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2021 AutoCross/Track car build thread

52K views 271 replies 17 participants last post by  ConeHugger01  
#1 · (Edited)
I'm a long time autocrosser (20y), new Kappa (Sky Redline) owner and I thought I'd make a build thread to document some of the things I'm doing and what I run into. I know it's 'Solstice Forum' but there are a couple thousand more members here than SkyRoadster, and maybe a few more autocross/track oriented folks with tips or just general interest.

So the car: 2008 Sky Redline, salvage title. 69k miles. Bought from another forum member actually. Hit mildly in rear, no evidence, hit harder in front - hood replaced, still a little not-perfectly-aligned (seems like the frame is a little bent still). But as it's a race car, that's not too big of a deal for me, though I'm going to try to tidy up the front a bit. The best part is the GMPP tune on it, wooot love the power! (BTW if you don't have the GMPP tune on your turbo, you really need to spend the money and get it!)

The plan: roll bar, competition seats, coilovers/lower it (gosh it looks like a 4x4 truck with the big wheel gaps), wider wheels/tires (probably 275s I'm thinking), chassis stiffeners, bigger radiator, relocate PS reservoir, brembo brakes from the Cobalt, I have some interesting bigger vented discs for the rear from the previous seller, maybe a bigger intercooler, replace timing chains and water pump etc all at once, oil cooler, maybe PS cooler, smaller battery, EU brake reservoir, gauges for coolant, oil pressure, oil temp, voltage; maybe remove the radio/speakers to save weight. Maybe a big gaudy rear wing, and maybe a front lip/splitter. And wrap it in a nifty color.
More power isn't on the table, at least not this year, and what I would want actually is more power lower in the revs if possible, ie at autocross powering out of a slow corner is needed a lot more than top end power. Not sure if it's going to be CAM-S class or ASP.

Here's the car as I got it December 2020:
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TOC:
Engine disassembly, page 1 : 2021 AutoCross/Track car build thread

Engine, timing, page 1 : 2021 AutoCross/Track car build thread

Brake res, rear suspension, page 1 : 2021 AutoCross/Track car build thread

Rear WRP brace, page 2 : 2021 AutoCross/Track car build thread

Tow strap, page 3 : 2021 AutoCross/Track car build thread

Wheel hubs and spacers, page 3 : 2021 AutoCross/Track car build thread

Brakes, page 3 : 2021 AutoCross/Track car build thread

Seat, frame, page 3 : 2021 AutoCross/Track car build thread

Wheels, page 4 : 2021 AutoCross/Track car build thread

Roll bar cross beams, page 4 : 2021 AutoCross/Track car build thread, 2021 AutoCross/Track car build thread

Wheels test fit, spacing, etc, page 5 : 2021 AutoCross/Track car build thread

Weights, page 5 : 2021 AutoCross/Track car build thread

Seat cushion, top water proofing, page 5 : 2021 AutoCross/Track car build thread

Microphone solution, page 6 : 2021 AutoCross/Track car build thread

Phone mount, page 6 : 2021 AutoCross/Track car build thread

Wrapped, page 6 : 2021 AutoCross/Track car build thread

Quickjack plates, page 6 : 2021 AutoCross/Track car build thread

Camber/Caster, page 7 : 2021 AutoCross/Track car build thread

KappaHaus diff brace, page 8: 2021 AutoCross/Track car build thread
 
#2 ·
2020.12.26: Fixed the ripped passenger side fender liner. Just some aluminum and pop rivets. Jacked it up using my QuickJack (highly recommended) which is the larger size, it just fit under the car. There are some places where the hood hinges contact the turbo pipes and it's already dented/scored them so I need to grind down the hinge corners. But first for PA inspection since its R title I need a special inspection, and I may do that before doing anything that they could be picky about.

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#3 ·
Is there a minimum weight for the class you're looking at? I'm running 215 pounds of ballast and need to leave 4-5 gallons of fuel to get to my last year's weight of 2849 with me in the car (NA car). All stock panels still. Full cage. Muffler and full size battery still there. Interior is gone, save for the dash. No sound deadening, no unnecessary wires left (from the firewall back - still need to attack the underhood wiring.)
 
#4 ·
The 2020 CAM rules sheet says CAM-S is 2500 pounds min. I'm sure I'm not going to be able to get close to that. I don't see a min weight for ASP. I want to be wary of weight, but not sure how far I'd go with stripping. To me, interior door panels are nice and make it livable as a car that will go on the street for more than "only" racing events.
 
