12:05 Garage- ’70 Duster build
- Thread starter racerjoe
- Start date
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racerjoe
Well-Known Member
Yessir! I'm famous...
DionR
Well-Known Member
Clicking on the link gets you an even bigger picture. Didn't realize it until I went further.
Nice job!!
Sorta funny that they used a ‘70 for the “73-76 a-bodies” category. Lol
racerjoe
Well-Known Member
I thought the same thing!
DionR
Well-Known Member
).
DionR
Well-Known Member
I've been looking at wheel studs for my brake kit and was looking at this post for other reasons when it dawned on me that when you said you needed studs with longer shoulders, it was because that was how you centered up your rotor wasn't it. I've been noodling how to get the SP front rotor centered on the hub and hadn't thought of that until I realized that maybe that's what you were talking about.
Is this the stud you used?
ARP 100-7707
I did up some tubes on my 3D printer that fill in the space around the current stud on my hub and it seemed to work well, but not sure if I can get them made without costing an arm and a leg. I also setup a ring that piloted on the bevel on the backside of the rotor, but the best price I found to get that made was almost $200 each for metal 3D printed. Machining was significantly more. Not an option.
I also thought about a 3D printed plate that would pilot on the studs and the holes in the rotor and allow for a couple of nuts to be tightened down to lock the rotor and hub together. It would also have a pilot to use to punch the rotor and then the plate could be removed (leaving the nuts) and the rotor and hub could be match drilled and tapped for a small countersunk screw. Biggest issue with this idea is it would make it harder to replace a rotor if something happened 1000 miles from home. Haven't given up on the idea, but your studs make a lot of sense.
Last question, did the hole pattern in the rotor match the bolt pattern in your hub? Can't tell from the pictures for sure. Being that it is an LX/LC rotor, in theory there should be some misalignment. Weird thing is, on my OEM JY rotor, it is definitely a 4.5"/114.3mm bolt pattern in the rotor. Five concentric tubes fit over the studs and the rotor slips on and off easily. Hard to believe they would do that if the hole pattern was 115mm. I wouldn't be surprised if the aftermarket rotors for an LX/LC are actually 5x115mm and the hole in the rotor large enough to fir over the studs, but it appears this OEM rotor from an '06 Magnum SRT-8 had a 5x4.5" bolt pattern.
You could use a hub centric ring like Mustang Steve uses on his cobra brake kits. I’ve got one of his kits on my Duster and the hub centric ring works very well.
DionR
Well-Known Member
Mustang Steve?
Wonder if there is one the size I would need. The size wouldn’t be the same size as one for a Mustang.
He might have a few different sizes, not sure. The ones I have are to put 99-04 cobra brakes on a mustang ii spindle. It uses a 66-72? Mustang hub. I’ll see if I can find info on the size.
Doesn’t say what sizes they are, but here are the rings.
Rotor Centering Rings - MustangSteve
racerjoe
Well-Known Member
Yes, the longer shoulder on the studs is what centers the rotor on the hub. I don't recall the part number studs I used, but those look like them. The lug holes in the rotors are quite large. I want to say they are around 5/8". This is another reason I wanted the shoulder because the rotor would have been able to move on the threaded portion of the 1/2" stud. The .0275" difference in the bolt pattern is easily overcome by large holes in the rotor. What I should have done is had the center of the hub turned down to match the center hole of the rotor. I don't recall the size difference but it wasn't much. I just opened it up with a die grinder and sent it. I didn't put a dial indicator on the outside of the rotor, but I did spin in it while closely watching the clearance to the caliper. My eyeball measurement showed zero runout and I have no vibration.
I think you may be overthinking it (not a bad thing). If I were to do it again, I'd turn the OD of the hub down a touch so the rotor fit perfectly. Other than that, it's quite easy. If I remember correctly, the Mustang rotor center hole was a bit smaller also.
I did consider drilling and tapping the rotor/hub to hold the rotor on, but it didn't seem necessary after everything was fit up. The brake pads pretty much hold the rotor in place when the wheel is off.
DionR
Well-Known Member
The rear rotor must have a different size pilot bore.
The front rotor has a center bore that is bigger than the unmodified snout by about .03" overall. If the hole were smaller, I would get the hub turned to match whatever the size was on a Challenger, but being that it is bigger that doesn't work. And being such a small amount I can't just grab a ring that is 2.85" OD with a wall thickness of .015" as I doubt anyone can make such a thing. Which is why I looked at centering it using the chamfer on the inside of the rotor bore. The more I think about that, the less I like it since it probably isn't held to a very tight tolerance by the rotor manufacturers so even if I get one to work, a replacement might not.
The hubs I am currently running have been turned down to 2.80" at the hub flange to match the '98 Cobra rotors. But even then the difference is only .05" overall. The snout of the hub was turned to 2.78" OD to match the Mustang wheels I am running, and if I got the rotor pilot area turned to that OD as well, I would be up to .07" difference overall.
