280z FP Build

[ryant67]

Thanks for the info!  Clearance shouldn't present too much of a problem - the EFI Hardware air horns I use have a separate flange, and then a set screw holds the horn into place once slid in.  Solves some mounting headaches.  Right now I have an ITG Megaflow JC100/65 mounted onto a grommet secured backplate.  Your solution is tidier and more secure though!

[Ben280]

Man been a while since I updated. Must be having too much fun racing to post here. For those who don't know, following BrokenJawRacing on instagram and facebook will get you SLIGHTLY more frequent updates, and sometimes a video if I can manage it. 

 

Since we last hung out, well, lots has happened. Firstly, got the car tuned with the ITB's. English Racing in Camas WA has been my go-to shop for this for the past couple years, and they did a great job getting it set up out of the box. Put down 223whp and 200tq. For comparison, we popped off the filter and picked up 4hp and 3tq, but I think the longevity of the motor is more important than a pretty minor HP gain. 

 

First couple events of the year were wet, so we couldn't even make use of all the power. The car did earn a new nickname while it was wearing some street tires, and now has a "hovercraft mode" if it gets too wet outside. First dry event that we had with even a slightly warm/grippy tire and we broke the u-joints in the drivers side halfshaft. These were recently rebuilt with good MOOG joints, so I was a little disappointed that they failed so soon. It was a good excuse to buy the Wolf Creek Racing CV kit, especially considering the next event was in California on even grippier concrete. 

Hovercraft mode with some 15x6.5" 240sx SE wheels on the car

Dry weather = broken u-joints

Futofab kit, mmmmmmmm shiny

 

The Crows Landing event was a lot of fun, if a bit stressful. Had some early issues with the tune, since I was finally able to run at wide open, I found that the tune was loading up and dumping way too much fuel into the car. Once we leaned it out it ran great. The ITB's are funny, and require a fair bit of maintenance to keep optimal, particularly as weather/barometric pressures change. Also ran into a fuel pickup issue, where the fuel cell foam caused the holley hydramat to sit on top of the fuel when its around 3 gallons. Once all those got figured out, it was just a matter of running the course and keeping up with a very fast XP field. 

 

Crows Landing NASA Test Facility. Best concrete on the west coast

 

The rest of the season went pretty smoothly. Sticky, hard throttle cable got replaced with a custom Pegasus piece, perpetual tuning and fiddling with the ECU and ITB's, it will be interesting to see where the car sits when I bring it in for its annual baseline this winter! The Packwood NT and ProSolo were a lot of fun, did well at the tour, managed to hang onto the back of what I think is the car to beat nationally in the class. The Pro was fun on its own, didn't place well, but the R2 category is one of the hardest classes IMO. 

 

Fixing the throttle cable at the Packwood ProSolo, with the PRE Evo behind us.

More of the field for the ProSolo, K swapped Lotus and FD RX-7 with a monster turbo. The FD driver has been a national champ more than once with that car.

 

This winter has been "light" on the upgrades, compared to the past two years. The major outline is to change out the Arizona Z Car struts for Koni double adjustables, and build a new exhaust. Lots of other little maintenance projects and cleanup as well, but those are the highlights. Excited to get the car back on the ground soon, and see where these changes put me! 

[seattlejester]

Yay an update!

 

Have you had any problems with the foam deteriorating in the fuel cell? Hope to see you out at the autocross this year!

 

[Ben280]

On 1/5/2018 at 5:31 PM, seattlejester said:

Yay an update!

 

Have you had any problems with the foam deteriorating in the fuel cell? Hope to see you out at the autocross this year!

 

 

So far, I haven't had any issues with the fuel cell foam. However, I have only used clear 92 and VP 110 gas. When I spoke to the people over at Fuel Safe, they said that any ethanol content at all would cause problems.

 

I'm trying to get up to one or more of the Bremerton events this year, although we had an event at the end of last year at Packwood where myself, zredbaron and JonMortensen were in attendance! Need to coordinate a big Z autox weekend at some point. 

[seattlejester]

Hmm then there goes that idea, anytime I'm under 30% fuel, sharp decel will audibly cause a change in the fuel pump. 

That would be really cool, a chance to get properly schooled!
 

[simone17]

Great progress and awesome build. Thanks for keeping this updated. 

