Lewis7789 MS6 GT build thread

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'86 RX-7 Base, '79 RX-7 GS
Is the pushrod in the brake booster adjustable for the MS6? If so, make sure it's adjusted properly or you could end up with either excess play in the pedal or unintended lock-up. This process was a royal PITA on my RX7 because, even though the FSM specifies the procedure, it requires special tools from Mazda, which no one has. Basically, I had apply a vacuum of ~20 in. Hg to the booster and check the clearance between the pushrod and the MC. Because I didn't have the tools I ended up shortening the pushrod to its minimum, put some red bearing grease on the end, and increased its length incrementally until I saw contact with the MC, then backed it off 1/8 turn.
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
Sounds good, MonkeyAss.

Jon, thanks VERY much for the info. I do believe the pushrod on the booster is adjustable and I didn't adjust anything. The pedal feels good and the car rolls freely on slight hills and getting pushed around the garage but I'll double check the rod and refer to my service manual. Good looking out, buddy!
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
Well, had a great weekend at Mid-Ohio with NASA. Had a few issues but still had a blast. Still fighting with the brake pedal. It felt great and very firm once the new master cylinder, brake booster and booster hose were on and bled. But once I got on track the pedal would be firm on one corner and spongy the next. Then was spongy the rest of the weekend. Kinda hard to brush brake when there is so much pedal travel. And haven't had a CEL in about two years and have a "system too lean at idle" pretty much all weekend as well as a random misfire. So gonna go over everything this weekend.

The most interesting bit of the weekend was my last session of the weekend with the HPDE1/2 grouped together. I lined up 2nd behind a very quick Camaro with slicks and was able to clock my fastest lap of a 1:46.58 on the pro course, which is still pretty slow, but again, that brake pedal... But I heard this wump-wump-wump sound at speed. Sounded like a tire went down but car still felt great. I got the meatball flag, acknowledged it and came in. The pit worker said my rear bumper became disconnected. lol I couldn't see with my helmet and harness on so I tilted teh side mirror down and sure enough my rear bumper was hanging off at a 90 degree angle. Guess the rear bumper couldn't handle my speed, bro! Or got jealous of the canards (which held up great over the weekend) on the front bumper. Pablo to save the day with a ziptie and I was able to drive home. Seems like the kids at the high school removed the rear bumper for paint and forgot a bolt or clip so now the rear bumper has an ugly crease. I'll take a better look at it this week. But regardless of the issues, still had an amazing weekend and the HPDE2 class were all great guys/girl and all very good with point-bys. Got quite a few compliments on Fatty and got some people hip to the Mazdaspeed6 version.

Look at all these hard parkers.


Thanks again, Will, for letting us use your pimp trailer.


I'll hopefully have some good on track pics soon. I'll upload my quickest lap from the GoPro as well.

Looking forward to sorting out the brake pedal, CEL's, rear bumper and headed to PittRace with AutoInterests May 7th! :)
 
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13 CX5
Cant stand racing with shitty brake feel. I hope all my brake problems are gone, otherwise the car will be gone. Looking forward to the video!
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
This brake pedal is so frustrating. I'm going to bleed the system and clutch one last time and check the WSM for the brake booster procedure like Jon talked about. If that doesn't fix it then she's off to the dealership to get fixed. Sad when my DD has better brakes...

This is video from my 2nd to last session, not my fastest but fun nonetheless. my fast lap (which is still pretty slow on the Procourse) of a 1:46.58 didn't get recorded on the GoPro, of course. But I do love the Harry's Lap Timer app.

<iframe width="420" height="315" src="https://www.youtube.com/embed/2VENeY18kYg" frameborder="0" allowfullscreen></iframe>
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
Oh, also had Fatty on the scales this weekend : 3527lbs

Fatty gonna fat.
 
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13 CX5
So thats how nasa works huh? Love that track. Its got a ton of elevation change along with off camber blind turns. But it looks like you got that line down very well too.

I like haw around 14:30 you are waiting for a point by and as soon as you get it you stomp on the gas and your head goes back. Dont think I have that problem in mine lol.
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
I do apologize for the crappy video quality, I'm new to my GoPro but Will sorted it and it should be much better next time.

This was my first official event with NASA (I had two Hyperdrives before, classroom and one 20min session with an instructor) and it was great, I'll definitely be back with this club. They are very professional, very helpful and very safety concerned. Which is really nice when sharing the track with people who you have to trust aren't going to do anything stupid and wad up both your cars with no insurance coverage.

I'm still working on my lines as I'm certainly no expert. But I'm slowly getting it. :)

I don't know if Fatty has enough power to snap my head back. Maybe I sneezed or something? haha
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
So I'm 90% positive I figured out my soft brake pedal and lean at idle issue, wrong brake booster. I don't know why Mazda would offer two part numbers for my car but the master cylinder o-ring wasn't making contact with the brake booster I bought. I called Mazdaspeed and verified I have the wrong brake booster and a new one should be here tomorrow. I'm a pro at installing brake boosters and master cylinders by now and this will probably be the 7th time I've bled my brakes in the last 6 months...

So this o-ring on the MC seals against the brake booster.


Original brake booster hole diameter;


The one I bought and ran at Mid-Ohio and didn't die;


I've been battling a soft brake pedal since August of 2015 so I really hope this will finally get a firm brake pedal so I can have confidence in the braking system and push harder as everything else on the car feels great.

