In reply to infernosg :
But the side mount does not run into the FFE trigger kit either? interesting - as that is my setup as well lol. Thats why I enjoyed reading your thread I was thinking how similar we have had issues but from 2 totally different applications. That tapered bore was exactly the one I wanted to go with as well. I'm torn on not having to relocate the alternator as I like keeping high up and out of the way of water crossings but it is heavily covered underneath however its still incredibly dirty always but that's rally I guess...
Apart of me is still considering just do a IDA for sake of packaging and ease and it will all have to be changed anyways when the semi PP comes into play.
For my gearing I really need to move the peak RPM closer to 9k or even a little over 9k as shifting at 7500-8k where mine runs out of steam puts me just a bit below my peak torque. If I can shift at 8500 its a perfect sweet spot to stay in the powerband. Not sure yet if I will stick with the 4.10s or go to 4.857s from mazdatrix but that option is on the table still.
Pete:
No presilencer! just 5' runners going to a 2.5" pipe right to the muffler! I think he is running just a streetport as well.
I should have recored the roller dyno at the car show, it was all quiet until I started getting going up the RPM range and everyone starts to turn around because they can't hear anything anymore.
In reply to fidelity101 (Forum Supporter) :
Yah, a friend of a friend had a Subaru meet at his dyno shop, and I was invited along. So after all these sweet clean Subarus and some Chargers and a sweet MA70 Supra and a RB25DET swapped S14 were on the rollers, finally this beat to E36 M3 looking barely idling car goes to the rollers. Now Eric knows rotaries so when I told him to run 2500 to 10000 in 3rd he just nodded 
The funny thing is I had not really a rev limiter but a power killer, at 9000rpm the MS would add 25% fuel so the engine would lay down, which is safer than the shock loads of a cut. Peak power was at 9000 and then it just dropped like 20%... then started climbing a little again 
He was like man, it would have done another 20whp if it didn't do that.
Meanwhile during the run, everybody stopped milling around and watched as the revs went up.. And up... And up. And then up some more. Beat the 240 by almost 30whp too
In reply to Pete. (l33t FS) :
On the old setup I did do a few dyno pulls without the filters. It only added a couple WHP but by that point my IATs had already started to skyrocket. Sucking in air from the engine bay is no good. It's also possible the losses from the long intake made the entire system insensitive to the filters. Oddly the new setup didn't really shift my power curve at all. It just keeps going now to 8200 RPM before falling off. The one time I dyno'd the new setup was without filters. I haven't been back since installing the airbox. I anticipate some power loss but the benefit of IATs that are <10F over ambient is much better.
In reply to fidelity101 (Forum Supporter) :
My side-mount kit came with little 10 mm spacers for the front cover since the front side housing is wider. Conveniently that is also the same width of the mounting bracket of the FFE kit. So I just ditched the spacers and used the FFE bracket in place. The only negative about the side-mounted configuration is I'm running a slightly larger FD alternator. In order to remove it I have to undo the oil cooler line at the front cover because the lower, long pivot bolt interferes.
My slightly-lower-than-average powerband is due because of the 4 port engine, I think. The benefit is I make 160 ft-lbs of torque. I know IT guys used to run stock or mildly-ported 6 port engines with IDA carbs and saw 190-200 whp at like 9500 RPM but only made like 120 ft-lb. I've been shifting at 8500 RPM but would probably do better to shift at 9000 since that would put me nearer my peak torque at 7500 RPM with Miata gears. 9500 would be even better but I'm loosing a ton of HP at that point. I'm running the 4.30 rear end, which is an improvement but I think something like 4.77 would be better.
Right now, my ideal build would be the largest possible street port on 13B-RE side housings with lightened, clearanced and scalloped RX8 rotors. The RE housings have the largest port area of any 4-port side housing but still over all less than the combined secondary and aux ports on a 6-port engine. So I'd get the benefit of even more top end and the scalloped, higher-compression rotors would hopefully minimize the torque loss. That and I still have a somewhat streetable engine that will idle at 1000 RPM.
good details! the oil cooler situation was a concern of mine as well it looked tight, I run FD alternator as well - I wonder if rx8 alternator is any different... I should check.