[Ben280]

Ok, few events in and there are some updates! 

 

Mods over the winter went smoothly, if a bit slow. Lots of new suspension parts, custom top hats, "custom" housings, Koni 8611 double adjustable shocks and some freebie ground control perches and we're off! Got some first run T3 aluminum hubs as well, but they haven't made it on the car yet, got some other very trick parts that need to be designed first!

 

 

Helps to have buddies with CNC machines! I did get frustrated half way through this project with using up all my machine shop points, so I bought a lathe. That's helped a bunch with some of the more fiddly parts I've had to make since!

 

Another big project was getting my exhaust sorted out. The one that came with the Rebello motor was very hacked together and left a lot to be desired. Crimp bends, weirdly necking down from 2.5" to 2" and back to 2.5" and just general rust were but a few reasons to throw it all in the scrap pile. I got a good deal on a bunch of parts, and busted out the welder. I decided to go full 3", with two mufflers to keep the sound down. Having been on the wrong side of the "DB meter-o-lies" I wanted to make sure I didn't get booted out for ignoring simple things. As most of you know, getting exhausts in these cars with ground clearance is easy until it really isn't, particularly around the diff. I opted to solid mound the exhaust and get better clearance, and added some proper flex joints in the header to keep everything happy. 

 

Nice Vibrant flex joints welded to 2 notches above garbage. Don't judge me!

 

We've gone full danger noodle! This is out of the center muffler, around the diff and into the secondary muffler. Solid mounts to the diff cross member and fuel cell cage

 

Glorious ground clearance! Pipe is as tucked as possible. This perspective is tricky, the entire center muffler is above the frame rails. 

 

Crammed in there! You can sneak the driveshaft out tho, so it's a win in my book!

 

Last mod before the season started was to get a proper alignment and corner balance. I've been working with the guys at PRE in Portland (Zack the shop manager has a pretty wizard Evo that I have to race against) and they were the obvious choice for the first real alignment this car has had in years. 

On the rack. Check that rear wheel gap, it's gonna pop up later!

 

Adding/moving around some ballast. Lost a bit of weight over the winter, need to add it back!

 

Before we started balancing and moving weight around. This is with my weight in the drivers seat, fully ready to rock. No after pic cause I forgot, we got it close though!

 

We were able to make some great adjustments for CAI, scrub, caster and camber. The alignment rack had a feature showing us wheelbase, and so we were able to even those out. The car had been in a crash before I got it, and the drivers side tension rod pocket was about an inch further back. With new exhaust, suspension, alignment and corner balance, we were ready to rock and roll!

[Ben280]

First event of the year was a wet race at the PIR lot, and essentially useless for determining if any changes needed to be made to the suspension. We were able to figure out (using math!) that the ideal starting place for the adjuster knobs was slightly below the bottom of the Koni adjusters. So that made it easy, just leave everything at full soft and add as needed for balance.

 

Second event was the National Tour stop at Crows Landing, just outside of Paterson CA. We made a quick detour to visit Steve Parmley and pick up a new windshield, as my numbers matching piece finally cracked after I got a little rough with it trying to save the gasket. Pretty funny loading the car on the trailer without front glass! Upshot of this was some cosmetic changes in the cabin that should make driving the car much nicer. Being the first real event on the car, the test day at crows was a literal s$!& show. Right off the trailer it was idling like dirt, so we did a couple pulls and added some fuel to the accel enrich map. That smoothed out the idle, but it was still misfiring like a bastard. Pulling the plugs found that the #3 cylinder had come in contact with the plug and closed the gap. No gap, no spark, no explosion. We re-gapped it and clocked it correctly, and we were good to go. Ish. We actually were worse than we started. We never corrected out that fuel we'd added to make up for no #3 spark. So now it was running so rich, it couldn't accelerate its way out of a paper bag. After 2 hours, frustratedly downloading Megalog Viewer at the end of a runway, and doing a couple terrible practice runs, we reset the tune to the start of the day, and all was well. 

Off the trailer with a new windshield! Thanks Steve!

