After 3-4 years of zero problems here, we are suddenly having issues with the down pipe studs and nuts backing off, just like the Manifold use to do before we fitted Trackspeeds inconel kit.

Anyone have any suggestions why this might suddenly be happening and / or any suggestions at a fix?

My only thought is to buy the TS kit and use it on the down pipe but it's only only four nuts and studs when we ideally would need 5.

Given that they only sell the 4 stud kit, I also wonder if we aren't having an unusual problem? Otherwise I imagine they would specifically sell 5 stud kits for this application too...

 

FM recommended oval/distorted thread lock nuts and those ridged washers... I will post what it was specifically in a few. I ordered some from McMaster Carr and I will be picking them up this afternoon.

 

Super clean setup!

 

https://www.atpturbo.com/mm5/merchan...egory_Code=FST

I ran hardware from here. Seems to be alright.

 

Sorry for clarity, already running the standard metal locking nuts (bronze colored) as suggested above.

Have nuts loose or gone and studs loose or gone, just suddenly. Very strange.

 

Stage8 locking hardware. Cured my downpipe issues. If you can use bolts instead of studs then they wont back out at all.

I had stage8 locking bolts holding my downpipe on for a few years.

Give them a call, very helpful, and can find you anything.

 

As for why, have you recently changed your tune? Retarded the timing, increased boost anything that would increase exhaust temps?

I retarded my timing few degrees for a track day to be safe and imediatly had stud problems.

 

The two-piece serrated washers are called Nord-locks. I've got those with zinc-plated stover nuts on my downpipe and it hasn't been an issue. If you're running hotter and see the same issue on the downpipe nuts as on the manifold ones, then using inconel studs there is probably a decent choice. I suspect that if you contact TSE directly they'd be happy to sell you 5 studs.

--Ian

 

We had a flexi joint do something weird pre xmas (photo below), was only 2-3 months old but it ended up blocked by steel strands, looking almost exactly like a cats furball stuck down it!

We now suspect it contributed to the strangely low exhaust noise the new 1800 made, the strange lack of expected power the 1800 should have had over the 1600 and the recent gearbox (4th gear circlip) failure, so to have also overheated the nuts and studs to failure isn't at all a surprise in hindsight.

We only found it because the gearbox people suggested we run a cooler to help the new modified circlip gearbox last. In relocating the exhaust to accommodate the required fittings we discovered the 90% blocked flexi.

We refitted the new gearbox, removed the flexi all in a rush pre Xmas for the dual header race meeting on the 5th Jan, Now preparing the car for the four and rotary Nationals show this weekend (its on the Superlap stand) I suddenly find all these stud problems and with your suggestions above belatedly realise its probably all associated to the Flexi issue even though we fixed that already. Dumb I guess .

On a side note I'm very proud and extremely greatful to Paul our race guru for all his efforts over Xmas sorting out those issues to have secured a clean sweep in the Classic Japanese races and won class in NZ Superlap.


Anyway, I think at this stage, asking Andrew about a 5 stud kit will hopefully be the best long term answer. Cheers. Blocked 2-4 month old (3 race meetings) flexi joint.

 

I was having issues, went with new studs and jet lock nuts from Pegasus racing. they are single use, and must be replaced when removed but they seem to work very well, no issues during the previous 4 or so track days. for me the downpipe design is a problem. it was very nicely built but the angles and clearances are a issue so I can't easily run a longer stud to accommodate nordlock washers. really the nordlock washers just reduce the nuts ability to get get looser, once loose. if the nuts stay tight, nordlock washers seem unnecessary but I'm not a expert. I say check out jetlock nuts and new studs, but have extra on hand just in case. they are supper low profile and fit very well for me. previously I had to thread the nuts a few threads at a time and work my way around because the downpipe would get hung up when the nuts interfere with the side wall.

