Go Back OFN Forums > Fabrication > Hotrod Fabrication

Hotrod Fabrication Hotrod Fabrication


Hotrod Fabrication Hotrod Fabrication

Reply
 
Thread Tools
  #861  
Old 01-31-2018, 04:35 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
Side story.... since I had finally had my welder back out, I figured it was about time to give my 7 year old a little lesson on welding. I didn't learn to weld until I was in my late teens, but I remember it opening my imagination to a whole new world of possibilities and creations. I hope it gives my son the same sense of limitlessness.

I started with a basic lesson on safety and suited him up with an apron and some welding gloves. I found by using some of my softer leather gloves, he was able to move his fingers okay despite them being over sized. I also sized my Miller Elite helmet down and was able to fit it to him - I figured an auto-darkening helmet would make this a lot easier.



We started by making some pretend passes on a plate with the machine off. I gave him basic pointers on gun position and travel speed.



The biggest challenge for him was holding the weight of the gun and hose, which were also awkwardly large for him to handle. I helped by supporting under his hand and holding up the hose behind the gun. He was really excited when it came time to make his first weld. As he was welding, I talked to him about travel speed and reminded him to keep the trigger held, move slowly, and maintain the right distance at the tip. He followed instruction like a champ.



The session culminated with him welding a 90 degree joint, which turned out better than a lot of the stuff I've welded myself. Proud kid - proud dad!



Nothing brings me more joy than sharing experiences like this with my kids. I can't wait to do the same with his younger sister, 4, when she's a little older.
__________________
Clint
Reply With Quote
  #862  
Old 01-31-2018, 04:36 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
So after looking over over my housing end welds closely I decided there were just too many start-stops and inconsistency, so I decided to rework them. Here is a video to get a closer 360 view of each. I noticed the first inch or so of each weld is cold and then starts to wet out more. The cold parts of the welds and questionable overlaps at the ends are what motivated me to rework.

Youtube Video - Old Welds

https://youtu.be/y7PC6gEBxSo


In retrospect I think I would have had better results if I preheated the housing, but even so I think the starts and stops and time to re-position the housing between welds were the main contributing factors to the result. So I decided to enlist my kids to help me make a rotisserie. Here's what we came up with:











The rotisserie we came up with is a simple set of stands made from 4x6 and 3/4 plywood remnants with opposing chair casters on top. Fixed wheels might work better, but I had these on hand. I'm hopeful they are far enough from welding heat that they won't melt. I bolted a pair of heavy steel lift/lowering blocks to the diff cover to balance it and formed a crank handle from a piece of scrap aluminum. Here's a video of it in action.

Youtube Video - Rear Axle Housing Rotisserie

https://youtu.be/h0cS8J92NiQ


I'm happy with how it works; it rotates smoothly and feels balanced enough that I can stop at any position and the axle housing doesn't try to swing around on me.

I ground out the old welds with a 4-1/2 grinder. Here is what they look like. There is a bit of a radius inside the corner due to how the grinding wheel wore on edge.

Youtube Video - Ground down housing end welds

https://youtu.be/skACc_e_Dag
__________________
Clint
Reply With Quote
  #863  
Old 01-31-2018, 04:36 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
This has been quite a refresher on welding (and grinding lol) for me. After getting the rotisserie figured out, I got everything setup on my welding table and proceeded on a second pass at welding this. Here is a video:


https://youtu.be/3Jf7DU67A7E


Unfortunately that attempt was ill-fated. The resulting weld was a narrow, piled-up glob-ring around the housing that I dared not photograph (the grinder came out faster than John Force). I walked away from the project for a few days while I pondered what went wrong. I talked to my brother who is more of a doer/fabricator than an over-thinker/engineer like me, and together we came up with a few conclusions:

First, the overall height of my welding table and the rotisserie stands put the housing too high - roughly armpit level - and instead of positioning the gun over the housing for a flat position weld, I had the gun on the side of the housing doing a vertical position weld. Second, the hand crank was large so I ended up positioning my head behind the nozzle where my view of the weld was obstructed (this also contributed to doing a vertical position weld). Third, I was pushing the weld and given I was looking at the front side of the weld and had obstructed view of the back, I didn't even notice the weld pilling up behind the gun. Fourth, I wasn't weaving nearly enough.

