magnumP5's RX-7 Build Thread

That last pic is giving me the weirdest boner right now... AWESOME! And great progress, man.

That's going to sound sooo good...

I know right. So badass!
Thanks guys. Just getting this thing mocked up is making me eager to get it running. This was the inspiration I needed to continue working...

Damn that looks good! Might be interested in the fuel lines and an fittings...
Thanks! I'll let you know about the line and fittings once I'm done with the fuel system.

There's not really too much to update at this point. I did get a nice liquid-filled fuel pressure gauge to mount on the FPR and I did get the intake manifold installed on the dummy engine in the car. It looks like hood-clearance with the throttle bodies/fuel rail may be an issue but I've yet to confirm. I can always mount the fuel rail below the TB's instead of on top so that would give me a little more clearance. The hard part is going to be making an airbox as I currently don't have any kind of air filter (dust ingestion is killer for rotaries). I'm thinking about just making a box out of aluminum sheet and using a flat panel filter but space is tight. I've got to carefully watch the clearances to 1) the hood, 2) the throttle linkage, and 3) the fuel rail. That and I've got to make some kind of aluminum box without a TIG...

Work is going to be slow over the next few weeks busy my day job is keeping me occupied on weekdays and I have family visiting the next two weekends and Mid-Ohio is after that.
 
Looking good Jon keep it up and you'll be on track in no time.
I'm really hoping to have everything together for next season. It's going to be a busy Summer/Fall. It really is painful to keep reading about all you guys going to Mid-Ohio, etc.

Itbs are cool and all but theyre such a pain in the ass lol
Yeah. I still haven't been able to come up with an air filter solution. There are Weber IDA intake kits available (K&N) but it doesn't look like any will fit due to the fuel rail and throttle pull position. The other issue I'm running into is the size. Most IDA carbs are 48 mm whereas my throttle bodies are 55 mm. I don't think even the largest K&N oval filter will fit around my velocity stacks. The only option I've found is those little sock or mesh filters that fit over the velocity stacks. Are those worth a crap? The downside with those is I don't have any mounting point for the IAT sensor.

In better news I discovered my hood still does fit (yay!) and the rest of my fittings came in as well as did my alternator relocation bracket. I spent most of the holiday weekend out in the yard so I really didn't get too many chances to work on the RX-7.
 
I have the foam filters that fit over each volocity stack, they work the same way theK&N filters with the foam being oiled to do the filteration. they seam to work well. I remove them and clean the in the beging of the season with simple green and then hose them off, let them dry and reapply oil.
 
is the part number on the pump Aeromotive 340 Stealth 11141?
That's the one they have listed for the RX-7 and the one I went with. It isn't a "drop in" fuel pump as you can see from my pictures.

Which relocation kit did u get?
I went with the Xtreme Rotaries kit. I could have made something similar but it wouldn't have been aluminum and it wouldn't have been as nice. I know Mazdatrix and some other companies offer kits but the Xtreme Rotaries one seemed to be of better quality (see below).

The Xtreme Rotaries alternator relocation kit:

2012-05-29_17-30-39_140.jpg


I'm pleased with the quality of the kit. 100% milled and polished aluminum and all bolt holes are counterbored/countersunk. I went with this kit due to the OEM-style tensioning system. All the other kits I saw used heim joints. Installation was straightforward and I think I had more difficulty removing the studs from the front cover and front iron than setting up the alternator. Installed in the car:

2012-05-29_19-10-32_735.jpg


It looks tight between the engine and the frame rail but even at both extremes of the tensioning range there is clearance. The only issue I ran into was with the tension arm. With the alternator installed the tension arm is about .25" away from the alternator mounting point. The stock tension arm has a couple bends in it where the arm included with the kit does not. This was easily fixed with a few washers. The only concern I have is how close the alternator is to the wiring harness and if that is going to cause interference issues with the CAS wires.

Here's a couple shots of the intake setup on the car. I've got all the fittings in place and I'm ready to finish the fuel lines. You can also see the new fuel pressure gauge in this picture.

2012-05-29_19-11-06_339.jpg


I think I mentioned the tight clearance between the TPS sensor and the water temperature sensor. This last picture shows just how close that is. I think I can still squeeze the TPS pigtail in there but if I absolutely have to I can relocate the water temperature sensor to somewhere else on the water pump housing.

2012-05-29_19-11-28_122.jpg


Where are some other locations for a good water temperature sensor signal? This is for the Haltech so I want it to be a representative of the water temperature in the engine as possible.
 
is that relocation kit as much as the mazdatrix? they are freaking ridiculously expensive...

that looks sweet, but idk if imma be able to move mine like u did. clearance issues... u know the drill
 
is that relocation kit as much as the mazdatrix? they are freaking ridiculously expensive...

that looks sweet, but idk if imma be able to move mine like u did. clearance issues... u know the drill
I want to say it's comparable in price. More than I wanted to pay but it was necessary. Is the B-series narrower between the frame rails than the FC RX-7? I would think it would be wider being a truck and all. If you'd like I can try to take some measurements for you.

I've been working on an air filter setup. So far I've come up with two options: simple and cheap and elegant and expensive. Simple/cheap is what I have mocked up in the picture below. I found a K&N filter that should fit over the lip on the end of the velocity stack and clamp down. I took a $30 risk and sure enough it works. I don't know how well the "ram tube" aspect will work with this kind of filter. The other downside is the filter is too long and will interfere with the oil filler neck. Unfortunately K&N doesn't sell a shorter version of this filter so I would have to cut it down and re-seal it myself or move the oil filler neck. The idea would be to have two filters like this with one tapped for the IAT sensor. Total cost = $30 x 2.

