loose downpipe nuts. support bracket
#21
The issues are generally thermal related. The super strong ARP stuff doesn’t help much. Safety wire them in doesn’t help if they snap when things heat cycle a bunch of times. Inconel studs seem to be the most effective at reducing failures. I just use regular nuts with Nordlock washers. Jet nuts shatter and any other locking nuts I have tried basically loose there locking function with a few sessions worth of heat cycles and they can also make it more difficult to take apart and put back together should you need to service something.
#22
Inconel is key! Two reasons:
1. Retains strength at elevated temperatures (no thermal creep).
2. Coefficient of thermal expansion is almost identical to iron and steel. The torque you put on it cold is the torque it retains at high temp.
No other material fulfills both of the above requirements. Plus, there are many OEM studs and bolts in Inconel available from car manufacturers that are pretty inexpensive.
ARP high-strength steel studs will not hold up to extreme temperatures. For a milder street driven car, they would probably be OK on the turbo to downpipe connection (NOT on the manifold to turbo). On a tracked car or a car making Bob's kind of power, they are a no-go.
1. Retains strength at elevated temperatures (no thermal creep).
2. Coefficient of thermal expansion is almost identical to iron and steel. The torque you put on it cold is the torque it retains at high temp.
No other material fulfills both of the above requirements. Plus, there are many OEM studs and bolts in Inconel available from car manufacturers that are pretty inexpensive.
ARP high-strength steel studs will not hold up to extreme temperatures. For a milder street driven car, they would probably be OK on the turbo to downpipe connection (NOT on the manifold to turbo). On a tracked car or a car making Bob's kind of power, they are a no-go.
#23
you guys with manifold talk are fracking up my thread.
what do you think about these nuts? for down pipe /turbo?
https://www.034motorsport.com/hardwa...5-p-18954.html
I got a couple good butt clamps to kinda copy FM exhaust bracket but the clearance is somewhat of a issue. I want my downpipe supported pre flex joint so the fm kit for something similar will not work.
I'm thinking about welding 2 tabs or bung on the downpipe so i can tie the downpipe to the exhaust manifold. not sure if would be better to tie the downpipe to the manifold or the transmission. in theory the trans would be better. thoughts?
what do you think about these nuts? for down pipe /turbo?
https://www.034motorsport.com/hardwa...5-p-18954.html
I got a couple good butt clamps to kinda copy FM exhaust bracket but the clearance is somewhat of a issue. I want my downpipe supported pre flex joint so the fm kit for something similar will not work.
I'm thinking about welding 2 tabs or bung on the downpipe so i can tie the downpipe to the exhaust manifold. not sure if would be better to tie the downpipe to the manifold or the transmission. in theory the trans would be better. thoughts?
https://www.pegasusautoracing.com/pr...p?Product=MJET
My experience with them was they split in two and fell off in pieces after several hard sessions on the turbo beast. I sure did like the small size hex for installation though.
#24
Great... maybe I'll need to get a friend to follow behind me to pick up the pieces that fall off, like I did when I raced a British car...
Q: When ran chevy's, the rule of thumb for exhaust bolts was "locked and loose". A little leakage was acceptable. A little looseness in the stud assemblies countered the expansion stresses. The locking apparatus held it from rattling off. I wonder if this could also be an exhaust fastener solution for the downpipe attachment?
Q: When ran chevy's, the rule of thumb for exhaust bolts was "locked and loose". A little leakage was acceptable. A little looseness in the stud assemblies countered the expansion stresses. The locking apparatus held it from rattling off. I wonder if this could also be an exhaust fastener solution for the downpipe attachment?
#25
Great... maybe I'll need to get a friend to follow behind me to pick up the pieces that fall off, like I did when I raced a British car...
Q: When ran chevy's, the rule of thumb for exhaust bolts was "locked and loose". A little leakage was acceptable. A little looseness in the stud assemblies countered the expansion stresses. The locking apparatus held it from rattling off. I wonder if this could also be an exhaust fastener solution for the downpipe attachment?
Q: When ran chevy's, the rule of thumb for exhaust bolts was "locked and loose". A little leakage was acceptable. A little looseness in the stud assemblies countered the expansion stresses. The locking apparatus held it from rattling off. I wonder if this could also be an exhaust fastener solution for the downpipe attachment?
#26
I wonder if those nuts are really different than these?
https://www.pegasusautoracing.com/pr...p?Product=MJET
My experience with them was they split in two and fell off in pieces after several hard sessions on the turbo beast. I sure did like the small size hex for installation though.
https://www.pegasusautoracing.com/pr...p?Product=MJET
My experience with them was they split in two and fell off in pieces after several hard sessions on the turbo beast. I sure did like the small size hex for installation though.
I found these
http://www.fastenal.com/web/products/details/0162564
Last edited by psreynol; 05-31-2013 at 09:27 PM.
#27
This type of clamp would be better, actually it's on the rear of my exhaust.
Exhaust Band Clamps, Exhaust Band Clamps, Exhaust Clamps
eBay:
http://stores.ebay.com/Racing-Parts-...9017391&_rdc=1
Exhaust Band Clamps, Exhaust Band Clamps, Exhaust Clamps
eBay:
http://stores.ebay.com/Racing-Parts-...9017391&_rdc=1
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