Those factors all contributed to a bad result so I set out on a plan to right my wrongs. First I put the rear end all the way down on the floor instead of up too high on the welding table. As a result I had to kneel on the floor to make the weld, but I was able to more easily do a flat position weld which would help the weld lay flat and wide instead of narrow and built-up. Second, I shortened my hand crank to essentially just stick out from where the bolt of the housing end would normally go. This made it harder to crank, but freed space so I could put my body in front of the housing end and get my head closer to see what I was doing. Third, I switched from a "pushing" technique to a "pulling" technique by rotating the housing in the opposite direction, angling the gun slightly from vertical toward the direction of welding, and viewing the weld from the back of the puddle. I placed a jack stand as close to the housing as I could to use as a hand rest and did a dry run. Here is a video (ignore my muttering):


https://youtu.be/oFxGp53rx4Y


The dry run went well. I had to adjust my position a little to get angle on the gun and visibility while the spring perch swung around, but for the most part this worked. Time to weld. This time I made a wider weave and I paused momentarily at each end of the weave.


https://youtu.be/7P_RI_gJ_Gg


That worked out quite well. The first side went smoothly and I got a flatter, continuous bead all the way around the housing. While welding the second side I had to stop and restart twice, first because my hand crank got caught in my welding apron (Murphy's law) and second because I accidentally dipped the tip into the weld. But I corrected those issues pretty quickly and the start-stops are not too noticeable. Here are a couple photos showing the finished welds:





I am happy with those results. They are a little built-up and could probably have wetted out more at the housing tube side, but I think they'll be just fine.

I think next I'll mock up the brake lines and add any necessary mounting tabs before getting the housing blasted.

I also managed to assemble the new Strange axles. First step was installing the new 1/2" screw-in wheel studs with red Loctite and the appropriate torque. Along with the vise, I used a piece of square tubing across two studs to help resist the tightening torque. The vise alone just wasn't enough.







The photo below compares the stock 12bolt axle end to the Strange setup. The 1/2" studs are a little more substantial than the stock press in 7/16" studs. Also you can see the flanges are thicker than OEM and with the way the axle necks down slightly, it's likely if the axle ever does break, it will break inside of the bearing and the wheel will stay on.



With the studs in I could move on to assembling the bearings and retaining/wedding rings. I am using the F-body brake bracket to retain the axles, so I had to put the backing plates on first, then the tapered bearing with seal, and finally the wedding ring.



I brought the assembly to my 12ton shop press fitted with a 20ton bottle jack. I supported the wedding ring with the press plates and pressed both the bearing and the wedding ring on at the same time. Some prefer to do the bearing first then ring since it takes less press force, but this worked out fine for me - even though it took some doing I could tell when they bottomed. I took a "hyperlapse" video of the process with my cellphone


https://youtu.be/CYBUorkx9yM


My only problem here was pressing against and destroying the fancy gel-like logo sticker Strange puts inside the end. I didn't have a suitable size puck to place over the end of the axle otherwise I could have avoided this! Maybe they will send me a replacement.

__________________
Clint
Reply With Quote
  #864  
Old 01-31-2018, 04:37 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
More progress on the rear end. I picked up a pair of Powerslot (now Stoptech) slotted rotors for the "LS1" brake swap. They are directional vane, P/N 126.62065SL (left) and 126.62065SR (right).



As you may know I like to get my son into the garage as often as I can, so I he helped me mock up the axles and brakes. Here's a little hyperlapse video of us.

https://www.youtube.com/watch?v=MvRaX1sOSa4





I'm happy to see everything fit as it should and I hit my target overall width WMS-to-WMS within 1/16th inch. To summarize, I narrowed the housing using Strange H1143 GM pattern housing ends and used strange B1105D spacers for tapered Ford bearings. The brakes are "LS1" calipers and backing plates from a '02 Camaro and the axles are custom length Strange axles. The overall WMS-to-WMS has been narrowed by 2in from 60-1/4" to 58-1/4" (1in per side). The goal is to fit more common 0 offset wheels (for example 18x9 w/ 5"BS) instead of getting 1" offset wheels (for example 18x9 w/ 6"bs) which are virtually unavailable without going to 2 or 3pc wheels.