#5 ·
You may want to consider the XS-A class. It's essentially the same rule-set as CAM, but allows aero and has a more favorable minimum weight of 2,750lbs.
 
#6 ·
2021.01.10: Slow disassembly continued for the past 2 weeks. The entire front end is practically apart. A lot of parts ordered, still waiting on the radiator before I drain it all and really get into the engine for the chains.

The hood hinges touched both the charge tubes just enough to create a little scar on them, so I ground off the offending edge, and the intake tube to the manifold also touched the suspension bracket corner so I ground that down to make clearance.

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taking off the turbo intake showed a minor amount of PCV oil.
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Not a worrying amount but I'll probably install a can. Q: Is there a real need to have the PCV lines be stainless braided? The DDM kit uses standard rubber hoses. That one "hose from hell" on the front of the valve cover is ridiculous, why did they not leave enough room to get a tool onto it?

Most of my parts I can get from online, except the pcv hose flange on turbo for front tube, 12605965, I could only get at GM.
 
#8 ·
I'm hardly an impartial judge, but my plate is generally very well received at autoX events.
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#9 · (Edited)
2021.01.18 This past long weekend the disassembly continued for 2 more days. I got the new dual core radiator, very nice.

Drained the radiator. The radiator drain was normal, but the plug on the water pump was an all-or-nothing, as in the coolant would not drain slowly when opened a little, the plug just let it all out. And there is no space for a reasonable funnel, it's a big sloppy mess. The thermostat was about what most videos say: 1 bolt easy to get to, the other one required moving the hose clamp at least by about 90 degrees. But once moved, the bolt was easy enough to take off from an angle at the firewall with a long extension. Not much extra water came out when opened.

I could not see a good way to get the water pump off without taking off the turbo. I didn't want to do it, but then I decided it would make everything easier.
My turbo had been off before by the 2nd owner, so bolts were really easy to break/get started.

The oil line at the top I did not want to remove (from the block mounting), it was a little difficult to move out of the way, but there was just enough flex. The turbo -almost- came off with no problem, but the top front stud is about 1/2 inch too long to allow free exit of the flange. So we loosened the right side motor mount, jacked up about 1 inch, and then had enough space.

The thermostat housing and tube spider came off easily, but did require removing the temperature sensor.

I removed the upper hose from the top of the intake manifold side, the hose that goes to the overflow tank, and the nipple there was totally clogged. Since coolant probably doesn't normally "flow" much through there, it makes sense, and it's probably a hidden issue (maybe not "problem") that everyone's car has if not serviced there much.

The radiator came off without fanfare (HA!). We zip tied the AC condenser and PS cooler so it would not hang.
I took off the valve cover, as expected required some prying to break the seal.

The balancer/belt pulley was a little tougher than expected. I tried to get by without locking the flywheel, so I used the technique I read elsewhere to put the trans in 5th gear, put on parking brake. With the radiator off, there is definitely enough space to get an impact wrench in the front, and I have a big one (Milwaukee). It loosened the main bolt with no problem. But it did seem like there was some play when before taking off the bolt, trying to test if the engine was locked, that there was some movement. Maybe my clutch is slipping.

Taking off the balancer was tricky, because though its not pressed in, there was still a lot of initial friction. I had to buy a 3-jaw puller (the tool rental with the y-shaped yoke is useless). I had to grind down the teeth of the jaw puller a bit to fit properly. Then I could pull the balancer a bit, back out the main bolt, then pull some more. I had to loosen and move out of the way the power steering lines in front of the block.

I wanted to lock the flywheel after I saw that I had Top Dead Center, my cams properly aligned at 10 and 2, crank key at 12.
Taking the starter off is actually not as hard as it seems or others make out to be. Yes you can take off the intake manifold. But if you're reasonably dexterous and have worked on cars in tight spaces, the starter is nothing new. One bolt from the bottom- super easy. Take off the intake elbow from the manifold. Remove electrical connections from starter, the harder part was removing the wax that was protecting the bolt. Then the rear bolt is easily accessible with a deep impact socket, a 3 inch wobble, plus a U joint and 6+ inch extender. There's honestly lots of room for you hand, and you -can- see what you're working on. I've done some jobs where I could not even see the bolt I needed to work on (spark plug #8 on a 4th gen f-body anyone? rear header bolts on 4th gen?).

