Dumb Question Thread - No Flaming Allowed

[Tbonem3]

I've never seen such marks in all the dozen+ header jobs I've done, only much more minor if anything. Maybe the flanges weren't very straight either, not just loose nuts.

[davidinnyc]

Is this too much exhaust leak coming from the exhaust head outlets? I pulled gaskets off (they had about 6 months of use) and this was the result from banks 1, 2 and 4. Did I not tighten the nuts down enough? Maybe - was hard to torque everything down.





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[Tbonem3]

Rebound is the resistance you feel when pulling the collapsed strut shaft out of its body. Rebound is not the apparent power the damper has to push the shaft out.

[IamFODI]

That is not encouraging either, how are the preventing foaming under high speed damping? That is the main reason of gas filling.

Seems like valve design can reduce foaming, and I know oil formulation can. But yeah, nothing prevents it like gas pressure.

I've seen the odd brand new damper without enough gas pressure to cause the piston to return. E.g., rear Konis for... I think a MkIV Jetta back in the day? AFAIK it's not that they prevent foaming some other way; it's that someone thought foaming wasn't worth worrying about in that application.

[Slideways]

That is not encouraging either, how are the preventing foaming under high speed damping? That is the main reason of gas filling.

Yes, that was my question as well. I recently watched a few videos showing the difference between monotube and twin tube dampers:

In the video above, it appears that the piston/shaft in the twin tube is rebounding back to its initial position.

[maupineda]

Factory damper with 120k, new KW, and new Ohlins all went back to their full length after compressing them. Rear factory dampers with 120k did not and were put in the bin.

Tested a set of used TCK SAs that a friend was looking to buy and the rears would not rebound. Fronts had springs installed and could not be tested.

Edit: Non-gas filled struts can do this apparently, so I guess TCKs don't have a gas charge.

That is not encouraging either, how are the preventing foaming under high speed damping? That is the main reason of gas filling.

[Slideways]

Yeah, thats unfortunate as they are new, but shit happens, hopefully they have some working units in stock.

I really thought they were bad after test fitting a camber plate and just the weight of that almost fully compressed the struts.

Edit: After an email with TCK they say this is normal as the front struts are not filled with gas and therefore will not rebound, as long as there is resistance when pulling the strut back up, all is well.

I believe them, but a strut that doesnt rebound..? Whats the point, its all spring then.

Factory damper with 120k, new KW, and new Ohlins all went back to their full length after compressing them. Rear factory dampers with 120k did not and were put in the bin.

Tested a set of used TCK SAs that a friend was looking to buy and the rears would not rebound. Fronts had springs installed and could not be tested.

Edit: Non-gas filled struts can do this apparently, so I guess TCKs don't have a gas charge.

[Flow]

If it's an oiled filled strut it's normal.
The strut is just there to damp the spring.

[Cubieman]

It sounds like the fronts are done and need to be serviced. Usually, its the rears that go first.

Yeah, thats unfortunate as they are new, but shit happens, hopefully they have some working units in stock.

I really thought they were bad after test fitting a camber plate and just the weight of that almost fully compressed the struts.

Edit: After an email with TCK they say this is normal as the front struts are not filled with gas and therefore will not rebound, as long as there is resistance when pulling the strut back up, all is well.

I believe them, but a strut that doesnt rebound..? Whats the point, its all spring then.

[Slideways]

I just bought/received some TCK SA's and am out dicking around in the garge, I can very easily compress both front struts with one hand, even 2 fingers, and they won't extend back up on their own.

The rears I can compress, this takes notably more effort and they do extend back on their own.

My suspension knowledge is quite bad, but if any other strut did this I would tend to think only one thing, its blown out.

Tell me why I am wrong here.

It sounds like the fronts are done and need to be serviced. Usually, its the rears that go first.

[Cubieman]

I just bought/received some TCK SA's and am out dicking around in the garge, I can very easily compress both front struts with one hand, even 2 fingers, and they won't extend back up on their own.

The rears I can compress, this takes notably more effort and they do extend back on their own.

My suspension knowledge is quite bad, but if any other strut did this I would tend to think only one thing, its blown out.

Tell me why I am wrong here.

[Arclitgold]

Thanks everyone!

[IamFODI]

It will take longer to get to operating temp if you idle it, which also means the ECU will run the engine richer for longer and that can cause more fuel to end up in the oil, thinning it out. All bad stuff for a modern engine.

Fire it up, wait 10 seconds or so, and drive off with light throttle input while preferably keeping it under 3k RPMs. Once the oil temp starts to rise, medium throttle input and 4k RPM is fine. Once at operating temp (200F oil temp), rip it 8k RPM

^ This

Also, combustion quality sucks when the engine is cold, so there are a lot of byproducts that also end up in the oil.

Idling up to temp seems reasonable because you're running the engine as gently as possible until the oil heats up and isn't super thick any more. But it takes much longer to get to that point than it would if you just drove off, and in that time all the other problems with cold engine running are worse. So, on balance, better to give it just enough time for the oil to make it to the top end and then drive gently until everything's warm.

[Slideways]

The owners manual says to not warm the car up by idling… but it seems weird to not let the carget up to temp. What does the hive mind say about this?

It will take longer to get to operating temp if you idle it, which also means the ECU will run the engine richer for longer and that can cause more fuel to end up in the oil, thinning it out. All bad stuff for a modern engine.

Fire it up, wait 10 seconds or so, and drive off with light throttle input while preferably keeping it under 3k RPMs. Once the oil temp starts to rise, medium throttle input and 4k RPM is fine. Once at operating temp (200F oil temp), rip it 8k RPM

Disregard the warmup lights on the tach unless you get them recalibrated. The warmup lights turn off a bit too quickly with the factory settings.

[0-60motorsports]

I let it idle for about 1-2 minutes, then drive conservatively (keep rpms below 3.5L) until oil temp reaches 1/4 marker, usually about 10 min or so depending on ambient temps.

SAme for me in summer plus i have the CSL warm up lights coded so that is a good helper too. Its so damn hot here even if i drove off after 1 min warm up the car will be up to water temps fast LOL