Happy with the brake mockup, I picked up some new brake hoses. The original "LS1" hoses have a 10mm banjo at the caliper and a 10mm bubble/DIN connection at the other end. I decided to swap them for '05 Blazer hoses which are a couple inches longer and have a 3/8-24 inverted flare for 3/16" tubing. They are Dorman H380469 / Napa P/N 380469 and cost about $10 each. By comparison, braided stainless lines of the same size are around $25ea.



For mounting the hoses, I picked up some precut tabs for Currie CE-6013-TAB. They didn't have a slot for removing the brakeline, so cut a slot with my bandsaw. This will allow me to remove the brake lines from the axle without opening up the brake system, so i can just hang the calipers and lines from the car if I want to remove the rear end - no bleeding needed.



Once I figured out where I wanted them, I used a Dremel and a carbide cutter to make a notch for the anti-rotation tab. Then I tacked and finally welded them on. I used Allstar brake line clips ALL50150 to retain the hoses lines.







That was it for fabrication, so it was finally time to strip it back down for clean and paint. I got an electric pressure washer a couple months go. After a series of soaking in degreaser and spraying inside and out with the pressure washer, it was ready for paint.









I decided to get an LPW racing diff cover, not so much for the cap support girdle but because I'm more confident the cast cover will seal well and it has drain and fill ports. One of my goals for the car is no leaks!

__________________
Clint
Reply With Quote
  #865  
Old 01-31-2018, 04:38 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
Now it's time to reassemble the diff. I have done a handful of gear installs on Toyota diffs, but this is my first time assembling a 12bolt. I am reusing all the old gears and bearings, so I am confident the pinion depth is already set. First step was dropping the yoke-side bearing into the housing and installing a new pinion seal.



Many moons ago I made this pinion flange holder for doing Toyota diffs. I was able to drill a new hole in it and use it to secure the yoke on the 12bolt. The holder is basically a long piece of square tubing with a tab welded on and I clamp it to the workbench to keep the pinion from rotating while torquing it down. I'm reusing the gears and bearings, but a new crush sleeve is required to make sure the bearings have proper pre-load.



I used a 1/2" breaker bar and a long piece of square tube to crush the sleeve. I would have started the crush sleeve in a press, but it didn't seem like it had very far to go so I went straight for the cheater bar. This is a bit risky because you can easily turn a 1/2" breaker bar into a 1/2" broken bar. I decided to take the risk and it worked out this time, but I have previously broken these when setting up diffs. A 3/4" drive would be much better suited for the task.



And for giggles, here is me doing the same job on a Toyota diff about 10 years ago. It looks like I may have even used the same piece of tubing for leverage.



Once I got the sleeve crushed most of the way, I removed the nut and added Loctite. The pinion nuts on a Toyota diff can be staked into place, but this 12 bolt pinion doesn't have that provision. Hopefully Loctite is sufficient.



If you've never done a gear install before, one must-have tool is an in-lb toque wrench for checking bearing preload. I got this one from a bicycle shop. There are better more expensive versions out there, but this does the job.



I read the target for new pinion bearings on a 12 bolt is 20-25in-lb and used bearings should have 10-15in-lb. When I got to 10in-lb, I decided to give it just a hair more and unfortunately overshot to 20in-lb. Then I did a little more research and found specs as low as 6-8in-lb for used bearings! So it seems 20in-lb is just way too much. I will have to get a new crush sleeve and redo it. I definitely don't want to grenade my pinion bearings over a $5 crush sleeve and a little bit of time to get it right.
__________________
Clint
Reply With Quote
  #866  
Old 02-01-2018, 12:37 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
Yesterday I picked up a new crush sleeve and reset the pinion preload. This time it's at a easy-turning 7.5in-lb. I have seen specs of either 6-8in-lb or 10-15in-lb. I haven't seen a definitive answer on which is "right", but I have seen a few threads where gear techs recommended the lower spec. It was also pretty freewheeling when I took it out, so I'm going to err to the low end.

