearance and better spread the load on the aluminum parts.

     

    Thanks for looking.

     

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  15. I think he's talking about Supertrapp: https://supertrapp.com/shop-products/universal/auto-s-c-elite

     

    If you're not familiar with them, they've been around forever....since the 1970s at least.  There are a series of baffles at the end of the exhaust pipe.  To increase flow/noise you add more baffles, to quiet things down you go with fewer.  I know these devices work, but I don't really understand how.  It seems like the design would KILL exhaust flow, but somehow it doesn't.  They have been used on a lot of racing cars and bikes over the years to take the edge off of a really loud exhaust.

  16. It's funny...I have heard a wide range of opinions about Heim jointed cars.  Some say they wear and start "clicking" almost immediately, others say they get thousands of trouble free miles out of them.  I guess I'm about to find out, as my project car has a crap load of them.

     

    I am interested in the R joints in concept, but I don't understand what makes them superior to standard Heim joints, other than costing 3X as much.  They do not appear to be "sealed" from dirt and moisture, and while the metal ball rides on a plastic bearing surface, that is true also of many Heim joints that are Teflon lined.  I am also a bit dubious of some of their claims about poly bushings.  They repeatedly cited "squeaking" as one of the major faults of poly bushings, but if they are properly lubed with Teflon grease squeaking is a complete non-issue.  I have a track car on poly bushings that I greased/installed almost 20 years ago.  Not a squeak in 20 years.

     

    My point being, hard to separate the truth from BS marketing with the R joints.

  17. I had similar issues as I learned how to weld on mine.  The copper backing works great, but in some places isn't really an option.

     

    What worked for me was to go pretty hot on the weld, but do it EXTREMELY quickly, like just a split second weld.  The short duration helps prevent blowing through and keeps the weld from stacking too high (more to grind off), but the high heat setting still gives good fusion.

     

    Like you said, once you have a few solid tacks, it's easy to keep adding more to them.  It is also critical IMHO to have a slight gap (1/16" or less) between the two panels being welded.  Otherwise, once the weld is ground flat, you will have countless pinholes to be filled.

     

    Some recommend TIG for thin sheet metal, but I tried TIG and it was a disaster for me.  It is by nature a slower process, and I found controlling the heat to be a nightmare.  

  18. 5 hours ago, 280Z-LS3 said:

    What's the advantage of going with a Jeep wiper motor and what car was it sourced?

     

    Looking forward to the reports of getting your car fired up and suspension sorted!

     

     

     

    The main advantage over the stock motor is just that they are available...

     

    But I used the Jeep motor (from a '90s Cherokee IIRC) because the common Honda wiper motor swap was a bad fit for my particular car.  I am using a PDM for electrics, which can only switch +12V and the Honda motor is designed to work by switching to ground.  The PDM cannot send a ground signal.  Yes this could be overcome by using relays and such, but I figured this motor would be easier, simpler, and cleaner.

     

    All I did was look at photos of various wiper motors for sale, and chose this one because it used a similar mounting arrangement to the stock motor.

  19. Well, things are moving along.  Slowly, but moving....

     

    I got the engine and transmission installed and wired.  That all went fairly smoothly.  I got the clutch working...but doing so required upping the master cylinder from .75" to .875"....for the clutch to fully release before the pedal hit the firewall.

     

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    The Jeep wiper motor works and parks the wipers correctly.  Not sure there whether I was lucky or good....but it was surprisingly easy.

     

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    Shifter installed.

     

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    Driver's door mounted and panel lines sorted (as good as they are going to get).

     

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    Honestly what has really slowed things down has been trying to route/shield/design all the engine mounts and wiring and hoses and the starter so that they are not burned by the headers.  I hope all these heat shield products do what their manufacturers claim, or the car is going up in flames soon after I start it up.

     

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    Thanks for looking.

  20. 7 hours ago, HS30-H said:

     

    And yet the Porsche 911 is one of the most successful road car-based models in motorsport history. That's a "massive mistake" a lot of other manufacturers would be happy to have made.

     

    In a strictly pointy-headed-theorist sort of way, I suppose the 911 is poorly designed....

     

    The 911's racing success proves that in all of motorsport short of the absolute engineering pinnacle (F1),  weight distribution is of relatively low importance compared to a myriad of other factors.  Committed manufacturer support of a race program is one of them.

     

    The most dominant 911 based car was no doubt the 935.  I used to watch them during the late '70s and early '80s.   Compared to the Dekon Monzas, Greenwood Corvettes, and BMW turbos, the 935 did handle poorly.  But while their competition had perhaps 650 HP, the 935s had more like 800 HP.  And, their rear engine arrangement enabled them to put the power to the ground very efficiently.  They would dawdle through the turns, then take off like rocket sleds in the straights.  Couple that with the fact that they were actually built by Porsche rather than some racer in their garage, in general they had a huge reliability advantage.

     

    So the 935 won, pretty much everything in their era, weight distribution be damned.

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