1987 RX7 LS1 Swap

Any updates? 

I recently purchased a 1987 FC that I plan to swap. 

Gonna work on updating and un-Photoberking this thread in the coming days so I can start documenting my exploits this summer. TL/DR version is the swap is pretty well finished, seems to run and function fine, but has been sitting in my garage all winter still without a full on road test. First auto x is 3.5 weeks out and I'll have the car tagged, insured, and sorted by then.

So unfortunately it looks like I am missing a chunk of pictures from the end of the swap, not sure if I accidentally deleted them or what. The good news, I guess, is I got kind of lazy at documenting things by then anyways, so I don't think too much is missing, aside from the exhaust build. So here's a bit of a random picture dump:

DIY driveshaft loop. A bit crude, due to my lack of proper equipment and the need for a goofy, oblong shape to fit the tranny tunnel, but it should be plenty strong. I had to heat and beat the steel strip into shape in my vice, then brouht it into work to TIG weld it (which I am horribly out of practice with.) Bolted through the floor to a backing plate on the inside.

Another little bit of fab work here in the battery mount. Base is made from a couple pieces of angle and some flat plate to tie into the floor of the passenger side storage bin.

Interior more or less back together. Threw water temp and oil pressure gauges in the A pillar pod that came with the car.

Current state of the engine bay. I removed the hood latch and installed hood pins and built a bit of a heat shield for the ECU a couple weeks ago. Still want to move/replace the coolant reservoir and the fan relay to get them out from in front of the radiator, and ultimately scheme up some ducting for it as well.

Last weekend I was looking for things to fiddle berkeley with and I changed the oil in the motor and rear diff and gave the car a good washing. Then I found a bottle of Meguires polish that I had forgotten I bought in a misguided attempt to improve the appearance of my XJ. Dabbed a little of it on a pad and hand buffed a small spot on the hood just to test it and was so encouraged by the results I soon pulled out my barely used HF DA polisher and went to town on it.

Here's the hood in progress:

Whole car shot, before washing and polishing:

And after:

The pictures really don't do the results justice, the car is REALLY looking good now. Very pleased with the results.

Also, i don't think I've whored off my new wheels yet. Enkei RPF1s, 17x8 front and 17x9 rear shod in 225 and 255 section width Falken Azenis RT615ks. Maybe not the most cutting edge of the 200tw tires, but Tire Rack had them on sale for pretty cheap last fall.

The other little project for last weekend was putting together some cribbing and turn plates for alignment work, which I'll finish up this weekend now that my cutting boards have arrived. I'll also fashion a string  box out of some jack stands and pieces of conduit. Need to pick up a camber gauge, too.

This weekend I'll be working on the suspension, installing the Racing Beat springs and KYB shock/struts I got with the car. I'm thinking this may end up getting replaced with a Ground Control setup down the line, since it seems no one makes camber plates compatible with the stock diameter springs? Not in the budget right now anyways, so the plan is to do the suspension in a few stages. Along with the shocks/struts and springs, I'll be replacing the front control arm and rear DTSS bushings as well.

I don't know about FCs in particular, but on a lot of cars there's no point in camber plates with stock-diameter springs because the spring fouls something as soon as you start trying to add significant negative camber. The smaller-diameter springs buy you a lot of room.

Anyhow, that's a really good-looking car! I've always thought the V8/FC package must be awesome for autocross, doubly so now that Street Mod allows cross-manufacturer engine swaps.

man, you have that thing looking good!  If I didn't have the racecar project, that's exactly what I would have done with this car!

well done.  how much do you want for it?  

It is easier to replace the 2 spindle to hubs bolts with slightly smaller diameter bolts and change the angle between hub and strut to get more camber.

also, you can slot the top of the shock tower to get more camber and caster.  you will get about 1/4 inch movement before the spring top fouls the strut tower.

did I give you the drivers door trim piece?  If not, I probably have another one somewhere.

In reply to Ransom :

I was thrilled to death to see the engine swap rule change with street mod this year, I had no intention of ever building to the limit of e mod rules, nor running Hoosiers. Street mod fits my near-term plans for this car just about perfectly, gonna get the suspension sorted out then start messing around with aero a bit later in the season. SSM is also a class of roughly ten for us at an average event, versus one or two cars in e mod.