After getting the pinion preload set, I was ready to drop in the carrier. It was tough getting out with a pair of prybars so I didn't expect it to be easy to go back in. I was thinking a spreader would be needed, but I saw a few videos of people successfully installing the carrier shims with a dead blow so I thought I'd give that a try.





So yeah that didn't work out so great. The shim was scooting in with each blow from the hammer, but it couldn't take the shock. Now I'll have to order a set of shims and I guess I'm going to build a case spreader and/or a shim driver.
__________________
Clint
Reply With Quote
  #867  
Old 02-01-2018, 07:34 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
I did a little research and made a couple phone calls... I think my problem here is that I was beating on a brittle cast shim. Apparently the aftermarket shims can take more of a beating, so once my new "super" shims show up I'll give this method a second try without using a spreader. Yukon tech advised against using a spreader on this housing because "more often than not people end up damaging the case". Their advise was to use a dead blow.
__________________
Clint
Reply With Quote
  #868  
Old 02-02-2018, 11:50 AM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
Had a little downtime so I designed this autocross theme vinyl sticker for the rear end. My wife helped me cut it out and layer the vinyl with her crafting machine (Cricut).

__________________
Clint
Reply With Quote
  #869  
Old 02-02-2018, 02:01 PM
alwaysFlOoReD's Avatar
alwaysFlOoReD alwaysFlOoReD is offline
Master Fabricator
 
Join Date: Jan 2010
Location: Red Deer,AB Canada
Posts: 720
Quote:
Originally Posted by TheBandit View Post
Had a little downtime so I designed this autocross theme vinyl sticker for the rear end. My wife helped me cut it out and layer the vinyl with her crafting machine (Cricut).
love it.
Reply With Quote
  #870  
Old 02-07-2018, 09:44 PM
CarterKraft's Avatar
CarterKraft CarterKraft is offline
Master Fabricator
 
Join Date: Oct 2009
Location: DFW
Posts: 910
Quote:
Originally Posted by TheBandit View Post
Had a little downtime so I designed this autocross theme vinyl sticker for the rear end. My wife helped me cut it out and layer the vinyl with her crafting machine (Cricut).
Yep, excellent.
Reply With Quote
  #871  
Old 02-09-2018, 02:48 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
Thanks guys. I felt like I came up with a neat original idea that works. I imagine it will get copied and that's fine with me.

Family life is picking up steam right now. My son just started baseball and this year I've taken on assistant coach duties. We had our first practice and I was really missing the fun of taking my son in the Nova like we did all last season. He loves baseball and he loves going out in the car, so putting those together makes for some special memories. I've got to get this thing back together soon - he'll only be 7yrs old once.

I once again used an opposing set of crowbars to pull the carrier out and fetch the broken shim. I learned that this is a cast shim and is much more brittle than the aftermarket shims I've dealt with in the past. It was broken in several places so I took a measurement in order to replicate the thickness..





I bought a set of "super shims" from Yukon Gear (they are manufactured Motive) and matched the thickness to the thousandth. Then I proceeded to drive them in after placing the carrier into the housing. What I realized is that this really is not a good order for installation. The shims are thin and when you pound then between the bearing race and the housing, they are not well supported and more easily damaged, not to mention it's very hard to strike a good hammer blow as they get deeper. I would not suggest doing what's shown in the photo below unless you have a shim driver and/or case spreader in use.



When I realized what I was doing wrong, I pulled the carrier back out and changed the order of things. I wiped some grease on the shims and placed them into the housing. The grease helped stick them to the surface while I carefully dropped the carrier in. With this assembly order, the shims are fully supported on one side against the housing and I could use the dead blow against the carrier itself to drive it in. It took quite a few blows to get it in with the smallish 3lb dead blow I have, but it got home without any observable damage to the shims or bearing races.





Once the carrier was in, I proceeded to install the bearing caps. I have this neat Snap-On ratchet (the ONLY Snap-On tool I own) that converts to a speed wrench. It's great for stuff like this.