160tq is pretty sweet, I can't seem to crest 140ft lbs but with the dyno has shown is that I start out around 100ft lbs at 3500 and only gain 30-40 over the whole rev range so its pretty flat I just need to lay in the gas more.
4.30s isn't a big jump from the 4.1s even with my rx8 s2 gearbox for the same money nearly 4.777-4.78s seem to fit better, 8.8 IRS swap isn't really needed either not sure I need that big of a ring gear for 130-160ft lbs lol...
Right now my future build is going to be something of the similar:
- re grind f/r irons with existing streetport (s4 or s5 4 ports)
- increase port on center iron to racingbeat renesis streetport template
- semi PP S5 NA housings with custom exhaust sleeves (inconel again)
- lightened, clearance and scalloped RX8 rotors (full race rotors) using rx7 apex seals
- retain rx8 stat gears
- custom intake?
I'm aiming for 220-230whp if possible.
In reply to fidelity101 (Forum Supporter) :
Weren't you petitioning ARA to start allowing more than two rotors? What happened with that?
In reply to infernosg :
4 ports have it all over the 6 port engines The engine I talked about upthread was an old school 4 port. 12A end housings and GSL-SE center. I think you would collect air all the way around if you tried to make the runners even Turbo II sized. The mid range felt a little stronger than my old Turbo II based engine but only barely.
I like the 13B-RE idea (especially after Logan's build) but have you even seen one for sale anywhere? One popped up on eBay over the winter with a BIN of something crazy like $7k. Mazda still churns out brand new FD engines for about $4k.
¯\_(ツ)_/¯ said:
In reply to fidelity101 (Forum Supporter) :
Weren't you petitioning ARA to start allowing more than two rotors? What happened with that?
I am but thats a wasted effort, plus I need like a solid 15k to 3 rotor swap which is a bit out of the question at the moment but maybe one day! or the next rally car or I just sitck to NASA events but I'm so close to some good ARA events. I could always just enter and say F U because in the end nobody cares.
it would be ideal to run a 3 rotor, streetport/EFI hardware ITBs custom exhaust, different haltech elite unit to run it but if 3 rotor is allowed makes me wanna do a more wild port and look at AWD NA class car then but its purely speculation at that point - the rules will change and everything will be a moot point or it will be a new named organization run by basically 90% of the same people and nothing will change.
In reply to fidelity101 (Forum Supporter) :
I've eyeballed the Ford 8.8 swap as well since the number of available ratio options is enticing. Problem is, once you factor in all the costs you're well over the $1000 places like Mazdatrix are asking for custom 4.77 gears for the stock rear end. There's also the weight penalty of the 8.8. For now I've been content to wait and see if any of the old Mazda Comp 4.77 units pop up for sale. Once I get a few other things sorted out I'll probably seriously consider dropping the cash for a custom pinion gear. The thought of rebuilding the rear end is somewhat daunting, though.
If my dyno results are even remotely accurate those numbers should be easily obtainable with that plan. The biggest restrictions in these cars are the intake, exhaust, tune and how driveable you want the car to be.
In reply to Pete. (l33t FS) :
I'm actually running Logan's street port template on my S4 TII side housings. It's pretty aggressive. We scrapped a front side housing because it was a thin casting. The RE housings should offer even more area. You can also get aftermarket cast IDA manifolds for them just like I have for the TII so other than making a new engine it would be a pretty minimal impact on my entire setup. I personally haven't seen any come up for sale for a while. I keep telling myself if an entire engine or even just the side housings pop up I'm going to grab them.
In reply to infernosg :
I have always wondered how hard it would be to use a Miata dropout in an FC. That way you can use common ring and pinions, like the Sportage 4.78s that I used to pick up for $100ish all the time. Or for that matter, use the Sportage dropout. The whole assembly was plug-n-play for an '84-85 rearend, even the driveshaft fit. (Flange is also used by the 1.6l Miata) I figure you'd have to do some creative surgery on the crossmember, maybe make a removable center section so you could get to the driveshaft bolts.