Looking forward to getting the brake system sorted this week, hopefully the rear bumper will be repainted and ready to reinstall in time for PittRace this weekend.
 
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Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
Oh, and yay pictars! Thanks again to Will for buying my picture set. haha





Also impulse bought some Alpinestars gloves from Track First at the track. T'was a wise investment. They are so comfy and grip the wheel/shift knob really well. And I figured the yellow would be easiest to spot point-bys and other obscene hand gestures. :)
 
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13 CX5
Trying not to be a dick, but in a power boosted system when you have a vacuum assisted system... does not the brake pedal become harder to push with less vacuum? Like in instance a vacuum leak or a too low of a idle?

been trying to get my P5 to stop consistently since 2013. will be looking into market value for a car like mine here just to be prepared to put it up for sale the day after my new new new new brakes don't work again.
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
Trying not to be a dick, but in a power boosted system when you have a vacuum assisted system... does not the brake pedal become harder to push with less vacuum? Like in instance a vacuum leak or a too low of a idle?

been trying to get my P5 to stop consistently since 2013. will be looking into market value for a car like mine here just to be prepared to put it up for sale the day after my new new new new brakes don't work again.
Yes? No? Quite possibly? Heck, I don't know. haha. All I know is I was using the wrong booster and the new one is on the truck today. I'll install it and get the system bled (again...) and that should be fixed. I've replaced just about every brake system on the car so it should be good.
 
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'86 RX-7 Base, '79 RX-7 GS
Yeah, a failed seal would mean a loss of vacuum, which would mean a stiffer brake pedal. That would explain the lean condition at idle though. Did the pedal just feel soft or was braking force reduced as well? The booster you received first appears to be built for a larger MC: 42.34 vs 40.80 mm, or a difference of about .060 in. Larger MC's usually run with larger diameter boosters since more force is required. I'm wondering if, even with the poor seal, your brake system was over-boosted. That is, less pedal force for the same braking force. Either way, here's to hoping the correct booster fixes the problem. Can't you install the booster without removing the MC?

FWIW, this is a problem I'm concerned about with the RX7. I'm running both a larger MC and booster from a RWD 929. I went from a 15/16" MC and a 9" single diaphragm booster to a 1" MC and a 8/9" dual diaphragm booster. If that's too soft for my liking a can drop down to the Turbo II's 7/8" dual diaphragm booster. IIRC, this kind of swapping/intermixing is fairly common in the Miata world as well.
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
Well praise baby Jesus my brake pedal is healed! I put in the new master cylinder and brake booster and adjusted them to match the old unit. Put the new Hawk HP+ pads up front and lubed all the slider pins for the calipers as most of them were dry. I'm not sure which step fixed the problem but I've got consistent pedal pressure/feel and travel so I'm happy.

Went to PittRace with AutoInterests on Saturday and had a blast. Car ran great and no issues except after my 4th session my dip stick popped due to crank case pressure, very common with MS3/MS6's but is a first for me. I was running through the esses in pretty high RPM in 3rd and would hit the rev limiter a twice each lap before hard braking so not sure if it was just a combination of those or what. But I decided to sit the rest of the day out. Still managed a 2:08.91 which isn't bad. I'm getting more confident in the brakes again and still left plenty of time on the course by braking too early. But I'll be back for sure, the new course is very fun and always great hanging out with friends at the track.

Thanks again to Will for letting me use his trailer shade and cramp his style.


Got home and washed the brake dust off the car and went to hard park at Superfly. Someone took this shot from the parking garage overlook.


As I was pulling in a Superfly volunteer was scoffing at my car and said "pffsht... gay.". I just laughed.

Hard parking is tough without my Miata tug boats to back me in.


Though hard parking does get your big wang featured in a video. haha
 
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'86 RX-7 Base, '79 RX-7 GS
It's great you got the brake issues sorted. I'm still confused how using the wrong booster would cause all those problems. How can you have a vacuum leak AND an over-boosted system? Not that it matters though. So what's in store next?
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
I honestly don't know. I'm wondering if the caliper sliders pins were getting hung up? Because they had very very little grease on them.

Next project is a vented oil catch can that Martz is going to help me build/install, weather he likes it or not. Then swapping out the clutch slave cylinder for good measure. Then sign up for SCCA Track Night June 8th at PittRace. The car doesn't really need anything and feels great, just maintenance.
 

aMaff

High Speed Low Drag
Moderator
:
1992 Miata / 2003 Pathfinder
Sounds like there was probably a leaky seal in the Master cylinder. That can cause some pedal wierdness & inconsistency.
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
Also forgot to mention a thank you to my homie Marc for dropping off and picking up my rear bumper from repair in time for the weekend.

If you squint real hard you can see a black MS6 on track.
 
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'86 RX-7 Base, '79 RX-7 GS
Sounds like there was probably a leaky seal in the Master cylinder. That can cause some pedal wierdness & inconsistency.
I totally missed he said he got a new master cylinder as well. I've heard the remanufactured ones can be hit-or-miss. I've got a somewhat squishy pedal in the RX7 as well, which has me slightly nervous of a defective master cylinder.
 

Lewis7789

Evan aka "Lady Hands"
Contributor
:
1995 MX-5, 2006 MZ5, 2001 Yamaha R1
I heard that too, Jon. So I ordered one from Mazdaspeed directly. But with 180k miles on my chassis now I'm gradually swapping out just about everything. :)
 

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