So the coolant overflow tank is below the level of the radiator?  How do you bleed the system like that?  Usually that tank is the high point of the system and it'll self bleed/burp through the tank...

In reply to wvumtnbkr :

I've got the door trim, just haven't gotten around to putting it back on yet. And I think I'll be hanging onto this car for a while 

I've thought about slotting the upper mounting holes, but I am a little hesitant to do that if I am gonna throw camber plates on in a few months anyways. At the same time, I know I'm gonna be severely camber limited until then. Just did the drivers front corner and didn't slot them, though. I did throw a camber bolt on, since I found a set in the box of struts and springs ypu gave me. Any idea how much camber I'll be able to get on there?

In the rear, my thoughts are to put delrin bushings in the subframe and diff mounts and Mazdaspeed rubber in the trailing arms so I can use the 'jangle rods' or whatever you wanna call them to adjust camber without inducing bind. That's not gonna happen before the first event, though, I decided to do the front control arms instead because they look to be in worse shape. Also snagged a set of ST swaybars on eBay last night because they were ridiculously cheap with the 20% off coupon.

In reply to docwyte :

There's a bleed valve in the upper radiator hose.

get the front sway only.  the rear should be thrown away.

how much do you want for it?

use Mazda comp bushings for diff.  get toe eliminators.  get a pinion snubber to help the rear diff from moving.  it will save the diff mounts.

how much for the car...

oh, you can get enough camber with the camber bolts to ruin street tires in 5k miles....  corded on inside!

So last weekend I tackled phase 1 of the suspension, which entails shocks, springs, and poly front control arm bushings. Phase 2 will encompass a full rebuild of the rear as time and money allows. Everything went together in a lazy Saturday afternoon without much drama, save for me trying to gun the wrong nut on the drivers side strut and having to spend the better part of an hour filing threads. Doh!

All buttoned up:

Then off came the control arms to relieve them of their well worn bushings. I had the full array of my implements of bushing destruction on hand:

The ball joint press made quick work of the front bushings, which are pressed into the ID of an eye, as is typical. The rear bushings press over a barbed nub on the control arm and can't be pressed off easily. I figured my best bet was a death wheel on the angle grinder to cut down through the metal sleeve and try to peel it off, which worked surprisingly well. The control arms themselves are actually rather pretty pieces in cast aluminum, so I gave them both a quick scrub down before reassembly. 

Popped the poly bushings in, threw the control arms back on, and that's where I left it for last week.

This weekend is my final weekend of wrenching before the car's first auto x event, so the main objective was getting it aligned and doing a bit of a shakedown. First things first, I had to finish putting together my turn plates. Rather than use $12/ea cutting boards, i decided a couple of $.69/ea laminate tiles would work just as well. Pair of tiles placed face to face with a generous layer of 75w-90 in between did the trick:

Picked up a Tenhulzen Automotive caster/camber gauge from Summit Racing for something like $150. Pretty nice piece, frame is aluminum so it's nice and light and the gauge itself is digital. Can zero it on the floor, which saved a lot of headache tring to shim the cribbing level. The only downside is it has just two points of contact, so it won't hold itself in place like some of the other gauges, but it's still easy enough to use and reads repeatably. 

For toe, I made a string box with a couple pieces of conduit and some jack stands. Tried drilling holes to tie the string to, but i made them too small to thread it through and ended up just wrapping it around instead. I'll probably cut grooves in the pipe next time instead. Spent a lot of time meticulously squaring everything up and then checked and rechecked prior to each measurement.

This is the first serious home brew alignment I've attempted, aside from "just get it good enough to drive to the shop without killing yourself" type deals. (Although the last one of those I did, when I lifted my Jeep, I actually nailed everything pretty much dead nuts mostly through dumb luck and measuring toe between the tread blocks of the tires.) I think it turned out well, all my measurements were double-triple-quadruple checked and seemed to repeat reliably. Results are documented below:

Up front, I pretty much dialed in as much camber as I felt comfortable with given clearance available. The inside shoulder started getting dangerously close to the spring much beyond .7 degrees, although I could get as much as 1.3-1.4 on the drivers side. The passenger side didn't seem to want to go as far, but I just set it to match the drivers side anyways. Caster is about even and seems reasonable, not that I can do much to adjust it anyways. I set 1/16" of total toe out on the front, which seems like a reasonable starting place for a dual purpose street/auto x car. Rear is set to zero toe and camber is at -1.8 since I cant really do anything to adjust it for now.

