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Whatever_Racecar Endurance 745T

rb92673 said:
I forgot to add, the 940 donor sedan for the axle had a sway bar, going to give that a try. We have always run without one since we got the car.
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I scrolled back a few pages, noticed a note about a newbie driver. If you can try the sway bar during a test day, absolutely give it a shot. Even better if you can get the same driver to test it with and without. We had a car that was slight-understeer and wasn't tail happy in transitions, so it was on the safer side. At least one of our drivers was a couple/few seconds a lap slower, and he had an off from time to time, so that's who I think the car needs to be setup for.

I would also expect the G80 to work better without the rear bar.

Also, the recap on the race where the studs broke off the turbo and the wastegate housing was held on by only the downpipe...that sort of race sounded VERY familiar. Lots of stuff goes wrong, but it's still a fun weekend. Ours broke the downpipe at the turbo once, got louder, and louder, and LOUDER..OK, I'll pit now. We also had the WG actuator loosen up. Another time I think a motor mount broke and we punctured the oil filter. Part of the fun for me was trying to anticipate and prepare for failures.
 
So... We had out best weekend yet. Briefly we were leading class B on Saturday before we started our weinerschteppen. A black flag, then a shifter mount came loose, then a unexpected change when a driver overheated. Shifter mechanism was still loose after our quick fix, so lots of 4th to 3rd money shifts. Lots... I was the last driver for the day, so car felt hot and tired. Boost was down a bit. Still it was faster than before and I got my best time at that track. Ended the first day 5th in class, 16th overall.

Saturday night we reattached the shifter mechanism, adjusted so we could find 5th, lock-tighted all the bolts. Sunday morning I noticed the rod between the actuator and flapper was not attached at the actuator. I don't know how, but it unscrewed itself at the actuator. Fixed and got out on track.

Sunday we tried to run with only two driver changes. First driver is our slowest and usually doesn't use as much fuel. Before our fuel tank change we only put in 14 gallons when the car was sputtering. At first change it took all three 5 gallon jugs...we should have been more worried. In order to run two driver changes we needed to drive for 2 hours and 5 minutes. At about 1:50 I started sputtering on the second stint. I was half a lap behind second at that point and was gaining. Emergency driver change and fill up and we were back on track. Third driver got a black flag and we were in and out quickly. We had to add a splash for the last 30 minutes. We ended up 3rd in B and 13th overall. Our best finish yet. I managed to take 2.5 seconds off my fastest lap at that track.

- Tried rear sway at Friday practice. I didn't notice any change for the worse so we kept it. Throughout the weekend I thought it helped slightly with wheel spin. We didn't have any spins or tank slappers, so it will stay.
- G80 locker didn't help anything. I probably didn't modify the weight enough.
- I liked the 3.73 gearing, I saw a 5 mph increase at the end of the esses. It sucked when 5th was hard to get into.
- We need a new shifter for our CD009. Open to recommendations of something that can be abused.
- We ran a .5 bar spring, which is a downgrade from our .8. I think we will keep that as it might keep the car a little cooler? I do want to make a push to pass for those annoying drivers who think blocking is racing.
- Fuel tank swap to the 19.8 gallon worked. We need to carry more fuel to the hot pits now.
- We now have a large exhaust leak past the turbo, I didn't look at it before it went on the trailer, but team mate thinks it's the flex pipe.
 
Glad you swapped to the bigger tank, if you are enduro racing one of these cars using the largest factory bolt-in tank is a no brainer.
 
Well hell. These studs were safety wired, nordlocked and had crimped copper nuts. This is how it came off the track
 

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You need to mechanically lock the studs to the flange or just use bolts that are safety wired.... if the studs themselves are not secured... mayhem can happen.

If you want to still use studs, i would add a retaining pin to the turbine housing for each stud.
 
blkaplan said:
You need to mechanically lock the studs to the flange or just use bolts that are safety wired.... if the studs themselves are not secured... mayhem can happen.

If you want to still use studs, i would add a retaining pin to the turbine housing for each stud.
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I drilled a hole in each stud and safety wired them together. What do you mean by a retaining pin? Drill a hole through the housing and stud and lock them in?
 

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rb92673 said:
I drilled a hole in each stud and safety wired them together. What do you mean by a retaining pin? Drill a hole through the housing and stud and lock them in?
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The problem I see with your setup is you have nothing actively keeping those nuts from twisting (beyond the nordloks), once the nuts twist and lose preload,,, its game over as the stud can work its way loose.

You would be better off using bolts that are safety wired or have sheet metal lockers than having the unnecessary extra components like the studs and nuts.

If you want to keep the studs,,,

I would drill and tap 4mm hole in the turbine housing that intersects with the studs thread. Once you have that hole, take a punch and peen the threads of the stud... then thread a set screw in that hole that keeps the stud from spinning loose. You can also drill through it and use a spring pin, which might be better from a vibration perspective.

Another thing to keep in mind is you want to have a fastener with a similar thermal expansion coefficient (CTE) as the item you are clamping,,, so if you housing is stainless,,, make sure your stud has similar expansion properties. when things expand at different rates, that's when keeping preload gets real difficult.
 
The issue isn’t the fasteners vibrating out, the issue is the studs getting so hot that all tension is released from the stud stretching. I was able to tighten up all the fasteners, do a few hard runs (single digit miles of racing) and have the fasteners be loose again. It was the studs being loose in the housing, the jet-nuts were still in the same place on the studs.
 
culberro said:
The issue isn’t the fasteners vibrating out, the issue is the studs getting so hot that all tension is released from the stud stretching. I was able to tighten up all the fasteners, do a few hard runs (single digit miles of racing) and have the fasteners be loose again. It was the studs being loose in the housing, the jet-nuts were still in the same place on the studs.
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Yes, thats why I mentioned the CTE, obviously if the studs are turning into putty because of the temps..... that should be address first.
 
The ATP studs are just standard "automotive" studs you can get from the hardware store. Grade 5-ish, black oxide steel. Look up the service temp and be amazed at it's 450°F service limit (same for Grade 8 due to it's 800F tempering)
 
culberro said:
The ATP studs are just standard "automotive" studs you can get from the hardware store. Grade 5-ish, black oxide steel. Look up the service temp and be amazed at it's 450°F service limit (same for Grade 8 due to it's 800F tempering)
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Sent ARP a message, told them about glowing turbos and stretching studs. They said "It sounds like it maybe too much heat for our standard off the shelf studs and as you stated something in either Inconel or A286 would be the route to go. if you would like to request a quote and lead time on having them made please contact our special orders division at (805) 525-1497."
 
rb92673 said:
Sent ARP a message, told them about glowing turbos and stretching studs. They said "It sounds like it maybe too much heat for our standard off the shelf studs and as you stated something in either Inconel or A286 would be the route to go. if you would like to request a quote and lead time on having them made please contact our special orders division at (805) 525-1497."
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Be ready to spend 1 million dollars.

Volvos 90+ turbo manifold studs are inconel I think.... I'm sure someone will correct me if I'm wrong. Last time i bought them in 2008 they were like $14 each,
 
blkaplan said:
Be ready to spend 1 million dollars.

Volvos 90+ turbo manifold studs are inconel I think.... I'm sure someone will correct me if I'm wrong. Last time i bought them in 2008 they were like $14 each,
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Ya, I wasn't planning on calling them. =P If $14 each solves my problem, it will save me a lot of money. I need to get studs EDM burned out of two hotsides.
Swedbrick said:
The manifold studs are steel, the flange studs on the turbo are inconel, part number should be 1357769
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I might try stopping by a Volvo dealer today. Thanks.
 
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