BRAKE UPGRADE 3000GT vr4

[shift1313]

im still working on brakes for those interested but ive been updating another thread.

 

http://www.starquestclub.com/forum/index.p...40&start=40

 

i did a bunch of fea modeling to finalize the design/thickness.

 

a friend at work has some 300zx calipers but they are the 30mm thickness variety so i still need to source some calipers to work with the stock rotors as well as some that will work with larger OD and thickness rotors. I took some numbers off crown vic rotors and they are just over 12" diameter. about 1.125" thick(91+ 300zx rotors will work on that). and ive measure the offset but i dont have a stock rotor to compare it too yet. Ive also got another set in mind but ill update once i have the widebody parts in hand.

[shift1313]

got in and measured the 5lug rotors today. im going to make some drawings of the rotors(since i need to anyways to draw rotor hats) and ill post those when i get them done.

 

It looks like the offset of the stock rotor from the front face is 1.66". the crown vic rotor was 1.5". The nsx rims on my flatty are 1.59". This can all be accounted for with the caliper bracket. The hub center on the rotor is 3.05 and the vic is 2.75 so that would have to be machined out. The vic rotor was 1.125" thick and the stock 5 lug is .934" thick so the stock calipers could not be used with the vic rotors. The nsx rotors are 1.125(close) and the stock calipers would not work on those! The vic rotors could be turned down or you could do a caliper upgrade.

 

ill try to post up the rest of the rotor numbers later tonight.

[88TSI_Rob]

I'm a bit late, but here are my numbers Matt. I notice already a couple differences...we may have to account for some variability in the molds by different manufacturers.

 

A - 24.2mm/0.953"

B - 42.1mm/1.657"

C - 76.5mm/3.012"

D - 159.4mm/6.275"

E - 12.5mm/0.5"

F - 58.4mm/2.30"

G - 146.5mm/5.768" - The area right where the hub is in contact is slightly smaller, but I couldn't get a measurement in that spot. See last photo.

H - 44.5mm/1.75"

I - 165mm/6.5"

J - 55.5mm/2.185"

K - 34.85mm/1.372"

L - 7.25mm/0.285"

 

http://farm4.static.flickr.com/3281/2639900127_9bb654272b.jpg

 

 

http://farm4.static.flickr.com/3077/2639895739_e12063680c.jpghttp://farm4.static.flickr.com/3004/2640724374_22ddb9cec0.jpg

http://farm4.static.flickr.com/3173/2640722442_ed21d29137.jpg

Edited July 6, 2008 by 88TSI_Rob

[slowquest]

The hub center on your crown vic rotor being too small is strange, mine fit with no problems. I'm also using 3kgt front calipers, but i'm not happy with the fact that the pads don't "cover" the entire face of the rotor.

[shift1313]

I'm a bit late, but here are my numbers Matt. I notice already a couple differences...we may have to account for some variability in the molds by different manufacturers.

 

 

http://farm4.static.flickr.com/3281/2639900127_9bb654272b.jpg

A - 24.2mm/0.953"

B - 42.1mm/1.657"

C - 76.5mm/3.012"

D - 159.4mm/6.275"

E - 12.5mm/0.5"

F - 58.4mm/2.30"

G - 146.5mm/5.768" - The area right where the hub is in contact is slightly smaller, but I couldn't get a measurement in that spot. See last photo.

H - 44.5mm/1.75"

I - 165mm/6.5"

J - 55.5mm/2.185"

K - 34.85mm/1.372"

L - 7.25mm/0.285"

 

 

 

thats great rob. Yeah there are some small differences but again the ones im measuring are rusty and they could have been turned down at some point as well. Thanks for posting that info!!!

[shift1313]

The hub center on your crown vic rotor being too small is strange, mine fit with no problems. I'm also using 3kgt front calipers, but i'm not happy with the fact that the pads don't "cover" the entire face of the rotor.

 

 

what year vic did the rotors come from? also do you have any pics of the rotor and caliper installed so i can see the pad area.

 

thanks

[shift1313]

here is the difference between flatty and wide body rotors

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/4v5side.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/4v5top.jpg

 

looking at the hub design id say the 4 lug hubs would be stronger than 5 lug if they had larger studs.

[shift1313]

http://i268.photobucket.com/albums/jj39/shift1313/Starion/Starion5lugBrakeRotor-Model.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/Starion5lugBrakeRotor-Model2.jpg

 

both are the same just two different methods of dimensions. Some people find it easier to read a section view. thats all i had a chance to do so far.

[88TSI_Rob]

3SX has an Ebay auction for some 3kgt calipers and posted some good pics. I thought I'd save them and post them here for reference. They are bigger than I thought...

