The 510 Realm

I’m about ¾ of the way toward finishing this project, seems like a fine time to finally write something about it. I guess I’ll start at the beginning, and I’ll try to be brief.
A little about me and my car-related resume…
FIRST, I am a husband and father to two boys. I am an electrical engineer, presently working for a large tier-1 supplier to the auto industry who makes bearings and engine components. I used to road race with SCCA and NASA with a ITS/PS1 2nd generation RX-7. I still occasionally instruct for a few East Coast on-track driving schools. I’ve also completed several neat street car projects including RX-7’s and, most recently, a S14 240SX with a S15 SR20DET, 6-speed, Haltech E6K, etc., and a Volvo 850-R with 5-speed conversion. Because of greater obligations and a shift in priorities, brought about by my getting married and the arrival of my two sons, now ages five and two, I sold my previous projects. The 510 is a way for me to have an enjoyable “project” that can serve many purposes, without seriously impacting the family budget. The criteria for this project, both self imposed and otherwise, were for reliable, outstanding performance in normal street use, and occasional on-track or autocross use, as well as service in the daily tasks of parenthood. I plan to use this car to get to work and pick up the boys from soccer practice, while still being very capable for track use. This is not going to be a racecar! It will have an interior that is live-able for trips, and can’t be too stiff. So that I could carry more than one student at a time, and more than one son home from practice at a time, it needs to have a back seat. The investment had to be reasonable (i.e.very small), and fit within the family budget without any borrowing, meaning using funds from the sell of the other cars only, basically. Of great importance is that it must be faster than my Father-in-laws Z3, and friends ’76 T/A 455, Impala SS, M3, 240SX, and at least close to the Miata turbo and modified EVO. I’m shooting for 12 sec. quarters, and lap times similar to my old ITS car, reasonably quiet and good fuel economy. What one car could do all of this? How about an antique Japanese economy car, what else, right? Huh?

Things started out pretty radical. I purchased the entire underpinnings from a 1993 FD RX-7. Why? Simple, the wheelbase is the same as the 510, meaning that the PPF (Power Plant Frame, a rigid truss connecting the transmission to the differential) could be retained without modification. Forged aluminum suspension arms with near-perfect geometry. Torsen diff. I love rotaries (there’s a rotor and housing on my desk at work). Same general structure as the 510, that being unit-body with bolt-on subframes front and rear. All I had to do was mount the FD subframes in the “right” attitude on the 510 unit body and I’d have a 2000lb FD/510, AWESOME. And I still think so, but then reality set in. With the family taking the new focus, I eventually decided that I would never have the time to finish such an ambitious project. So I boxed up all of the RX-7 parts (after having all of the aluminum suspension parts bead blasted and powder coated clear, beautiful, thanks Mark) and set it aside for the next track-only 510 project. If anybody wants to continue this project, contact me, I have what you need.

I recently decided that it was time to get realistic, or the 510 was going to sit in the garage forever. I’m now using the stock suspension arrangement, with normal (simple and affordable) performance updates, with a SR20DET. Some are surprised that I’m installing a SR as a simpler alternative to my initial plan. But it really is pretty simple, more on that later. The suspension is made up of Troy Ermish coil-overs up front, on 280ZX strut housings, adjustable camber upper mounts with needle roller bearing, Eibach 200lb 2 ½” springs, later-model (1971) lower control arms with poly bushings. New later-model ball joints and tie rods. The steering system uses a rack-and-pinion unit from a ’88 Toyota MR-2. The tie-rods are machined/welded hybrid of MR-2 inner ball housings, and Cressida outer threaded end. The rear suspension also uses a coil-over arrangement. The rear control arms have been slightly re-shaped for greater tire clearance, reinforced at the shock mounting point, re-welded on all open seams, and poly bushings installed. The rear cross-member has been slotted and the exhaust hole enlarged to 4”. I also added two strips of 1” steel angle to the bottom of the cross member to make up for any bending stiffness that I may have lost. A penultimate design to better align the pivot axis of the two bushings is in the works. All of the suspension components have been de-burred, and powder coated dark gray by a good friend of mine, Mark Ciepela, using an Eastwood sprayer. He does outstanding work!

Although the suspension has been simplified, the brakes are still pretty radical, but that’s just my personal fetish. I’ve got 4-pot Porsche Brembos on all four corners. I’m using a Tilton reverse-mount under-hung pedal assembly to give front/rear adjustability, and to remove all brake and clutch hydraulics from the engine compartment. The rear set-up is unique in that I’m using Z32 300ZX internal parking brake drums, with corresponding 300ZX vented rotors, see...

http://www.the510realm.com/PNphpBB2-vie ... -5672.html

Front rotors will be two-piece Brembo, sized appropriately. Wheel bolt pattern is 5 x 114.3 by using Z31 front hubs, and re-drilling the original rear hub flange. This was done because the wheel I want to use is not available in 4 x 114.3. The wheel is a 15 x 7, with back-side and O.D. clearance for the unusually large brake set-up. A custom machined ring was pressed onto the back of the Z31 hub in order to have a place to mount the 280ZX oil seal at the correct depth.

