Ben280

Going back through and re-reading my old build thread on Ratsun, just because that's fun sometimes. Bit of nostalgia to see the car in its original form, all the moves along the way and things I stumbled on. I for sure know how I'd do the car differently now, but after almost 8 years, this little car is like a younger brother. I can remember most of the welds, hits, scrapes and dents on this thing, each tells a story. Was a different time, back before the explosion of facebook groups and when you could still find these cars in the junkyards. If you want to go way back and see what somebody does building their first car: https://ratsun.net/topic/44762-first-project-car-77-280z-auto-xtrack-car/ Couple big mods in the off season this year. Jerico 4 speed that I got from Troy Ermish going in now, (realized that I'm still using the AZC light weight flywheel, one of the first "performance parts" I bought for this car back in June 2012. That and the control arms are probably the only parts on the car from the version 1 of the build. Bunch of new front air flow parts going on as well, but the trans is the big upgrade. Changing up the rear springs (going a little softer since the rear weighs so little) and a few other maintenance bits and bobs, but it's going pretty smoothly. Hopefully I'll post some photos, usually I get too focused on the work and don't want to get my camera filthy!

If it runs and is getting solid AFR data, that's enough of a base. You might have to babysit it for a little bit, but it should get you in the ballpark. It won't be perfect, but unless you are taking the car to a dyno, you're not going to have a fully optimized tune. If you're fouling plugs, it sounds like something is way off. I'd go back and make sure your initial injector settings are correct, and use the test modes to ensure that they are opening/closing correctly, rather than stuck open. Other things to do if you can: Look at your AFR reading when you're at idle to verify you're running rich. Then, look at your VE and AFR Target tables while it's idling, there might be some obvious changes you can make. You can also do some searching over at MSExtra and see if someone there has a base tune.

If you have a wideband AFR installed, Tuner Studio will auto tune as it idles/drives around if you set up "AutoTune". If you don't have a wideband installed, you need to install one ASAP.

FWIW, I'm running the Wolf Creek R200 Axles on my car and haven't had this issue with them. Thinking it through, since the R200 is wider, you'd be stretching the axles on a R180, not over compressing them. 1.5" difference seems like too much, and leads me to wonder if something else is off with your setup? It might be time to cycle the suspension through its range on each side, and turn the axles to see if you can further isolate the issue.

The axle will be fully extended at full droop. Sounds like your combination of adapters etc just means your axles are too long. Have you verified with Wolf Creek/Futofab that you have the correct lengths for your application? If one side is still in a bind, the problem will persist. I can't remember on the R180's if the driver and passenger side axles are symmetrical or not, might be worth verifying your measurements.

If you are comfortable getting the B series bell housing machined to fit on the C series, the only other modifications you need to make are getting a new driveshaft and crossmember. If you're handy with a welder, the crossmember is a piece of cake, or you can order one from Techno Toy Tuning. Godzilla Race Works also sells conversion driveshafts, but I imagine being in Europe, you'll have an easier time just getting one build over there. I've been running a C series transmission for a while and really enjoyed the improved shifting, particularly after I upgraded the springs in it's shifter housing. Got nice and tight after that. Best of luck, hope you can get the shifting where you like it!

There's no return spring. Much of what you end up feeling in there is the check balls. If you want snappier shifting and have yours apart, just about the only thing you can "adjust" are those springs. That will control how "tight" the shifter feels going into a gear. I've never messed with the internals on the B series so I'm not sure if there's actually any adjustment to be made there. Unfortunately the design of the shifter is vastly different on the FS5W71C. While the tail section is the same bolt pattern and can be easily adapted to a B series bellhousing, the rest of the casting is completely different, and uses a much more modern shifter style. A C series transmission might be what you're after if you want NB2-esque shifting in your Z.

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I keep a youtube with some footage from current and past seasons. Trying to add more data overlays, but your mileage may vary!

I have a full KA/SR trans swap that I'd sell. Trans + shifter, crossmember for the 280z, and driveshaft.

You'll be fine on the frame. There's a lot of suspension arms and sway bar to run into before you hit the body of the car, and even those are tricky to hit. I had wheels in almost the exact same spec (mine were 15x10 4.5"BS and 15x11 5"BS). Only reason it works was I used a quick steer knuckle, bringing the tie-rod closer to the hub and more inboard.

A 15x10 -25 in the front will hit the steering knuckle ball joint. Even a -38 comes close.

Those are Atara racing wheels. Not sure what sizes they make, but you can always send them a message on facebook: https://www.facebook.com/AtaraRacing/ Watanabe wheels do get into the 17's but not the width you are hoping for. You might be better off looking for or building a set of Panasport C8's.

Thanks man! We can only get about 1g of acceleration, (22mph per second), some of our competitors can get close to 1.8!! Could do with a slightly more torquey gear to pull out of corners, but that really hurts top speed. Dang tradeoffs!