 

On the practice course, we decided that we were crashing into the bump stops on transition, and we didn't have enough droop travel to keep the inside rear down when in a turn. Remember that teeny tiny rear gap? Well as cool as it looked with flares, it lead me to be super conservative when setting my bump stops. So we weren't hitting the body, but we were getting infinite spring rate mid slalom. No bueno! But as prepared cars go, we got F'n Prepared and proceeded to remove most of the rear suspension so we could trim the bump stops, and space down the tophats. More droop, and more bump. Well, that didn't go exactly as planned! We couldn't get washers small enough to let us space the top hats down, so we cut the bump stops, pre-loaded the springs, and added some compression to try and hold up the rear of the car. The contingency plan was to throw some spring blocks in as well, and go from 500/400 to 600/450. Not ideal, but we didn't have a better option! As we went to put the car back on the ground, the final gut punch to a rough day came in the form of a deck screw in the center of the rear tire. We threw the wheel in the back of the truck and went to the hotel for beer and showers. 

 

If you can't make it worse, at least make it something!

 

Bright and early on race day. Right where we left her (and the toolbox too!)

 

Yup, we were so exhausted that we left the toolbox out overnight! Lucky for us, auto-crossers are a trusty bunch. One of the guys from Oregon Region that we were hanging out with had a patch kit that he generously loaned us, we slammed the patch in and she held air. Now to shift focus from thrashing to driving and having fun! 

 

Looking good! Hawk DTC-60's are the best braking dust pad I've ever used!

 

We were running in XP, and massively outgunned by a pair of RX-7's. I drove off pace Saturday, but got some much needed confidence Sunday and managed to be more in the mix. I landed predictably in last place, but Zack drove the wheels off the car and got 2nd. A positive result and I had a long list of mods to make before the next event!

 

[Ben280]

Once I got back from California, the mods started right away. First was getting more travel in the suspension. I had my friend who machined the top hats make some spacers to adjust them down 1.5". This let me move the spring perch down 1", effectively gaining more droop travel and raising the car .5" (it was really low before!). With the droop travel solved, I went after the bump. There's lots of room in the car for that, I just had to cut some more body out to get there! The rear of the car is essentially tubbed now, no more conservative ZG flare cut for this Z!

 

Full (pre mod) droop to ride height. Full compression came right before the tire hit the body. Not enough!

 

Little bit of persuasion with a grinder, hammer, MIG welder, more hammer, more welder and some foil tape and we got suspension travel for days!

 

Another big modification that needed to be addressed was the rear roll center. I've done the common modification of drilling holes in the front cross member to get better angle in the control arm, and the car really turns as a result. The rear however was a mess, and would "fall over" in roll, causing the car to porpoise under heavy acceleration. Not ideal! The solution was partially raise the rear of the car, and then lower the outboard control arm mount. I drilled out some 1.5" cold rolled steel on the lathe, bored it to 5/8" and welded it to the bottom of the knuckle. 

Heavy metal! Three passes with the knob cranked to 11 (on a 220v machine). 

 

Much better control arm angle. The factory hole at this ride height is about level, and .5" lower was angled 5-8* upward.

 

Had a chance to test out all these mods two weeks ago at the NWR ProSolo, and I have to say it went real smoothly. Particularly in comparison to the California event 3 weeks prior! The ProSolo revealed a couple more flaws, but the mod list is getting shorter and shorter each event. Really looking forward to the Packwood NT/ProSolo events in July!

[Ben280]

On a side note, I'm wondering about organizing a Z-day/Auto-x meet up at one of the Packwood events later this summer. The site is phenomenal, great pavement and a cool chance to test out your Z. Matt and Jon were out to an event last year, and we mentioned the potential of getting a bunch of people together for a day. Its about 2.5 hrs from Portland and Seattle, free camping on site, and has high BBQ potential! 

[JMortensen]

I'm rubbing nickels together but should be able to get mine up and running again in a month or two. Have a bad master and need to replace the tires just due to age. Was carb tuning last time I ran it, too. Big problem for me is that I was way over the dB limit last time. I put Supertrapp tips on my mufflers, so hopefully I can just adjust it until it passes, but that might affect the carb tuning and all the rest. If I do get there, don't expect a lot is what I'm trying to say...

[seattlejester]

Yay an update! 

 

I would love to make the trip. Packwood really is gorgeous. 

 

I'll be happy to hold down last place. At best I'm a bench racer, I've made my peace with the fact I'm not a very good driver, plus my modifications are all over the place. 

