Years in the making: Franken Wankel! 1986 RX7

When I refreshed my rocker panels I had a gap in the back side that I needed to close out to keep from dirt accumulating and then found I needed some additional rust repair. luckily I had cut out some rockers from a car in the junkyard so it should look pretty nice versus my drunkenly welded mess of sheet metal. 

ughh, its in a hard to reach spot going to take some time making patch panels here but luckily they wont be seen. 

pin stands got added by a friend of mine who is a far better welder than I am:

and then to cover that slop:

here it is mocked up before welding it to the car, don't worry the pin stand holes will poke through, just got to clean this up and then do the driver side plus some rust repair by the other rear pin stand mount. I feel like I'm doing cab corners but the front cab corners have long been replaced. 

now just to do some heavy grinder action and repeat the fix for the other side: 

I forgot to cut out the space for the pin stand before but the hammer really helps you find it ad hoc which is nice. quick hole saw action and were back in business. 

Rebuilt the rear suspension/brakes/wheel bearings/etc, shocks have new springs and fully serviced/functional and I was ready for our SCCA's region's rallycross!  I'll tackle the front end this month in preparations for rally(s) in the springtime. Because this was tarmac event, I needed some new tires and I just so happen to pickup tire streets as a tire sponsor so I got a good discount on some accerla 200tw tires and was awarded some MRF gravel rally tires!

haven't had fresh summers on this car in about 10 years, I had to dismount my OG rivals finally as they were pretty bald and starting to rot but based on the amount of pavement driving I do Im sure these tires will last me another 10 years haha.

but anyways enough rust repair and cosmetic stuff/weld roasting me: EPAS!

took a bit to get used to, the center is a bit numb and it kind of feels like a video game but the effort to slide this around is so much less I'm excited for whats to come, unfortunately after the parade lap I took a hard first run and ended up with the steering column in my lap:

Rivnuts were a terrible choice for this application (its now through bolts, hardened washers)

as I was bolting the steering rack through the chassis and threading into these m8 rivnuts that were in the sheet metal dashboard, I think this has been fatiguing for a while and was bound to happen any time, possibly even before without the extra mass from the EPAS unit. Glad this happened here and not out on stage so because of that terrible run I was out of competition effectively for the day, took a mechanical to fix it and went back at it for the fun of it and further testing... and by testing I mean drifting!

pictures from this event were epic and I think with the revised intake setup and hood/bodywork I can now tackle low water bridges or huge puddles without the fear of sucking up water as I went WOT through standing water multiple times per run and had no skip or hesitation from any ingestion of water, which is a huge plus. 

I wished I had power steering a long time ago, it was far easier to slide around and correct, I have a few videos (helmet cam & exterior) I'll need to post up soon too. Lots of fun!

Man, this really has me considering EPAS. I never really notice it on track but after a full weekend my arms are pretty fatigued. One thing I don't understand is how much control the kit's control module offers. Does the assist adjust based on steering angle/load or is it pretty much one level of assist provided by the potentiometer? My pipe dream EPAS system would be speed dependent with the assist controlled by a variable output from the Haltech ECU. Would this kit support something like that? The other concern is the power draw. The kit is offered with a 60A fuse. Does it pull anywhere near that?

In reply to infernosg :

That was the driver for me I kept getting elbow/hand/wrist/arm/finger injuries from catching the wheel/having the wheel ripped out of my hand, rock impacts or sudden movements because I needed to use my whole body to throw the car into the corner given the transition. The module seems very linear its just a knob if you want more or less assist, it has no sense of speed but I'm sure you could integrate that into some aftermarket ECU but like all aftermarket ECUs it is a pretty dumb CAN system. OEM systems do this now but are more heavily integrated into the vehicle platform and electronics, doing on an end user scale is much simpler less configurable. There is no SAS on this. As far as power goes I would really need an inline ammeter to see how the power usage is but I had no voltage issues out on track for the minute/minute 15s runs I took. 

For example, during this event I stalled the car on one of my spins and I needed to battery key cycle it for the EPAS ECU to turn on, I had no assist for the rest of that run. the dashboard works like this too, if the ECU doesn't pick up the dash upon power up (or vice versa) it shows me only the data that is hard wired to dashboard display which is only battery voltage and fuel level. 

Oh man... remembering the last Detroit event I ran with the black car, post quickener install, and there were corners I had to take sideways if possible because I did not have enough upper shoulder strength to turn the steering to carve the corner.  Which is why I spun a few times.

EPAS is awesome but it needs BEEFY mounting!

I have a EPAS unit from a Saturn VUE, and a controller from a Prius.  Supposedly the Prius controller will work with it, and it is self-contained, it doesn't require a speed signal from CAN to work, so the assist will feel natural and have proper feedback.  Was going to mount it in the RX-7 but the fabrication involved threw me off.  I will probably put it in the Quantum if only to get rid of the hydraulic pump that likes to lose all assist halfway through a run and not come back until you shut the engine off.

