ok so im puting the rotors and 4 point calipers off my 91 vert onto my new 89 gtu and my buddy at local speed shop told me i might need to change my brake porportioning valve. dose anyone have experience with this?


also im looking into geting a coilover kit for minor street and autoX use. have about 1300 to spend looking at tein as #1 contendior.

p.s just cause u drove a slammed honda dosent mean u know what ir talking about
xD
please help drom experienced rotory enthusiest and fellow autoX racers

opions about valving ajustability and ride quality.

PLS

 

I'm pretty sure Mazda used the same prop valve for all models, regardless of caliper.

For "minor" street/autoX use I think you're much better off with decent strut inserts/springs and investing in tires.
The problem with cheap/inexpensive adjustable suspension pieces (and yes, in Suspension World, $1300 is cheap) is:
-Most people have no clue how to set them up and/or lack the specialty tools to do so.
-The adjustments are not precise/repeatable.

Remember, the more adjustments available, the more chances to get it wrong.

 

Thought GTu had the heavy duty brakes?

 

The GTU was a base/stripper model...the GTUs was the hotrod.

 

im decently fimillier with the concepts of compression and rebounf along with spring rate. from motocross experience though motocross and autocross are totaly different worlds. i can still transfer over some basic knowlage and understanding. 1300 is cheap in the world of supencion but im not looking to go crazy just get a stiffer more controled ride with all around better control over the lowend KYB supencion that came on the 89 i just got. ive herd good things about tein and the flex A or mono flex its around the price range.

also with the brakes im using four points in the front the singles in thhe back (also ordering powerstops slotted and drilled rotors) i want to make sure the porportioning the same cause i figure bigger calipers need different fluid rate and i dont want to end up with unbalenced braking system. ill see if i can find a thread with someone else who has done it

 

Oh, I've done that swap- single to four piston calipers- multiple times.
The prop valve doesn't change because I don't think Mazda even has an option.

What you can (and IMO, should) change is the booster and master cylinder.

 

I concur. Subaru 1 1/16" MC and booster here, great pedal feel. I think it's still Clokker's favorite choice ATM as well, unless he's recently discovered some other crazy combination.

 

By chance do you guys have a part number or a year and model info for this MC and booster?
Thanks Rikk

 

Roughly, a mid 90's Legacy. However, many Subarus use this MC. If you do some junkyard diving the MC will be stamped with the 1 1/16 mark on the side.

 

Just for clarification, the '88 GTU had the 4-piston front calipers and vented discs all around. The '88 GTU is NOT the same as the '89 GTU. Mazda did a disservice to to people by not making a distinction. Quite a few got "fooled." Many are still confused.

About '90 or '91 I met a guy with an '89 GTU at an autocross / tire eval event. I forget the context, but I had to politely burst his bubble and explained the differences. Besides showing him the differences, I tossed him my keys and said, "Check it out."

I've had the car since new, so I know her well. The 1988 Road & Track article is what ultimately convinced me to get this over the 10th AE Turbo. Actually, I didn't even what the headaches at the time. Salesman tried to push me into a GXL at the time. No chance! Quite a few miles on SoCal and NV tracks and still fun to drive!

 

I would spend a bit more and get some konis:
Ground Control - 86-92 RX-7 Super Street Kit

They're going to be a much better damper, and you can choose your spring rates.

if you can't make that work, get some bilsteins and some coilover sleeves (like ground controls) and get the bilsteins revalved (now or later) for the spring rates you want to run.

Also, read this:
Autocross to Win (DGs Autocross Secrets) - Buying Shocks

(I've been autocrossing for a long time, go look at my build thread: https://www.rx7club.com/build-thread...turbo-1031251/ )

 

I made a thread in the Suspension/Wheels/Tires/Brakes section looking for advice on a quality setup in the $1100 range and got tons of help from guys like eage8.

I bought cheap front struts off ebay, had a machine shop cut and gut them so I could put Bilstein strut inserts in, Bilstein shocks for the rear, went with the Ground Control coilover kit with 440lb front and 300lb rear springs (GC's recommendation for my 'vert) and Techno Toy Tuning camber plates and upper hats. I'm really happy with the setup and it's so much fun to drive but I would probably go with the GC/Koni setup if I had to do it again. The new suspension bits cost $1175, plus the Ebay front struts I bought so I could use the housings, trips to the machine shop, paying for machine work, etc. I think I'm close to $1500 into this suspension including having multiple alignments done from stupid things like installing the camber plates sideways and not realizing until it was on the rack (first timer haha).

I couldn't waste time on my friend's lift waiting for the fronts to be modified, that's why I bought the set off Ebay and got everything ready to drop in before taking it over there. I highly recommend reading the article that eage8 posted regarding buying shocks. Then when you're done, read the rest of it at least a couple times because there is loads of great information in there. Information what will tell you that buying from companies like Tein probably isn't worth it, and the only people you'll see using them are the slammed Honda's you're looking to avoid and people who are getting paid to use them. That article is a huge eye-opener.

 

just did this swap on mine last week. the mc and booster i got came out of a 99 legacy gt. its the 1 1/16" 2 port cylinder. i managed to fit everything nicely reusing some of my stock brake lines, one new one around 8", and a tee and banjo fitting. i still have to get a new reservoir for it since the subaru one isn't great for our setup but can't recall what clokker used.

this is the tee i used i got the m10 banjo fitting and bolt from there as well
3 Way Tube Tee - M10 x 1 - 10mm mount hole

 

I used the stock Subie rez but always wanted to adapt a Mitsubishi remote reservoir.
I acquired the parts but never got around to doing it permanently (it would work though!).
Both Honda and Nissan use 1"MCs/boosters that will work fine as well but need slightly more modding to fit.
The 1 1/16" Subaru combo is still my first choice though.

 

were there any other reservoirs you considered trying on the subie cylinder other than the remote mitsubishi one. my engine bay is a little cramped with intercooler piping to have the res off the mc.

 

Not really, space was never a major concern in my case.

The problem would be finding a reservoir with the exact port spacing to match the cylinder.
It's highly likely such a thing exists but my options are limited to what shows up in my yard and I didn't find one.

 

i have been planning on making a trip to the pick n pull out in pa sometime soon so i'll have to do some hunting then i suppose. i may pull a mitsubishi remote one just in case i cant find a match and try to squeeze it in somewhere