Little bit of video from the last event of the season.

Another season done and dusted. Huge improvements in the car, just really figuring out how to wheel this machine! The car ran 10 events with the OR-SCCA and scored in the top 5 (overall) 5 times, and got 3 fast time of the day! Pretty excited to be getting to this level, there's still some optimizing on the car, but a lot of it is just going to be improving the driver! Hoping this off season to complete the switch to e85 and put in a new steering rack. I've already got quick knuckles and the 240z rack, but it's still not quick enough, I'd really like to be at 1.5 turns lock to lock. Steering is pretty limited by tire clearance, so the middle shouldn't be too twitchy. Will be doing some measurements and then calling Woodward.

How have I never seen this build before!! Good lord this is gorgeous. Excited to see what livery design you decide to go with.

https://www.silverminemotors.com/240z-260z-280z-camber-plates-bolt-in-lowering-kit These might do the trick for you, would be easy to make a spacer if you wanted some height back in the nose of the car.

I am running Koni 8611 inserts. Don't remember the specific lengths, but they come in a variety of sizes. I've had several conversations with Lee Grimes at Koni NA and he has said that the spring rate/weight of the car are well within the capabilities of these shocks. They are also rebuildable and have custom valving options if you need to get wild. The front bar isn't adjustable, but I'm planning to switch to a speedway style 3 piece bar this winter. I'll be making that somewhat adjustable, but more importantly, getting rid of the damn rubber endlink! You might be able to re-drill the upper mounts to get some more camber, but without switching away from the OEM rubber pile, I don't think you have enough range of motion. I can't remember how much room is in there with the factory suspension, but I suspect it's not much. I would guess tho that you could use some combo of the T3 upper spring seats along with their bolt in camber plates, and not lower the car toooo much. Would be a small investment and parts you could easily sell or put on a shelf for when you do get coilovers.

I'd look for a tube nut that corresponded with that tube size, then use a male/male adapter to get to -6AN. I'm guessing that the tube you referenced in the other thread is a -5 AN size (most of the hard lines on these cars are) but I'd measure it with a vernier caliper before buying tube nuts! Parts list if this is the correct solution: Tube Nuts - https://www.summitracing.com/parts/ear-581805erl/overview/ Tube Sleeve - https://www.summitracing.com/parts/aer-fbm3679 Adapter - https://www.summitracing.com/parts/ear-991907erl/overview/ Again, this assumes the tube on the tank is a -5AN size. Otherwise, just buy the appropriate pieces! Another note, -3AN will be 3/16", -4AN will be 1/4" and -5AN will be 5/16". Get the tube clean and measure the OD!

Cars always develop slowly, but it looks like you're heading in a solid direction. Lap data is the best! Nice work analyzing. I've used RaceRender for lining up video for comparison, and had pretty good luck. Although with an 11 second gap it might become not super useful quickly. For reference on getting rid of body roll etc, I am a big fan on these cars of controlling the roll with springs. My car might not be the best example since it's auto-x focus and the setup is fairly aggressive, but I'm running 500lbs front springs, 400lbs rear, the 1" MSA front bar and no rear bar. The rear end has a very aggressive 1 way KAAZ diff and 3.90 gears. It's also very low, and I've got roll center adjusters in the front along with quick knuckles and have re-drilled the front subframe to further correct the roll centers. The end result is a car with a super responsive front end, but it's not a struggle to keep the rear end under control. Post up some video links if you get a chance!

First, a dumb question. I know Mid-Ohio has two configurations, were these laps done on the same track layout? Second, an essentially OEM strut and spring, refreshed balljoints and poly bushings do not a race car make, even with a sticky tire. All that with a stock front bar make me think that if the car felt great and you were getting loose on corner exit, you probably aren't anywhere near the performance envelope of the tire. If this is going to be a track car I'd look into a good alignment, making sure you have good brakes, verify power levels/healthy motor, then start ticking off bigger projects like a good coilover setup (Koni or MCS), lowering the car and putting heavier springs/sway bar on it.

Looking good!

Drill and tap the intake runners!!! I'm assuming the intakes you are all using don't have bosses already, but that's where you should be drawing vac from if you don't have dedicated ports. The kit for the Jenvey ITB's from Datsun Spirit have these ports built into the manifold. Boogering up the ITB bodies are not the way to do this, the OER piece tioga mentioned is a nice way to add the port as well if you don't want to mess with drilling and tapping the intake.

Fair! My motor rarely lives in a high vacuum area of the VE table, I guess I am/was assuming OP's motor will be in a similar state, which isn't a good position. In my initial post I think I was hung up on the idea of a rising rate FPR in terms of boost, and was confused why OP would want that on a NA car. (I also mis-read IAC as IAT, soooo maybe I should have my reading comprehension skills checked lol!) Thanks for clarifying and adding some facts!