Hello. Im looking to convert to LS1 brakes on my 91 Z. Can someone please help me find a link to a thread showing a complete step by step directions on converting. The help is greatly appreciated. I need to know what needs to be modified and what LS1 parts are used. What brake booster, master cylinder and prop. Valve do I use. So far I have a complete rear from a 98 Z and all the front brake components from that same car. Again help is greatly appreciated thanks

 

I'm planning on doing the same upgrade down the road and this is the link that I've found:
http://lukeskaff.com/?page_id=329

And concerning the rest, as far as I know, the stock rear disc prop valve can be used assuming you have rear disc already. But you might possibly need new/longer ebrake cables to hook it all up. Oh, you will also need the caliper bracket to mount the fronts on your modified spindles.

 

Thanks for the link. When u say modified spindles. Do I use the LS1 spindles and
If I do, do u know what needs to be modified on them. Is the caliper bracket a factory bracket or a modified aftermarket. Thanks for replying

 

The spindles are 3rd gen. The Luke Skaff article is about as good as it gets in it's description on how they're modified.
Brackets can be home made or purchased (as I did) from Flynbye Performance (Ed Miller).
http://flynbye.com/catalog/i36.html
You will also have to modify a pair of 3rd rotors and convert them into hubs. Luke Skaff explains that too.

 

Awesome. Just checked out the lukeskaff link, wow get detail in step by step procedures on modifying the hubs and spindles. Can't wait to start the project. Thanks skinny z and firechickenv6 for the help

 

The only heads up I can give is double check the spec for the size of fasteners used to attach the conversion brackets to your modified spindles (it's part of the mod to drill and tap for new bolts). Skaff, Flynbye and GM all have different thread sizes. For what it's worth, I went 12mm all around.
One other thing I just thought about. If you use Flynbye, he's notorious for being somewhat difficult to reach. Phone calls rather than e-mail, work best (I find).

 

easy enough to make the brackets. any machine shop can "make" the hubs for you fairly reasonable. i got a deal at 50 for set but i supplied the rotors. don't know what your local machinist may charge tho. agree with the 12mm fine thread fasteners. i used hex head tho for space reasons.

 

my hubs ended up running me about $80 to get turned locally. you'll save a few bucks if you cut the "hub" free from the rest of the disc ahead of time. gave my buddy a chance to try out his new plasma cutter, so who was i to say no?

 

Has anyone actually completed the Luke Skaff bracket design LS1 front brake design?
I've collected all the needed parts and have started seeing how things are fitting together. I haven't actually modified anything yet (spindles/rotors) but I just got the brackets made yesterday (CNC) so I started laying it out.

It looks like there's a clearance problem between the back side of the bracket and the caliper piston bore bosses. It looks like I need to grind on the long end to get it to clear. Take a look at the pics and see if I'm missing something.

Thanks!

 

more pics:

 

i had to grind that area of the bracket as well. going on 20,000 miles and no signs of failure yet so i wouldnt worry. mine are tight tho. i didnt wanna remove to much.

 

Sweet. Yea I wasn't worried about strength reduction, more just that something got screwed up or that the placement of the holes wasn't right. If you look at Ed's design it makes it look like the caliper is pushed out more relative to the spindle but then that would mean the rotor would have clearance issues. But if you're not having that problem then I guess it's just too much material from the holes to the edge of the bracket. Maybe once I modify them I can adjust the CAD file and send it to Luke for an update. I know he used the C4 upgrade for his car so maybe he didn't work through all of the bugs with the LS1 setup.

Was there anything else you had to adjust? I just picked up a set or rotors today to modify. I didn't want to sacrifice the original rotors and have the car out of commission for that long and I didn't know where to get a set of used ones for cheap so I just picked up a new set of Valuecraft from Autozone for $25/ea. I'd never use their rotors for the actual braking surface but what could be bad about using just the hubs/races/wheel studs?

