Frunk easy close spring mod

[zhu-]

Brian from i1Tesla put out this new spring mod video that makes the frunk way easier to close and also opens without that loud thud. They're only $5 so I bought it mostly because those struts were sold out for months after his video but I'm not entirely sure how safe these are yet. Thoughts?

Skip to 2:35 to see how easy it closes.

 

[Speed2k]

Don't have a Tesla yet, but this is definitely a mod I would consider!

 

[sumitkgarg]

I question the safety aspect of this mod. I will stay away from it.

 

[dmurphy]

Brian from i1Tesla put out this new spring mod video that makes the frunk way easier to close and also opens without that loud thud. They're only $5 so I bought it mostly because those struts were sold out for months after his video but I'm not entirely sure how safe these are yet. Thoughts?

Skip to 2:35 to see how easy it closes.

So if it’s that simple, why don’t they use such a spring at the factory?

 

[DS 5/15]

If anything, I would worry about the hood flying up on the freeway if this mod diminishes the holding power of the latch. All of the gas cars I've owed had the second safety latch you have to reach under the hood to release, after pulling the release in the car. I don't know if there's any kind of fail-safe double latch on the 3.

Edit: Maybe the gas cars had the second latch because you could pull the release inside while driving. You can't do that in the Tesla interface.

 

[Dre78]

I like that Brian also includes a test of the latch opening while driving. Despite the emergency latch being triggered, the hood doesn't open. In the comments, he says he pulled on the hood and it remained latched.

 

[HelloJohnny]

I also subscribe to i1Tesla on Youtube and ordered the new spring right away from Amazon. Can't wait to do this mod!

 

[PCRover]

I did this mod today with a heavier spring than what was suggested, but weaker than the factory spring. It is so much better now, no more violent bang when it opens. The stock one must be something like 30lbs or stronger as it is stout.

 

[bedoig]

I haven't inspected the mechanism, but I'd assume the heavy spring is there to make sure the secondary latch catches even when going freeway speeds - something that lighter spring may not accomplish. That said, I might do it anyway.

 

[jaytee0401]

I did this mod today with a heavier spring than what was suggested, but weaker than the factory spring. It is so much better now, no more violent bang when it opens. The stock one must be something like 30lbs or stronger as it is stout.

Where did you buy the heavier spring than what he suggested?

 

[S2000]

Where did you buy the heavier spring than what he suggested?

I would like to know this answer about the heavier spring too. I feel that spring from Home Depot is too soft and won't work correctly without the strut mod. Thanks!

 

[Lanzer]

Thank you for sharing this video!

I'm very excited to try out this mod. Though while I want a easier to close frunk, I don't think being able to close with two fingers is what I need, and part of me do worry about safety aspects with such a light spring. Also, the suggested spring is 1 7/8" instead of the stock 2.19", and I'd like to see if there are any springs closer to the original length.

Dimensions:
The stock spring in the M3 is 2.19" inner length, with an outer diameter of 0.578 and wire thickness of 0.078", which gives it a spring rate of around 10 to 15 lb/in, depending on type of steel used.
The spring that is used in the video has a wire diameter of 0.025", which has a spring rate of about 0.21lb/in. The spring is stretched a bit more at rest which I assume will bring the rate slightly higher, maybe about 0.25lb/in.

I've just ordered a few springs from Amazon, ranging from 1.5lb/ft to 6lb/ft of spring rate. They're technically much heavier than the 0.21lb/in spring but then it's still way lighter than the stock spring at 10~15lb/in. Their lengths are at 2.25 as it's harder to find 2.19 or 2.125 springs on Amazon. Once I have the weight I like I'll find one closer to 2.19" in length.

The springs should arrive on Tuesday and I'll report back on how they perform.

 

[Jerick]

Thank you for sharing this video!

I'm very excited to try out this mod. Though while I want a easier to close frunk, I don't think being able to close with two fingers is what I need, and part of me do worry about safety aspects with such a light spring. Also, the suggested spring is 1 7/8" instead of the stock 2.19", and I'd like to see if there are any springs closer to the original length.