The front cross member has been modified for the SR engine. The curve of the cross- member was reversed to accommodate the front-sump design oil pan. Ironically, the SR engine will fit onto the stock L-series motor mount perches, if the original 510 motor mounts are used. However, these rubber mounts are fairly small, and have been known to break when placed under a lot of stress. In addition, the motor sits a little too far forward on these perches, which naturally increases polar moment, and limits radiator/fan mounting space. So I rebuilt the perches using 3/16 mild steel and positioned them in such a way as to use the SR motor mounts, and move the engine rearward 40mm. I’ll also be making a brace which will bolt to the back side of the now-reversed cross member, and tie in the back side of the front control arm mounting bolt. Currently our heavily stressed front control arm is attached single shear to the cross member. Although I hear that no one has had these M8 bolts break (two per side), I’m still not comfortable with it. This brace will help me sleep at night. The new perches were made with an additional land for a brace that will go to the TOP of the frame rail, and attached to the cross member on the bottom of the frame rail with a large bolt. I’m not trusting the four tiny M8 screws that currently hold the cross member (and engine and front suspension) to the car body. This will also help me sleep.

The original gas tank has been modified to use an in-tank Walbro 255lph electric pump. I’m using the pump bracket from a S13 240SX which is basically a 7” round plate which bolts to the top of the tank, with a bracket that extends down into the tank holding the pump, fuel lever sender, and fuel warning switch. I cut a 5” hole in the top of the tank, and welded in some steel strips to reinforce the area where the flange will seal, and give material to tap into for the six M5 mounting screws. I made a gasket out of a sheet of 1/8” thick Buna-N fuel-resistant rubber. The inside was treated with a 3-step process from POR-15 to recondition and seal the tank. Both fuel lines have been replaced with steel 3/8” fuel tubing. Filter is from a 300ZXTT (I think, I’ll check). Fuel fill was at one time relocated to the trunk, but I think I have decided that this is a bad idea. I will retain the stock fuel door, but eliminate the key lock and use a remote cable-operated mechanism. The trunk is already remote, and the key hole will be filled before painting. I did this by reversing the stock mechanism so that the latch is on the body, and the striker is on the trunk. It’s pretty slick, I’ll have a photo of it in later. I use the floor-mounted levers from an Eclipse to open the trunk and fuel door, it’s very stock looking.

The interior is mostly unfinished at this point. I have replaced the drivers-side floor with new metal, and treated the whole inside of the floor with POR-15. The firewall openings for brake and clutch have been filled. The car came with a set of early MR2 seats. Some on this forum have commented on these, and I agree that they are quite supportive, and seem to be a good fit in the 510. I also have a good set of seats from a 1st gen. Miata. These are nearly as supportive, and have a more traditional look. I’ll decide which of these I’ll be using later. Back seat is tricky, however. The stock wooden with steel springs back seat is very heavy, and I imagine bouncy. The modern sculpted foam seats are much lighter, and more comfortable. I’ll be looking for one to install, and hopefully the colors and fabrics of the front and back with match. I want a very tidy interior look. There are no plans for any type of roll cage. My motivation for the dash is from photos of early G.P. cars, Cobras, and early Italian interiors. Classic 60's sports car is the idea, nothing modern looking. I’m certain that I’ll make a custom dash panel, aluminum sheet or wood, either in a black wrinkle finish, with classic black gauge faces. Luckily my dash cap is in very good condition. Instrumentation is a tricky matter. I want all of the gauges to match. The gauges will extend straight across into the area formerly occupied by the radio, remember that this is a ’69, so the heat/vent controls are below the dash, not in the center. I may make a center section later that will extend from the center, below the dash panel, to the transmission hump that will house a radio, but no tunes for now. In addition to the standard gauges, I also want EGT and an analog display for the wide-band O2. This is a stumbling point. I can’t find a wide-band O2 display meter, in the same family as the other gauges. So, since these are mainly tuning gauges, I may mount them in the lower radio panel behind a decorative (black wrinkle) cover. I don’t want one gauge that doesn’t match the others to stick out. Is that being fickle, maybe? So in the main dash area, it’ll just be the more traditional: speedo, tach, water temp, oil press, oil temp, fuel level, boost. Switches for all accessories will be standardized and mounted neatly in a common area. Under the dash, I’ve modified the heater core to better align with the SR motor. After the water flow valve, I added a 90 deg elbow, a section of tubing, and another 90deg. elbow to bring the two connection points out side-by-side. Standard ½” copper pipe is a nearly perfect fit with the pipe of the heater core. I sweat soldered all of the copper, except where it attached to the water valve. There is a plastic disc inside the valve that would not hold up to the heat of soldering, so I used a brand-name two-part metal epoxy, with a service life of 600 deg.F., and made for use with copper and brass. Note that some metal epoxies specifically warn against use around anti-freeze. The stuff I chose is anti-freeze safe. OK, I used JB-weld, I admit it!! It had all of the characteristics I needed. I REALLY hope that it doesn’t leak!! Also under the dash is the Tilton pedal assembly. The reasons for this are many. Adjustable brake bias, and proper pedal feel with the big brakes are the main reasons. Second reason is that it will remove ALL brake and clutch hydraulics from the engine bay. In the place of all of the engine comportment master cylinders, reservoirs, and fluid lines will be a smooth empty wall. This keeps the fluids away from the heat of the turbo which lives right in that area, and drastically cleans up the look of the engine area. Another future plan for the interior is a automotive PC with touch screen, in the place of the secondary panel under the dash, hidden by a wrinkle black cover of course. Why? I won’t have to carry a laptop computer for tuning the stand-alone engine computer, I can do it right there. No radio needed, no cluster of accessory gauges, it’ll all be viewable from the screen. PLUS, the kids could watch movies, I could integrate GPS and even wireless internet. But mainly, I like the idea of the tuning gauge panel, and having access to the engine computer at all times.