Taking off the front cover of the engine was easy enough, nothing special of note.
Be sure to make sure nothing drops into the oil pan when you take the front cover off! It's literally open to the pan right there. Stuff a clean rag quick.

My issue was immediately apparent - the balancer/WP tensioner arm had broken completely through. It was probably "in place" until I took the cover off and it fell out. There was a big scar on the chain area so it had been out of place at least for a little bit. All the work was justified so far.

I've got a small battery ready to go in, saving me 21 pounds over stock.

Turbo off:
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Thermostat thingy
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Getting starter bolt on top:
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That's my problem:
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Why aren't all the guides made of metal with plastic guides, like that big vertical one in the center? I'd gladly pay more for that, if it was more reliable.
 
#10 ·
I've decided at this time to not use a catch can, as I think the oil is very minor in the intake. There was nothing in the intercooler I could see. If I were, I would definitely buy a McNally can. They are one of the most advance design, and also the biggest (oy!).
 
#11 ·
2021.01.24 Things learned about doing timing chain replacement/service:
I watched a number of YT videos about doing the job, specifically the Cloyes one here has most of the relevant steps once you get into the engine:
But that leaves out most of the important tips you want, like what happens when you have trouble! So in roughly build order, here are my takeaways and tips:
  • To get to the front of the engine, if you want a reasonable amount of room to work, you need to remove the radiator fan at the very least, and also the whole radiator too. With the entire rad removed, I was able to fit my large Milwaukee impact gun with shorty socket on the crank bolt.
  • To get full access to the crank pulley, I had to take the mounting feet off the power steering hoses that are in front of the engine.
  • I was going to rely at first on the method to secure the crank from turning, by using the method of putting the transmission in 5th gear and putting on the parking brake. I did not feel comfortable relying on that if the clutch slipped. I took out the starter, and used the official flywheel holding tool. Removing the starter is honestly not that complicated or cramped, esp if you've ever worked on a car before it's par for the course. The holder tool I found for $15 on eBay.
  • My impact gun made quick work of loosening the crank bolt (400+ ft/lbs).
  • You probably need a 3-jaw gear puller to remove the pulley. NOT the Y-shaped/peace sign style. No need to rent the gear puller set at the parts store, just buy a 3-jaw puller.
  • I had to grind the 3 jaw teeth to fit precisely on the pulley. Once pulling, it was easy to get off. I used the old bolt as the pivot point.
  • If you're doing a water pump replacement at the same time - the WP gear does fit in/out of the hole for the WP.
  • To take off the WP pulley bolts, I made a bar with 2 holes to allow me to keep the WP from turning while loosening and installing those bolts. I used an alum bar with holes 1-5/8 apart on center, to put one bolt with a 3/4inch plastic spacer in the WP pulley threaded hole, and using the big WP bolt on the boss near it.
  • Removing the cam gear on the crank required the 3-jaw puller, it's not easy to slip off/on by hand, there's a good amount of friction at the installed position.
  • Removing the bolts from the balance shafts is a joke. I did not replace them as I bent my punch when I tried to loosen the bolt. Remember these parts have been going through thousands of heat cycles and everything can be stuck together. The video of Cloyes or Melling use clean, demo-only engines. Not real life engines. Also, IMO, it's not required to replace every piece. The markings on the OE balance sprockets are marked but hard to see without good light.
  • The main cam gear on the crank had plastic cushioner on it. There was a thin shim on the front of it that covered the part number and the timing mark dot, but it was so precisely fit it was hard to see until I took off the whole gear and touched the shim. In hindsight I might have been able to keep that gear honestly.
  • The main chain for the cams likes to fall off the crank gear. Have a helper to keep it in place while you work.
  • The balance shaft gear on the crank has a springy action to it so you can't try to turn the balance chain drivetrian after that's all in place.
  • The vertical metal tensioner only seemed to fit into place from the top, not the bottom.
  • Buy the plug/bolt replacement for the top vertical chain guide on the driver side from ZZP so you don't have to fret about losing that top bolt taking it out of the big hole.
  • Most of the bolts are 89 inch-pounds but the GM book specifies 106 for some of the bolts actually.
  • I ground a tiny slot mark on the outside of the main pulley to mark TOP and painted an arrow. Hopefully there's no "next time".
  • Putting the main pulley back on doesn't require a special tool, just used the old bolt. I was able to push and wiggle the pulley on for an inch or so, then used the old bolt to press it down. Easy.
  • Tightening the crank bolt to 100Nm + 125 degrees required 2 passes on the degree bar, about 60 degrees each time, as there's not enough room IMO to go all at once. It's the most bolt tightening I've even done. You NEED a 24 inch or longer bar, I used a breaker bar, ie no ratcheting. The degree measure tool from the parts store is like $12.