 

I was having issues, went with new studs and jet lock nuts from Pegasus racing. they are single use, and must be replaced when removed but they seem to work very well, no issues during the previous 4 or so track days. for me the downpipe design is a problem. it was very nicely built but the angles and clearances are a issue so I can't easily run a longer stud to accommodate nordlock washers. really the nordlock washers just reduce the nuts ability to get get looser, once loose. if the nuts stay tight, nordlock washers seem unnecessary but I'm not a expert. I say check out jetlock nuts and new studs, but have extra on hand just in case. they are supper low profile and fit very well for me. previously I had to thread the nuts a few threads at a time and work my way around because the downpipe would get hung up when the nuts interfere with the side wall.

https://www.pegasusautoracing.com/ke...rdStart=jetnut

 

Spoke to Andrew this morning and have ordered the inconel kit + 1 stud and spare lock hardware.

Hopefully this is a long term solution. I don't like these niggly, race or performance costing issues.

 

It's also possible the nuts were over-torqued at some point, causing the studs to yield and reducing pre-load. I'm not sure that the blocked flexi completely explains repeated loss of pre-load after the flexi had been fixed. Increased temperatures cause bolt load loss through dissimilar thermal expansion; but unless it got so hot that the metallurgical properties of of the bolts were permanently altered, they shouldn't loose pre-load again once the blockage was removed and temps brought down. At least, that's how I understand it. Anyway, just something to keep in mind; watch the torque.

 

You hit the nail on the head, studs got hot enough to yield, that's how you loose pre-load. So by definition once that's happened the stud is compromised and will continue to stretch since it's yielded. They ded......

 

I've just had a trackday at Silverstone GP last weekend and had a few turbo hotside fastener issues. It was my first dry trackday in this car, at a track with a very high percentage time WOT..... To make matters more complicated, I've got another trackday booked for next weeked so don't have long to solve these issues.

Spec as run at Silverstone
Garrett GTX2860, FM2 hotside parts. 2.5" exhaust. 10-16psi (16psi to overtake non-compliant traffic) EGT 900C (1650F) max on 99 RON pump fuel. Revving to 7500rpm (ST heavy doubles)

The issues (in the order which I noticed them)

1. Turbine housing to DP locknuts with nordlock washers came undone
2. FM2 lower DP half to midpipe flange bent! (bolts took a fair bit of torque when I went to tighten them, fastener stretch?)
3. 2 of 6 turbine housing bolts fell out (perhaps one use? I had removed turbine housing and reused bolts)
4. One of the FM stage 8 nuts (on inconel studs) came loose (one of the ones I can't get a torque wrench on, too loose?)

After noticing the first fastener issue and spanner checking everything else, I limited myself to 10psi and 7000rpm but issue 1 would re-occur.

I'm guessing inconel studs are the answer to 1, though getting some in time for next week will likely be an issue.
I was going to machine the flange flat and perhaps add a gusset for 2, and replace the normal nut and bolt with some form of high temperature locking fastener. Interestingly, it was the thicker FM flange (8mm) that was most warped, rather than the 6mm flange of the midpipe.
3 may be installer error (me). I couldn't get a torque wrench on them. I've bought new Garrett bolts.
Though for 4, I don't know what to do. Have others seen this? Or is it user error and I need a better calibrated arm (or some crows foot spanners...)

Or perhaps, am I just wasting my own time and money trying to get the FM2 kit to work at 300hp on track and I really ought to bite the bullet with a TSE kit? On the plus side, when the car was working, it was absolutely brilliant. First dry day with 9J 6ULs, 225s and Supermiata big grip kit.

 

Many before you have tried and failed. FM kits are simply not designed for your usage. TSE kits are.

 

**** your gaskets off and use inconel and stage8 on everything.

Solved.

Dann

 

That's the conclusion I'm coming to. If the turbo kit works as well as your brake kit.... Despite 132mph on the Hangar straight and just 2.5" ducting, I could only turn the lowest temperature strip of my brake disc thermal paint.

 

I did 4.5hrs in my turbo car last weekend and lifted the hood once, on Sunday morning, to check the oil.

(It hadn't used any.)

 

Gaskets gone already except in midpipe. Will give that a try.

That is the stuff of dreams. Rather than me making it 3 laps before hearing a new exhaust blow that wasn't there the session before....