 

http://farm4.static.flickr.com/3091/2641930989_66c17b7eac_o.jpghttp://farm4.static.flickr.com/3146/2642757390_98844a7d6e_o.jpg

http://farm4.static.flickr.com/3020/2641930755_6f56f602de_o.jpghttp://farm4.static.flickr.com/3099/2641931271_c3cb8168af_o.jpg

http://farm4.static.flickr.com/3165/2642757476_f3eaf70a6e_o.jpghttp://farm4.static.flickr.com/3091/2642757186_4a2bc8f609_o.jpg

http://farm4.static.flickr.com/3116/2642757690_40b9ce38a0_o.jpghttp://farm4.static.flickr.com/3121/2641931479_7e736c1005_o.jpg

http://farm4.static.flickr.com/3079/2642756952_6d7233447e_o.jpg

 

Has anyone commented on brake pedal feel after they mounted these up? Is a bigger MC required? It looks like they use a lot more fluid than the stock calipers.

[shift1313]

yes a bigger master or something is required. the stock 3kgt master on the non abs cars is 1" bore, the abs cars is 1 1/16" bore. Ive been thinking about buying a 3kgt master and booster setup and seeing if the bolt pattern is the same on the firewall. I spent some time at a local autoparts store looking through different masters for different cars with no luck so far. once i get my pads in and front lines im going to experiment with moving the pivot location on the pedal. You would loose some of your leverage on the pedal but get greater travel(if its there). That would be the easiest solution if it works. If not the next thing is an adapter for another master cylinder. I wont know yet until the brakes are on the car, my pads are supposed to come in this week, hopefully.

[88TSI_Rob]

The 3000gt MC has the mounts on the sides rather than top/bottom.

 

http://i13.ebayimg.com/06/i/000/c8/db/41b9_1.JPG

 

Just to keep the discussion on master cylinders going, I'm starting to like the tandem MC that Wilwood makes. The mounting hole spacing is 2.25" vs. the stock 2.5" but I don't see a huge issue with ovaling out the holes. It's not ideal, but it appears that there is enough metal in the area to do it without significantly weakening it or effecting how it works. The main force is going to be pushing in-out of the firewall, hardly anything rotational. I'd probably use washers to distribute the force a bit more.

 

http://farm4.static.flickr.com/3279/2643500947_473d420d45_o.jpghttp://farm4.static.flickr.com/3042/2644537866_271a5ba7ce_o.jpghttp://farm4.static.flickr.com/3050/2643511847_1f7f471c57_o.jpg

 

The Wilwood MC is available at Summit for $122

 

I'm seriously thinking about ordering it and seeing how hard it is to make fit. According to rockauto.com a new Starquest MC runs ~$100 and a VR-4 3KGT MC/ABS runs ~$140 and up, so the price is right in line with our other options.

[shift1313]

ive thought about that master rob but its only available in 1" bore and if i was going to upgrade id like a little larger bore because i plan on upgrading the rear calipers as well. I know the 3kgt master mounts different, i was going to make a master adapter and have to use a custom brake rod or clevis at the pedal. it would push the master out 3/8" from the booster but i think its doable if needed. Ive also considered doing away with the brake booster but im not sure i really want to do that, but im thinking about it...

 

i agree about ovaling out the wilwood master. even if you had to slot it all the way to the edge i think it would still be fine.

 

what i want to do is find a simple option for those who are just upgrading the front calipers to 4piston units. There obviously will be no substitute if you are upgrading all 4 calipers and possibly running a small single piston ebrake caliper set.

 

 

i still need to pull the stock master apart and see what can be done with it.

 

ive seen several 3kgt masters on ebay for $25buy it now and a few $50 with booster buy it now but they couldnt tell me if they were from an abs car or not, only that it was stock.

 

 

im thinking the easiest option is finding a brake booster that bolts on, im sure that bolt pattern is more standard than the master cylinder.

Edited July 7, 2008 by shift1313

[88TSI_Rob]

im thinking the easiest option is finding a brake booster that bolts on, im sure that bolt pattern is more standard than the master cylinder.

 

Good point, I hadn't even thought about that. I'll see what I can dig up tomorrow.

[shift1313]

sweet, and keep all the good info rolling rob.

 

i know the bolt pattern on our brake booster is rectangular. I can probably pull mine off tomorrow if you need or get you rough numbers with it installed. I measured it before to see if it could be turned 90degrees and didnt write the numbers down. I know the firewall can be redrilled but it would be sweet if a booster from another car would bolt right in:)

[shift1313]

rob i did a quick measure on my booster while it was still on the car. looks like the bolt spacing is 3 1/4" wide x 15/16 tall. again this was in the car so its not easy to get to.

[88TSI_Rob]

Thanks Matt. Info on the bolt pattern of boosters on different cars is harder to come by, but I'll keep looking.

[shift1313]

depending on how long the studs are in other boosters an adapter plate can be made but that will push the booster farther away towards the shock tower which is already a very tight area. I was hoping to have my brakes up and going by this weekend but it doesnt look like my plates will be cut this week so it will be next week sometime and then i can comment on the pedal travel/feel.