Holder tool for WP bolts
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GM balance gear markings
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New Cloyes gear for the main cam chain here
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Mark the pulley for "top"
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#12 ·
2021.01.30: Put on a Tim Ronak heat sheild on the water pump but I didn't like it how it sort of interfered with the electronic connector on the turbo, so I modded the piece a bit. Also added some reflective heat tape in the corner where it was IMO the most exposed to the header.

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I modded up a small battery tie down today with bar aluminum.

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I was excited to get everything put together, but I measured the radiator inlet/outlet tubes before putting the hoses on, and they measured 1-1/4 inches not the same as stock 1-11/32 inches and I'm not going to hook that up until find out why the difference, something is kind of fishy with this radiator.
 
#13 ·
This is an upgrade you will probably want to do. I can give you the list of materials needed to get it done.

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if you look at my upper radiator hose it is stainless steel. and it is not braided stainless either, it is corrugated stainless steel tubing and is rated for 1500psi burst pressure. I replaced all of the rubber lines in my coolant system with stainless. The only rubber pieces are some O-rings and the silicone couplers on the ends of the upper and lower radiator hoses.

I also removed the "T" connection that is in the lower radiator hose where the oil cooler attaches to the hose. I used a Y instead which helps to promote more flow of coolant through the oil cooler. I re routed the lower radiator hose so it is not between the engine block and the frame and instead it now sits on top of the frame.

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In the photo above the areas circled in red are the ends the hose came with. I scrapped those as they were crap and I had a company make silicone reducing couplings that were the correct size (odd ball size). I used t-bolt clamps to make the connections.

The green circle is the lower radiator hose the section of the hose that has the 2 red circles is where the "Y" connector is for the oil cooler. I made a bracket from 3/4" x 1/8" aluminum flat bar to support the "Y" connector. the bracket attaches to the frame of the car. there are bolt holes in the frame that are available for use.
 
#14 ·
What I opted to do instead of making a heat shield for the water pump was to help correct the problem instead of correcting a symptom. The problem is heat buildup and it not getting removed from the engine compartment. I already see that you have replaced the battery with a smaller one. This is good. Move that battery over to the door area instead of the wheel house side.

Once you do this if you look under the fuse box in the direction of the turbo you are going to see a bunch of wiring and a metal bracket. That metal bracket supports the fuse box.. A little large isn't it?? it doesn't need to be that big. GM made it that way so it would act like a heat shield for the wiring under the fuse box. If you remove all of the wire loom on the harnesses under the fuse box and also remove all of the tape, then put new loom on (PET) and use 3m super 33+ electrical tape it will make the harnesses far more flexible. You will be able to move the harnesses up and towards the firewall and out of the way. You can then trim that bracket down and make a clear opening to the turbo. It looks like you know what you are doing with metal fab. use a piece of galvanized or aluminum sheet tin and tin knock a duct that goes from the fender to that bracket. I made one that looked like a "C", I used a sheet of DEI gold heat shield and spray glued some fiberglass cloth to the back of it and then spray glued it to the wheel house and also the hater box. 3m super 90 spray glue is the only glue to use, it is a high temp glue and wicked strong adhesion. it is a contact type of glue, both surfaced have to be sprayed and the pieces put together when the glue is tacky.

For this mod to work you will have to have functional fender vents.

Before I made this mod with the car 100% stock, when I would drive the car hard I wouldn't be able to get my hand even close to the turbo area before it was too hot. Now I am running in the upper 400's for horse and have an EFR6758 turbo (much much larger turbo) and I can just about put my hand right on the heat shield over the turbo.

by increasing the flow to the oil cooler and adding that duct to remove the heat from the turbo I have not seen coolant temps above 205 and that is with an OE pump, radiator and fan, this is when I am hammering on it. when cruising I am in the 190 area.

before the mods cruising temp was 205 and driving hard was 215 to 220.
 