I also picked up a new set of ST sway bars for stupid cheap with the eBay 20% off coupon a couple weeks ago. Just threw the front bar on for now.

Today I needed to get a shake down run in, get everything up to full temperature, run it at road speeds, make sure nothing leaks, or vibrates, or falls off, or whatever. Still haven't gotten the antique plates in, which were apparently held up over a $5 fee the tag and title place failed to collect, so I just ran around the block on a few back roads.

First of all, holy E36 M3 does this thing rip! I wasn't even getting on it a lot, but it freakin moves! No weird vibrations, drove straight, alignment felt fine, and the only minor leak is from a coupler in the one heater hose that i thought I had fixed before. Speedo isn't working for whatever reason either, but the fan is functioning as it should, which I was worried about since I pretty much guessed at the wiring on the Volvo relay. More concerning was that the front tires seem to be rubbing the fenders, which I had worried about just eyeballing things after putting the springs on.

Hella tucked, yo 

Tires looked fine, but I was taking it super easy around corners and this definitely needs to be fixed before next weekend. I'm fighting a few competing factors for space up front, the huge ass springs on the inside and the fenders on the outside. The wheels are 17x8 +35 with a 6mm spacer. Obviously I can take the spacer away and solve the fender clearance issue, but then that severely limits how much camber I can dial in. Think the most expediant solution is going to be a slight fender roll, as it won't take much at all. Ultimately I really need smaller diameter springs, though, for a couple reasons.

Sitting in pretty good shape now for next weekend, gonna be auto crossing all day Saturday and Sunday. Can't wait!

Good work!

That is the dream I had for this car!  Thanks for completing it for me!

Looks beautiful! 

Want to build mine? 

Thanks for the compliments Rob, really happy with how it's turning out as well! If and when the time ever does come to sell, I'll give you first crack at it. 

Andy,

What's the status of yours? I'd be happy to lend a hand along the way and you're more than welcome to come check mine out sometime. 

Next week I plan to start pulling the engine out of my doner vehicle. I've said that for the last three weeks. The thing I'll eventually need help with is wiring and fueling the new engine up. 

Yesterday I finally got to autocross this beast for the first time, since our March event was canceled due to snow. Weather really wasn't a whole hell of a lot better yesterday, with heavy rain and even lightning at times.

The rain had let up, but the course was soaking wet for my "morning" heat (which didn't get underway until well after 1pm due to a stoppage for the aforementioned lightning), making for challenging conditions, to say the least, in which to learn the car. Having also not driven competitively in nearly a year and a half (That enough excuses yet? Oh, wait, tires weren't really scrubbed in yet either ), I had a lot of rust to knock off as well, so my first four runs were super conservative, just kind of puttering around the course to times in the 64-65 second range. 

By the time my afternoon heat was ready to run, the course, while still mildly moist, had dried significantly and grip was notably improved. So, of course, I came out super aggressive and looped it not once but twice in my first run. Things picked up from that point, however, and I started steadily dropping time, which culminated in a 60.668 my last run of the day, good enough for 4th in SSM. I beat a Miata with a stock 1.6 making probably <1/3 of the power I am and an Elise that was a DNS, and was still 4.5 seconds off of the class leader.

Nonetheless, I'm encouraged with the results.  There is a lot more  time yet to be had out of both the car and (especially) the driver. I really wasn't even beginning to find the limits of the car until the last few runs and should be a lot more competitive as the season rolls on. The car ran great and held up well all day, though I've got some random thoughts to collect below, for my own benefit as much as anything:

-Spent a lot of time fiddle berkeleying with tire pressures. 32psi all around seemed to work well in yesterday's conditions.

-Going through the cones, the size difference between this thing and the Camaro feels massively amplified. This car is way easier to thread through the cones in comparison.