Maybe I should just grab a .015" feeler gauge and stick it in the gap and leave it there. Or use the hubs I am running right now and a .025" feeler gauge.
The most annoying thing right now is that if I had chosen the GT500 calipers and rotors instead of the Scat Pack ones, I wouldn't be worried about it as the center bore on those rotors match the Cobra rotors I am already running. And in the end it looks like the GT500 caliper would have been easier to build a bracket for as well. The narrow mounting hole spacing on the SP caliper makes it really tight with the spindle holes and only works (best I can tell) with a 14.2" rotor or bigger. Ah well, 20/20 hindsight.
DionR
Well-Known Member
See my post above. The ring would have to be 2.85" OD with a wall thickness of .015" to work.
racerjoe
Well-Known Member
I wouldn't sweat it. The lug studs will hold it centered and the lug nuts will lock it in place once the wheel is sandwiching it.
racerjoe
Well-Known Member
Me and a few friends participated in a fund raiser that consists of a cruise around Lake Ponchartrain with 9 checkpoints. It ended up being just over 150 miles. It was cold (at least for a southern dude) and windy but we still managed to have a good time. The wife and teenage kids tagged along with me this year so I had endless entertainment from those goofballs. The car ran flawlessly!
Red Stripe
Well-Known Member
Awesome photo in front of the water!
racerjoe
Well-Known Member
I'm sure that most people that follow along here know I have the full TTI exhaust. When I purchased the exhaust kit, I wasn't thrilled with the turbo mufflers they supply, but didn't want to fight with making something else work on a system that was designed around those mufflers. As I'm sure most know, turbo mufflers are very quiet. Heck, you can't even hear it running in all of the videos I have of my car on the autocross! I also knew these mufflers are the largest HP stealers of any muffler on the market. I've always liked Borla mufflers, I had their straight through bullet mufflers on the car when I used to drag race. I purchased a set of their 2.5" Pro XS mufflers with offset inlet and center outlet, just like the turbo mufflers. The offset distance was about 1" difference, but fortunately, I was able to manipulate the tailpipes enough to make them work without reworking the X-pipe.
I didn't take any dB readings with my phone, but at idle, it sounds almost exactly the same. It may be a touch louder, but it is negligible. I did immediately notice throttle response was improved. Slower speed driving also seems to be very similar and wide open throttle may be a little louder, but who cares at WOT. Steady state cruising at highway speeds is actually quieter. I can't even hear the engine at cruising speed. Now for the good stuff. The increase of power is crazy. The motor revs way quicker and pulls much harder through the upper RPM range. I seriously cannot believe the difference. I originally thought it was all in my head until a found a guy on youtube that changed out some chambered mufflers to the Borlas like I have. He had what I assume is a stockish big block and 3" exhaust, but the same principle applies. On his first drive, he also commented on throttle response and how much stronger it felt, but didn't know if it was mental or real. He followed it up with a trip to the drag strip. He had very well documented time slips including density altitude, temp, etc. his car went .27 quicker and 2MPH faster with just a muffler change in worse air! After seeing this, perhaps the improvement I feel isn't mental.
So moral of the story is, don't use turbo mufflers! For very similar sound (and better at cruise) why not get a better muffler and keep all the HP your motor is making. Sure a pair of turbo mufflers are probably $150 cheaper than the Borlas I bought, but where are you going to get this much increase in power for $150? I don't even understand why TTI sells those things! The turbo mufflers went right were they belong, in the trash!
I didn't take any dB readings with my phone, but at idle, it sounds almost exactly the same. It may be a touch louder, but it is negligible. I did immediately notice throttle response was improved. Slower speed driving also seems to be very similar and wide open throttle may be a little louder, but who cares at WOT. Steady state cruising at highway speeds is actually quieter. I can't even hear the engine at cruising speed. Now for the good stuff. The increase of power is crazy. The motor revs way quicker and pulls much harder through the upper RPM range. I seriously cannot believe the difference. I originally thought it was all in my head until a found a guy on youtube that changed out some chambered mufflers to the Borlas like I have. He had what I assume is a stockish big block and 3" exhaust, but the same principle applies. On his first drive, he also commented on throttle response and how much stronger it felt, but didn't know if it was mental or real. He followed it up with a trip to the drag strip. He had very well documented time slips including density altitude, temp, etc. his car went .27 quicker and 2MPH faster with just a muffler change in worse air! After seeing this, perhaps the improvement I feel isn't mental.
So moral of the story is, don't use turbo mufflers! For very similar sound (and better at cruise) why not get a better muffler and keep all the HP your motor is making. Sure a pair of turbo mufflers are probably $150 cheaper than the Borlas I bought, but where are you going to get this much increase in power for $150? I don't even understand why TTI sells those things! The turbo mufflers went right were they belong, in the trash!
