magnumP5's RX-7 Build Thread
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Not a disadvantage per se but the 929 MC has a 1" bore versus 7/8" on the stock MC. The larger bore pushes more brake fluid for a given stroke so there should be less overall pedal travel. I just hope the 929 booster doesn't overboost the braking. I had to use it because the 929 MC isn't compatable with my stock booster. If I don't like the feel I'll look for a smaller booster. I think there are some from various years of Miatas that work.
So apparently there are off-the-shelf MC braces for the RX7. Basically, it bolts to the strut tower and pushed against the front of the MC rather than physically bolting to it. The only questions now are: (1) Do they come in black, and (2) Is it worth $90 for a cool, anodized, milled piece, or should I just make my own?
Of the MC or the brace?
It should work with the 929 MC as there's some adjustability built in. If not I'm sure I could modify it to work. Here's a picture of the prototype installed in a car:
The finished product as sold on their site:
The design is simple. I'm sure I could make something myself but it wouldn't look anywhere near as nice. Now if only I can get it in black or unfinished...
The finished product as sold on their site:
The design is simple. I'm sure I could make something myself but it wouldn't look anywhere near as nice. Now if only I can get it in black or unfinished...
Doo eet! My friend and I were trying to rig up a MC brace for our P5's using an off the shelf product but gave up. That's awesome you have a bolt in option. And $90 is pricey for a minor improvement but you've got this far, what's another $90? haha. Just spray paint wrinkle black that sucker.
LOL, the problem with that mentality is I end up spending way more than I ought to. I need to save up for a bit as I've still got two big expenses coming up with the rest of the exhaust and paint/body work. It's too bad I don't have any hookups with either...
No wrinkle though; just black. I don't like the idea of stuff getting stuck in the wrinkles. I am a little disappointed in how poorly the high-temp paint seems to be holding up. I followed the instructions to the letter and it still chips off very easily (see booster).
If I make it myself, it'll be mild still and welded. I've got some ideas in my head.
So I've not been completely idle. Here's a quick photo of the new MC and everything buttoned up for good:
I'm glad to be done with that for the time being. Eventually I'll start working on a MC brace. My major goal this weekend was to start working on the fan shroud. I didn't get much as much time on it as I'd like but I made up the final design and get the frame together.
Everything is made out of MDF. The bottom rectangle is the overall size of the radiator including the endtanks. This flat portion will be the "flange" mounted to the radiator. The 3/4" quarter round is where the core begins. The idea is to give the air as smooth a transition as possible. The top, circular piece is the profile of the fan mounting flange. The difference in height is 1" from end-to-end (3" to 4"). The current plan is to have the 4" side at the bottom to try to angle the fan so it's pulling air through the radiator and blowing it through the vent in the hood. Should I run into clearance issues, and I shouldn't, I can always reverse it so air is blown more horizontally over the engine. The next step is to stretch, staple, and glue felt over the frame to generate the shape of the shroud.
At this point I'm still unsure I want have the felt be part of the shroud or make it a mold from which I make the shroud. The former is easier but will be thicker and heavier in the end and there may be some issues getting the shroud off the MDF frame. The latter is more complicated as I'll have to soak the felt with resin, allow it to dry, then fill, sand, paint, sand, and wax it until I have a super smooth surface. Once that's done it gets sprayed with mold release and then the fiberglass work begins.
I'm glad to be done with that for the time being. Eventually I'll start working on a MC brace. My major goal this weekend was to start working on the fan shroud. I didn't get much as much time on it as I'd like but I made up the final design and get the frame together.
Everything is made out of MDF. The bottom rectangle is the overall size of the radiator including the endtanks. This flat portion will be the "flange" mounted to the radiator. The 3/4" quarter round is where the core begins. The idea is to give the air as smooth a transition as possible. The top, circular piece is the profile of the fan mounting flange. The difference in height is 1" from end-to-end (3" to 4"). The current plan is to have the 4" side at the bottom to try to angle the fan so it's pulling air through the radiator and blowing it through the vent in the hood. Should I run into clearance issues, and I shouldn't, I can always reverse it so air is blown more horizontally over the engine. The next step is to stretch, staple, and glue felt over the frame to generate the shape of the shroud.