[88TSI_Rob]

rob i did a quick measure on my booster while it was still on the car. looks like the bolt spacing is 3 1/4" wide x 15/16 tall. again this was in the car so its not easy to get to.

 

Matt, did you mean to write 15/16" or 1 - 5/16"?

 

I'm hoping it's the latter because I don't see anything even remotely that looks that rectangular. It also looks more like that in this photo.

 

http://www.cardone.com/Imagesftp/53/535080-01.jpg

 

So far I have looked at the boosters from older domestic cars. Most of them are 3.375" x 3.375" from what I read. The pattern on the 3kgt booster looks very square so that's probably out.

 

If it is 1 - 5/16, the early '90's Toyota pickup and early '90's Hyundia's look like they might work. I don't know if they are 9" though.

 

If the Toyota trucks fit...maybe the ones from the Supra will fit also. Or the combo of the truck booster + the Supra master might work?

 

I have to keep looking.

[shift1313]

under an inch rob:(

but i will remeasure it again and try to get more accurate numbers.

[shift1313]

alright rob. I pulled the master off(and apart) and i pulled the booster off my car, which i dont recommend doing if your intake manifold(or at least TB) is still on. Ive got tons of numbers and thins and ill try to make technical drawings tonight or tomorrow, plus i took lots of pics.

 

Here is the general idea.

Booster

 

Bolt pattern is 1.89" high(between studs) x 3.145"

 

the interesting thing i forgot is there is a spacer block thats cast aluminum and its pretty thick, thick enough to make an adapter plate if we needed to.

 

The booster itselft is 9.25" OD and 4.25" thick from the front face back to the back face of the mounting flange(without the spacer). From there its 5" back to the center of the clevis on the brake pedal.

 

The master cylinder studs on the booster are 2.3525" apart and the actual bore of the master with the guts removed is .94"

 

ill definitely get the pics uploaded tonight but im not sure about the drawings(probably not tonight)

[shift1313]

http://i268.photobucket.com/albums/jj39/shift1313/Starion/MasterCyl3.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/MasterCyl2.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/MasterCyl1.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/MasterCyl.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/booster7.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/booster6.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/booster5.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/booster3.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/booster2.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/booster1.jpg

 

http://i268.photobucket.com/albums/jj39/shift1313/Starion/booster.jpg

[88TSI_Rob]

Holy smokes you went to town tearing things apart! I don't have the guts to do that to my car right now so I appreciate the effort.

 

I haven't found much more info. The one thing I am finding is that very few cars have a master cylinder larger than 1". The last gen Supra Turbo and Nissan 300ZX Turbo both had 1" masters. The oldest Toyota I have found that had a 1 1/16" master was the 1993 T100 non-ABS pickup. I think all Nissans are out, Honda is out, and I haven't fully checked but I think all Hyundai's over 10 years old were too small to have a 1 1/16" master.

 

We may be limited to adapting either a 3000gt or a Toyota T100 booster/master to work.

 

The only other thing left that I could probably check is those Mitsubishi FUSO trucks.

[JamesR]

Try a booster from a 240sx with a master cylinder from a 300zx. artinist was going to try this setup, but I don't know if he ever completed it.

 

The top 2 bolts of the 240sx match the starquest, you would just need to drill to holes for the 2 bottom bolts. Use the 1 1/16" master cylinder from the 300zx which is a common swap for 240 guys.

 

I was also going to try this setup, but currently I believe my brakes are finally working right for now. I've got a booster, but not the master cylinder.

[88TSI_Rob]

What year & engine 300ZX? I looked through all combinations (NA, 2+2, turbo) on the later years (94-96) and didn't see a 1 1/16" MC listed.

[shift1313]

Holy smokes you went to town tearing things apart! I don't have the guts to do that to my car right now so I appreciate the effort.

 

I haven't found much more info. The one thing I am finding is that very few cars have a master cylinder larger than 1". The last gen Supra Turbo and Nissan 300ZX Turbo both had 1" masters. The oldest Toyota I have found that had a 1 1/16" master was the 1993 T100 non-ABS pickup. I think all Nissans are out, Honda is out, and I haven't fully checked but I think all Hyundai's over 10 years old were too small to have a 1 1/16" master.

 

We may be limited to adapting either a 3000gt or a Toyota T100 booster/master to work.

 

The only other thing left that I could probably check is those Mitsubishi FUSO trucks.

 

 

rob my car is not going anywhere until the brakes are done so there was no harm in pulling the stuff apart. Besides i drained the brake lines to replace the calipers anyways so it was perfect timing .

 

I would really like to figure out what bore size is enough. 1" is definitely an upgrade but is it enough? After pulling the master off i think there is plenty of room to make an adapter to fit another master to our booster and i believe there is enough adjustment at the clevis to make it work. I think im going to order a 3kgt 1 1/16 bore master off ebay and see if i can make that work cause that would be the easiest(except for having to make an adapter). Moving the pivot point of the clevis on the brake pedal is out of the question, there isnt enough room.