-I may need to make some tweaks to my cooling fan setup, as the coolant temp started climbing a bit more than I would like to see during an extended period of idling in grid due to a timing malfunction. I've got the fan set to come on at 215 degrees right now, IIRC, and temps will climb to about 220 before the fan stabilizes them and they start to drop. Once it kicks on, it seems to handle things fine, I just think I need to drop my "fan on" temp by maybe 10 degrees for a little extra margin of safety. This has been an issue sitting in traffic on warmer days as well, though anytime the car is moving cooling is more than adequate. 

-Balance tended strongly towards understeer, which was most noticeable in the higher speed sweepers (though that's probably because that's where I was pushing it the hardest.) This is not surprising to me in the least due to the staggered tire setup and limited camber on the front. I think I'm going to try slotting the holes in the strut tower to hopefully get at least -1.5 degrees  of camber, which should open up some more room for bigger tires as well and maybe jump to 245s or so at some point this season.

-I've got mixed thoughts on the manual steering setup for autocross. On the one hand, the feel/feedback is superb and it's incredibly easy to find the edge of grip and drive the car right on the limit in steady state cornering. I like it a lot on the street too, and the effort hasn't bothered me at all, aside from being a minor PITA to maneuver in and out of the garage. BUT, the effort required made it really difficult to keep up with the steering inputs required in autocross. I found myself getting "behind" the car at times, shuffling hand position on the wheel, and think I could have possibly saved both my spins had I been able to correct more quickly. And of course if I go to larger front tires at some point that's only going to make things worse. I'm undecided whether I want to make a change yet, but I'll be thinking about it going forward. 

-Had some issues with wheel hop off the line, which I haven't experienced yet. Not sure if that's just due to the conditions yesterday or because I've been taking it easy on the street, but stiffer diff mount and subframe bushings, along with a pinion snubber, should help. 

Next event for Susquehanna region is only 2 weeks away, and I'd like to try to  sign up for auto x at the Carlisle Import Show this weekend as well, so I'll run the car as is at least for those next couple. I still have a ways to go until I'm driving up to the car's limits anyways. I'll try to post some videos from yesterday too when I get home tonight. 

In reply to Andy Neuman :

How's you build coming along?

Fuelling is actually pretty easy, I kept the factory hardlines up to the firewall, then ran some AN6 adapters and lines from there up to a C5 'Vette filter/regulator on the firewall. That's the key to adapting the returnless fuel system on the motor (though I think this varies depending on what donor the engine came from) to the return style setup on the chassis, as the C5 filter/FPR has ports for both send and return to the tank, as well as a single outlet to the fuel rail. From there, more adapters and AN6 line to the fuel rail. I can try to put together a parts list for you when the time comes. I didn't do anything with the fuel pump, but IIRC it already had an upgraded Walbro pump when I bought the car. I'm also not running any kind of evap system.

For the wiring harness, I had mine sent out to Ronin to strip out all the unnecessary crap and mod it, which was $250 well spent IMO. They sent the harness back with everything labeled and ready to go, all I had to do was run the wires where they needed to go and solder it all up. 

I suppose I should update this thread, since it's been a while and I've been tinkering again lately. But first, let's back up a step. 

The car's first full driving/racing season was largely a success, as the car proved to be mostly rock solid reliable and a blast to drive. I had one major breakdown that resulted in it missing an auto x, caused by the cheap circuit breaker for the battery failing, but other than that just little things here and there. I did delrin subframe bushings, a pinion snubber, poly front control arm bushings, rear toe bushing eliminators, and stainless braided soft lines for the brakes sometime last summer. Along with some tweaks to the alignment, it's handling better and understeering a bit less, but still needs some work. Other than that, I don't think much else has changed on the car since my last update.

So lately I've been trying to clean up some little things that maybe could have been done a bit better and have been nagging at me. First and foremost was the unused wiring plugs hanging around the engine bay. One day I just started picking at some of it and before long I ended up with this mess:

Went through everything with the factory service manual and made pretty sure I knew what it was before trimming the wiring back to the fire wall and heat shrinking the ends. I then re-wrapped the harness with that braided loom that, IMHO, looks so much better than the plastic corrugated stuff. The results are subtle and it's purely an asthetic thing, but it makes me feel a lot better.