#15 ·
Good stuff @kgschlosser thanks! I will look into some of that. My plan was to have functional/open hood vents instead of the silver trim pieces, and take the side fender faux-vent things off the fender so they are truly open. I appreciate the tips and detailed description!
 
#16 ·
when I take the fenders off mine to finish up the body work on them I will take some photos of the duct and what I did exactly.

As far as the cooling lines go, you can buy the upper and lower radiator hoses from Amazon as a kit. You would need to get 2 4 foot kits to do the upper and lower, the cost comes in at something like 50 a kit. I would have to check the exact sizes needed for the t-bolt clamps and also the couplings, I got clamps that were 2mm to small and I had to grind down the nub on the clamp where the nut sits in order to give that that little bit of extra I needed to get the nut on. It worked out nice because there is no threads that are sticking way out after tightening them.

for the overflow lines, turbo feed line, oil cooler, coolant fill and heater core I went to Lows and picked up CSST (Corrugated Stainless Steel Tubing) gas line and the fittings needed to either connect the CSST to CSST or to convert the CSST to NPT where I used an adapter/reducer to attach to the barb fittings, There is one barb fitting you will have to replace, and that is the banjo bolt to barb. you can buy a banjo bolt to 3/8 NPTF from Autometer I believe, from that you put a 3/8 NPTM to 1/2" NPTF elbow.

For connecting to the turbo feed line you cut the barb off the steel line and a 3/8 compression to 1/2 NPTF does the trick. you can do the same for the overflow where it attaches to the bottle. You have to use the tube insert and to get that into the bottle you will have to use a drill bit and make the hole a smidge larger.

At the very least you need to either make a bracket to hold the upper radiator hose away from the fan shroud or you need to use the CSST. the rubber hoses when they get hot they droop in the middle and it sits on the fan shroud where there is this little plastic tit that sticks out and rubs on the upper radiator hose. My stock hose was almost rubbed all the way through...
 
#17 ·
You may also consider upgrading you serpentine belt to a Gates K050400RPM belt. These are high RPM belts that are designed to with stand the additional heat cause by friction from running at high RPM.

The Gates belt is 400mm long where the stock one is 402 or 403mm long. It does fit, the trick is to put it onto the tensioner last, if you try to put it onto any other pulley last it is not going to work. The tensioner doesn't have much in the way of a lip on it. You will have to have the tensioner cranked all the way.. The belt is going to stretch after you run it a few times so there will be travel in both directions on the tensioner.
 
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#19 ·
There are some suggestions that don't cost a whole lot to do and can keep you from having issues when you run the car. the upgrade to the coolant lines is the most expensive at 350 to 400 tops.
 
#20 ·
2021.02.07 Still waiting on resolution on the radiator, as I can't accept trying to pinch down a bigger hose onto a smaller outlet.

Replaced the brake reservoir with the european version, used. It took over a month to get it shipped from Britain... it made a stop about 3 hours away from my house back in early December! I could have driven to pick it up. Then it sat for a good 3 weeks in Indiana, until it finally got processed. It came from a Saab 9-3, GM part number 32067070. There's a lot of other posts about these. I actually bought it with the MC and just didn't use that. So I also got extra grommets with it.

Replacement started by using a turkey baster to suck out as much old fluid as possible. Carefully removed the clutch line, keeping it vertical and moved off to the side, to not lose any fluid. Then I blanketed everything below the reservoir in shop rags, and had my used oil bucket sitting up at the wheel well, and a form-a-funnel taped just under the MC. I carefully rocked the reservoir off and soon as it popped, let it drain into the bucket. The MC still had fluid in it, in the grommets. So a very careful minor cleaing of them, and I lightly coated the plugs of the new res with brake fluid, and pushed it down on carefully. So there should be no air getting into the MC. Reattached the clutch line. I filled the unit with fluid, and it's a multi-chamber thing and the clutch section is last to fill and was hard to see if it got fluid. I made a vacuum cap from one of my spare caps and did several cycles of vacuum pulls on it to get fluid to the clutch section. I believe I actually got it filled all the way but it was difficult to see. I pumped the clutch pedal many times and I seemed firm enough (tho using the vacuum on it made the pedals feel spongy for a bit).