In reply to fidelity101 :

That's what I'm still confused about. Is the assist level constant and all you do is adjust how much assist there is? The various installation instructions seem to indicate there's some kind of sensing function but I guess I'm not sure that applies to this application. If it's just a constant assist with variable level via potentiometer it would be really easy to bypass the potentiometer and use a variable voltage output from the ECU based on vehicle speed, etc.

In reply to infernosg :

That is the way GM controllers work, they get a speed signal via CAN.  The aftermarket boxes bypass that.

The Prius controller does not do it this way, it is simple negative-feedback control like hydraulic power steering.  In hindsight, they probably do it this way because Priuses have a honking big battery and a very good DC-DC converter to keep the power steering fed.  No need to worry about overloading an alternator.

In reply to infernosg :

its just a knob, anti clockwise is less assist, clockwise is more assist. 

In reply to fidelity101 :

This is definitely something I'll have to look into if I ever find myself with an excess of funds...

I meant to ask on the previous page. Regarding your front hubs do you set the bearing pre-load based on the FSM instructions, just torque the retaining nut to a certain ft-lb, or something else?

In reply to infernosg :

I'll reach out to the guy who made the kit and see if I can get any window of operation or parameters for this that could help. I am not sure if he is using some aftermarket controller or a modified OEM one. 

For the front hubs I set them like a trailer axle just a touch tighter as they will loosen a tiny bit to spec. I have no torque measuring method for how the FSM calls it out. as long as the hub spins freely/nice and has no axial play. I just send it. I will usually go through a season or two before putting the hubs in the oven and pressing the races out. I don't mind tossing a set of cones in it every year with fresh grease. Which is actually the plan to do this week to get ready for this years race season and hopefully next!

In reply to fidelity101 :

I've always tried to follow the FSM - torque the nut to ~20 ft-lb, back off to finger tight, measure drag and then tighten until desired pre-load is met. I have a small spring scale I use to pull on a wheel stud to measure the force it takes to spin the hub. I don't remember the FSM spec but I usually shoot for around 2 lb of pre-load on top of whatever drag caused by the oil seal, grease, etc. I just went through my front hubs this past weekend: pulled, cleaned, and inspected everything, re-packed the bearings, etc. I ended up torquing both sides to 8 ft-lb. I haven't put the wheels back on to verify play because I still need to bleed the brakes. I may go back and bump the torque up to 10 ft-lb because as you say they do loosen a bit. I keep thinking I've read that some guys torque them all the way up to 20 ft-lb or something.

So, what have we learned? EPAS needs some more reinforcement like Pete mentioned, even after my quick fix I was playing around with it in the garage and noticed that the mounting points do tend to flex a lot so I need to reinforce those with some more metal bracing, add that to the to do list but it looks like I still don't know what I'm doing drifting as I have a lot of wheel work even to make the most subtle early corners, get lost in the wheel enough to make me re-visit my increased steering speed idea, take a look at the helmet cam and see for yourself.

this was a short run that got red flagged for other reasons, not me, and not much drifting is available for the rest of the course, just this part. 

So I opted to go the drifty boi route and get new knuckles, which are pretty beefy in comparison to stock but you can tell the original ones were mass concerned, where as this design was more focused on the cost of the tooling to make it. 

we have another rallyX at the same location in a few weeks so it will be a good comparison and if I don't like it I can go back to stock and try again but while we are in there good idea to service the shocks, overhaul the front suspension while I have the time and get the rally prep work done.

rear is all set now so its time to look at the front which lead to some interesting observations... 

remember this? 

well here was the landing!

I had serviced my front shocks just before that event (March of 2021) and haven;t touched them sense. can you guess which side this top hat came from that also has a collapsed shock insert?

yikes! it guess with these all bowed out it explains why I had such a hard time adjusting camber on the passenger side because it was wedging itself against the car. no biggie, just thicken the stack!

then just weld them up and replace the hardware and reinstall once I get the shocks returned to me, meanwhile I can work on steering shaft mounting reinforcement and clean up my rocker job. 

car should be all set for another 1-3 years of abuse depending on frequency of events, not much left to do which is good because its about to get busy this spring/summer with rallies!!!! <3

Definitely following for feedback on the PSM knuckles. Probably not something I'd ever do without first going EPAS but for the price they're a good alternative to OEM with the stock ones eventually wear out. I'd be really tempted to try to take some of the mass out of them, but in your application probably just leave them alone.

Also, this picture scares the crap out of me...