At this point I'm still unsure I want have the felt be part of the shroud or make it a mold from which I make the shroud. The former is easier but will be thicker and heavier in the end and there may be some issues getting the shroud off the MDF frame. The latter is more complicated as I'll have to soak the felt with resin, allow it to dry, then fill, sand, paint, sand, and wax it until I have a super smooth surface. Once that's done it gets sprayed with mold release and then the fiberglass work begins.
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I'm getting scatterbrained again. Last night while attempting to clean the garage I started staring at my rear fenders. While the roll and pull I did should leave enough clearance I'm not sure I'm happy with the look. The issue I'm having is with the tire-to-fender gap. The best way to illustrate is with the following pictures:
To level the car with the engine installed the rear will have to come down something like 1/2 in. While that's not usually a problem you can see that'll leave about a 1/2" gap between the rear tire and fender while the front will be even lower. I'm not super OCD like Evan but this difference is enough to bug me. There are two reasons for this: (1) the new front fenders have a lower arch (supposedly 20 mm), and (2) the fender pull raised the rear slightly. The only way I see to improve this is to go with rear overfenders from the same company. Like the fronts, they also lower the wheel arch. They just require a lot more work to install. Something like this:
To level the car with the engine installed the rear will have to come down something like 1/2 in. While that's not usually a problem you can see that'll leave about a 1/2" gap between the rear tire and fender while the front will be even lower. I'm not super OCD like Evan but this difference is enough to bug me. There are two reasons for this: (1) the new front fenders have a lower arch (supposedly 20 mm), and (2) the fender pull raised the rear slightly. The only way I see to improve this is to go with rear overfenders from the same company. Like the fronts, they also lower the wheel arch. They just require a lot more work to install. Something like this:
Haha, yeah that car has no rear end. No really, it's completely cut out and that's why the bumper cover sags like that. The biggest issue I see is getting the overfenders to line up with the stock body where they meet in front and behind the wheel. I'm not sure how I feel about the riveted look either but I really don't want to have these molded in. Not trying to spend a fortune on body and paint work.
Haha, I'm flattered.
Is it just an aesthetic thing? Or a function thing?
Mostly aesthetic but I'm also slightly concerned I still may have fender-tire contact issues even with the fender pull. Rear camber is -1 degree right now and I'll be upping that to -2 but you can see what I mean:
If you've got the specs and offset you desire for the rear wheels and tires you want and it clears the rear quarter panels I can't see you, being the function guy you are, wanting to spend more money just to make it look pretty.
Once you start driving her again and tracking the crap out of her you'll be glad you spent that money on more track time/go fast parts and not over fenders. But the rear fenders do look cool. But at what cost and is it worth it to you?
disclaimer- I'm not a race car driver nor claim to be. But even in the few auto-x'es I've done I care less and less about looks and more and more about function and using that money towards more seat time.
Once you start driving her again and tracking the crap out of her you'll be glad you spent that money on more track time/go fast parts and not over fenders. But the rear fenders do look cool. But at what cost and is it worth it to you?
disclaimer- I'm not a race car driver nor claim to be. But even in the few auto-x'es I've done I care less and less about looks and more and more about function and using that money towards more seat time.
I guess the picture above isn't the best. Basically, the fender lip clears the tire but it's at like a 45 degree angle to the body. I'm worried under hard loading conditions the tire will contact the fender on the inside. Overfenders would bring the entire body out 20 mm giving me inside clearance as well. Cost-wise I'd be looking at another $325 for the fenders and whatever additional body work needed. Also, while this car will never be a 10/10 in the looks department I do draw the line at mismatched/unpainted body parts. If I did rear overfenders they'd likely be riveted in like the car above.
Did you ever get your brakes bled? I replaced the MC on my '87 Sport the other day and had the same trouble as you. I tried bleeding it half a dozen times. I tried using my brake bleeder and doing it the old fashioned way and could not get any pedal. I finally had to take it to a garage and let my mechanic buddy bleed it for a couple hours before we finally got enough pedal to make it safe to drive on the road.