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I moved to the rear suspension and I installed the DDM brace and PerformanceAutoWorks lower brace. The DDM piece is really nice, well designed. I had no problems drilling, and my foam in the frame member was rather solid and came out in nice pieces, not like dust at all. The Werks piece fit on nicely also. Because of adding 2 more layers of metal to the lower rear suspension cover area, I had to get longer M8x1.25 flange bolts, 30mm (tho 25mm would do) to handle the extra steel. With (what I believe is) the stock exhaust pipes and muffler, ther's a good 1 inch of clearance between the exhaust tube and the Werks bar. The front mount on the Werks bar is pretty tight tho, I can't understand how to install the nuts with split washer in such a tight area, in the front lower suspension box. Loading the suspension to get the arms to rotate up will help; and another topic on the forum talked about adjusting the camber bolt to the "up" position to get some space.
I didn't use the washers or correct lock nuts just yet as I have a roll bar install coming up soon and I might need to remove the exhaust again to get into the tunnel area. I'm hoping I can remove the tunnel brace without having to take down the exhaust, or even the driveshaft, to get to what I need.

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I also finished up the power steering reservoir move. The supply hose seemed a little pinched so I got a 90° brass hose end (Home Depot 3/4 inch pex, yes, shame on me) and used some sealant on the joint. I also added loads of duct tape on the fender edge that the hose almost touches so it doesn't rub and cut. I made a vacuum stopper from a big rubber stopper (yay hardware store!) and pulled vac on it after I filled the canister. Got a lot of air out.

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#21 ·
If you really want to give the rear suspension a bump in how well it performs you might consider doing what I did. It made a HUGE difference in how the car handles.

If you jack up the back end of the car and let the suspension hang then snap a photo if the Werks frame brace from the rear of the vehicle, so you are looking at the back most bar from it's edge. The lower the car back down putting the weight back on the suspension then take another photo. compare the 2 photos. You will see that the bar is bending. This is deflection because the flat bad has no real rigidity to it along it's wide side. You can also test by taking the brace out of the vehicle placing 3 blocks on the ground at 3 of the corners have a person stand on the corner opposite the one that has no block and then step on the corner that has no block. It drops right to the ground.

what I did was I picked up some 1" x 1" x 1/8" steel angle iron and bolted to to the frame brace every 3" or so around the outside perimeter. Now when the previous test is done the 2 people can stand on it and the corner without the block doesn't even move.

I also bolted the Pro Beam and the Werks frame brace together at the control arm mounts using a piece of 1/4" plate steel.

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the reason why the 2 pieces i added on either side look crooked is because the pro beam is bent upwards because it matches the curve of the factory cross member.
the tops of those brackets are bent at 90 degrees and the 2 bolts on either side that bolt the side brackets that cam with the pro beam to the pro beam also bolt the ones I made. so there are a total of 6 bolts holding those side brackets in place.

The purpose to adding these is it keeps the rear mounts for the rear control arm square to each other.

sorry for the crude drawings but it will help to visualize the problem and why those brackets and L channel make a huge improvement.

So this is what the mounting system looks like for the lower control arms as seen from the back of the vehicle.
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this is the right rear control arm from a birds eye view

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This is what happens when taking a left turn. there are massive lateral forces being applied to that lower control arm on the right side. and this is what happens

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while both the Pro beam and the frame brace do help they do not have enough meat and potatoes to them to stop this from happening. they will make the amount of the movement smaller. The frame brace is going to deflect in the middle between the 2 rear lower control arm mounts and the pro beam simply sits to high up to stop it.


This kind if a design failure causes a very dangerous alignment change to the back of the car when taking a hard corner. you end up with + camber so the top of the tire will be out more then the bottom, and because the front mount on the control rm doesn't move and the back one does it toes the tire out. This will make the back of the car unbelievable loose and want to slide.


If you jack up the car and let the suspension hang. loosen the 4 bolts that hold the frame brace in place, back them out almost all the way, then lower the car back down you are going to see a gap form between the the frame brace mount and the lower control arm mount. and the gap isn't small either. between 1/8" and 1/4" on either side.

This is happening from only the weight of the car and no lateral forces involved!!!!

So when you drive the car and if you want the back of the car tighter keep this in mind.
 