As far as drivability, from '10ish to 2018, I had half bridge and full bridge engines in my car. Daily drove them, drove cross country, noise and annoyance factors were the same as a street port. I had over 55k miles on the full bridge before I got a hole in my air filter and killed the side housings. Boo.
In reply to Pete. (l33t FS) :
I know the aluminum rear "housing" with the wings is nearly identical between the FC and the Miata. Miata guys claim the FC housing is stronger and swap them directly. It's a good idea, though. The only things I think that need to be sorted are some kind of front mount to prevent the assembly from twisting up/down and then a longer driveshaft to account for the length difference of the 3rd member. I'm probably oversimplifying. I imagine if it were this easy SOMEONE would have done it by now given the rear end options available for the Miatas.
I guess that's where driveability being subjective comes in. I chickened out from a bridgeport because I didn't want an on/off switch for a throttle. I'll admit to have never driven one and I'm only going off what I've read.
In reply to infernosg :
Total Bob Costascat, and the increase in low end and midrange torque was awesome compared to the street port's all top end surge. The only annoyance is trying to cruise at certain speeds, where the engine is in its stutters. A stock weight flywheel makes this tolerable, it was beating up transmissions and clutch disk springs with the 9lb. It can be tuned out with ignition timing tweaks.
The FC pinion is way long, and IIRC the aftermarket gears were so expensive because they were welding extensions on the end of short nose gears.
okay i got filterpwned.
mazdatrix still does this for their 4.78/5.12 R&P which makes me hesitant for a rally application but I'm curious none the less...
If I don't go semi PP I would probably just half bridge these and call it a day, thats a happy medium with plenty of around townability still. I really liked the responsiveness but @Dave Etsey can comment on this engine better than I can because he ran the one I built for him this way for about 5 years.
A little side by side comparison, out with the old and in with the new!
just need to pack it up and ship it out for some jethot coating now then wait about a month or so to get it back.
So meanwhile the exhaust is now on its return trip back I got busy on doing some pre-race season maintainence.
pretty much everything....
needed to fix some of the damage from CUPR and re-attach the upper mounts for the oil cooler:
also these fixed headlights have been in shambles for quite some time now and have been more problematic than anything so I am going back to fixed pop ups given that 4x6 or 7" round LED headlamps have become so cheap and effective over the last 10 years so I don't need to resort to this patchwork garbage of neatness (J30 headlamp housings, stock J30 high beam, low beam was retrofitted with S550 Europe Mustang bi-function HIDs, so yes I had 2 high beams) but the old plastic housings could not take the abuse and they were barely hanging on in there so they needed to go.
still a lot of work left to do there cleaning up wiring and bolting on the popup structures but meanwhile in the front I have to overhaul the front shocks, they are sticking and I never serviced them over the several rallies I did on them (bad idea) so these need attention:
I have no idea how to overhaul these but I've heard they are pretty easy.
also to rebuild the strut tops:
the rest of the front end seems fine and will just get greased.
so moving onto the rear, the diff needed to come out and be inspected because it was mostly and open diff after a few corners and found this:
this diff was put together in the fall of 2015 so I think it had a good run but I'm sure ive been on an "open diff" for the past few years.
so with some of the LSD rebuild parts being NLA I opted for a rally tailored 1.5 clutch type diff, cusco doesn't make one and the KAAZ units in rally I have heard don't do well (from fiesta to Subaru and then some...) so I opted for a nice clutch type from OS Giken which has great reviews. The problem is that with my Non turbo rear end/7" ring gear there isn't a lot of options but you can order a 94+ 1.8L miata diff and swap it in, I use my rx7 ring gear and ta da! Even the bearings are the same part number between the two...
easiest way to remove the diff in this car is to lower the subframe, so I went to town cleaning many pounds of mud/sand/silt/rocks from within the crossmember and ontop of the diff,. I am also using this time to freshen up anything that needs attention.