Since I thought I would be done, I went ahead and torqued the caps down.



Next I figured I should run a pattern. I've been running these gears for about twenty years and in this build I haven't changed bearings or pinion shims, so my hope was to just put it back together the way it came out. I've heard used gear patterns can be all over the place, but I thought I'd give it a shot just to see.

The coast side on this location looked pretty centered heel to toe, but maybe a tad shallow/toward the face.



The drive side looked okay, maybe a bit toward the toe and deep/ toward the root. I'm thinking with the coast side a little toward the face and the drive a little toward the root, pinion depth is probably okay since I couldn't really center one without messing up the other.



Next I checked backlash. It seemed a little excessive when I pulled the rear and the measurements back that up. In the image below I measured 0.017in, but when I rechecked and moved the ring around to a few different locations, it was more like 0.020in! The spec for new gears is 0.006-0.010in.



Unfortunately I just can't unsee that. I was tempted to put it back together knowing it has been running like this for a long while without issue, but I also think I'd be kicking myself if I had problems out of the rear as a result of excessive backlash. So I'm currently in the process of swapping shims.
I'm anxious to get that sorted so I can shove the axles back in and start working on brake lines. I got a little motivation this week when another set of "parts" arrived.



I can't wait to get this thing back on the ground!
__________________
Clint

Last edited by TheBandit; 02-12-2018 at 06:44 PM.
Reply With Quote
  #872  
Old 02-12-2018, 06:45 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
I did some more research and found a typical backlash for used gears is around 0.012in. Most recommendations are to measure match the original backlash that the gears have worn into since they've already lapped into that position, but in my case I can only guess they had too much backlash to begin with. What to do?

I decided to swap shims and hope the gears are happy lapping themselves into a slightly new position. After measuring the angle of the gear teeth, I calculated I would need to move 0.011in shim to get the backlash down by 0.008in to hit a target of 0.012in backlash. So that's exactly what I did and that's exactly the result I got (how often does that happen? I had a little engineergasm when the indicator gave me exactly what I was going for).

With that set, I torqued the caps down again and thought I would see how the pattern looked. Unfortunately I used up the last little bit of gear marking compound I had on hand and when I went to get some from my local source, they were out. So I decided to try some old oil based paint I had on hand.



After applying, I let it dry a couple minutes before running a pattern. I was really surprised at how well the paint worked. It definitely does not replace purpose-made gear marking compound, but in a pinch it did the trick.





Now as to the pattern, I really am not sure how to read the tea-leaves. Used gears never give a textbook pattern (heck neither do new ones) and these are no exception. To me the drive side looks like the pinion could have less shim but the coast side looks the other way. Since I haven't messed with pinion depth (same bearings and shims that came out of it), it was running without problems previous, and the patterns average on center, I am not going to make any changes.

At this point I could finally stab the axles in and verify the length was proper to completely engage the splines on the spider gears. Yup! Thank you Strange for providing accurate numbers.





With all that buttoned up it was time to drop the cover on. I used a fiber gasket with some Permatex Gear Oil RTV on the housing side and dry on the cover side. Before I put the cover on I snapped a photo of the leveling feet that are used to add support on the bearing caps.

__________________
Clint
Reply With Quote
  #873  
Old 02-12-2018, 06:45 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
Finally it was time to do brakelines on the rear axle. The first step was straightening out some 3/16 steel using my DIY vise straightener. Here's an old photo of using it on the 3/8 fuel line.



And here's a video straightening the 3/16"


I've had nothing but trouble in the past using cheap autoparts flaring tools. I can't remember the last time I needed to do an inverted flare, but I do remember having problems with the tube slipping and the flare being off center. I decided to invest in a better tool so I picked up an Eastwood Pro Flaring Tool. It has a slick little multi-operation turret and lever/cam operation. I have heard nothing but good about it and after doing a few flares on it I am very happy with the output.

Here is a video doing my first flare with the Eastwood tool:








I did the driver's side first and I'm very happy with how it turned out.