DionR
Well-Known Member
Interesting. There is a TTI exhaust on my Duster, installed by my buddy when he owned it. Haven't paid much attention to the mufflers, but pretty sure they are DynoMax? I get a pretty good drone at 60-65 and figured a louder muffler would only make it worse, but your results make it sound like I might pick up some power and quiet it down too. Hmm...
Funny thing is, I have the H pipe off the car while I work on some upgrades. Might be the right time to mess with it some.
Thanks!
Funny thing is, I have the H pipe off the car while I work on some upgrades. Might be the right time to mess with it some.
Thanks!
racerjoe
Well-Known Member
100% no drone. All I hear are the gears on my transmission.
Just finished plowing through your whole thread. Great work! Planning to do Moparty again this year? I only live about an hour from there so am excited to make my first trip to that show this year.
racerjoe
Well-Known Member
That's the plan. I'm hoping to have the G3 swap done by then too, but no promises on that. Lots of life is going to get in the way this summer, but I'll keep forging ahead as much as I can.
racerjoe
Well-Known Member
I contemplated which oil pan to get for the G3 for a while. I really like the road race Milodon with the kick outs on the sides, but I questioned whether the TTI headers I intend to purchase would interfere. I was about to call them to ask when they updated their website and it clearly says that pan won't work. I'm glad I didn't buy it. My main concern is/was oil control during cornering. It seems Holly modeled their cast aluminum pan off the factory pans with the casting in the bottom to direct oil. I pulled the trigger on their cast pan. I have to say, it is a nice piece. The windage tray appears to fit up tight near the rotating assembly and the extra baffle above the sump seems like it will work well. The nice things about the G3 is the oil from the heads had dedicated drain back holes that go all the way to the pan. I also got new valve springs, retainers, locators, keepers, locks, and seals. The springs are good to .625" lift, which I won't exceed. I was very heavily leaning toward the Comp 221/233, .594/.594 "supercharger stage 1 cam", but I have now decided against it. I feel like the wider LSA is going to give up some low end torque/HP. I came across the Cam Motion "Titan 2" which has more duration than the comp and has a 114 LSA compared the 116 on the Comp. I may sacrifice some top end power, but this isn't a drag car. Average torque is what will make my car work well. A bonus is Cam Motion is about 50 miles from my house. I have no idea how I didn't know that. They also grind their own cams, they don't outsource them. I'll be happy to support a "local" business, especially if they have something that should work well.
racerjoe
Well-Known Member
Officially registered for 2023 Moparty Grand Champion. LET"S GO!
My confidence that the 5.7 will be installed by Moparty is beginning subside. I ordered the TTI engine mounts so I could get to work on modifying them and the cross member. But guess what- no stock anywhere. TTI is even out of them. I can't say I'm surprised, but why wouldn't they have a pile of these in stock. The design is super simple and I would imagine assembling them can't take that long compared to their headers. I would make my own, but I want to make sure the engine is in the proper position to work with their headers. I just don't want to create problems that will bite me in the *** later. Their production is scheduled for late May, so I'll be here waiting until then.
I'm not the type of person that will be down to the last hour before I have to leave working to get it complete. I want at least a month on the setup before I travel 9 hours to beat on it. As much as I'd love to get the swap done over a weekend, in reality, that won't happen. I have to plan for at least a couple weeks. That put me pulling the 408 in July. It doesn't seem like a reality. The good news is, the car is currently running perfectly and I don't plan on changing anything until then.
My confidence that the 5.7 will be installed by Moparty is beginning subside. I ordered the TTI engine mounts so I could get to work on modifying them and the cross member. But guess what- no stock anywhere. TTI is even out of them. I can't say I'm surprised, but why wouldn't they have a pile of these in stock. The design is super simple and I would imagine assembling them can't take that long compared to their headers. I would make my own, but I want to make sure the engine is in the proper position to work with their headers. I just don't want to create problems that will bite me in the *** later. Their production is scheduled for late May, so I'll be here waiting until then.
I'm not the type of person that will be down to the last hour before I have to leave working to get it complete. I want at least a month on the setup before I travel 9 hours to beat on it. As much as I'd love to get the swap done over a weekend, in reality, that won't happen. I have to plan for at least a couple weeks. That put me pulling the 408 in July. It doesn't seem like a reality. The good news is, the car is currently running perfectly and I don't plan on changing anything until then.
mygasser
Well-Known Member
at this point i'd hang the motor in there with the tti headers attached and make mounts. with the headers already on you can ensure there's clearance. 
neil.
neil.
racerjoe
Well-Known Member
There's way more to it than that. This would require me to pull a motor just to make mounts. I don't even have a camshaft for the motor yet. I'm trying to reduce down time with the car, not make it longer.at this point i'd hang the motor in there with the tti headers attached and make mounts. with the headers already on you can ensure there's clearance.
neil.
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