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#22 ·
Good stuff there, I also wondered if the Werks piece should really have been square tubing, as I read their very first version may have been. I can drill holes and I also know someone with a welder, and know I have it installed I can really understand what kind of clearances I have. I'm defintely going to add some beef to that piece. This was my #1 concern for the suspension on the car when I started learning about it.
@kgschlosser What shocks are you running? I assume you autocross (roadrace?). What's your tire setup?
 
#23 ·
I do not race, I have the stock shocks as they are Bilsteins and aren't bad to begin with and for sneakers I am running Firestone Firehawk Indy 500's I do not remember the exact size off hand, I know they are wider and have a slightly smaller sidewall then the stock tires. I will say that these things grip exceedingly well, damned close to the Yokohama Advan A048 (Lotus compound). Tires only last 10k-12k miles but that is to be expected because of the soft compound. They aren't horribly expensive, I paid <650 for a set of 4 mounted, balanced, disposal fee, changing all of the seals in the TPM sensors and taxes. The tires work fantastic on wet roads as well. snow on the other hand..do a whole lot of go no where really fast.. they have a stiff sidewall so I run them at 26PSI or so for some comfort. If I was to use them for autocross I would bring the pressure up to 30 or so, and I will say that they can be used in autocross no problem.

I know it is hard to find the right tire for a car, I will say that this tire is a really good match for the car's weight handling characteristics, suspension spring rate.. I have to replace mine in the spring and I will definitely be getting the same tire perhaps wider if I don't end up with to much cupping..

Where are you located? I can ship you the old set when I get them changed, they will be at or close to the wear bars so still have some usable tread on them.

it originally was square stock, it is shown on their website as square stock, I asked about it and was told that there wasn't any difference between the flat and the square in term of performance. I said bullshit, that's impossible. I can bend that flat bar by hand, and there is no way that I would be putting as much force on it then what the car is going to do to it. I had my buddy follow me with the brace in the car before I modified it. I left the rear valance and exhaust off the car. only a trip around the block. he said he could see the thing bending when I was taking corners and when I went over bumps. Even using the L channel it still bends a little. I can see it when I take the weight off the suspension. I have really been considering changing from the 1x1x1/8 to 1x1x1/4.. Can't really make the return on the L to much bigger then an inch because of the exhaust and If I notched it so the exhaust wouldn't hit it defeats the purpose of having the larger return and is also going to push all of the energy into a single spot making it bend much easier.

Welding it would also be better then bolting it, tho the bolts do add an aesthetic appeal to it.

Bending that 1/4" plate to make the 90 was fun.... I took a 6x6 piece of lumber and cut a 90 degree V out of the middle of it. used 3 high output propane torches to get the metal cherried. I set the metal in the block and used my shop press to push it into the V. Heated it up again and set it in the block, then use a 5lb hand sledge and a masonry chisel to bend it in the rest of the way and give the inside a nice clean 90 with no curve. I let the metal cool down in it's own time as I didn't want to temper it and make it brittle.
 
#25 ·
After taking a look, my plan is: Weld 3/4 inch square tube along the back brace, along with some corner braces that are parallel to the ground, about 4 inches, just to cover the width of the suspension pickup. In an ideal world, the exhaust wouldn't be in the way and I could put diagonal braces from the pickup point up to the upper rear member, but in this case I can go to the DDM bar with a nice diagonal bar, and on the driver side, a diagonal bar but of course can't go to the right spot either at the top or bottom. I feel the diagonal brace like this will eliminate a lot of the flex, as we've all heard triangles make for rigid stuctures. I'm not sure how I feel about needing to reinforce the horizontal diagonals built into the Werks unit. There could be some value in that, but I don't have finite element analysis to calculate the stresses. It seems that they are needed for sure, but the load they carry is probably a lot lower than the rearmost crossbar. It's always something I could add later.

111109
 
#26 ·
There is no need for that much strengthening, but if you want to do it, go for it. Keep in mind that if you go with a muffler-less Solo exhaust later in life it's not going to fit.

For reference, when GM developed the track-spec Z0K package, all they did was add a doubler plate to the rear cross-member, and that solved the rear suspension issues. And those cars were running slicks and generating far more lateral force than something on street tires ever will. There is plenty of other documentation/development on this topic from a decade ago if you search it here or on the Sky forums, but the general consensus is always Z0K Beam=Pro Beam >> Werks Brace/ReBar.

I have not tested this myself, but I suspect you could probably remove the bolt on "fingers" of the pro-beam that drop down and there would be a negligible change in compliance.
 
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