The process I followed for bending these is pretty much the same as what I did for my fuel lines a few years ago. I started by making a short sample piece of tube, marking the start point for the bend relative to a start point on the bender. I also marked a reference distance from the end of the tube and measured after flaring to see how much was used up in the flare (1/8" in this case). This sample piece helps me with layout and deciding where to cut the tube in the future. I can hold the piece up to where I want to route a bend and transfer the bend start mark to the new tube. Hopefully the pictures following help explain it.







If you look above, you can see how I transferred the center point of the bend on my sample tube to the new tubing. Then I used my protractor to determine the angle of the bend and carefully replicated it to get things where they needed to go.





I am really pleased with how the lines turned out. Experience and good tools have really payed dividends in this area. I added stainless steel spring wrap protection before adding the last fitting and flare. I think the results look pretty darn OEM.

With that done, I had a friend help me heave the axle off my workbench and put it on some stands on the floor. I remembered that I needed to drill the spring perches still to accept larger 5/8" U-bolts. The holes are very oblong from the factory, so I started with a uni-bit to get an initial pilot hole and then followed with the standard twist bit. If you've ever twisted your arm off trying to drill a hole like this, try the uni-bit trick first. The unibit uses the closest diameter to help pilot the next cut so the bit doesn't wonder or get caught off angle. You could make the whole hole with a unibit but they aren't cheap when they wear out, so I suggest just getting an initial hole going and swap over to a cheaper twist drill to finish it through.



Finally it was time to put the rear back under the car. A transmission jack makes this job easy. I leave the leaf springs attached at the front, but detached at the rear, then simply roll up the rear end, crank it high enough to reattach the leafs to the shackles, and drop it back down onto the leafs and install u-bolts.

Here is a hyperlapse video of the install.


It's really nice to see the rear back home where it belongs.



I mounted up the new 18x9 wheels (did I mention I got new wheels?) and jacked under the rear until the springs were fully supporting the car (aka ride height). Then I took a measure on inside wheel clearance. Both sides had 7/8" to the inside, which is right in line with what I expected.





That's where she sits for now. Tires are on order and should be here in a couple days, but I have plenty to keep me busy in the meantime: install shocks, reattach brake lines, install sway bar, figure out parking brake cables, plumb in a proportioning valve, fluids, etc. I am really excited to see the new stance and wheels. I hope all this work was worth it.
__________________
Clint

Last edited by TheBandit; 02-13-2018 at 11:36 AM.
Reply With Quote
  #874  
Old 02-12-2018, 07:42 PM
Graham08's Avatar
Graham08 Graham08 is offline
Master Fabricator
 
Join Date: May 2006
Location: Denver, NC
Posts: 1,737
Quote:
Originally Posted by TheBandit View Post
I had a little engineergasm when the indicator gave me exactly what I was going for
We refer to this situation as a "nerd boner" in my office.

It all looks great. Nice work! After all that work I'm happy to see things are falling in place for you. Are you waiting to do the full reveal on the wheels until it's sitting on the ground?

Reply With Quote
  #875  
Old 02-12-2018, 08:31 PM
alwaysFlOoReD's Avatar
alwaysFlOoReD alwaysFlOoReD is offline
Master Fabricator
 
Join Date: Jan 2010
Location: Red Deer,AB Canada
Posts: 720
Nice work.
I've had really good experience buying cheap uni-bits from Canadian Tire or Princess Auto [harbor Freight clone]. They come in a 3 pack for $10-12 when on sale. I buy 3 or 4 packs. I was successful in drilling my leaf springs with these, only burnt up 3 for both sides, 8 total springs. I tried cobalt but they chipped out too quick. Probably not enough meat and the edges caught.
Reply With Quote
  #876  
Old 02-13-2018, 09:24 AM
juicedz4's Avatar
juicedz4 juicedz4 is offline
Master Fabricator
 
Join Date: Jan 2011
Location: Rochester, NY
Posts: 549
Lookin goooooood.
Reply With Quote
  #877  
Old 02-13-2018, 11:23 AM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
Graham - "Nerd boner" ha! I'll be sure to wear that out. Yes, I'm waiting to get tires on it and get it on the ground before I post photos. Wheels just don't look right danging at full droop without tires.They are loaded up and off to the tire shop today, so it wont be too long.