2012-05-31_17-30-22_284.jpg


The other option is, IMO, more elegant but also much more expensive. I've been in contact with EFI Hardware in Australia, who makes my throttle body, and they have a IDA-style filter setup. I copied a few shots from their website below (I would have a taller filter). In this configuration the "ram tubes" should function as normal and I now have a common intake source to mount the IAT sensor. The downside is I'd have to order the intake kit (filter, base, and top), shorter velocity stacks, a TB-to-filter base adaptor, and potentially some spacers to get the filter base away from the fuel rail. Total cost quoted to me by EFI is $641! ($100 of that is shipping).

rotary-pro-street-kit_2203.jpg


rotary-pro-street-kit_2207.jpg


Comments/thoughts?
 
if your FI setup if Weber carb based then try either webercarbsdirect.com or piercemanifolds.com they both carry Weber carbs and parts they may have the base and filters that your looking for and there US based.

btw I am using the dual filter set up that you have in the first pic. It seems to work fine with my Weber carb.
 
What about something like this?

53.JPG
I can't see the picture at work so I'll try again at home.

if your FI setup if Weber carb based then try either webercarbsdirect.com or piercemanifolds.com they both carry Weber carbs and parts they may have the base and filters that your looking for and there US based.

btw I am using the dual filter set up that you have in the first pic. It seems to work fine with my Weber carb.
The issue I have is my throttle bodies are 55 mm and all the IDA kits I've seen for Weber carbs are 48 mm. The other issue is the bellmouth on my velocity stacks are so big they won't fit inside the typical K&N IDA filter so I'd have to get different velocity stacks. Did you ever try running different setups on your DCOE? I think for the time being I'll stick with the dual filter setup and I'll try to modify the filter height. I really only need them to be like 3" tall so all I need is another filter and to figure out how to make them shorter.
 
I used to use the single K&N filter that you have in your pic, and the car ran fine with that setup as well. I do have a 48dcoe on the car right now. I will get you the name and part # of the filters I am using right now they are foam with a stainless frame on the inside to hold the shape anda screw type clamp that goes around the volocity stack.
 
^^^ Pipercross, nice. I wonder what P/N filters they're using. Unfortunately I've only seen them available from the UK so with shipping the price is comparable to the K&N filters. K&N does have a custom filter surface so I shot them an email to see what they can do. If they can make me a custom filter I'm hoping the cost will be reasonably seeing as it is just a shorter version of a filter they already offer.
 
It's been a little while since I've updated. Three weekends of friends and family visiting followed by a weekend at Mid-Ohio have really kept me out of the garage. The little time I have spent in the garage has mostly been me staring at the car thinking. I think the only real update I have is that I've wired in the injectors. Next is the TPS and I'll be able to finish up the wiring harness on the passenger's side. In the meantime I'll take a page from Evan's build thread and talk for a bit...

I find it funny when the Protege guys complain about the lack of or cost of exhaust manifolds. I just dropped $815 on something that has half the number of runners and collectors like it was nothing, LOL! I've been talking with Logan at Defined Autoworks and he thinks my primaries should be 50-55 inches in length! That puts the collector somewhere around where the driveshaft bolts to the differential. That doesn't leave a lot of space for multiple mufflers and/or pre-silencers. Logan has a neat idea that consists of squishing two oval mufflers side-by-where the stock passenger's side muffler was. The exhaust would run from the collector, under the passenger's side axle, and into the stock passenger's side muffler cavity. It would enter and exit new muffler one, then pull a 180 and enter new muffler two and exit with a turn-down in the stock cut out. This gives the benefit of increased sound reduction and increased secondary length, which should provide a small boost in torque. I don't want to run a dual exhaust because I want to keep the driver's side muffler cavity open in case I decide to build a fuel surge tank in the future.

I know I talked a lot about air filters at Mid-Ohio and how K&N came back with a $54/per cost for my custom application (catalog price is $30). When I got back home on Sunday I stared at the filter I had for a while and decided modifying it would be more difficult than I thought. It looks like the filter media is molded into the rubber top and base so it's not a simple heat up, separate, cut, and re-glue operation. Taking that into consideration I said screw it and sent $108 plus shipping to K&N. I'm at the point in this build where I just want to get crap done so if that means paying a little bit more then so be it. Being at Mid-Ohio with everyone and their modified cars just makes me want it done that much more!

Driving around Mid-Ohio in the parade laps had me thinking about the passenger seat mount. Knowing now how much of a pain the driver's side was, and knowing the passenger's side will be MUCH worse has me less enthusiastic about starting that project. That's also not considering the fact I currently can't work on that side of the car too much due to it's position in the garage. I'm tempted to just go out and buy an aftermarket seat mount. Sure it means $100+ I don't have to spend but I see it this way: I'm never sitting there so I really don't care about helmet head room (sorry instructors/passengers), and if the RX-7 does become "because racecar" that seat will likely be coming out anyway so why go through all the crap just to remove it? Going this direction I can go out, buy another OMP seat and brackets, buy a PLANTED passenger's side mount and once delieverd, have everything installed in <30 minutes. Again, more money but crap gets done faster and I need a passenger's seat for HPDE.

On a lighter note, and I guess now is as good a time as any to bring it up, but some of you at Mid-Ohio might have noticed another "build" going on that has Beth, my wife, much happier ;) We're about 22 weeks into the "build" and the scheduled "completion" date is October 17. Beth likes to make fun of me saying her "build" will be done before mine but I'm quick to point out her's require(s/d) significantly less work on my part, LOL!

That's probably enough rambling for now. My plans for this week and weekend assuming I'm not rebuilding a lawnmower engine or replacing a garage door opener are:

1. Finish passenger's side engine harness,
2. Finish fuel lines,
3. Start/finish alternator and starter wiring,
4. Work on ignitor mounting and wiring, and
5. Work on driver's side engine harness

in no particular order.
 

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