Totally unoriginal LQ1 build thread

[The Dark Side of Will]

Going to spend some time adapting the C5 brakes to the 88 calipers. The first thing to overcome is the adaptation of the drum ebrake setup onto the 88 rear knuckles.. One of the goals I'm after is to attach the ebrake drum to the knuckle without utilizing the hub bolts thereby moving the hub away from the knuckle as I plan on installing achieva bearings on the rear. The achieva bearings already require a 1/4" spacer on the axle and any ebrake drum bracket that utilizes the hub/bearing bolts will move it further from the axle spline and reduce the engagement to the splines that much more.

The solution I'm contemplating is building a 3/16" to 1/4" bracket that clears the hub / bearing bolts and utilizes the dust shield bolts for attachment. I think its safe to say that the stock bolts and holes for the dust shield would be insufficient for the sheer force encountered by an ebrake engagement at speed. Nor do I think simply changing to a grade 8 / 10.9 bolt would be enough either. There's not much room widen the holes due their proximity to the edge of the casting but it may be possible to drill larger holes just inset of the dust shield tap holes but utilizing the area where the holes exist. However how do I drill and tap a new hole into the casting without the bit walking into the original hole. Screw a bolt in and grind off the head and use that as just base material to drill into for the new holes?

Also, any ideas what sheer calculations would I need to deduce the size of the bolts needed?

I don't think C5 Corvette rotors will work with 1988 calipers... they are too thick. Yes, the '88 calipers come apart into a steel bridge and aluminum hydraulic unit, but the profile of the bridge and the location of the bolts is such that spacers between these two components do NOT allow the use of thicker rotors.

C4 Corvette rotors are commonly used with '88 calipers.

Regarding parking brakes... if you fab a backing plate that bolts on top of the mounting ears on the hub cartridge, you'll still have easy hub replacement. All P-brake components should bolt to the backing plate. If you fab this backing plate to stack on top of the hub bolts, then when you remove the bolts, both hub and backing plate come off the knuckle. If you shape the center hole in the backing plate correctly, you will be able to rotate the hub 120 degrees and remove if from behind the backing plate.

[draven]

C5 rotors are indeed too thick for 88 calipers.. I'm going with the C5 calipers and C5 ebrake... looks like it can all be done. The backing plate for the ebrake will utilize the 3 dust plate holes with 10.9 M6x1x20 flanged bolts which accounts for a 3/16" inch plate which will contour around the hub flange. Going with a 20-25k Jbody/Achieva hub and already will have to account for 5mm+/- axle to hub bearing separation.

[draven]

double post

[The Dark Side of Will]

C5 rotors are indeed too thick for 88 calipers.. I'm going with the C5 calipers and C5 ebrake... looks like it can all be done. The backing plate for the ebrake will utilize the 3 dust plate holes with 10.9 M6x1x20 flanged bolts which accounts for a 3/16" inch plate which will contour around the hub flange. Going with a 20-25k Jbody/Achieva hub and already will have to account for 5mm+/- axle to hub bearing separation.

Due to the 7+" diameter drum in the hat, the C5 rear brakes are fairly shallow radially... they also use pretty small calipers. The resulting brake bias may not be appropriate for the Fiero.

I'm working on using BMW E30 parking brakes, which use a 6.300 ID drum, which, when used with the appropriate Wilwood hat have a much greater radial depth and can be more easily balanced with big front brakes.

[draven]

Been a while since an update but I stripped down the 86GT I had and acquired an 88 GT from Paul Vargys to work from.

Coming together... BallEngines.com did the boring, reconditioning, balancing and assembly of the block.


I'll never see timing cover this clean again


Note the oil drain back porting (props to Series for bringing this to light although its pretty obvious when you overlay the head gasket)


More porting..


Gasket matched..


Mahle/Clevite valves.. The seat of the stockers looked like swiss cheese.


Quick check of new head alignment pins..


Bottom taping head bolt holes to gain a few mm's for ARP's to fit.


ARP Head stud, washer, and nut Part #'s... The head bolts are from the Mazda JDM V6 for the MX6 4 of the head bolts are short to clear a cam sensor boss in their head and puts them "just" within reach of fitting into the LQ1 with the appropriate thread.