Still need to move that stupid fan relay, but the factory coolant overflow bottle is now gone. I picked this guy up on eBay and need to make a mount this afternoon. Probably going to hang it off the driver's side head on a piece of aluminum angle where the power steering pump would normally mount.

The other task for this weekend is fixing a fuel leak that has developed. I have a feeling this has been going on much longer than I had initially realized, as the gas mileage has been less than expected for a while, but since being parked for the winter it's worsened to the point of a steady drip after the fuel pump runs.

I traced it to the hardline on the feed side, which necessitated dropping the subframe again to get it out.

Here's the culprit:

I'm about to run to the auto parts store now to grab a roll of hardline, gonna bump it to 3/8" from 5/16" while I'm at it. Also debating whether to move the 'Vette fuel filter/regulator to the back, which would simplify the plumbing and clean up the engine bay a bit, but I'm not gonna drop a small fortune into more fittings and lines to do it. Have to play around a bit and see how much of the current setup can be reconfigured and reused.

So more to come later, and I'll fill you in on whats next on the agenda 

Time for another update:

The fuel line has been replaced. I decided to leave the setup as-is, with the filter/regulator mounted on the firewall. There just wasn't a good spot for it out back so it wasn't worth messing with.

Made a mount for the new coolant overflow bottle. The only suitable piece of scrap aluminum I had already had some cuts and holes drilled in it, so that's why it's kinda goofy looking, but it works. Mounts on the driver's side head, where the PS pump would usually go.

After this, I pulled the carpet out and proceeded to spend many mind numbing hours with a hammer, screwdriver, and chisle scraping out the sound deadening tar. The upside to working in a freezing cold garage this time of year is the stuff was brittle enough that I could chip away at it in small chunks. Eventually I was left with this:

There had to be 20-30lbs worth of that stuff. I'm hoping a wire wheel will take care of the remnants still left on the floors, then I'll clean them up and paint them. But first, I've got some more work to do...

Back around Christmas, I scored a hell of a deal on a pair or Kirkey road race seats, with an extra brand new cover and three harnesses (one of which is still current). 

So of course if I'm doing fixed-back seats and harnesses, that is going to necessitate a roll bar. After researching some of the off the shelf weld in kits available for the FC, I just decided to get a custom bent bar from S&W Racecars in 1.75" OD .120" wall DOM. The main hoop will land on the crossmember underneath the storage bins, which I'll reinforce with .120" sheet metal. 

Faced with the prospect of welding a roll bar, I decided it was time to upgrade from my $99 Hammer Store special flux core welder and sprung for a Miller 211. This thing is berkeleying awesome.

Spent a couple weekends building a cart just to play with it before tackling any car projects.

While I'm waiting on the roll bar, yesterday I finally started looking at mounting the seats. I bought some pre-fabbed Kirkey brackets,  which were probably a waste of money in hindsight but oh well, and cut the stock mounts out.

And that's pretty much where I am. Going to spend some more time today trying to figure out the perfect seating position and a mounting solution, which is proving to be a challenge. 

I spent a lot more time sitting in the seat and moving it around, then staring at the floor yesterday. It needed to go about an inch right and a flat surface to mount to. So I borrowed some room from the trans tunnel:

Plenty of room there for the Y pipe and driveshaft, but the driveshaft loop needs to be remounted or, more likely, find a new home. I might just remake the thing since it's kinda E36 M3ty looking anyway.

Made up some mounting plates utilizing some Cardboard Aided Design and .120" sheet I bought for roll cage mount plates. "V" for vertical, "H" for horizontal.

Tacked them in place and made some filler plates for the gaps.

And finally seam welded it all in place.

That's as far as I made it. The seat sits right where I want it now and has good solid footing on the inboard side, but the outboard side needs to be spaced up about an inch. A 1"x2" tube welded to the floor and sill should do the trick. 

Should I add any additional reinforcement to the mounting points beyond this? I feel like I should at least replace the sheetmetal crossmember at the forward stock mounts with something.

First time I’ve read this thread. Car looks great!