alwaysFlOoReD - Thanks for the tip. I'll look into those. I have a couple Milwaukee unibits and they are holding up well so far. Very sharp.

juicedz4 - Thank you sir!
__________________
Clint
Reply With Quote
  #878  
Old 02-13-2018, 12:40 PM
juicedz4's Avatar
juicedz4 juicedz4 is offline
Master Fabricator
 
Join Date: Jan 2011
Location: Rochester, NY
Posts: 549
I too use the HF uni bits. For the price you cant beat them. I use them on stainless all the time, they just rip thru it surprisingly enough.

Dan
Reply With Quote
  #879  
Old 02-14-2018, 05:45 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
Thanks for the tips. I'll give 'em a try when my current ones give out.

Yesterday my better half took the wheels to the tire shop to have the new meats put on. I gotta say my wife is a total bad ass. - kickass mom for my kids and an amazing life partner and friend for me. She could tell I was eager to pick up the tires and she offered to do it for me while I was at work yesterday. When I got home, she had dinner going (usually I cook when I get home) so I could spend a little time fitting the wheels and oohing and awing over how they look and fit.

First I will say that selecting and fitting wheels and tires has been a really interesting experience. There are a lot of variables at play. Out back measurements were pretty straightforward because the inside of the wheel well is pretty flat and the area inside the quarter is relatively easy to measure from. I was able to calculate what I would need in terms of offset (which I ultimately cut/welded into the rear end) and use some simple math to compare tire section and tread dimensions to the available space.

Up front however there is more of a curvature going on and huge variables on camber gain, steering angle, etc that made it hard to estimate where the tire would need to be. What I did know from experience is that the 215/60R15s with -5/8" offset wheels (15x7 3-3/8bs) I had in there used to rub when I had stock springs, stock geometry and about 0 camber. However when I lowered the car with stiffer springs and swaybar, did the Guldstrand mod to improve camber gain, and added static camber, I no longer had any issues with rubbing. So this was a good known point for me as to where the outside of the tire could be without rubbing. The part that was more unknown was the shape of the tire, especially the radius at the edge between the sidewall and the tread. So to compare wheel and tire combinations, I took both section width and tread width dimensions from TireRack and calculated where the outside of the section and the tread would be for given tires, comparing my existing 215/60R15s to a range of 18" tires. What I found was that you definitely can not just go on section width when you are moving from 15" to 18" tires because 15" tires have much less tread with for a given section width than 18" tires.

After doing tons of research into tires, I found some of the best for absolute max grip / fastest times currently for autocross and track are the Bridgestone RE-71s (although there are some competitors that are also worth considering in that category). BUT I had to really think about whether I wanted that kind of tire for my use. While I want great ultimate performance when I do track the car, I have to admit to myself that the large majority of my driving is taking my kids to practice, going to car shows, and cruising around. So I decided not to get an ultimate max performance tire and instead dial it back ever so slightly to something that might be a little less harsh on the road that I could eek a few more miles out of. I narrowed it down to the Michelin Pilot Super Sport, Pilot Sport 4S (which replaces the PSS), and the Bridgestone S-04. Then I created a table to calculate where the outside of the tire would end up, assuming I will have plenty of space on the inside.



Now I'm sure you're going to notice I'm not trying to get 275s up front at the moment. I committed to using off the shelf 0 offset wheels of a particular design and that has been a major limiting factor for what I can fit up front. The Nova really needs some positive offset to fit anything bigger than the sizes in the above table. Long term if I do go for wider tires, I can either widen the wheel toward the inside or get 2pc wheels with more offset (same goes for the rear if I mini tub).

If you look closely at the table above you'll see there are a lot of differences from one tire to another even in the same size. For example, the 245 Potenza S-04 has almost 1/2" more tread width than the 245 Pilot Super Sport. You'll also see there is an enormous difference in tread width (say 1.5") for a 215/60R15 vs say a 225/40R18 even though the section width is pretty close (within 1/2").