 

Did you have to purchase longer wheel studs too? If so do you have a part number or size?

On one page of his site it said " The stock wheel studs are M12-1.5, Knurl Diameter: 12.73mm, Length: 41.5mm 1.63″, add the thinkness of the rotor hat mounting surface to the length and use studs closest to the new length".

 

http://bigbrakeupgrade.com/

This is where I got my LS1 brake upgrade kit. I also got a pair of 2" wheel spacers to use stock 4th gen wheels that clear the brakes. I definitely suggest this route if you havent started yet.

 

Do some searching on what adapters to use in the front when using LS1 brakes.

2" ADAPTERS (not spacers) are common when using 4th gen wheels on a stock thirdgen car. When you do the LS1 brake upgrade, you are basically cutting down your stock rotor hat into a hub, then ADDING the LS1 rotor on top. Its around 1/4", give or take a little, extra material.

I run 1.7" adapters in the front and my 4th gen WS6 wheels sit right where my original wheels sat.

2" will work. I think Ive seen others run them. But just be aware that you can also run a 1.7" if you want to tuck them in a bit.

I second bigbrakeupgrade.com for your parts though. Great company!

J.

 

Flynbye u will wait 2 years to get what u want and he won't answer calls. Bigbrakeupgrade.com he is cheaper and quick turn around. I built all of mine but the brackets. Its a big difference but I also have a umi torque arm which help with braking

 

I wish there was a way that you could run the 4th Gen offset wheels without adaptors. on some wheels it looks cheesy seeing the spacer in behind the wheel.

Any particular brand you all have liked or disliked?

 

I got my pair of adapters off eBay. Just cheap aluminum ones, and they work great. And I found a set of 16" aluminum wheels off a 97 v6 firebird for cheap. Looks pretty good and works even better. I got the 2 inch adapters so I could run a little bit bigger tires without rubbing. Fronts sit just a little wider than rears but it's not noticeable.

 

Do the 2" plus LS1 brakes cause any issues with the fender lip?? I rub a tiny bit on the inner fender plastic. But it clearanced itself and where it didnt I used a heat gun and fixed it. I welded in adjustable stops to help in some spots, but only to keep my calipers from getting smashed.

I run Skulte adapters. Although you cant get them anymore I dont think. Pretty sure they are hub and lug centric, which is why I liked them. I torque them properly, and check them pretty often. Never had any issues at all.

They always looked decent behind my WS6 wheels. Although the inside of my wheels are really dirty, so they stood out a bit. Im thinking about painting them black since Im painting my rotor hats and calipers. Make it look like part of the hub vs part of the wheel.

J.

 

My 2" havent caused any issues. You might see a problem if you lower the car. My wheels have enough material that you can't see the adapters through them.

 

Does anyone habe the drawings/dimensions for the brackets? I have a friend that works with stainless steel and he offered to make me a set if I get him the dimensions. PLease help with link or email the drawing to jc2005_130@hotmail.com

Thanks!

 

PDF an AutoCad files can be found at the following web page.

http://lukeskaff.com/?page_id=355

 

i swapped in an entire 2000 rearend.bolted right in including the brake hose except i couldn't use the parking brake cables.i ordered the conversion cables from flynbye using paypal and got them in about a week.i wasn't sure how to run them since as usual no instructions.i ran them under the axle tying them to the antisway bar.anyone got a pic of how the cables were run on a 98-2002 forth gen?

 

There is some info here:

https://www.thirdgen.org/ls1reardisc

RBob.

 

Does anybody have the bracket drawing with dimensions?

 

Read post #22.

 

I saw that. I can't open the auto CAD file in solid works. I guess I'll just have to work with the PDF. I was just wondering if anyone had a print with dimensions.

 

On your ls1 front brake assembly did you have to shim the caliper bracket or shim anything I got mine all installed and it looks like I need to shim it a lot. About 2 thick washers