3 Month Wait from ARP to see this sight...


Waiting on light weight lifters from WOT Tech as my originals were noticeably beveled from the PO. (lifters just arrived yesterday)

So while stripping and boxing up the useful bits of the 86. I began driving the new 88GT and shaking it down... rear rotors were warped so I was going to go over the brakes, bleed them, new rotors, and pads... All 4 sets of caliper sliders were siezed solid. Tried the usual fluids to loosen them up with no success on the rears and got one front to "move" under mallet impact. Also, the master cylinder was corroded enough that while bleeding the brakes I broke the cardinal sin of pushing the brake too far and blowing the seals.. Got a NAPA replacement and it leaked like a sieve out the front piston while priming it, took it back and luckily the 86GT brake cylinder primed up without issue. It's only 1mm larger bore than the 88 brake cylinder and its bore is exactly the same as the C5 master cylinder. When the 86Gt was running it did stop very very very well and this is comparing it to 13" brakes on a Panoz GTRA at road Atlanta that I have driven in the past.

So I decided to leave the 88GT on stands and get on with the brake upgrade while waiting on the lifters and ARP bolts. Since I had a spare set of 88 hubs from my spare 88 Cradle I decided to do the rear 20-25K delco hub upgrade. Here's the Stock 88/84-87 hub next to the 20-25k


Spacer's from the PO to account for the C5 ebrake backing plate ... looks like I might be able to use them for the hub spacers


Hubs bored out for a nice slip fit. KGMade.net did the machining.


FYI you can slot these nicely even with a cheap end mill bit from harbor freight, a drill press, patience, patience, patience, and lots of lubricant.


<dead pan voice>
tada.... as steven beat me to the punch by a few days...
</dead pan voice>



I'll get some pics of the new 88GT up... it's pretty nice but was driven infrequently and left sitting in a garage for much of its life as evidenced by the brakes, headlight motors, and other sundry items.

Next step is unobtrusive backing plates for the C5 ebrake.

[Series8217]

Nice! I'm very much looking forward to the ebrake setup. I want to swap in some monoblock calipers onto my car eventually and it would be cool to use an internal brake.

[draven]

C5 rotors are indeed too thick for 88 calipers.. I'm going with the C5 calipers and C5 ebrake... looks like it can all be done. The backing plate for the ebrake will utilize the 3 dust plate holes with 10.9 M6x1x20 flanged bolts which accounts for a 3/16" inch plate which will contour around the hub flange. Going with a 20-25k Jbody/Achieva hub and already will have to account for 5mm+/- axle to hub bearing separation.

Due to the 7+" diameter drum in the hat, the C5 rear brakes are fairly shallow radially... they also use pretty small calipers. The resulting brake bias may not be appropriate for the Fiero.

I'm working on using BMW E30 parking brakes, which use a 6.300 ID drum, which, when used with the appropriate Wilwood hat have a much greater radial depth and can be more easily balanced with big front brakes.

yes indeed.. they are "very" small as compared to the front. The rear pad size is more or less the same size as the stock 88's and I have a wildwood proportioning valve waiting to go in to balance things out which I'm positive will be needed.

[draven]

Nice! I'm very much looking forward to the ebrake setup. I want to swap in some monoblock calipers onto my car eventually and it would be cool to use an internal brake.

Going to first try some 3/16-1/4" 7075 T6 aluminium plate to hold the ebrake. After a quick eyeball of the stock c5 knuckles, to use the stock caliper bolts for the calipers it looks to necessitate adapters 1" thick so I very well might go with steel for those with new bolts.

All this will also require new wheels and I'm a sucker for 5 spokes and I can't find anything other than your motegi mr116's that will support a 205/17 in the front with 88 offset and a 265/18 rear. The closest I've found are the SSR GTV01's but the largest 5x100 is 8.5", not to mention their elevated price next to the motegi's but still not "too" spendy as compared to custom or a set of rays/volks...

[draven]

Finished lexan mock-up of the ebrake bracket. Looks similar to the 88 brake dust shield just extends all the way around the hub flange with tight slip fit so that it might gain some additional support from the flanges outside of the 3 10.9 M6x1x20 bolts I installed...

Just reshaping the already hacked up backing plate to fit around the hub at the new orientation. The C5 backing plate has a spring clip and raised bevel to keep the ebrake shoe parallel to the knuckle face and rotor housing.

[draven]

Drew this Swage / Die up in CAD for stretching exhaust pipe into the port shape of the 96/97 LQ1 manifold to create port studs for headers.