I eventually finalized on Michelin Pilot Super Sports. Since they are an outgoing compound, they were close in price to the Bridgestone S-04s, appear from reviews to have a little better overall performance, and don't demand the premium of the new Pilot Sport 4S compound. I also needed to pick a size. Looking at the 'tread change" column, this represents how much closer I expect the tread to be to the fender opening. My old tires were very close but didn't rub. 225 would have been a very safe bet, but I decided I should go with either the 235 or the 245 since I eventually plan to swap to C6 brakes (which will improve offset by 0.240in). Comparing tread width, there is hardly a difference between the two, so I decided to go with 235/40R18s which are closer in diameter to my current tires.

Now that is a long long explanation for how I arrived at my tire size up front, but I think it's worth adding here if someone else is going through this themselves. I would strongly suggest finding wheels with at least some offset, since for every 1/4" of offset you can get roughly 1/2" more tread width. That just wasn't available in the style of 1pc wheels that I wanted to buy.

Here is what all those numbers look like in person. I now have front tires with 2" more tread width than before and a nice sticky summer compound. I expect a major improvement over what I had, even though it isn't all-out. By comparison, they look meaty.



On the car, not so much. They still look pretty narrow. But that's alright for now.



I also got the rear tires fitted. They are 255/40R18s. I did a similar exercise for calculating widths on these and ultimately arrived here. My only conundrum with the rears was whether or not I might want a 45 series sidewall to maintain overall diameter and give it more classic big & skinny look from the side. Ultimately I decided on the 40 aspect ratio because I don't think it would look right with 45 rear and 40 front (45 front would be too tall for the fender well). These photos show the tires at ride height.





Looking up into the fender opening, you can see there is plenty of clearance with the lip, but the tires are close to line-on with the inside of the quarter panel. I think this is going to work out just fine. I am more concerned about the inside clearance where I have roughly 3/4" to the sidewall bulge, but a fair bit more clearance to the tread at the top of the tire. I may add a 1/8 or 1/4" spacer down the road, but i think I will try running them like this and see what they do.

I still have a few things to sort out before I put it back on the ground, so bear with me. I will eventually reveal my wheel choice. I will say I am very very happy. I LOVED my old wheels but I like these new ones a lot too and they are allowing me to run a wider modern compound tire.

Still left to do:
- Clean/paint calipers
- Parking brake cables
- Reinstall/connect calipers and brake lines
- Add gear oil
- Install sway bar
- Install shocks
- Mount adjustable proportioning valve
- Remove residual valve from master. Remove hold-off valve and fixed prop valve
- Make brake lines for master to distribution block and prop valve
- Bleed brakes
- Test drive
- Wash car and take reveal photos

I am considering doing autocross on March 10, so that is my goal for getting the above work done. That gives me roughly 3 weeks.
__________________
Clint
Reply With Quote
  #880  
Old 02-15-2018, 03:58 PM
TheBandit's Avatar
TheBandit TheBandit is offline
Instagram @chevyhotrodder
 
Join Date: Jan 2006
Location: Ventura County CA
Posts: 4,407
Last night I witnessed the end of an era. I said goodbye to my Centerline Convo Pros. A local gentleman bought them for use on his Nova - glad to see them going to a good home. We loaded 3 in the trunk and one in his front seat and off he went. I nearly shed a tear.



Since it is "throwback Thursday", here are some photos I took the day I put these wheels on the car way back in 2002. I scrounged the money together while I was in college and bought them used in the very early days of ebay (back when it was mostly auctions and you really could bid on used things to get a deal). I had lusted after these wheels in the late 90s when the pro street craze was still in full force. Even today I love seeing a car with Convo Pros and I am truly going to miss seeing my car with them.









On to new and different things. Here's a photo of the new wheels (you can see them pretty clearly here ).



The car is still on jack stands, so the front is at full droop. I did raise the rear end to ride height though so you can get an idea of how much the tire tucks. 235/40R18 on 18x8 and 255/40R18 on 18x9.

I can't wait to see it on the ground but I gotta at least get the parking brake hooked up. I have a sloped driveway.
__________________
Clint
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:42 AM.

Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Template-Modifications by TMS
Copyright 2012, Offroad Fabrication Network