Revamping the Rx7

i also saved 10lbs via removal of the headlamps. also cleared some space and removed some wiring and relays.

car is on four wheels again! Been making a lot of progress! Just need to start buying somethings...

This project makes me very happy...

I've been daydreaming about building exactly this car ever since we saw how cheap and durable a turbo miata engine could be with our Frankenmiata Lemons car.

You know about Miata coolant re-routes, right? I very strongly recommend doing a re-route, as it has made our turbo miata cooing system bulletproof. Now, while the engine is going in and out 10 times a day, is the easiest time to do it.

-Dave

Quote
eyesoreracing
This project makes me very happy...

I've been daydreaming about building exactly this car ever since we saw how cheap and durable a turbo miata engine could be with our Frankenmiata Lemons car.

You know about Miata coolant re-routes, right? I very strongly recommend doing a re-route, as it has made our turbo miata cooing system bulletproof. Now, while the engine is going in and out 10 times a day, is the easiest time to do it.

-Dave

Don't allude, explain, dammit Janet!

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Short version:

Miata engine is based on a front-drive design that had inlet in front and outlet in back of the engine. Miata version put inlet and outlet in front, so coolant flow to the back of the engine sucks, leading to overheating.

Simple solution is to use the FWD parts to put the thermostat on the back of the head and run a radiator hose (pipe) down the side of the engine. You can run it down either side, as the thermostat housing bolts on either direction.

Later (post 2002ish, I think) engines fixed this problem with a new head gasket that forced coolant to the back, but earlier ones really benefit from the FWD coolant flow.

I've got some piccies and stuff if you need more details.

-Dave

Alex was up here in Cleveland this past week, during a whirlwind tour of the country before being deployed, and we talked a bit while I was at the shop shoehorning a Chrysler 300M fan assembly into my RX-7 (pair of shrouded-blade two-speed fans, needs a 40A circuit per speed, maybe this will be good enough finally?) and also so he could poke around and see how I put in the FC subframe and three linked the rear.

Nutshell, he's probably going to just run a stock port 13B just to get the car actually, you know, on the stages. Also probably going to be going for a 4 link because that's a more proven design, and I don't give a rat's ass if the car is squirrely over 80 and he kinda does.

The nice thing about the coolant reroute is, if you get a $300 Protege engine and a $60 eBay Miata intake manifold and $40 Miata oil pan, instead of a $1000 Miata engine which is otherwise the exact same crap, you have the bonus of having had the coolant reroute already done for you...

$1000 miata engine? Shit, my last Miata engine was $50.

Might be California pricing. Might be my preference for 1.6L engines. Might be that I buy busted engines and piece them together, but either way, I think $1000 is a bit much.

-Dave

That's boneyard, 90-day warranty 1.8 engines.

So while we're talking RX-7s here, what makes a 3-link (or your 3-link) squirrely at high speeds?

I've never played that much with solid axles, so maybe I'm being naive here.

-Dave

I have a shit-ton of antisquat, because my concern at the rear is that the rear tires bite when I hit the accelerator, care about nothing else. This isn't a 3 link problem, this is a Pete problem.


I also have fairly high (~200lb) rear spring rates, and the rear roll center is only 2" lower than stock while the front is a lot lower thanks to the poorer geometry of the FC front suspension. So everything is contributing to the car's nervousness at higher speeds, but for me that just means it's responsive. I tried stage rally spec rates and geometry and it didn't bite hard enough and wasn't very responsive, but I'm sure it feels just right on a stage. As it is, the steering does something useful no matter what's going on, and unless I'm going to spin anyway, accelerating makes the car STOP rotating. I countersteer a whole lot less than I used to, which is Good because that means I can place the car within a foot of where I want to even if I fuck up, no more chucking it in at the beginning of a corner and hoping that the arc I chose to carve is where I actually need to go.

We'll see how it works against everyone else in Tulsa. Just got my Mazdaspeed contingency sticker pack in the mail. I fully intend on this trip to pay for itself.



Edited 1 time(s). Last edit at 09/16/2011 05:59AM by Pete.

very nice ride

where did you get the flairs?

they were actually for a 240z. had them for a few years on a few cars now so i can't exactly remember the source.

i love some mystery parts

Quote
Pete
I have a shit-ton of antisquat, because my concern at the rear is that the rear tires bite when I hit the accelerator, care about nothing else.

How does that do for accelerating on a rough, like washboard, surface? Wouldnt a shit-ton of anti-squat tend to remove the compliance from the suspension and cause it to skip over the bumps and lose traction? Just from watching the f cup videos it seems that everything rwd sits down in back when they get on the gas, not much anti-squatting going on. Just curious.

so the rear suspension on the car seems to be less than stock, by a far amount. might be the bilsteins either not having the stroke or something else. ill be testing this out tomorrow. Something i noticed recently... ill measure as well.