If anybody else is interested in this let me know and I'll be more than happy to share the CAD file..

[The Dark Side of Will]

Why the big mismatch between tubing and port size/diameter/cross-section?

EDIT: Nevermind... this is for tubing that is much closer to the cross-section of the port than the snout of the form is. Are you planning to use tubing with the same perimeter as the port?

[draven]

Why the big mismatch between tubing and port size/diameter/cross-section?

EDIT: Nevermind... this is for tubing that is much closer to the cross-section of the port than the snout of the form is. Are you planning to use tubing with the same perimeter as the port?

Looking to use 1 5/8 primaries port studs / primaries. My biggest concerns at this point is if the top and bottom of the piping will flatten out against the mandrel. Furthermore, should I lengthen the transition as well as make the entry point closer to the final form much like FastIndyFiero did for his DOHC SD4 ports, yes..... a DOHC SD4.

About 3/4 down the page: http://www.fiero.com/forum/Forum3/HTML/000020-13.html

The 96/97 LQ1 exhaust port oval size is 29mm x 66mm. The more I visualize how the mandrel will press into the pipe it might be a good idea to make the snout an oval too.

[draven]

Polycarbonate template done of the C5 ebrake bracket.

Here's the pics displaying the assembly of the setup..

First, relieve a small amount from the knuckle to allow the ebrake mounting bolt head to clear.





Originally I was going to attempt to offset enlarge the dust shield bolt holes to 8mm up from 6 and use them as the sole mounting points of the bracket however the template above will also tie into the original caliper mounting bolts with a 1.5mm / 1/16th" washer between.











Now the only issue left to overcome is the backing plate to rotor clearance... with the adapter at 4.5mm / 3/16th" thick and the tri-chord relief cut to keep the mounting flange of the hub against the knuckle there is interference between the ebrake contact surface of the rotor and the backing plate. Shown in the pictures below:





Options are to:
1.) Mount the hub on top of the mounting bracket, without the tri-chord cutout and just the circle for the hub cartridge, giving the necessary clearance but also displacing the hub 5mm from knuckle thereby reducing spline engagement by the same amount.

2.) Mount a 2-3mm hubcentric spacer between the hub and rotor

3.) Remove the outer portion of the ebrake backing plate.

[The Dark Side of Will]

Reducing the diameter of the backing plate makes the most sense, IMO.

Any adverse effects from pushing the hand brake shoe further into the drum?

[draven]

Reducing the diameter of the backing plate makes the most sense, IMO.

Any adverse effects from pushing the hand brake shoe further into the drum?

No interference points found at this point Luckily the stock dimensions put the drum shoe's toward the back side of the rotor giving a bit to play with...

[draven]

Reducing the diameter of the backing plate makes the most sense, IMO.

Any adverse effects from pushing the hand brake shoe further into the drum?

No interference points found at this point Luckily the stock dimensions put the drum shoe's toward the back side of the rotor giving a bit to play with...

Actually there was.. if you notice on the drum contact cylinder of the rotor there is a chamfer. That chamfer provides about a mm worth of clearance from the ebrake actuator...

I removed the outer rim of the backing plate and cut back the mounting bracket which then revealed an ever slight bit ofinterference with the actuator. Took about .5mm off the casting and all is clear.

BTW since the 88 ebrake cable comes in towards the hubs from the front I've swapped the actuators so I can route the ebrake cable up and through a mounting point on the sway bar tabs so that it can pull "up" to actuate the ebrake there by minimizing any changes to the ebrake cable other than swaging a new end connector.

[The Dark Side of Will]

Reducing the diameter of the backing plate makes the most sense, IMO.

Any adverse effects from pushing the hand brake shoe further into the drum?

No interference points found at this point Luckily the stock dimensions put the drum shoe's toward the back side of the rotor giving a bit to play with...

Holy cow... last time I try posting from a mobile device.

[draven]

Just performing final assembly on the LQ1 and getting her ready for sale to start on the LF3 swap. Rewrapping and reconfiguring the wiring harness at the moment... After pulling refreshing, and installing 2 ford explorer 4.0 V6s and a Mazda 6s 3.0L V6 in two years, I'm still shocked at the size of the LQ1 when fully dressed, it's only an inch or two narrower than the fully dressed LF3 over in the corner...

[Shaun41178(2)]

That engine turned out great

[ericjon262]

agreed, looks awesome!