It was the shape of the 510 that attracted me to this project when I saw my first one at a track event years ago. I plan for the exterior shape to remain original and unmodified. I will clean it up a LITTLE by removing the locks from the gas door and trunk. The wheels I chose are a very classic look, nothing flashy. I would have preferred Panasports or Libre's, but fit and brake clearance overruled style. I also refuse to add flares, so the brake wheel package was that much more complicated.

The engine is a S13 red-top SR20DET. This engine choice won’t be justified here since there’s already plenty of discussion about this elsewhere on this site. The engine will be essentially stock. I’ve replaced the five main bearings, and lower rod bearings, and rear main seal. I’m altering slightly the SR fuel rail, mainly for ease of plumbing, and integration of a pressure gauge. I’ve modified the water lines under the intake manifold to better align with the relocated heater core attachment points (see interior section), and made a custom water neck for the upper hose. The radiator is an all-aluminum unit from Rod Davis. I plan to use a stand-alone ECU, probably AEM EMS. I used a Haltech E6K on my other SR20DET installation, and it was a HUGE benefit. I was able to tune for great power, as well as nearly 40MPG (39.6 MPG actually). The turbo will be a T28, bought from a friend. It’s been rebuilt, slightly ported, ceramic coated, and will be a slight upgrade from the S13 T25 that I have now. The intercooler is an all-aluminum bar-and-plate core, with home made aluminum end tanks. The core is made from two SAAB “Blackstone” intercoolers, epoxied together. It’s a great size for the front of the 510 and will fit between the original grill and the radiator with very little trimming. I plan to paint it black with a thermal dispersant it increase efficiency and make it less noticeable. The two 90º bends at each end of the intercooler are 2¼” mandrel bent smooth aluminum tubing with a large bend radius which should flow better than the usual 90º rubber elbow. The exhaust will be 3” all the way back, with a muffler (or two) to keep the noise to a minimum.

Sounds vaguely familiar except I am building a N/A KA24de and losing the rear seat

Please post some pictures!

Photos!!!!

Yeah us SR guys gotta take over this place!!!

hook me up with a motor icehouse!

Wow, what a post. You have it all there.
An idea for your EGT gauge; I just purchased, this week, an Innovate Wideband LC-1 & XD-16 display. The XD-16 has a crazy amount of display combos that you can play around with (chrome bezel, black bezel, white face, black face...) check out the link. Maybe you can make this match your gauge cluster arrangement that you are planning.

http://www.diyautotune.com/catalog/inno ... p-120.html

Here is a link to the wide band controller:

http://www.diyautotune.com/catalog/inno ... -p-41.html
The package retails at $399 US (Gauge and wide band controller with all the bits), Rob and I just purchased one each, I eagerly await it's arrival.
I wouldn't mind seeing some pics.
Didn't you post some of the reverse mount Tilton set up? I can't remember but couldn't find any links.
Byron

This guy has it for $332brand new - Ebay

I think the LC-1/XD-16 is the way to go! I intend on running this setup!

Recently I've only been doing some desk work on the 510. That means that I've been sitting at my desk at work thinking about the Datsun project. That's the way I've worked out many bugs in this project before I made them. Recently I've been thinking about the steering a lot. Getting the rack in the right place is the last thing that I have to do before I can remove the motor for, hopefully, the last time. The next time the motor is put in I hope will be to start it up. I bought the two steering u-joints that I'll be using, and I've started working on the modifications to the steering tube that will allow the upper u-joint to actually be inside the firewall. This proved necessary because of the severe angle with the MR2 rack.

My wife actually had a talk with me about the project. Mainly she wants to know if it'll ever be done, and when I'll stop trickling the money into it. I actually put together a spreadsheet that shows all of my expenses, to date, and a section of estimated costs remaining. My advice, never do this. The final numbers are a little depressing. The worst part is seeing what I've spent to date, then looking into the garage to see what's to show for it.

MUST......KEEP........GOING.............