I had these spare control arms a while back that got powdercoated with a batch of wheels and I forgot about them until I accidently found them looking for other parts so these will get the bushings replaced and re-installed:
after that I found an rx7 in the junkyard that is surprisingly rust free and mostly picked over but I did manage to grab some more NLA parts and unique hardware!
the bolt on the right came off my differential and was purchased new in 2015 from Mazda, the one in the middle was off of the unknown mileage junk car, even the camber adjuster hardware came out effortless! Usually these seize in the bushings and need to be forcefully removed... with force.
well... back to work!
once the exhaust is back and the rear end is put back in the car I will get the tune updated and then I can begin on floor work + halos and 6 point belts as my current 5 point belts expire December this year so once this stuff is sorted out I can begin that aspect of the car.
In reply to fidelity101 (Forum Supporter) :
Fairly sure Evan has an RX-7 diff in his Miata. The only thing you have to worry about is '84-85 diffs don't have the receiver cutout for the stub axle retainer clip in FC and Miata.
yeah so I'm good, just waiting on parts to arrive so I can continue to put things together and drop off a bunch of stuff at a machine shop to get bearings and bushings pressed in.
which should arrive over the next few days. meanwhile I can plug away at small things and weld some stuff up.
EVERYTHING is being worked on the list.
final several days of free time is meaning lots of good progress, the list keeps growing too but for the good.
needed to fix some rust areas and also spent the time cleaning inside the fender areas and prepped for some stich welding and seam welding.
its not total but I got some areas that are known to be weak in this chassis but I have seen no signs of cracking or anything, metal welded up pretty okay too.
Diff is put back together and I've begun chopping up a spare subframe to reinforce the existing subframe. I seem to be making egg shaped holes where the lower rear control arm mounts to the subframe...
new seats and seat mounts arrived and the exhaust just returned from ceramic coating!
That coating makes it look like a single piece of cast iron- interested to see how it holds up.
In reply to ¯\_(ツ)_/¯ :
its their offroad coating they use its mid tier heat wise but is meant for baja 1000 vehicles because the smooth ceramic coating will peel away once it gets a chip and then just unravel.
car is back together, the to do list is nearly done.
reinforced the subframe heavily.. by sacrificing another subframe with cutting it up and grafting it to the one I use.
and put the old control arms that got reconditioned (Powdercoating, new bushings, spherical bearing delete) and then just spray painted the others because replacing the boots was too hard of a task...
rear end is completely back together and a fresh set of rear pads (I lost/mixed up my rear pads and gave up and ordered new, they are 20 bucks...) but right now I am waiting on the fronts to return from California where they were rebuilt at streetwise motorsports.
TA DA!
I also got my spares re-bearinged and had the axles rebuilt by a local shop which included my spares.
but is cosmetic and legal side of things I was able to freshen up the lighting and the front bumper after cleaning up and seam welding the under side of the frame below the fenders.
going back to pop ups and no more HID jank J30 headlight debochary I did years ago, off the shelf LED tech has become quite nice so this was an easy solution.
but I also did the tail lights too :)
now all I gotta do is hook up the dual wideband and dual EGT setup then get this thing re calibrated once the shocks arrive and the car is mobile again.
after that is done I have a lot of work on modifying the floor and installing new 6 point belts with halo seats!
all of this to do before February's Sno*drift but it doesn't look like I'll get the shocks in time for January's rallycross, so valuable car beating opportunity is gone :(
What's the scoop on the LED popups? The halogens in my MR2 could use an upgrade.
In reply to ¯\_(ツ)_/¯ :
std 5x7 off the shelf amazon special, I just got them from a name brand as my former lighting days lumileds is a brand within phillips who are very experienced LED maker for automotive applications. These look a lot better than the knock off or bug eye style
https://www.amazon.com/gp/product/B08DDFTVYQ/ref=ppx_yo_dt_b_asin_title_o07_s01?ie=UTF8&psc=1
but when I ordered them they were only about 115 each.... I dunno why the sudden price hike
there should be a similar style for 4x6 or 7" round as well. If you want the sharp cutoff line you will need a projector style still but this reflection type should be fine.
also they are perma popped up as I have welded the fixture together now.