There is tarmac rallyX round 2 this saturday so it should be a good back to back comparison, like usual I will over drive the car and drive it like a d-bag to see how it handles on the limit in a safe situation before I go hog wild in the woods and potentially hurt myself. I'm afraid I have to re-learn how to drive the car again but good news is I will do a double header at the end of the month for a back to back rallies. 

the increased steering speed was a godsend, I should have done this years ago.

In reply to fidelity101 :

Right???

In reply to fidelity101 :

That's the same reason I put power steering back into my FC.

With the depowered steering, I started to become concerned about taking turns too fast and losing grip on the wheel. And this isn't pushing it or anything, but just in regular use I would have to slow down more than usual.

My Rx7 is purely a street-car for the time being, but even so there are times when the heaviness and tendency to bump from depowered steering conspire to make the car slower than with power steering. 

funny how it all comes full circle lol 

so meanwhile I do some final prep we have a double header ahead of us! MCBRISTOL BABY!

April 29th weekend: NASA rally sport's McReary Gravel Rally in Kentucky

interrupted by a quick work trip to Chicago

followed by a Race just outside of Bristol Motorspeedway in Tennessee in the surrounding hills/forest with a special tarmac turnaround stage(s) too!

final prep and trailer packing to begin. 

its a race between the clock and my welding friends free-time: but this is on its way

after about 12 years of abuse my old radiator is starting to leak from the core, a quick call to griffin thermal products and a quick sketch I was able to get my inlets/outlets the correct size for the radiator tubing as well as a port for my heater core. I could have got the mounting tabs done too but they are at a funky angle and it would be hard to put them on a drawing correctly so the mounting tabs will go on ad hoc. 

refreshing the paint right now and a few tweaks then alignment and test drive meanwhile I continue to pack the trailer and vehicles in preparation for this camping rally adventure.

Bump!

In reply to ¯\_(ツ)_/¯ :

it sure was! Don't worry I'll get to my McBristol updates soon enough. rally hangover is hitting extra hard

Before we get into the event itself the weeks leading up to the event were busy too, having what I thought was thoroughly testing the updated suspension and steering and tested the cooling system and deemed the engine OKAY it was time to tidy up and get ready for an alignment. only a bad eye ball alignment was performed before the rallycrosses. Here is a bit of a sweep of the tire. 

In short, the new setup was quick to get used to and felt amazing. Very responsive, no more unnecessary lag of the wheel when at speed, always hard to tell with how it may feel from a rallycross because the sustained speeds are different. Luckily doing some transiting in Kentucky proved to be excellent, there isn't 100' of straight road where we was that wasn't the interstate very curvy fun roads to be had at low speeds and the immediate turn in was great. 

(driver side, tarmac tires, full lock left)

(dead on)

pretty good angle! curious to see how it felt out on stage:

Needless to say they were way off

since I was already doing brakes/wheel bearings (including refreshing spares) and all the steering updates I went with OEM new balljoints and outer tie rod ends and move the other parts to the "good known spares" box to bring with at events. 

but that was an easy fix. however spoiler alert! it was a McDouble-DNF for us due to suspension failures. 

The first rally was the McReary Rally and there we (likely) snapped an upper strut bolt that left us with quite the positive camber just before the end of SS1, we were able to cross the finish line but not much past that. It was a quick fix and came back after the 2nd service and enjoyed the fun roads and missed out on the car breaker one. The second event was Bristol Forest Rally and we made it to day 2 but failed early on in the beginning of the dirt portion of the stages; stages 1 &2 on Friday were tarmac.

this combo worked well serving as rally HQ, mobile rally living room, private sleeping quarters, coffee creation station, auxiliary electrical power and lighting unit, meal prep pod and of course ultimate rally self sustaining vehicle combination thing:

and lets not forget its comfy as heck for recce and fully equiped for anything weird, which usually happens. 

did shakedown and the car felt twitchy couldn't put my finger on it, we didn't see anything wrong visibly and shaking things didn't yield results so we moved on. 

shortly after the finish line of SS1 danger struck (video to come) 

we managed to steal a bolt and nut big enough from Nonack as a few others to fix it then I promptly broke the lower one tightening it causing me to scrounge for more hardware. My spares bag didn't have the right spares. This needs to be addressed and it always gets pushed out. When we rejoined the rally (fun runs) it was 2 turn around stages back to back, lots of switchbacks and ditch hooks, very flowy roads but climbing engine temperatures were unsettling so we backed of the pace to let it cool down from 230F to a more reasonable 215-222F window before getting on the gas again. Wasn't worth the push after already DNF-ing once. I really wanted to attempt to start the 2nd rally. 

quick re-prep and more speed holes, played with some of the ducting. I'm sure the hood scoop isn't helping now either. 

I may do the front bumper delete'and jam all that air in there... 

but shout out to team o'neil for the free BFR pic! 

I managed to finish the painting of the millen livery as a surprise for these events and nobody noticed :( 

but it does look good - and thats half the battle.