Dimensions:
The stock spring in the M3 is 2.19" inner length, with an outer diameter of 0.578 and wire thickness of 0.078", which gives it a spring rate of around 10 to 15 lb/in, depending on type of steel used.
The spring that is used in the video has a wire diameter of 0.025", which has a spring rate of about 0.21lb/in. The spring is stretched a bit more at rest which I assume will bring the rate slightly higher, maybe about 0.25lb/in.

I've just ordered a few springs from Amazon, ranging from 1.5lb/ft to 6lb/ft of spring rate. They're technically much heavier than the 0.21lb/in spring but then it's still way lighter than the stock spring at 10~15lb/in. Their lengths are at 2.25 as it's harder to find 2.19 or 2.125 springs on Amazon. Once I have the weight I like I'll find one closer to 2.19" in length.

The springs should arrive on Tuesday and I'll report back on how they perform.

I look forward to your findings! I would like a spring that's only as weak as it needs to be. I don't plan on doing the strut mod due to safety concerns as well, although Brian does not seem to have any problems.

 

[EV-Tiger]

I installed this lighter spring on my M3 frunk latch mechanism yesterday (purchased at Home Depot). Last year, I modified the frunk struts allowing the frunk to lift fully open by itself.. Hoods opening by themselves seem to be a rare event.

 

[TheLocNar]

I like that Brian also includes a test of the latch opening while driving. Despite the emergency latch being triggered, the hood doesn't open. In the comments, he says he pulled on the hood and it remained latched.

He was going 5 mph in his driveway. lol

I dare him to try it on the highway going 50.

 

[Hank101]

Correct me if I am wrong, but the golf balls, or anything pressing the electric interior frunk button would open the frunk hood the same, regardless of the size/strength of the spring - so the danger always exists, and is unchanged. The spring change only aids in reducing the closing force.

40 years ago, I had a VW beetle frunk open on me driving down the interstate. I was basically driving blind, broken windshield, spun out into a ditch. Wouldn't want a repeat, when this type problem happens, things go bad fast.

 

[chronopc]

On the youtube comments, people are saying you have to replace the struts or else the spring is not strong enough to open the frunk. Has anyone found a stronger spring that allows for easy close but doesn't require you to replace the struts?

 

[fsl2102]

On the youtube comments, people are saying you have to replace the struts or else the spring is not strong enough to open the frunk. Has anyone found a stronger spring that allows for easy close but doesn't require you to replace the struts?

I done some study based on pictures from eBay Model 3 Frunk hood latch lock mechanism. From my drawing below, you can see the function for this spring just to kick up the hood. This why use weaker spring can't open the Frunk. You need a spring strong enough to kick up the hood or need stronger struts to help open the hood. Also this spring is not part of the Primary or secondary (safety) latch locking mechanism.

 

[mhan00]

Correct me if I am wrong, but the golf balls, or anything pressing the electric interior frunk button would open the frunk hood the same, regardless of the size/strength of the spring - so the danger always exists, and is unchanged. The spring change only aids in reducing the closing force.

40 years ago, I had a VW beetle frunk open on me driving down the interstate. I was basically driving blind, broken windshield, spun out into a ditch. Wouldn't want a repeat, when this type problem happens, things go bad fast.

The concern was that the spring had something to do with the secondary latch system, which is what keeps the trunk from flying up while driving even if the release was hit somehow. But it looks like, based on the pics that fsl posted, that this shouldn’t be an issue.

 

[jaboki]

I done some study based on pictures from eBay Model 3 Frunk hood latch lock mechanism. From my drawing below, you can see the function for this spring just to kick up the hood. This why use weaker spring can't open the Frunk. You need a spring strong enough to kick up the hood or need stronger struts to help open the hood. Also this spring is not part of the Primary or secondary (safety) latch locking mechanism.
View attachment 406978 View attachment 406979

Does that mean if I do the lighter spring without the stronger struts the frunk will just be unable to pop up the hood? So essentially I have to be in front of the car while pulling up the hood while disengaging the lock via app.