[Ben280]

I'm more excited to see people come out and have a good time! As my project shows, these cars are always evolving, so you gotta take time and smell the race gas.

[Ben280]

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.

[Ben280]

 

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

[Jboogsthethug]

Man what a motivational video! Dang, I am impressed at the seeming acceleration that engine is putting out! You get up and go!

[Ben280]

On 9/28/2019 at 8:58 PM, Jboogsthethug said:

Man what a motivational video! Dang, I am impressed at the seeming acceleration that engine is putting out! You get up and go!

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! 

[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!

[Ben280]

Thought I'd give y'all the photo by photo update from the past 18 months since you've seen proper photos. We'll begin at the beginning, some time in January of last year! I usually take a car vacation from October through Christmas, trying to plan projects and generally procrastinate before having to thrash on the car to get it ready for March race events. 

 

January 2019: I decided that I need space in the engine bay for more parts, and having the master cylinders in the traditional location wasn't going to work. Also, the jenky cut up master factory pedal housing was just sad, and needed to be improved. I went with a Wilwood reverse hung pedal assembly, this would make packaging a bit of a hassle, but would give me the most possible space in the engine bay. Plus who doesn't like smashing in panels? Needed to make some clearance for the remote master inlets, but otherwise it fit better than expected. 

 

(Brackets on the firewall. Note the big hole that needs to be blanked off, I ended up doing that from the engine bay side)

(Pedals installed, need a little more clearance for those inlets)

 

I was also looking up upgrade the front hubs. I've been using the original hubs with Silvermine Motors front brake kit for a while now, and while the kit is great, I don't love having a pretty expensive front rotor package, that needs custom machining to work. It also weighs a bunch, so I figured it was a good place to save some weight. I bought some Aluminum Techno Toy Tuning hubs from a member, and wanted to match them with some equally light weight rotors. Here's where having machinist friends with CNC's in their garage is helpful. 

(T3 aluminum hub, custom aluminum rotor hat and Speedway scalloped 12" front rotors)

(Installed with fresh ARP wheel studs, total piece weighs 11lbs per side less than the factory setup)

 

I also figured that I needed to start doing some work to strengthen and stiffen the front end. Still a work in progress, but I added some bars connecting the frame rails and strut towers. A strut tower bar will be a welcome addition as well, but all in due time!

(Down bar connecting the upper and lower portions of the unibody)

(Strut tower to frame rail. I'm hoping to add to this area in the future)

[Ben280]

That brings us up to the beginning of the race season. I was still working on some of the front end cosmetics, but nothing that was keeping us from running the car. End of last year, I had attached the front airdam more permanently to the flares, but that made for a super unwieldy piece of body work. I needed to smooth it all out as well, maybe one day I'll pop a mold of these. Over the course of a few events, I was able to finish the body work on these, and sprayed them with some nice spray paint from the local pro paint shop. Really liked working with that stuff, did a regular black base, then a 2k epoxy clear. 

 

(Dirty wheels and clean body work!)

 

I was also beginning to work on relocating my fuel tank. The car is mostly to spec, and it's just about chasing marginal gains at this point. Having a large road racing fuel cell behind the rear axle isn't great for the poler moment, although it was nice for weight distribution (on paper at least). It was also annoying, even with a Holly Hydramat I had to run a fair bit of extra fuel in the tank to prevent fuel starve. A new custom tank will also provide incentive to begin to E85-proof the fuel system, in planning for upcoming mods.

(Removing the 65lbs of fuel cell and fuel cell cage left me with this hilarious hole, When full, this added almost 100lbs to the rear of the car)

(New fuel tank in its soon to be home! 5 gallon custom aluminum cell, set up to accept my 6x10 fill plate from the old tank. Ballast will go in the area where the passenger seat usually goes)

(And finished! Rules require that the tank be separated from the driver by a bulkhead. Some aluminum paneling, rivets and foil tape do the trick nicely.)

 

Car was fairly dialed in at this point. We went to the National Tour stop, did ok and had a lot of fun. Nothing else broke on the car which was great, getting in tune with all the preventative maintenance and nut/bolting this thing after every run day. 

(Ok, what fell off this time!)

 

I also took the Z international and did an event up in Canada. Was a lot of fun, found a couple more things to fix, and got some excellent photos of the car.